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The effect of the mode of applied breakage on coal yield

Profile image of Wilmeri PotgieterWilmeri Potgieter

2017

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Thank you for the encouragement and support throughout my studies. Byrone Malay, my love… Thank you for the support and believing in me. Toffie, Rambo, and Einsteinie… You paved the road to my heart with paw prints. vii ACKNOWLEDGEMENTS First, I would like to thank God for giving me the opportunity and strength to complete this research study. "So do not fear, for I am with you; do not be dismayed, for I am your God. I will strengthen you and help you; I will uphold you with my righteous right hand." Isaiah 41:10 I would like to show gratitude by thanking the following individuals for guidance, motivation, support, and assistance during the course of this research study:

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Figure 1.1: Global coal consumption by sector for 2013 (adapted from International Monetary Fund, 2016).
Figure 1.1: Global coal consumption by sector for 2013 (adapted from International Monetary Fund, 2016).
Figure 1.2: South African coal market distribution for 2013 (adapted from XMP Consultin¢ CC, 2014). Recoverable coal reserves worldwide were projected in 2008 at 411 billion tonnes (Pooe & Mathu. 2011), while the economically recoverable coal reserves of South Africa were estimated ai between 15-55 billion tonnes (Eberhard, 2011; Pooe & Mathu, 2011; WEC, 2013) of which 96 % are bituminous coal, 2 % are metallurgical coal, and 2 % are anthracite (Eberhard, 2011). It is estimated that these reserves may only last for the next 130 to 150 years at the current coa consumption rate (Pooe & Mathu, 2011). South Africa is facing a tremendous problem with coal supply, as coal reserves in South Africa are approaching exhaustion (Hartnady, 2010; Jeffrey. 2005), because of the increasing demand for energy due to South Africa’s growing economy. Moreover, the population increased in the recent years, resulting in a steady rise in coa Recoverable coal reserves worldwide were projected in 2008 at 411 billion tonnes (Pooe & Mathu,
Figure 1.2: South African coal market distribution for 2013 (adapted from XMP Consultin¢ CC, 2014). Recoverable coal reserves worldwide were projected in 2008 at 411 billion tonnes (Pooe & Mathu. 2011), while the economically recoverable coal reserves of South Africa were estimated ai between 15-55 billion tonnes (Eberhard, 2011; Pooe & Mathu, 2011; WEC, 2013) of which 96 % are bituminous coal, 2 % are metallurgical coal, and 2 % are anthracite (Eberhard, 2011). It is estimated that these reserves may only last for the next 130 to 150 years at the current coa consumption rate (Pooe & Mathu, 2011). South Africa is facing a tremendous problem with coal supply, as coal reserves in South Africa are approaching exhaustion (Hartnady, 2010; Jeffrey. 2005), because of the increasing demand for energy due to South Africa’s growing economy. Moreover, the population increased in the recent years, resulting in a steady rise in coa Recoverable coal reserves worldwide were projected in 2008 at 411 billion tonnes (Pooe & Mathu,
Table 1.1: South African local and international coal prices for 2015 (adapted from Campbell, 2016).
Table 1.1: South African local and international coal prices for 2015 (adapted from Campbell, 2016).
Figure 1.3: Representation of coal breakage and liberation for the ideal case. Size reduction of coal leads to the generation of fine coal which must be limited since processing, drying and handling operations are difficult when fines (-0.5 mm) are present (Weining et al., 2013). Not only has fine coal higher moisture retention than coarse coal, but processing of fine coal is also generally more expensive; and less efficient, and therefore coal must be processed at the coarsest possible particle size (O’Brien et a/., 2011). Despite these difficulties in fine coal processing, crushing of certain coal sources to smaller particle sizes prior to processing may be required to attain higher degrees of liberation. This generally results in an increase in the plant yield (O’ Brien et al., 2011), by liberation of values from the middlings. Middlings are defined as partially liberated coal fractions which still contain mineral matter after size reduction (Holuszko & Grieve, 1990) Comminution (size reduction) processes must therefore be controlled, and optimized, to ensure that adequate liberation takes place, but also that the particle sizes are suitable for utilization (Weining et a/., 2013). It is important that the mineral and maceral composition of the parent coal and daughter particles formed from crushing are known and understood to optimize liberation (O’ Brien et al., 2011). Knowledge of particle breakage will aid in the optimization of liberation, whilst limiting the generation/production of coal fines. Since it is unlikely to eliminate all fines in comminution processes, a balance between sufficient liberation of coal to attain a certain yield, and the formation of excessive fines must be achieved. Size reduction of coal leads to the generation of fine coal which must be limited since processing,
Figure 1.3: Representation of coal breakage and liberation for the ideal case. Size reduction of coal leads to the generation of fine coal which must be limited since processing, drying and handling operations are difficult when fines (-0.5 mm) are present (Weining et al., 2013). Not only has fine coal higher moisture retention than coarse coal, but processing of fine coal is also generally more expensive; and less efficient, and therefore coal must be processed at the coarsest possible particle size (O’Brien et a/., 2011). Despite these difficulties in fine coal processing, crushing of certain coal sources to smaller particle sizes prior to processing may be required to attain higher degrees of liberation. This generally results in an increase in the plant yield (O’ Brien et al., 2011), by liberation of values from the middlings. Middlings are defined as partially liberated coal fractions which still contain mineral matter after size reduction (Holuszko & Grieve, 1990) Comminution (size reduction) processes must therefore be controlled, and optimized, to ensure that adequate liberation takes place, but also that the particle sizes are suitable for utilization (Weining et a/., 2013). It is important that the mineral and maceral composition of the parent coal and daughter particles formed from crushing are known and understood to optimize liberation (O’ Brien et al., 2011). Knowledge of particle breakage will aid in the optimization of liberation, whilst limiting the generation/production of coal fines. Since it is unlikely to eliminate all fines in comminution processes, a balance between sufficient liberation of coal to attain a certain yield, and the formation of excessive fines must be achieved. Size reduction of coal leads to the generation of fine coal which must be limited since processing,
Figure 2.1: The formation of coal in terms of its grade, rank and type (adapted from Falcon & Snyman, 1986). with a short description of the coal properties and its primary use. The type of coal is associated with the organic matter composition of the coal, and differs according to the plant material from which the coal was formed (Falcon & Snyman, 1986; SACPS, 2015:13). Coal types found in the coalfields around the world thus vary since the deposition of naterial, and time of formation, vary (SACPS, 2015:13). The coal rank increases with an increase n the carbon content; thus lignite has the least carbon whereas anthracite has the most carbon Pinheiro & Cook, 2005). Table 2.1 gives a summary of the main rank classifications of coal along nith a short description of the coal properties and its orimarv use.
Figure 2.1: The formation of coal in terms of its grade, rank and type (adapted from Falcon & Snyman, 1986). with a short description of the coal properties and its primary use. The type of coal is associated with the organic matter composition of the coal, and differs according to the plant material from which the coal was formed (Falcon & Snyman, 1986; SACPS, 2015:13). Coal types found in the coalfields around the world thus vary since the deposition of naterial, and time of formation, vary (SACPS, 2015:13). The coal rank increases with an increase n the carbon content; thus lignite has the least carbon whereas anthracite has the most carbon Pinheiro & Cook, 2005). Table 2.1 gives a summary of the main rank classifications of coal along nith a short description of the coal properties and its orimarv use.
Table 2.1: Summary of the types of coal along with some properties of each (adapted from Falcon & Falcon, 1987; Falcon & Snyman, 1986; Speight, 2005:2-3; 42). Coals can be classified as coking and non-coking (thermal or steam) coal by referring to their coking properties (Speight, 2005:18). They are respectively used in among the manufacturing of iron and steel (Rosenfeld, 2012; Speight, 2005:199), and for electricity generation (Hanlon, 2013; Rosenfeld, 2012). The free swelling index (FSI), which is the increase in coal volume when heated according to conditions as specified in the standard procedure (ISO 501:2003), provides an indication of the coal coking characteristics (Speight, 2005:147). Gas formed during thermal decomposition of coals becomes trapped, and is responsible for the swelling of the coal (Speight, 2005:147). The FSI of bituminous coals usually increases as the coal rank increases (Speight, 2005:147). Table 2.2 indicates the consumption of coal according to its free swelling index. Southern African coking coals typically have a FSI greater than 8 (Powell, 2016). Some macerals, which are the microscopic constituents of coal formed from the remains of plant material, are responsible for the coking properties of coal (Falcon & Snyman, 1986), and will be discussed in Section 2.1.1. Coking coals are thus the coals that are able to soften and swell before solidifying (Kruger, 2013) throughout a carbonization process, where coal is slowly heated up to a specific temperature range (Falcon & Snyman, 1986; Kruger, 2013) between 350°C and 550°C (Kruger, 2013), during which some coal constituents will remain inert whilst others will become soft and porous, to form an ultimately hard product namely coke (Falcon & Snyman, 1986).
Table 2.1: Summary of the types of coal along with some properties of each (adapted from Falcon & Falcon, 1987; Falcon & Snyman, 1986; Speight, 2005:2-3; 42). Coals can be classified as coking and non-coking (thermal or steam) coal by referring to their coking properties (Speight, 2005:18). They are respectively used in among the manufacturing of iron and steel (Rosenfeld, 2012; Speight, 2005:199), and for electricity generation (Hanlon, 2013; Rosenfeld, 2012). The free swelling index (FSI), which is the increase in coal volume when heated according to conditions as specified in the standard procedure (ISO 501:2003), provides an indication of the coal coking characteristics (Speight, 2005:147). Gas formed during thermal decomposition of coals becomes trapped, and is responsible for the swelling of the coal (Speight, 2005:147). The FSI of bituminous coals usually increases as the coal rank increases (Speight, 2005:147). Table 2.2 indicates the consumption of coal according to its free swelling index. Southern African coking coals typically have a FSI greater than 8 (Powell, 2016). Some macerals, which are the microscopic constituents of coal formed from the remains of plant material, are responsible for the coking properties of coal (Falcon & Snyman, 1986), and will be discussed in Section 2.1.1. Coking coals are thus the coals that are able to soften and swell before solidifying (Kruger, 2013) throughout a carbonization process, where coal is slowly heated up to a specific temperature range (Falcon & Snyman, 1986; Kruger, 2013) between 350°C and 550°C (Kruger, 2013), during which some coal constituents will remain inert whilst others will become soft and porous, to form an ultimately hard product namely coke (Falcon & Snyman, 1986).
Table 2.2: Swelling index of South African coal (adapted from Horsfall, 1980). Properties of coking coals include an ash yield of 1-10 %, and volatile matter content of 18-45 % (Kruger, 2013). Mineral matter, especially sulphur and phosphorus, must be as low as possible in coal to be suitable for coking purposes (Falcon & Snyman, 1986). This is because the presence of these mineral matter affects the strength of the coke product (Falcon & Snyman, 1986). Coal that does not comply with these strict quality specifications, and that cannot be used for pulverised fuel injection, are generally sold as thermal coal (O’Brien et a/., 2011).
Table 2.2: Swelling index of South African coal (adapted from Horsfall, 1980). Properties of coking coals include an ash yield of 1-10 %, and volatile matter content of 18-45 % (Kruger, 2013). Mineral matter, especially sulphur and phosphorus, must be as low as possible in coal to be suitable for coking purposes (Falcon & Snyman, 1986). This is because the presence of these mineral matter affects the strength of the coke product (Falcon & Snyman, 1986). Coal that does not comply with these strict quality specifications, and that cannot be used for pulverised fuel injection, are generally sold as thermal coal (O’Brien et a/., 2011).
Table 2.3: Characteristics of the maceral groups (adapted from Falcon & Falcon, 1987; Falcon & Snyman, 1986). The inorganic mineral components, and the organic material (macerals), that coal comprises o (Falcon & Falcon, 1987; Ward & French, 2004) can be identified and distinguished by coa petrography (Falcon & Falcon, 1987; Falcon & Snyman, 1986; Khandelwal & Singh, 2010 O’ Brien et a/., 2011; SACPS; 2015:67). Furthermore, the reflectance of the vitrinite is used tc determine the rank of the coal (Falcon & Falcon, 1987; O’ Brien ef al., 2011; SACPS, 2015:20) Maceral groups are distinguished by among others their texture, shape and greyness undel incident reflected light (Khandelwal & Singh, 2010; O’Brien et al., 2011; Pan ef a/., 2013). The carbon content is directly associated with the amount of reflected light from the surface of the vitrinite, where a higher carbon content will result in higher reflectance (Falcon & Snyman, 1986) thus the reflectance of vitrinite increases with an increase in rank (O’Brien et a/., 2011). Table 2.¢ summarizes the material from which each maceral group originated, as well as the reflectance o each maceral group, in terms of its colour when under incident light, the rank, and the percentage of light reflected.
Table 2.3: Characteristics of the maceral groups (adapted from Falcon & Falcon, 1987; Falcon & Snyman, 1986). The inorganic mineral components, and the organic material (macerals), that coal comprises o (Falcon & Falcon, 1987; Ward & French, 2004) can be identified and distinguished by coa petrography (Falcon & Falcon, 1987; Falcon & Snyman, 1986; Khandelwal & Singh, 2010 O’ Brien et a/., 2011; SACPS; 2015:67). Furthermore, the reflectance of the vitrinite is used tc determine the rank of the coal (Falcon & Falcon, 1987; O’ Brien ef al., 2011; SACPS, 2015:20) Maceral groups are distinguished by among others their texture, shape and greyness undel incident reflected light (Khandelwal & Singh, 2010; O’Brien et al., 2011; Pan ef a/., 2013). The carbon content is directly associated with the amount of reflected light from the surface of the vitrinite, where a higher carbon content will result in higher reflectance (Falcon & Snyman, 1986) thus the reflectance of vitrinite increases with an increase in rank (O’Brien et a/., 2011). Table 2.¢ summarizes the material from which each maceral group originated, as well as the reflectance o each maceral group, in terms of its colour when under incident light, the rank, and the percentage of light reflected.
remaining ash yield (Oki et a/., 2004). Figure 2.2: Relation between the organic and inorganic matter of coal before and after material is combusted: (a) before any combustion of material, (b) after any combustion of material; (c) contents in coal substance and mineral matter (adapted from Oki et al., 2004).
remaining ash yield (Oki et a/., 2004). Figure 2.2: Relation between the organic and inorganic matter of coal before and after material is combusted: (a) before any combustion of material, (b) after any combustion of material; (c) contents in coal substance and mineral matter (adapted from Oki et al., 2004).
Figure 2.3: The effect of various types of mineral matter on washability (adapted from Falcon & Snyman, 1986). The breakage characteristics of coal is affected by the presence of mineral matter in coal (Falcon & Snyman, 1986; Shi, 2014), since coal particles of higher density contain larger amounts of mineral matter, making the particle more difficult to break (Shi, 2014). Also, soft minerals are generally eroded from hard minerals during inter-particle grinding, and concentrate in the finer particle size ranges (Singh et al., 2014). Minerals present within any given coal need to be known in order to identify the most effective beneficiation route for that coal, and whether it is economically suitable for the intended coal market (O’ Brien et a/., 2011). Particles with a small amount of mineral inclusions can be easily upgraded by some size reduction to liberate coal from the minerals. Particles with significant mineral inclusions would have to be crushed or milled to very fine sizes for significant liberation to occur, due to these mineral inclusions are very small (O’Brien et al/., 2011).
Figure 2.3: The effect of various types of mineral matter on washability (adapted from Falcon & Snyman, 1986). The breakage characteristics of coal is affected by the presence of mineral matter in coal (Falcon & Snyman, 1986; Shi, 2014), since coal particles of higher density contain larger amounts of mineral matter, making the particle more difficult to break (Shi, 2014). Also, soft minerals are generally eroded from hard minerals during inter-particle grinding, and concentrate in the finer particle size ranges (Singh et al., 2014). Minerals present within any given coal need to be known in order to identify the most effective beneficiation route for that coal, and whether it is economically suitable for the intended coal market (O’ Brien et a/., 2011). Particles with a small amount of mineral inclusions can be easily upgraded by some size reduction to liberate coal from the minerals. Particles with significant mineral inclusions would have to be crushed or milled to very fine sizes for significant liberation to occur, due to these mineral inclusions are very small (O’Brien et al/., 2011).
Figure 2.4: An example of the effect of beneficiation of two types of bituminous coals from the Witbank Basin on the distribution of the main constituents (adapted from Falcor & Snyman, 1986). As the carbon content of coal and the vitrinite reflectance, thus coal rank, increase, the porosity of coal, which will be discussed in Section 2.1.4.3, decreases. This influences the behaviour ot >oal during breakage and handling (Laubach et al., 1998; Speight, 2005:118). Breakage of coal s influenced by coal rank, for example, low rank coals are generally soft and break easily due to heir porous and less compact structure (SACPS, 2015:18). The uniaxial compressive strength ncreases with an increase in coal rank, which can be ascribed to less pore volume within the coal structure (Pan et al., 2013; Scholtés et a/., 2001). The strength of coal therefore decreases as the sleats within the coal particle increase (Jankovic et a/., 2000; Scholtés et al., 2001). Coals containing large amounts of mineral matter are likely to have larger cleat spacing than coals with AW mMinaral mattar crontant (| arnhach at al 190908) As the carbon content of coal and the vitrinite reflectance, thus coal rank, increase, the porosity
Figure 2.4: An example of the effect of beneficiation of two types of bituminous coals from the Witbank Basin on the distribution of the main constituents (adapted from Falcor & Snyman, 1986). As the carbon content of coal and the vitrinite reflectance, thus coal rank, increase, the porosity of coal, which will be discussed in Section 2.1.4.3, decreases. This influences the behaviour ot >oal during breakage and handling (Laubach et al., 1998; Speight, 2005:118). Breakage of coal s influenced by coal rank, for example, low rank coals are generally soft and break easily due to heir porous and less compact structure (SACPS, 2015:18). The uniaxial compressive strength ncreases with an increase in coal rank, which can be ascribed to less pore volume within the coal structure (Pan et al., 2013; Scholtés et a/., 2001). The strength of coal therefore decreases as the sleats within the coal particle increase (Jankovic et a/., 2000; Scholtés et al., 2001). Coals containing large amounts of mineral matter are likely to have larger cleat spacing than coals with AW mMinaral mattar crontant (| arnhach at al 190908) As the carbon content of coal and the vitrinite reflectance, thus coal rank, increase, the porosity
Figure 2.5: Butt and face cleats in coal (adapted from Scholtes et a/., 2001). seam a blocky appearance as illustrated in Figure 2.5 (Laubach et al., 1998).
Figure 2.5: Butt and face cleats in coal (adapted from Scholtes et a/., 2001). seam a blocky appearance as illustrated in Figure 2.5 (Laubach et al., 1998).
he thickest seam in the Moatize Coal Basin is the Chipanga seam, and is therefore the m: 2am used for exploitation (Hatton & Fardell, 2012; Vasconcelos ef a/., 2014). This coal se: ontains thick alternations of siltstones, carbonaceous siltstones and coal (Vasconcelos et . 014). The top part of the Upper Chipanga contains large amounts of phosphorus makinc nsuitable for coke production, whilst the Middle Chipanga contains thick carbonaceous siltsto nd siltstone intercalations resulting in relative low yields when washability tests were conduct /asconcelos et al., 2014). The Lower Chipanga revealed the highest potential for the exploitati F coking coal as the coal from the Lower Chipanga contains more than 90 % bright coal, | ineral matter content, and a low phosphorus content varying between 0.004 % and 0.085 /asconcelos et al., 2014). The thickest seam in the Moatize Coal Basin is the Chipanga seam, and is therefore the main
he thickest seam in the Moatize Coal Basin is the Chipanga seam, and is therefore the m: 2am used for exploitation (Hatton & Fardell, 2012; Vasconcelos ef a/., 2014). This coal se: ontains thick alternations of siltstones, carbonaceous siltstones and coal (Vasconcelos et . 014). The top part of the Upper Chipanga contains large amounts of phosphorus makinc nsuitable for coke production, whilst the Middle Chipanga contains thick carbonaceous siltsto nd siltstone intercalations resulting in relative low yields when washability tests were conduct /asconcelos et al., 2014). The Lower Chipanga revealed the highest potential for the exploitati F coking coal as the coal from the Lower Chipanga contains more than 90 % bright coal, | ineral matter content, and a low phosphorus content varying between 0.004 % and 0.085 /asconcelos et al., 2014). The thickest seam in the Moatize Coal Basin is the Chipanga seam, and is therefore the main
Figure 2.6: Compressive or tensile stresses causing strain of a crystal lattice (adapted from Singh et al., 2014; Usaini et a/., 2014; Wills & Napier-Munn, 2006:109). Stress applied to the material distributes according to the properties of the material, and will tend 2006:109). A crack can withstand only a certain amount of stress, and when the stress increases inter-atomic bonds at the crack tip (Usaini et a/., 2014). Increased stress at the tip of a crack will
Figure 2.6: Compressive or tensile stresses causing strain of a crystal lattice (adapted from Singh et al., 2014; Usaini et a/., 2014; Wills & Napier-Munn, 2006:109). Stress applied to the material distributes according to the properties of the material, and will tend 2006:109). A crack can withstand only a certain amount of stress, and when the stress increases inter-atomic bonds at the crack tip (Usaini et a/., 2014). Increased stress at the tip of a crack will
Figure 2.7: Concentration of stress at the crack tip (adapted from Usaini eft a/., 2014; Wills & Napier-Munn, 2006:109).
Figure 2.7: Concentration of stress at the crack tip (adapted from Usaini eft a/., 2014; Wills & Napier-Munn, 2006:109).
Figure 2.8: The disintegration of brittle particles due to compressive (F;) and tensile forces (F,) (adapted from Drzymala, 2007:127). applied to perform size reduction and to increase the surface area (Sushant & Archana, 2013 particles’ fracture strength. Energy equivalent to the bonds holding a particle together must be The level of stressing energy applied to perform particle breakage must be an optimum between the extremes of excessive high level of stressing energy which will break the particle finer than the size required, and very low stressing energy which is insufficient for breakage to occur, causing energy losses in the form of heat energy (Tavares, 2004). Material with different densities, and different sizes, require different breakage energy, for example, mineral particles are generally
Figure 2.8: The disintegration of brittle particles due to compressive (F;) and tensile forces (F,) (adapted from Drzymala, 2007:127). applied to perform size reduction and to increase the surface area (Sushant & Archana, 2013 particles’ fracture strength. Energy equivalent to the bonds holding a particle together must be The level of stressing energy applied to perform particle breakage must be an optimum between the extremes of excessive high level of stressing energy which will break the particle finer than the size required, and very low stressing energy which is insufficient for breakage to occur, causing energy losses in the form of heat energy (Tavares, 2004). Material with different densities, and different sizes, require different breakage energy, for example, mineral particles are generally
Figure 2.9: Fracturing of a particle when crushed (adapted from Directorate-General for Energy, 1990:6-10). Compression breakage Is acnieved by squeezing the ma which either one, or both, of these surfaces is doing compression for size reduction of hard and abrasive ma fines must be minimized (SACPS, 2015:91). The produc erial between two crushing surfaces of the work. It is recommended to use erials, non-sticky materials, and when resulting from compression will either be coarse due to the induced tensile breakdown, or fine because of the compressive breakdown at the force contact areas as seen in Figure 2.9. The quan ity of fines generated can be minimized by reducing the force contact area (Wills & Napier-Munn, 2006:110). A study done by Ozer & Whiten (2012), using compression breakage of a cylindrical particle bed, showed that an increase in the energy applied to the bed resulted in a finer particle size distribution (PSD) of the progeny. in the energy applied to the bed resulted in a finer particle size distribution (PSD) of the progeny 2.3.2.3 Attrition breakage
Figure 2.9: Fracturing of a particle when crushed (adapted from Directorate-General for Energy, 1990:6-10). Compression breakage Is acnieved by squeezing the ma which either one, or both, of these surfaces is doing compression for size reduction of hard and abrasive ma fines must be minimized (SACPS, 2015:91). The produc erial between two crushing surfaces of the work. It is recommended to use erials, non-sticky materials, and when resulting from compression will either be coarse due to the induced tensile breakdown, or fine because of the compressive breakdown at the force contact areas as seen in Figure 2.9. The quan ity of fines generated can be minimized by reducing the force contact area (Wills & Napier-Munn, 2006:110). A study done by Ozer & Whiten (2012), using compression breakage of a cylindrical particle bed, showed that an increase in the energy applied to the bed resulted in a finer particle size distribution (PSD) of the progeny. in the energy applied to the bed resulted in a finer particle size distribution (PSD) of the progeny 2.3.2.3 Attrition breakage
Figure 2.10: Illustration of impact breakage by a hammer mill. The hammer mill consists of round hammers mounted on a rotating shaft to induce a swinging motion, as illustrated in Figure 2.10. Coal breakage occurs when the material enters the crusher by falling, and also when the hammers thrust the material against the breaker plate (SACPS, 2015:103).
Figure 2.10: Illustration of impact breakage by a hammer mill. The hammer mill consists of round hammers mounted on a rotating shaft to induce a swinging motion, as illustrated in Figure 2.10. Coal breakage occurs when the material enters the crusher by falling, and also when the hammers thrust the material against the breaker plate (SACPS, 2015:103).
A roller mill consists of two cylindrical metal rollers which are mounted horizontal to one another, and are rotated along the longitudinal axis to compress the material (Sushant & Archana, 2013), as illustrated in Figure 2.11. Double roll crushers compress material between the rollers, during which few fines are generated (SACPS, 2015:98), whilst single roll crushers consists of a heavyweight frame with a crushing roll mounted inside containing an immobile breaker plate (SACPS, 2015:102). Figure 2.11: Illustration of compressive breakage by double roll crushers. Attritioning is generally performed in tumbling mills consisting of cylindrical shells with a wearin liner on the inside (Wills & Napier-Munn, 2006:149) and is rotated along the horizontal axi (Directorate-General for Energy, 1990:11; Sushant & Archana, 2013; Wills & Napier-Munr 2006:149). Attritioning mills consist mainly of a tank and a motor, making it relative inexpensiv to construct (Davis & Dawson, 1989). The hollow inside of the mill may contain grinding medie occupying not more than 50% of the container volume (Directorate-General for Energy, 1990:11 Sushant & Archana, 2013; Wills & Napier-Munn, 2006:143), which can be either balls, rods, c only lumps of the feed material, that can tumble freely as the container rotates (Directorate General for Energy, 1990:11; Wills & Napier-Munn, 2006:143). The movement of particles insid the mill cause a grinding action as illustrated in Figure 2.12 (King, 1999).
A roller mill consists of two cylindrical metal rollers which are mounted horizontal to one another, and are rotated along the longitudinal axis to compress the material (Sushant & Archana, 2013), as illustrated in Figure 2.11. Double roll crushers compress material between the rollers, during which few fines are generated (SACPS, 2015:98), whilst single roll crushers consists of a heavyweight frame with a crushing roll mounted inside containing an immobile breaker plate (SACPS, 2015:102). Figure 2.11: Illustration of compressive breakage by double roll crushers. Attritioning is generally performed in tumbling mills consisting of cylindrical shells with a wearin liner on the inside (Wills & Napier-Munn, 2006:149) and is rotated along the horizontal axi (Directorate-General for Energy, 1990:11; Sushant & Archana, 2013; Wills & Napier-Munr 2006:149). Attritioning mills consist mainly of a tank and a motor, making it relative inexpensiv to construct (Davis & Dawson, 1989). The hollow inside of the mill may contain grinding medie occupying not more than 50% of the container volume (Directorate-General for Energy, 1990:11 Sushant & Archana, 2013; Wills & Napier-Munn, 2006:143), which can be either balls, rods, c only lumps of the feed material, that can tumble freely as the container rotates (Directorate General for Energy, 1990:11; Wills & Napier-Munn, 2006:143). The movement of particles insid the mill cause a grinding action as illustrated in Figure 2.12 (King, 1999).
Figure 2.13: Motion of particles in tumbling mill (Wills & Napier-Munn, 2006:143; King, 1999).
Figure 2.13: Motion of particles in tumbling mill (Wills & Napier-Munn, 2006:143; King, 1999).
Figure 2.14: Liberation of mineral and gangue (Usaini et a/., 2014). recovered from coal middlings (Weining et a/., 2013); thus increasing the coal yield. 3reakage of coal particles leads to either single components of pure minerals or macerals, whi ther particles are composites with varying amounts of minerals and macerals present (O’ Brie at al., 2011). A cross-section of a particle is given in Figure 2.15 to demonstrate the proble associated with liberation. The regions (X) resemble the valuable mineral of interest and regior XX) are small particles of valuable mineral trapped between gangue. The products | -omminution varies from completely liberated particles, to particles associated with gangue < llustrated in Figure 2.15 (Usaini et a/., 2014; Wills & Napier-Munn, 2006:15). Particle 1 is minere ich and highly concentrated, whilst Particle 4 is considered as tailings because of the low valuab nineral content that is difficult to recover. Particles 2 and 3 are middlings and require furth size reduction is done to separate the mineral matter from the coal at the coarsest particle size
Figure 2.14: Liberation of mineral and gangue (Usaini et a/., 2014). recovered from coal middlings (Weining et a/., 2013); thus increasing the coal yield. 3reakage of coal particles leads to either single components of pure minerals or macerals, whi ther particles are composites with varying amounts of minerals and macerals present (O’ Brie at al., 2011). A cross-section of a particle is given in Figure 2.15 to demonstrate the proble associated with liberation. The regions (X) resemble the valuable mineral of interest and regior XX) are small particles of valuable mineral trapped between gangue. The products | -omminution varies from completely liberated particles, to particles associated with gangue < llustrated in Figure 2.15 (Usaini et a/., 2014; Wills & Napier-Munn, 2006:15). Particle 1 is minere ich and highly concentrated, whilst Particle 4 is considered as tailings because of the low valuab nineral content that is difficult to recover. Particles 2 and 3 are middlings and require furth size reduction is done to separate the mineral matter from the coal at the coarsest particle size
Figure 2.15: Cross-sections of ore particles before and after communition (adapted from Usaini et al., 2014; Wills & Napier-Munn, 2006:15). breakage or grinding to liberate the mineral matter from the gangue (Usaini et a/., 2014; Wills & Napier-Munn, 2006:15). The products of comminution can therefore be divided into three types of particles namely, fully liberated coal particles, particles containing both coal substance and mineral matter, and liberated mineral matter (Oki et a/., 2004). The combustible coal matter needs ‘0 be recovered from the incombustible mineral matter as explained in Section 2.1.3 by referring ‘o Figure 2.2. Complete liberation of the desired mineral particles is rarely achieved even when he ore is milled to obtain grain size particles (Usaini et a/., 2014). the ore is milled to obtain grain size particles (Usaini et al., 2014). The degree of liberation gives an indication of the mineral percentage that occurs as liberated
Figure 2.15: Cross-sections of ore particles before and after communition (adapted from Usaini et al., 2014; Wills & Napier-Munn, 2006:15). breakage or grinding to liberate the mineral matter from the gangue (Usaini et a/., 2014; Wills & Napier-Munn, 2006:15). The products of comminution can therefore be divided into three types of particles namely, fully liberated coal particles, particles containing both coal substance and mineral matter, and liberated mineral matter (Oki et a/., 2004). The combustible coal matter needs ‘0 be recovered from the incombustible mineral matter as explained in Section 2.1.3 by referring ‘o Figure 2.2. Complete liberation of the desired mineral particles is rarely achieved even when he ore is milled to obtain grain size particles (Usaini et a/., 2014). the ore is milled to obtain grain size particles (Usaini et al., 2014). The degree of liberation gives an indication of the mineral percentage that occurs as liberated
illustrated in Figure 2.16 (Drzymala, 2007:196). Particles that float on the liquid with density o 1.40 g/cm? will have a density between 1.30 g/cm® and 1.40 g/cm°. The method is repeated unti at the highest density as illustrated in Figure 2.16 (Drzymala, 2007:196). The fractions that floa and those that sink, are then analysed for the quality parameters of interest (Drzymala, 2007:101). When ZnCl solutions are used for the float-sink analyses, separate relative density fractions mus be rinsed with water immediately after separation, where after the respective relative density fractions must be air-dried. Zinc chloride solutions must be disposed of according to legislation as it creates environmental problems and are highly corrosive (SACPS, 2015:72). It is not known whether the use of ZnClz solutions for the float and sink analysis, weakens the coal structure to such a nature that it affects the liberation of coal from mineral matter. Research regarding this matter should be done. Figure 2.16: Float and sink analysis (Drzymala, 2007:195). matter should be done. the floats and sinks depends on the viscosity of the separation liquid used, the proportion of near
illustrated in Figure 2.16 (Drzymala, 2007:196). Particles that float on the liquid with density o 1.40 g/cm? will have a density between 1.30 g/cm® and 1.40 g/cm°. The method is repeated unti at the highest density as illustrated in Figure 2.16 (Drzymala, 2007:196). The fractions that floa and those that sink, are then analysed for the quality parameters of interest (Drzymala, 2007:101). When ZnCl solutions are used for the float-sink analyses, separate relative density fractions mus be rinsed with water immediately after separation, where after the respective relative density fractions must be air-dried. Zinc chloride solutions must be disposed of according to legislation as it creates environmental problems and are highly corrosive (SACPS, 2015:72). It is not known whether the use of ZnClz solutions for the float and sink analysis, weakens the coal structure to such a nature that it affects the liberation of coal from mineral matter. Research regarding this matter should be done. Figure 2.16: Float and sink analysis (Drzymala, 2007:195). matter should be done. the floats and sinks depends on the viscosity of the separation liquid used, the proportion of near
Table 3.1: Relative densities of materials used for densimetric analysis.
Table 3.1: Relative densities of materials used for densimetric analysis.
Table 3.2: Apparatus
Table 3.2: Apparatus
Table 3.3: Experimental overview of multiple particle breakage. Multiple particle breakage experiments were performed to investigate the influence of the mode of applied breakage on coal yield. The multiple particle breakage experimental runs are summarized in Table 3.3, where the first column indicates the mode of breakage applied, the second column the top size for breakage, and the third column the residence time for attrition breakage following the initial type of breakage. The last column indicated the number of experiments conducted for that particular combination of breakage modes. The top sizes were chosen based on the required sizes for industrial application, and to minimize fines generation. Duplicate experimental runs conformed to ISO 5725:1994 standards for repeatability.
Table 3.3: Experimental overview of multiple particle breakage. Multiple particle breakage experiments were performed to investigate the influence of the mode of applied breakage on coal yield. The multiple particle breakage experimental runs are summarized in Table 3.3, where the first column indicates the mode of breakage applied, the second column the top size for breakage, and the third column the residence time for attrition breakage following the initial type of breakage. The last column indicated the number of experiments conducted for that particular combination of breakage modes. The top sizes were chosen based on the required sizes for industrial application, and to minimize fines generation. Duplicate experimental runs conformed to ISO 5725:1994 standards for repeatability.
Figure 3.4: Cone and quartering of Moatize coal. section.
Figure 3.4: Cone and quartering of Moatize coal. section.
Figure 3.5: Lawn roller used for compressive breakage. Multiple particle impact breakage of each 6 kg coal sample was performed according to the SANS 401:2010 for “Standard test method of drop shatter test for coal’, by using a locally manufactured drop-weight impact rig (see Figure 3.6). The coal sample was placed within a single layer, again to prevent inter-particle breakage and cushioning effects, at the bottom of the drop- weight impact rig, together with either square tube spacers of 12.7 mm, or flat bar spacers o 6.0 mm, depending on the required top size of the experimental run performed. Spacers were used to minimize fines, and to ensure the desired top size. The steel plate, with a mass o 14.65 kg, was secured at the top of the rig by means of a safety pin as a safety precaution. After the coal sample was placed at the bottom of the rig, the steel plate was released from a height o 1.83 m to allow for optimum breakage. The steel plate was directed by a steel pipe to ensure a uniform impact force was applied to the particles. The orientation of the particles relative to the coal bedding plane was random. Removable steel sides at the bottom formed an enclosure, and ensured minimal particle loss during impact of the steel plate with the coal. They were also safety precaution, since the impact resulted in splattering of the particles. Again, the coal sample was screened to the top size using sieves with either 6.7 mm or 13.2 mm aperture size depending on manufactured drop-weight impact rig (see Figure 3.6). The coal sample was placed within a single
Figure 3.5: Lawn roller used for compressive breakage. Multiple particle impact breakage of each 6 kg coal sample was performed according to the SANS 401:2010 for “Standard test method of drop shatter test for coal’, by using a locally manufactured drop-weight impact rig (see Figure 3.6). The coal sample was placed within a single layer, again to prevent inter-particle breakage and cushioning effects, at the bottom of the drop- weight impact rig, together with either square tube spacers of 12.7 mm, or flat bar spacers o 6.0 mm, depending on the required top size of the experimental run performed. Spacers were used to minimize fines, and to ensure the desired top size. The steel plate, with a mass o 14.65 kg, was secured at the top of the rig by means of a safety pin as a safety precaution. After the coal sample was placed at the bottom of the rig, the steel plate was released from a height o 1.83 m to allow for optimum breakage. The steel plate was directed by a steel pipe to ensure a uniform impact force was applied to the particles. The orientation of the particles relative to the coal bedding plane was random. Removable steel sides at the bottom formed an enclosure, and ensured minimal particle loss during impact of the steel plate with the coal. They were also safety precaution, since the impact resulted in splattering of the particles. Again, the coal sample was screened to the top size using sieves with either 6.7 mm or 13.2 mm aperture size depending on manufactured drop-weight impact rig (see Figure 3.6). The coal sample was placed within a single
Figure 3.6: Drop-weight impact rig.
Figure 3.6: Drop-weight impact rig.
The rotation of the mill had to be at such a speed that only a cascading motion (as discussed in Chapter 2.3.3.1) occurred to prevent the particles from breaking further due to impact. The critical speed of the tumbling mill was calculated according to Equation 2-2 to be 68 revolutions/minute (rom), but to ensure that only cascading motion occurred, the actual rotation speed was significantly reduced to 20 rpm, which equated to 30 % of the calculated critical speed. gnificantly reduced to 20 rpm, which equated to 30 % of the calculated critical speed. only by the particles contacting against one another, and against the tumbling mill wall. A smal opening at the back end of the drum, allowed a decrease in pressure that might build up during attrition, to prevent a dust explosion or explosion of the drum. The total coal sample of about 6 kg was inserted into the tumbling mill, the lid was sealed to the mill using bolts to prevent the loss o' material. The mill was put in a horizontal position on the rollers, driven by a motor and gearbox responsible for the rotation along the cylindrical axis of the mill. The rotation of the mill took place within a steel cage ensuring a safe environment during operation.
The rotation of the mill had to be at such a speed that only a cascading motion (as discussed in Chapter 2.3.3.1) occurred to prevent the particles from breaking further due to impact. The critical speed of the tumbling mill was calculated according to Equation 2-2 to be 68 revolutions/minute (rom), but to ensure that only cascading motion occurred, the actual rotation speed was significantly reduced to 20 rpm, which equated to 30 % of the calculated critical speed. gnificantly reduced to 20 rpm, which equated to 30 % of the calculated critical speed. only by the particles contacting against one another, and against the tumbling mill wall. A smal opening at the back end of the drum, allowed a decrease in pressure that might build up during attrition, to prevent a dust explosion or explosion of the drum. The total coal sample of about 6 kg was inserted into the tumbling mill, the lid was sealed to the mill using bolts to prevent the loss o' material. The mill was put in a horizontal position on the rollers, driven by a motor and gearbox responsible for the rotation along the cylindrical axis of the mill. The rotation of the mill took place within a steel cage ensuring a safe environment during operation.
Figure 3.8: Normalized milling curve for Moatize coal (particle sizes 0.0-9.5 mm)
Figure 3.8: Normalized milling curve for Moatize coal (particle sizes 0.0-9.5 mm)
Figure 3.10: Industrial sieves used for particle size distribution. using the total mass of material within each density interval sample. During the PSD analysis of
Figure 3.10: Industrial sieves used for particle size distribution. using the total mass of material within each density interval sample. During the PSD analysis of
3.6.2 Densimetric (float-sink) analysis
3.6.2 Densimetric (float-sink) analysis
Figure 3.12: Densimetric analysis using a zinc chloride solution.
Figure 3.12: Densimetric analysis using a zinc chloride solution.
Figure 3.13: Float-sink analysis procedure when ZnCl2 was used. obtain a smaller quantity of material according to the manual sampling standard, ISO 18283:2006. This was done because of the limited funding, time available, and also due to the high cost of the organic liquids used for the float-sink tests. The sample was placed in the conical square bucket (see Figure 3.14) and the machine was switched on. The vibration of the machine caused particles to move down the chute into 6 sub-sample buckets. This type of splitting ensured a particle size distribution representative of the whole initial sample. To obtain half of the initial sample, either buckets 1, 3 and 5 or buckets 2, 4 and 6 were mixed together, and was used for This was done because of the limited funding, time available, and also due to the high cost of the
Figure 3.13: Float-sink analysis procedure when ZnCl2 was used. obtain a smaller quantity of material according to the manual sampling standard, ISO 18283:2006. This was done because of the limited funding, time available, and also due to the high cost of the organic liquids used for the float-sink tests. The sample was placed in the conical square bucket (see Figure 3.14) and the machine was switched on. The vibration of the machine caused particles to move down the chute into 6 sub-sample buckets. This type of splitting ensured a particle size distribution representative of the whole initial sample. To obtain half of the initial sample, either buckets 1, 3 and 5 or buckets 2, 4 and 6 were mixed together, and was used for This was done because of the limited funding, time available, and also due to the high cost of the
thermometer was used to determine the relative density of each solution, and relative density
thermometer was used to determine the relative density of each solution, and relative density
Figure 3.15: Densimetric analysis using organic liquids.
Figure 3.15: Densimetric analysis using organic liquids.
Table 3.4: Proximate analysis procedure
Table 3.4: Proximate analysis procedure
of intergranular fracturing and breakage according to the layered structure of the coal. The physical appearance of the coal samples, for example, brightness, and shape was investigated visually. Figure 4.1 and Figure 4.2 show the progeny (daughter particles) formed due to compression breakage to a top size of 6.7 mm. The shape of the particles are mostly angular and flaky. The relative density samples, F1.3 (material that floated at RD=1.30) and $1.3F1.4 (material that sank at RD=1.30 but floated at RD=1.40), are bright and shiny, and therefore vitrinite-rich. Material in the relative density fraction of S1.8, the material that sank at RD=1.80, have a dark appearance and are dull. The occurrence of bright and dull coal gives an indication of intergranular fracturing and breakage according to the layered structure of the coal. have a dark appearance and are dull. The occurrence of bright and dull coal gives an indication
of intergranular fracturing and breakage according to the layered structure of the coal. The physical appearance of the coal samples, for example, brightness, and shape was investigated visually. Figure 4.1 and Figure 4.2 show the progeny (daughter particles) formed due to compression breakage to a top size of 6.7 mm. The shape of the particles are mostly angular and flaky. The relative density samples, F1.3 (material that floated at RD=1.30) and $1.3F1.4 (material that sank at RD=1.30 but floated at RD=1.40), are bright and shiny, and therefore vitrinite-rich. Material in the relative density fraction of S1.8, the material that sank at RD=1.80, have a dark appearance and are dull. The occurrence of bright and dull coal gives an indication of intergranular fracturing and breakage according to the layered structure of the coal. have a dark appearance and are dull. The occurrence of bright and dull coal gives an indication
Figure 4.2: Physical appearance of particles 0.0-1.0 mm.
Figure 4.2: Physical appearance of particles 0.0-1.0 mm.
Figure 4.3: Ash yield for each relative density interval expressed on a dry basis.
Figure 4.3: Ash yield for each relative density interval expressed on a dry basis.
included according to a 95 % confidence range. Figure 4.4: The inherent moisture of Moatize coal expressed on an air dry basis. Figure 4.4 presents the inherent moisture results of Moatize coal as determined during the proximate analysis. Inherent moisture refers to the retained moisture within pores in the coal particle after all surface moisture has been removed (Falcon & Ham, 1988). Error bars are included according to a 95 % confidence range. It can be seen from Figure 4.4 that the inherent moisture varies between 1.2 % and 4.3 %. These
included according to a 95 % confidence range. Figure 4.4: The inherent moisture of Moatize coal expressed on an air dry basis. Figure 4.4 presents the inherent moisture results of Moatize coal as determined during the proximate analysis. Inherent moisture refers to the retained moisture within pores in the coal particle after all surface moisture has been removed (Falcon & Ham, 1988). Error bars are included according to a 95 % confidence range. It can be seen from Figure 4.4 that the inherent moisture varies between 1.2 % and 4.3 %. These
Figure 4.5: Free swelling index results. 95 % confidence range. Again as abovementioned, particles smaller than 1mm refers to th
Figure 4.5: Free swelling index results. 95 % confidence range. Again as abovementioned, particles smaller than 1mm refers to th
Figure 4.6: Calorific value results. particles larger than 1 mm are within the particle size range of 1.0-13.2 mm.
Figure 4.6: Calorific value results. particles larger than 1 mm are within the particle size range of 1.0-13.2 mm.
Figure 4.9: Size by washability graph for impact breakage to a top size of 13.2 mm followed by additional attrition breakage for 5 minutes. PNCCETUINZE EE a a Ria RANAMATUINZE TOCA CW I FT: Se SOE NN a VYUwW | ad PRETEEN NA OTE WN YAS Yt VIA TPs in the unit used for the attrition breakage was either 1, 2 or 5 minutes. It was expected that different residence times for attrition breakage would result in different degrees of liberation of coal from mineral matter. Attrition breakage additional to the initial breakage mode would ensure further liberation by chipping off the vitrinite-rich material exposed by the initial breakage mode. The effect of attrition breakage on the mass distribution according to relative density and particle size distribution was investigated. Figure 4.9 displays the size by washability graph for impact breakage to a top size of 13.2 mm followed by attritioning for a residence time of 5 minutes. breakage to a top size of 13.2 mm followed by attritioning for a residence time of 5 minutes.
Figure 4.9: Size by washability graph for impact breakage to a top size of 13.2 mm followed by additional attrition breakage for 5 minutes. PNCCETUINZE EE a a Ria RANAMATUINZE TOCA CW I FT: Se SOE NN a VYUwW | ad PRETEEN NA OTE WN YAS Yt VIA TPs in the unit used for the attrition breakage was either 1, 2 or 5 minutes. It was expected that different residence times for attrition breakage would result in different degrees of liberation of coal from mineral matter. Attrition breakage additional to the initial breakage mode would ensure further liberation by chipping off the vitrinite-rich material exposed by the initial breakage mode. The effect of attrition breakage on the mass distribution according to relative density and particle size distribution was investigated. Figure 4.9 displays the size by washability graph for impact breakage to a top size of 13.2 mm followed by attritioning for a residence time of 5 minutes. breakage to a top size of 13.2 mm followed by attritioning for a residence time of 5 minutes.
Figure 4.10: Size by washability graph for impact breakage to a top size of 6.7 mm followed by additional attrition breakage for 5 minutes. Although attrition breakage after impact breakage of 13.2 mm had no noticeable effect on the mass distribution of the material according to its relative density and particle sizes, this was however, not the case for attritioning after impact breakage to a top size of 6.7 mm. When comparing Figure 4.10 with Figure 4.8, showing the mass distribution of impact breakage to a top size of 6.7 mm without attrition breakage, it can be seen that the mass distribution was altered by the attrition breakage. An increase in mass in the relative density ranges F1.3 and 1.3-1.4 was observed after attritioning was performed. This is because breakage to the smaller top size of 6.7 mm exposed more of the coal macerals, which was then further released or liberated during attrition breakage after the initial impact breakage. Exposure of the coal macerals on the outer layer of the particles might have occurred during breakage to a top size of 6.7 mm. This might have increased liberation of the brittle vitrinite-rich fraction when attritioning was performed. Breakage to a top size of 13.2 mm was too coarse to expose all coal macerals entrapped between mineral materials. Size by washability graphs for attritioning residence times of 1 minute and 2 minutes can be obtained from Appendix C. These curves had similar results as Figure 4.10. Although attrition breakage after impact breakage of 13.2 mm had no noticeable effect on the mass distribution of the material according to its relative density and particle sizes, this was
Figure 4.10: Size by washability graph for impact breakage to a top size of 6.7 mm followed by additional attrition breakage for 5 minutes. Although attrition breakage after impact breakage of 13.2 mm had no noticeable effect on the mass distribution of the material according to its relative density and particle sizes, this was however, not the case for attritioning after impact breakage to a top size of 6.7 mm. When comparing Figure 4.10 with Figure 4.8, showing the mass distribution of impact breakage to a top size of 6.7 mm without attrition breakage, it can be seen that the mass distribution was altered by the attrition breakage. An increase in mass in the relative density ranges F1.3 and 1.3-1.4 was observed after attritioning was performed. This is because breakage to the smaller top size of 6.7 mm exposed more of the coal macerals, which was then further released or liberated during attrition breakage after the initial impact breakage. Exposure of the coal macerals on the outer layer of the particles might have occurred during breakage to a top size of 6.7 mm. This might have increased liberation of the brittle vitrinite-rich fraction when attritioning was performed. Breakage to a top size of 13.2 mm was too coarse to expose all coal macerals entrapped between mineral materials. Size by washability graphs for attritioning residence times of 1 minute and 2 minutes can be obtained from Appendix C. These curves had similar results as Figure 4.10. Although attrition breakage after impact breakage of 13.2 mm had no noticeable effect on the mass distribution of the material according to its relative density and particle sizes, this was
Figure 4.11: Size by washability graph for compressive breakage to a top size of 13.2 mm with no additional attrition breakage. 4.12 was 6.7 mm, the sizes on the x-axis will be up to 13.2 mm as for Figure 4.11 for easy Figure 4.11 and Figure 4.12 give the size by washability graphs for compressive breakage to top sizes of 13.2 mm and 6.7 mm, respectively. These experimental runs had no additional breakage following the initial compressive breakage. The size by washability graphs s mass percentage of the whole sample as distributed according to its relative density and size distribution. The mass distribution percentage (y-axis) will once again reach 20 % attrition how the particle or ease of readability and easy comparison with other graphs. Although the top size for breakage of Figure 412 was 6.7mm. the sizes on the x-axis will be uo to 13.2 mm as for Figure 4.11 or easy of readability and easy comparison with other graphs. Although the top size for breakage of Figure
Figure 4.11: Size by washability graph for compressive breakage to a top size of 13.2 mm with no additional attrition breakage. 4.12 was 6.7 mm, the sizes on the x-axis will be up to 13.2 mm as for Figure 4.11 for easy Figure 4.11 and Figure 4.12 give the size by washability graphs for compressive breakage to top sizes of 13.2 mm and 6.7 mm, respectively. These experimental runs had no additional breakage following the initial compressive breakage. The size by washability graphs s mass percentage of the whole sample as distributed according to its relative density and size distribution. The mass distribution percentage (y-axis) will once again reach 20 % attrition how the particle or ease of readability and easy comparison with other graphs. Although the top size for breakage of Figure 412 was 6.7mm. the sizes on the x-axis will be uo to 13.2 mm as for Figure 4.11 or easy of readability and easy comparison with other graphs. Although the top size for breakage of Figure
Figure 4.12: Size by washability graph for compressive breakage to a top size of 6.7 mm with no additional attrition breakage. As explained in Section 4.3, focus was set on the material with relative density of 1.4 and lower As explained in Section 4.3, focus was set on the material with relative density of 1.4 and lower due to the “clean” coal at these relative densities. Material with relative density of less than 1.3 will firstly be discussed followed by material in the relative density range of 1.3-1.4. As for impact breakage, material with a relative density of less than 1.3 mainly occurred in the particle size range of 1.0-4.75 mm. When comparing the amount of material in this relative density range, it can be seen that there was a slight increase in the amount of material by breakage to a top size of 6.7 mm compared to a top size of 13.2 mm. Therefore, compressive breakage to a smaller top size of 6.7 mm resulted in a higher amount of liberated coal macerals than that for a top size of 13.2 mm. Compressive breakage to a top size of 13.2 mm had no increase in the amount of material occurring in the relative density interval of 1.3 and lower compared to that of raw coal as given in Figure 3.3. breakage, material with a relative density of less than 1.3 mainly occurred in the particle size
Figure 4.12: Size by washability graph for compressive breakage to a top size of 6.7 mm with no additional attrition breakage. As explained in Section 4.3, focus was set on the material with relative density of 1.4 and lower As explained in Section 4.3, focus was set on the material with relative density of 1.4 and lower due to the “clean” coal at these relative densities. Material with relative density of less than 1.3 will firstly be discussed followed by material in the relative density range of 1.3-1.4. As for impact breakage, material with a relative density of less than 1.3 mainly occurred in the particle size range of 1.0-4.75 mm. When comparing the amount of material in this relative density range, it can be seen that there was a slight increase in the amount of material by breakage to a top size of 6.7 mm compared to a top size of 13.2 mm. Therefore, compressive breakage to a smaller top size of 6.7 mm resulted in a higher amount of liberated coal macerals than that for a top size of 13.2 mm. Compressive breakage to a top size of 13.2 mm had no increase in the amount of material occurring in the relative density interval of 1.3 and lower compared to that of raw coal as given in Figure 3.3. breakage, material with a relative density of less than 1.3 mainly occurred in the particle size
Figure 4.13: Size by washability graph for compressive breakage to a top size of 13.2 mm followed by additional attrition breakage for 5 minutes. Attrition breakage additional to compressive breakage was done for residence times of 1, 2 or 5 minutes. Figure 4.13 indicates the mass distribution as a percentage according to relative density and particle size for compressive breakage to a top size of 13.2 mm followed by attrition breakage for 5 minutes.
Figure 4.13: Size by washability graph for compressive breakage to a top size of 13.2 mm followed by additional attrition breakage for 5 minutes. Attrition breakage additional to compressive breakage was done for residence times of 1, 2 or 5 minutes. Figure 4.13 indicates the mass distribution as a percentage according to relative density and particle size for compressive breakage to a top size of 13.2 mm followed by attrition breakage for 5 minutes.
Figure 4.14: Size by washability graph for compressive breakage to a top size of 6.7 mm followed by additional attrition breakage for 5 minutes. Material with a relative density greater than 1.8 showed a decrease in the particle size range of 4.75-6.7 mm while material with relative density lower than 1.3 and particle sizes of 2-4.75 mm slightly increased. Again, this can be attributed to the exposure of coal macerals on the outer layer of the particles after compressive breakage. Attritioning therefore resulted in an increase in liberation by chipping off the exposed material. There was no noticeable difference in the other relative density ranges. Size by washability graphs presenting the effect of attritioning for 1 minute and 2 minutes gave similar results and are included in Appendix C. Material with a relative density greater than 1.8 showed a decrease in the particle size range of
Figure 4.14: Size by washability graph for compressive breakage to a top size of 6.7 mm followed by additional attrition breakage for 5 minutes. Material with a relative density greater than 1.8 showed a decrease in the particle size range of 4.75-6.7 mm while material with relative density lower than 1.3 and particle sizes of 2-4.75 mm slightly increased. Again, this can be attributed to the exposure of coal macerals on the outer layer of the particles after compressive breakage. Attritioning therefore resulted in an increase in liberation by chipping off the exposed material. There was no noticeable difference in the other relative density ranges. Size by washability graphs presenting the effect of attritioning for 1 minute and 2 minutes gave similar results and are included in Appendix C. Material with a relative density greater than 1.8 showed a decrease in the particle size range of
13.2 mm can be obtained in Appendix C (Figure C.88). Figure 4.15: Ash curve for impact breakage to a top size of 13.2 mm. cumulative floats mass yield for the raw coal prior to testing. Figure 4.15 shows the ash curve for
13.2 mm can be obtained in Appendix C (Figure C.88). Figure 4.15: Ash curve for impact breakage to a top size of 13.2 mm. cumulative floats mass yield for the raw coal prior to testing. Figure 4.15 shows the ash curve for
“igure 4.16: Ash curve for impact breakage to a top size of 6.7 mm.
“igure 4.16: Ash curve for impact breakage to a top size of 6.7 mm.
Figure 4.17: Ash curve for compressive breakage to a top size of 6.7 mm. It can be seen from Figure 4.17, that compressive breakage to a top size of 6.7 mm followed by attrition breakage, also resulted in an increase in the cumulative floats mass yield compared to that of the raw coal. The increase is, however, not as substantial as that for impact breakage to a top size of 6.7 mm followed by attrition breakage. The highest cumulative floats mass yield attained at a cumulative float ash yield of 10 %, for compressive breakage to a top size of 6.7 mm was 49 %, for the sample subjected to 2 minutes of attritioning. This was much lower than for impact breakage followed by 1 minute of attritioning, which gave a yield of 60 %. Impact breakage to a top size of 6.7 mm thus resulted in a much higher cumulative floats mass yield compared to RnAmMmMnracensa hraakana
Figure 4.17: Ash curve for compressive breakage to a top size of 6.7 mm. It can be seen from Figure 4.17, that compressive breakage to a top size of 6.7 mm followed by attrition breakage, also resulted in an increase in the cumulative floats mass yield compared to that of the raw coal. The increase is, however, not as substantial as that for impact breakage to a top size of 6.7 mm followed by attrition breakage. The highest cumulative floats mass yield attained at a cumulative float ash yield of 10 %, for compressive breakage to a top size of 6.7 mm was 49 %, for the sample subjected to 2 minutes of attritioning. This was much lower than for impact breakage followed by 1 minute of attritioning, which gave a yield of 60 %. Impact breakage to a top size of 6.7 mm thus resulted in a much higher cumulative floats mass yield compared to RnAmMmMnracensa hraakana
Figure 4.18: Float ash per particle size for impact breakage to a top size of 6.7 mm followed by attrition breakage for 1 minute. Again, a hypothetical ash yield of 10 % will be used to compare the outcomes of the various
Figure 4.18: Float ash per particle size for impact breakage to a top size of 6.7 mm followed by attrition breakage for 1 minute. Again, a hypothetical ash yield of 10 % will be used to compare the outcomes of the various
Another possible solution, instead of crushing the particle size fraction of 4.75-6.7 mm further, is to screen the coal at a particle size of 4.75 mm. This will ensure that the cumulative floats mass yield and the relative low cumulative float ash yield of the particles smaller than 4.75 mm is not lowered by the presence of material larger than 4.75 mm. Figure 4.19 presents the ash curve for impact breakage to a top size of 6.7 mm fol was used to compare the cumulative floats those larger than 4.75 mm. The cumulative because the particle sizes are presented 4.75 mm, and those larger than 4.75 mm wil owed by attrition breakage for 1 minute. This curve mass yield of particles smaller than 4.75 mm and loat mass yield does not add up the 100 %. This is separately. Together, the particles smaller than add to 100 %. 4.75 mm, and those larger than 4.75 mm will add to 100 %. Figure 4.19: Ash curve for impact breakage to a top size of 6.7 mm followed by attrition breakage for 1 minute.
Another possible solution, instead of crushing the particle size fraction of 4.75-6.7 mm further, is to screen the coal at a particle size of 4.75 mm. This will ensure that the cumulative floats mass yield and the relative low cumulative float ash yield of the particles smaller than 4.75 mm is not lowered by the presence of material larger than 4.75 mm. Figure 4.19 presents the ash curve for impact breakage to a top size of 6.7 mm fol was used to compare the cumulative floats those larger than 4.75 mm. The cumulative because the particle sizes are presented 4.75 mm, and those larger than 4.75 mm wil owed by attrition breakage for 1 minute. This curve mass yield of particles smaller than 4.75 mm and loat mass yield does not add up the 100 %. This is separately. Together, the particles smaller than add to 100 %. 4.75 mm, and those larger than 4.75 mm will add to 100 %. Figure 4.19: Ash curve for impact breakage to a top size of 6.7 mm followed by attrition breakage for 1 minute.
Figure 4.23: Cumulative fractional yield of liberated coal macerals (with RD<1.4) within the particle size interval of 0-4.75 mm. When comparing the cumulative fractional yield of the liberated coal macerals at a particle size
Figure 4.23: Cumulative fractional yield of liberated coal macerals (with RD<1.4) within the particle size interval of 0-4.75 mm. When comparing the cumulative fractional yield of the liberated coal macerals at a particle size
Figure 4.24: Densimetric curve for impact breakage to a top size of 13.2 mm. As illustrated in Figure 4.24, impact breakage to a top size of 13.2 mm did not show an increase in the cumulative floats mass yield compared to that of raw coal, prior to any testing. Attrition breakage additional to impact breakage had no effect on the floats mass yield attained, regardless of the residence time used for attrition. This confirms the statement made in Section 4.3.2 that attrition breakage additional to impact breakage to a top size of 13.2 mm had an insignificant effect on the yield. Impact breakage to a top size of 13.2 mm followed by attrition for 1 minute was considered to be an outlier. It was seen that the cumulative floats mass yield of the raw coa will also be given to compare whether the yield was increased by the applied mode of breakage.
Figure 4.24: Densimetric curve for impact breakage to a top size of 13.2 mm. As illustrated in Figure 4.24, impact breakage to a top size of 13.2 mm did not show an increase in the cumulative floats mass yield compared to that of raw coal, prior to any testing. Attrition breakage additional to impact breakage had no effect on the floats mass yield attained, regardless of the residence time used for attrition. This confirms the statement made in Section 4.3.2 that attrition breakage additional to impact breakage to a top size of 13.2 mm had an insignificant effect on the yield. Impact breakage to a top size of 13.2 mm followed by attrition for 1 minute was considered to be an outlier. It was seen that the cumulative floats mass yield of the raw coa will also be given to compare whether the yield was increased by the applied mode of breakage.
Figure 4.25: Densimetric curve for impact breakage to a top size of 6.7 mm. of 6.7 mm as well as for cases when additional attritioning was performed. Although attrition additional to impact breakage to a top size of 13.2 mm had no effect on the floats mass yield, Figure 4.25 shows that this was not the case for impact breakage to a top size of 6.7 mm. Again, this confirms the effect of attrition breakage additional to impact breakage of a top size of 6.7 mm as described in Section 4.3.2. Impact breakage to a top size of 6.7 mm resulted in exposure of vitrinite-rich material. The brittle vitrinite-rich material was chipped from the exposed surface during attritioning. This resulted in an increase in the amount of material with a density of 1.4 and less; the yield of coal was thus increased. When comparing the curves showing attrition breakage additional to impact breakage to a top size of 6.7 mm, it can be seen that there was a 5-10 % yield increase after a a relative density of 1.4 for the raw size of 6.7 mm resulted in a cumula tritioning was performed. The cumulative floats mass yield at coa ive prior to any testing was 26 %. Impact breakage to a top loats mass yield of 33 % at a relative density of 1.4, while that for the case of additional attritioning was up to 45 %. Not only does this graph show that attrition breakage further increase he 6.7 mm was done, but it also shows loats mass yield when impact breakage to a top size of hat a higher floats mass yield was attained by impact
Figure 4.25: Densimetric curve for impact breakage to a top size of 6.7 mm. of 6.7 mm as well as for cases when additional attritioning was performed. Although attrition additional to impact breakage to a top size of 13.2 mm had no effect on the floats mass yield, Figure 4.25 shows that this was not the case for impact breakage to a top size of 6.7 mm. Again, this confirms the effect of attrition breakage additional to impact breakage of a top size of 6.7 mm as described in Section 4.3.2. Impact breakage to a top size of 6.7 mm resulted in exposure of vitrinite-rich material. The brittle vitrinite-rich material was chipped from the exposed surface during attritioning. This resulted in an increase in the amount of material with a density of 1.4 and less; the yield of coal was thus increased. When comparing the curves showing attrition breakage additional to impact breakage to a top size of 6.7 mm, it can be seen that there was a 5-10 % yield increase after a a relative density of 1.4 for the raw size of 6.7 mm resulted in a cumula tritioning was performed. The cumulative floats mass yield at coa ive prior to any testing was 26 %. Impact breakage to a top loats mass yield of 33 % at a relative density of 1.4, while that for the case of additional attritioning was up to 45 %. Not only does this graph show that attrition breakage further increase he 6.7 mm was done, but it also shows loats mass yield when impact breakage to a top size of hat a higher floats mass yield was attained by impact
as well as the results when additional attrition breakage was performed. Figure 4.26: Densimetric curve for compressive breakage to a top size of 13.2 mm.
as well as the results when additional attrition breakage was performed. Figure 4.26: Densimetric curve for compressive breakage to a top size of 13.2 mm.
Figure 4.27: Densimetric curve for compressive breakage to a top size of 6.7 mm. Figure 4.27 indicates the cumulative floats mass yield for compressive breakage to a top size of 6.7 mm. Attrition breakage additional to compressive breakage to a top size of 6.7 mm had a noticeable effect on the cumulative floats mass yield. As seen from Figure 4.27, there was a slight increase in the amount of floats mass yield at each relative density, though this was not as much as the increase in floats mass yield produced by the results for impact breakage to a top size of 6.7 mm followed by attrition breakage. It was seen that the cumulative floats mass yield of the raw coal was higher than that for compressive breakage to a top size of 6.7 mm with no attritioning, al relative densities of 1.6 to 1.8. This might be because of sampling split or experimental errors.
Figure 4.27: Densimetric curve for compressive breakage to a top size of 6.7 mm. Figure 4.27 indicates the cumulative floats mass yield for compressive breakage to a top size of 6.7 mm. Attrition breakage additional to compressive breakage to a top size of 6.7 mm had a noticeable effect on the cumulative floats mass yield. As seen from Figure 4.27, there was a slight increase in the amount of floats mass yield at each relative density, though this was not as much as the increase in floats mass yield produced by the results for impact breakage to a top size of 6.7 mm followed by attrition breakage. It was seen that the cumulative floats mass yield of the raw coal was higher than that for compressive breakage to a top size of 6.7 mm with no attritioning, al relative densities of 1.6 to 1.8. This might be because of sampling split or experimental errors.
Figure 4.28: Densimetric curve for impact breakage to a top size of 6.7 mm followed by attrition breakage for 1 minute.
Figure 4.28: Densimetric curve for impact breakage to a top size of 6.7 mm followed by attrition breakage for 1 minute.
given run. The percentage yield increase was calculated by using Equation D-2.
given run. The percentage yield increase was calculated by using Equation D-2.
(at the relative density of 1.39) at a particle size, for example, 4.75 mm will be 62.0 %. Figure 5.1 shows the hypothetical density wash of the raw coal. The cumulative particle size distribution for the feed material, as well as for the product floats after subjected to washing at a relative density of 1.39 (as indicated in Table 5.1) are shown. The cumulative floats mass yield (at the relative density of 1.39) at a particle size, for example, 4.75 mm will be 62.0 %. Figure 5.1: Hypothetical density wash of raw coal.
(at the relative density of 1.39) at a particle size, for example, 4.75 mm will be 62.0 %. Figure 5.1 shows the hypothetical density wash of the raw coal. The cumulative particle size distribution for the feed material, as well as for the product floats after subjected to washing at a relative density of 1.39 (as indicated in Table 5.1) are shown. The cumulative floats mass yield (at the relative density of 1.39) at a particle size, for example, 4.75 mm will be 62.0 %. Figure 5.1: Hypothetical density wash of raw coal.
Figure 5.2: Hypothetical density wash of coal subjected to impact breakage to a top size of 6.7 mm with additional attrition breakage for 1 minute.
Figure 5.2: Hypothetical density wash of coal subjected to impact breakage to a top size of 6.7 mm with additional attrition breakage for 1 minute.
Figure 5.3: Industrial application. It is suggested that run-of-mine coal are fed to a primary crusher, preferably one that uses impact breakage as the main breakage mode. The reason impact breakage is preferred, is that results obtained during this study have shown that impact breakage resulted in a higher yield of liberated coal macerals (material with a relative density of 1.4 and lower). Another reason why impact breakage is preferred to compressive breakage is that compressive breakage resulted in a larger quantity of fines generation. As discussed in Section 4.4, the fines generation during compressive breakage can be ascribed to the compressive forces that were applied directly to the surface of the particles. suggestion, by means of a flow diagram, of how the breakage modes can be implemented for obtained during this study have shown that impact breakage resulted in a higher yield of liberated
Figure 5.3: Industrial application. It is suggested that run-of-mine coal are fed to a primary crusher, preferably one that uses impact breakage as the main breakage mode. The reason impact breakage is preferred, is that results obtained during this study have shown that impact breakage resulted in a higher yield of liberated coal macerals (material with a relative density of 1.4 and lower). Another reason why impact breakage is preferred to compressive breakage is that compressive breakage resulted in a larger quantity of fines generation. As discussed in Section 4.4, the fines generation during compressive breakage can be ascribed to the compressive forces that were applied directly to the surface of the particles. suggestion, by means of a flow diagram, of how the breakage modes can be implemented for obtained during this study have shown that impact breakage resulted in a higher yield of liberated
Table B. 1: Proximate analysis, calorific value analysis and free swelling index analysis results for particle sizes 0.0-1.0 mm ( basis).
Table B. 1: Proximate analysis, calorific value analysis and free swelling index analysis results for particle sizes 0.0-1.0 mm ( basis).
Table B. 3: Initial particle size distribution for raw ROM coal.
Table B. 3: Initial particle size distribution for raw ROM coal.
Table B. 5: Initial particle size distributions for impact breakage to a top size of 6.7 mm.
Table B. 5: Initial particle size distributions for impact breakage to a top size of 6.7 mm.
Table B. 8: Intermediate particle size distributions for impact breakage to a top size of 13.2 mm.
Table B. 8: Intermediate particle size distributions for impact breakage to a top size of 13.2 mm.
Table B. 12: Final particle size distribution for raw ROM coal.
Table B. 12: Final particle size distribution for raw ROM coal.
Table B. 13: Final particle size distributions for impact breakage to a top size of 13.2 mm.
Table B. 13: Final particle size distributions for impact breakage to a top size of 13.2 mm.
Table B. 15: Final particle size distributions for compressive breakage to a top size of 13.2 mm.
Table B. 15: Final particle size distributions for compressive breakage to a top size of 13.2 mm.
Table B. 16: Final particle size distributions for compressive breakage to a top size of 6.7 mm.
Table B. 16: Final particle size distributions for compressive breakage to a top size of 6.7 mm.
able B. 17: Mass of -1 mm particles for float-sink analysis (raw ROM coal)
able B. 17: Mass of -1 mm particles for float-sink analysis (raw ROM coal)
Table B. 18: Mass of -1 mm particles for float-sink analysis (impact breakage to a top size of 13.2 mm).
Table B. 18: Mass of -1 mm particles for float-sink analysis (impact breakage to a top size of 13.2 mm).
Table B. 21: Mass of -1 mm particles for float-sink analysis (compressive breakage to a top size of 6.7 mm).
Table B. 21: Mass of -1 mm particles for float-sink analysis (compressive breakage to a top size of 6.7 mm).
Table B. 22: Raw data for raw ROM coal
Table B. 22: Raw data for raw ROM coal
Table B. 23: Raw data for impact breakage to a top size of 13.2 mm with no attrition (Run 1).
Table B. 23: Raw data for impact breakage to a top size of 13.2 mm with no attrition (Run 1).
Table B. 24: Raw data for impact breakage to a top size of 13.2 mm with no attrition (Run 2).
Table B. 24: Raw data for impact breakage to a top size of 13.2 mm with no attrition (Run 2).
Table B. 25: Raw data for impact breakage to a top size of 13.2 mm with no attrition (Run 3).
Table B. 25: Raw data for impact breakage to a top size of 13.2 mm with no attrition (Run 3).
Table B. 26: Raw data for impact breakage to a top size of 13.2 mm with 1 minute attritior breakage (Run 4).
Table B. 26: Raw data for impact breakage to a top size of 13.2 mm with 1 minute attritior breakage (Run 4).
‘able B. 27: Raw data for impact breakage to a top size of 13.2 mm with 2 minutes attrition breakage (Run 5).
‘able B. 27: Raw data for impact breakage to a top size of 13.2 mm with 2 minutes attrition breakage (Run 5).
Table B. 28: Raw data for impact breakage to a top size of 13.2 mm with 5 minutes attrition breakage (Run 6).
Table B. 28: Raw data for impact breakage to a top size of 13.2 mm with 5 minutes attrition breakage (Run 6).
Table B. 29: Raw data for impact breakage to a top size of 6.7 mm with no attrition breakage (Run 7).
Table B. 29: Raw data for impact breakage to a top size of 6.7 mm with no attrition breakage (Run 7).
fable B. 30: Raw data for impact breakage to a top size of 6.7 mm with no attritior breakage (Run 8).
fable B. 30: Raw data for impact breakage to a top size of 6.7 mm with no attritior breakage (Run 8).
Table B. 31: Raw data for impact breakage to a top size of 6.7 mm with no attrition breakage (Run 9).
Table B. 31: Raw data for impact breakage to a top size of 6.7 mm with no attrition breakage (Run 9).
Table B. 32: Raw data for impact breakage to a top size of 6.7 mm with 1 minute attrition breakage (Run 10).
Table B. 32: Raw data for impact breakage to a top size of 6.7 mm with 1 minute attrition breakage (Run 10).
Table B. 33: Raw data for impact breakage to a top size of 6.7 mm with 2 minutes attrition breakage (Run 11).
Table B. 33: Raw data for impact breakage to a top size of 6.7 mm with 2 minutes attrition breakage (Run 11).
‘able B. 34: Raw data for impact breakage to a top size of 6.7 mm with 5 minutes attritior breakage (Run 12).
‘able B. 34: Raw data for impact breakage to a top size of 6.7 mm with 5 minutes attritior breakage (Run 12).
Table B. 35: Raw data for compressive breakage to a top size of 13.2 mm with no attrition breakage (Run 13).
Table B. 35: Raw data for compressive breakage to a top size of 13.2 mm with no attrition breakage (Run 13).
Table B. 36: Raw data for compressive breakage to a top size of 13.2 mm with no attritior breakage (Run 14).
Table B. 36: Raw data for compressive breakage to a top size of 13.2 mm with no attritior breakage (Run 14).
Table B. 37: Raw data for compressive breakage to a top size of 13.2 mm with no attritior breakage (Run 15).
Table B. 37: Raw data for compressive breakage to a top size of 13.2 mm with no attritior breakage (Run 15).
Table B. 38: Raw data for compressive breakage to a top size of 13.2 mm with 1 minute attrition breakage (Run 16).
Table B. 38: Raw data for compressive breakage to a top size of 13.2 mm with 1 minute attrition breakage (Run 16).
Table B. 39: Raw data for compressive breakage to a top size of 13.2 mm with 2 minutes attrition breakage (Run 17).
Table B. 39: Raw data for compressive breakage to a top size of 13.2 mm with 2 minutes attrition breakage (Run 17).
Table B. 40: Raw data for compressive breakage to a top size of 13.2 mm with 5 minute: attrition breakage (Run 18).
Table B. 40: Raw data for compressive breakage to a top size of 13.2 mm with 5 minute: attrition breakage (Run 18).
Table B. 41: Raw data for compressive breakage to a top size of 6.7 mm with no attrition breakage (Run 19).
Table B. 41: Raw data for compressive breakage to a top size of 6.7 mm with no attrition breakage (Run 19).
Table B. 42: Raw data for compressive breakage to a top size of 6.7 mm with no attrition breakage (Run 20).
Table B. 42: Raw data for compressive breakage to a top size of 6.7 mm with no attrition breakage (Run 20).
Table B. 43: Raw data for compressive breakage to a top size of 6.7 mm with no attritio: breakage (Run 21).
Table B. 43: Raw data for compressive breakage to a top size of 6.7 mm with no attritio: breakage (Run 21).
Table B. 44: Raw data for compressive breakage to a top size of 6.7 mm with 1 minute attrition breakage (Run 22).
Table B. 44: Raw data for compressive breakage to a top size of 6.7 mm with 1 minute attrition breakage (Run 22).
Table B. 45: Raw data for compressive breakage to a top size of 6.7 mm with 2 minute: attrition breakage (Run 23).
Table B. 45: Raw data for compressive breakage to a top size of 6.7 mm with 2 minute: attrition breakage (Run 23).
Table B. 46: Raw data for compressive breakage to a top size of 6.7 mm with 5 minutes attrition breakage (Run 24).
Table B. 46: Raw data for compressive breakage to a top size of 6.7 mm with 5 minutes attrition breakage (Run 24).
Table C. 2: Proximate, calorific value and free swelling index analysis results for particle sizes 1.0-13.2 mm expressed on a dry basis.
Table C. 2: Proximate, calorific value and free swelling index analysis results for particle sizes 1.0-13.2 mm expressed on a dry basis.
Particle size distribution data: Table C. 3 to Table C. 30 presents data for the calculation of the amount of mass occurring i each particle size range. The mass of the sample along with the sieve mass was measured, an therefore Equation D- 3 needs to be used to determine the sample mass _ onl) Equation D- 4 was used to recalculate the mass of material with particle size smaller tha 4.75 mm, as split for the PSD, to be as for the total sample. The final mass was calculated b using Equation D- 5. The mass loss, relative to the initial sample mass, was also included b employing Equation D- 8. The initial, intermediate and final masses was recalculated to be | normalized mass percentage by using Equation D- 9.
Particle size distribution data: Table C. 3 to Table C. 30 presents data for the calculation of the amount of mass occurring i each particle size range. The mass of the sample along with the sieve mass was measured, an therefore Equation D- 3 needs to be used to determine the sample mass _ onl) Equation D- 4 was used to recalculate the mass of material with particle size smaller tha 4.75 mm, as split for the PSD, to be as for the total sample. The final mass was calculated b using Equation D- 5. The mass loss, relative to the initial sample mass, was also included b employing Equation D- 8. The initial, intermediate and final masses was recalculated to be | normalized mass percentage by using Equation D- 9.
Table C. 4: Particle size distribution of impact breakage to a top size of 13.2 mm with no attrition (Run 1).
Table C. 4: Particle size distribution of impact breakage to a top size of 13.2 mm with no attrition (Run 1).
Table C. 5: Particle size distribution of impact breakage to a top size of 13.2 mm with nc attrition (Run 2).
Table C. 5: Particle size distribution of impact breakage to a top size of 13.2 mm with nc attrition (Run 2).
Table C. 6: Particle size distribution of impact breakage to a top size of 13.2 mm with no attrition (Run 3).
Table C. 6: Particle size distribution of impact breakage to a top size of 13.2 mm with no attrition (Run 3).
Table C. 7: Particle size distribution of impact breakage to a top size of 13.2 mm with no attrition (Run 1-3 average).
Table C. 7: Particle size distribution of impact breakage to a top size of 13.2 mm with no attrition (Run 1-3 average).
Table C. 8: Particle size distribution of impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 8: Particle size distribution of impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 9: Particle size distribution of impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 9: Particle size distribution of impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 10: Particle size distribution of impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 10: Particle size distribution of impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 11: Particle size distribution of impact breakage to a top size of 6.7 mm with no attritioning (Run 7).
Table C. 11: Particle size distribution of impact breakage to a top size of 6.7 mm with no attritioning (Run 7).
Table C. 12: Particle size distribution of impact breakage to a top size of 6.7 mm with no attritioning (Run 8).
Table C. 12: Particle size distribution of impact breakage to a top size of 6.7 mm with no attritioning (Run 8).
Table C. 13: Particle size distribution of impact breakage to a top size of 6.7 mm with no attritioning (Run 9).
Table C. 13: Particle size distribution of impact breakage to a top size of 6.7 mm with no attritioning (Run 9).
Table C. 14: Particle size distribution of impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 14: Particle size distribution of impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 15: Particle size distribution of impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 15: Particle size distribution of impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 16: Particle size distribution of impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 16: Particle size distribution of impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 17: Particle size distribution of impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 17: Particle size distribution of impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 18: Particle size distribution of compressive breakage to a top size of 13.2 mm with no attritioning (Run 13).
Table C. 18: Particle size distribution of compressive breakage to a top size of 13.2 mm with no attritioning (Run 13).
Table C. 19: Particle size distribution of compressive breakage to a top size of 13.2 mm with no attritioning (Run 14).
Table C. 19: Particle size distribution of compressive breakage to a top size of 13.2 mm with no attritioning (Run 14).
Table C. 20: Particle size distribution of compressive breakage to a top size of 13.2 mm with no attritioning (Run 15).
Table C. 20: Particle size distribution of compressive breakage to a top size of 13.2 mm with no attritioning (Run 15).
Table C. 21: Particle size distribution of compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 21: Particle size distribution of compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 22: Particle size distribution of compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 22: Particle size distribution of compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 23: Particle size distribution of compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 23: Particle size distribution of compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 24: Particle size distribution of compressive breakage to a top size of 6.7 mm with no attritioning (Run 19).
Table C. 24: Particle size distribution of compressive breakage to a top size of 6.7 mm with no attritioning (Run 19).
Table C. 25: Particle size distribution of compressive breakage to a top size of 6.7 mm with no attritioning (Run 20).
Table C. 25: Particle size distribution of compressive breakage to a top size of 6.7 mm with no attritioning (Run 20).
Table C. 26: Particle size distribution of compressive breakage to a top size of 6.7 mm with no attritioning (Run 21).
Table C. 26: Particle size distribution of compressive breakage to a top size of 6.7 mm with no attritioning (Run 21).
Table C. 27: Particle size distribution of compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 27: Particle size distribution of compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 28: Particle size distribution of compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 28: Particle size distribution of compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 29: Particle size distribution of compressive breakage to a top size of 6.7 mir with 2 minutes attritioning (Run 23).
Table C. 29: Particle size distribution of compressive breakage to a top size of 6.7 mir with 2 minutes attritioning (Run 23).
Table C. 30: Particle size distribution of compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 30: Particle size distribution of compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Figure C. 1: Particle size distribution for raw ROM coal.
Figure C. 1: Particle size distribution for raw ROM coal.
Figure C. 3: Particle size distribution for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Figure C. 3: Particle size distribution for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Figure C. 5: Particle size distribution for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Figure C. 5: Particle size distribution for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Figure C. 7: Particle size distribution for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Figure C. 7: Particle size distribution for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Figure C. 9: Particle size distribution for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Figure C. 9: Particle size distribution for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Figure C. 11: Particle size distribution for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Figure C. 11: Particle size distribution for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Figure C. 13: Particle size distribution for compressive breakage to a top size of 13.2 mr with 5 minutes attritioning (Run 18).
Figure C. 13: Particle size distribution for compressive breakage to a top size of 13.2 mr with 5 minutes attritioning (Run 18).
Figure C. 15: Particle size distribution for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Figure C. 15: Particle size distribution for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Figure C. 17: Particle size distribution for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Figure C. 17: Particle size distribution for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 31: Mass percentage distribution for raw ROM coal. The partition data presents the mass distribution of the whole sample according to its relative density and particle size distribution (PSD). Equation D- 10 was used to calculate the mass in each interval, as the sieve mass and sample mass was weigh together. The fractional mass yield occurring in each relative density interval, and particle size interval was calculated to be as a percentage of the total mass according to Equation D- 11. The calculated mass percentage distributions are given in Table C. 31 to Table C. 59.
Table C. 31: Mass percentage distribution for raw ROM coal. The partition data presents the mass distribution of the whole sample according to its relative density and particle size distribution (PSD). Equation D- 10 was used to calculate the mass in each interval, as the sieve mass and sample mass was weigh together. The fractional mass yield occurring in each relative density interval, and particle size interval was calculated to be as a percentage of the total mass according to Equation D- 11. The calculated mass percentage distributions are given in Table C. 31 to Table C. 59.
Table C. 32: Mass percentage distribution for impact breakage to a top size of 13.2 mm with no attritioning (Run 1).
Table C. 32: Mass percentage distribution for impact breakage to a top size of 13.2 mm with no attritioning (Run 1).
Table C. 33: Mass percentage distribution for impact breakage to a top size of 13.2 mm with no attritioning (Run 2).
Table C. 33: Mass percentage distribution for impact breakage to a top size of 13.2 mm with no attritioning (Run 2).
Table C. 34: Mass percentage distribution for impact breakage to a top size of 13.2 mm with no attritioning (Run 3).
Table C. 34: Mass percentage distribution for impact breakage to a top size of 13.2 mm with no attritioning (Run 3).
Table C. 35: Mass percentage distribution for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Table C. 35: Mass percentage distribution for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Table C. 36: Mass percentage distribution for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 36: Mass percentage distribution for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 37: Mass percentage distribution for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 37: Mass percentage distribution for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 38: Mass percentage distribution for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 38: Mass percentage distribution for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 39: Mass percentage distribution for impact breakage to a top size of 6.7 mm with no attritioning (Run 7).
Table C. 39: Mass percentage distribution for impact breakage to a top size of 6.7 mm with no attritioning (Run 7).
Table C. 40: Mass percentage distribution for impact breakage to a top size of 6.7 mm with no attritioning (Run 8).
Table C. 40: Mass percentage distribution for impact breakage to a top size of 6.7 mm with no attritioning (Run 8).
Table C. 41: Mass percentage distribution for impact breakage to a top size of 6.7 mm with no attritioning (Run 9).
Table C. 41: Mass percentage distribution for impact breakage to a top size of 6.7 mm with no attritioning (Run 9).
Table C. 42: Mass percentage distribution for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 42: Mass percentage distribution for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 43: Mass percentage distribution for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 43: Mass percentage distribution for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 44: Mass percentage distribution for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 44: Mass percentage distribution for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 45: Mass percentage distribution for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 45: Mass percentage distribution for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 46: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13).
Table C. 46: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13).
Table C. 47: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with no attritioning (Run 14).
Table C. 47: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with no attritioning (Run 14).
Table C. 48: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with no attritioning (Run 15).
Table C. 48: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with no attritioning (Run 15).
Table C. 49: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 49: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 50: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 50: Mass percentage distribution for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 51: Mass percentage distribution for compressive breakage to a top size o 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 51: Mass percentage distribution for compressive breakage to a top size o 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 52: Mass percentage distribution for compressive breakage to a top size o 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 52: Mass percentage distribution for compressive breakage to a top size o 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 53: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19).
Table C. 53: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19).
Table C. 54: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with no attritioning (Run 20).
Table C. 54: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with no attritioning (Run 20).
Table C. 55: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with no attritioning (Run 21).
Table C. 55: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with no attritioning (Run 21).
Table C. 56: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 56: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 57: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 57: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 58: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 58: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 59: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 59: Mass percentage distribution for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Figure C. 19: Size by washability graph for impact breakage to a top size of 13.2 mm with no additional attrition breakage (Run 2).
Figure C. 19: Size by washability graph for impact breakage to a top size of 13.2 mm with no additional attrition breakage (Run 2).
Figure C. 21: Size by washability graph for impact breakage to a top size of 13.2 mm wit no 1 minute attritioning (Run 4).
Figure C. 21: Size by washability graph for impact breakage to a top size of 13.2 mm wit no 1 minute attritioning (Run 4).
-igure C. 24: Size by washability graph for impact breakage to a top size of 6.7 mm wit no attritioning (Run 8).
-igure C. 24: Size by washability graph for impact breakage to a top size of 6.7 mm wit no attritioning (Run 8).
Figure C. 26: Size by washability graph for impact breakage to a top size of 6.7 mm with minute attritioning (Run 10).
Figure C. 26: Size by washability graph for impact breakage to a top size of 6.7 mm with minute attritioning (Run 10).
Figure C. 29: Size by washability graph for compressive breakage to a top size of 13.2 mm with no attritioning (Run 14).
Figure C. 29: Size by washability graph for compressive breakage to a top size of 13.2 mm with no attritioning (Run 14).
Figure C. 31: Size by washability graph for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Figure C. 31: Size by washability graph for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Figure C. 33: Size by washability graph for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19).
Figure C. 33: Size by washability graph for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19).
Figure C. 35: Size by washability graph for compressive breakage to a top size of 6.7 mm with no attritioning (Run 21).
Figure C. 35: Size by washability graph for compressive breakage to a top size of 6.7 mm with no attritioning (Run 21).
Table C. 60: Particle size per density for raw ROM coal Table C. 61: Particle size per density for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Table C. 60: Particle size per density for raw ROM coal Table C. 61: Particle size per density for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Table C. 62: Particle size per density for impact breakage to a top size of 13.2 mm with minute attritioning (Run 4).
Table C. 62: Particle size per density for impact breakage to a top size of 13.2 mm with minute attritioning (Run 4).
Table C. 63: Particle size per density for impact breakage to a top size of 13.2 mm with < minutes attritioning (Run 5).
Table C. 63: Particle size per density for impact breakage to a top size of 13.2 mm with < minutes attritioning (Run 5).
Table C. 64: Particle size per density for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 64: Particle size per density for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 65: Particle size per density for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 65: Particle size per density for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 66: Particle size per density for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 66: Particle size per density for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 67: Particle size per density for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 67: Particle size per density for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 68: Particle size per density for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 68: Particle size per density for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 69: Particle size per density for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13).
Table C. 69: Particle size per density for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13).
Table C. 70: Particle size per density for compressive breakage to a top size of 13.2 mn with no attritioning (Run 14).
Table C. 70: Particle size per density for compressive breakage to a top size of 13.2 mn with no attritioning (Run 14).
Table C. 71: Particle size per density for compressive breakage to a top size of 13.2 mn with no attritioning (Run 15).
Table C. 71: Particle size per density for compressive breakage to a top size of 13.2 mn with no attritioning (Run 15).
Table C. 72: Particle size per density for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 72: Particle size per density for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 73 Particle size per density for compressive breakage to a top size of 13.2 mr with 1 minute attritioning (Run 16).
Table C. 73 Particle size per density for compressive breakage to a top size of 13.2 mr with 1 minute attritioning (Run 16).
Table C. 74: Particle size per density for compressive breakage to a top size of 13.2 mn with 2 minutes attritioning (Run 17).
Table C. 74: Particle size per density for compressive breakage to a top size of 13.2 mn with 2 minutes attritioning (Run 17).
Table C. 75: Particle size per density for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 75: Particle size per density for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 76: Particle size per density for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19).
Table C. 76: Particle size per density for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19).
Table C. 77: Particle size per density for compressive breakage to a top size of 6.7 mn with no attritioning (Run 20).
Table C. 77: Particle size per density for compressive breakage to a top size of 6.7 mn with no attritioning (Run 20).
Table C. 78: Particle size per density for compressive breakage to a top size of 6.7 mn with no attritioning (Run 21).
Table C. 78: Particle size per density for compressive breakage to a top size of 6.7 mn with no attritioning (Run 21).
Table C. 79: Particle size per density for compressive breakage to a top size of 6.7 mn with no attritioning (Run 19-21 average).
Table C. 79: Particle size per density for compressive breakage to a top size of 6.7 mn with no attritioning (Run 19-21 average).
Table C. 80: Particle size per density for compressive breakage to a top size of 6.7 mn with 1 minute attritioning (Run 22).
Table C. 80: Particle size per density for compressive breakage to a top size of 6.7 mn with 1 minute attritioning (Run 22).
Table C. 81: Particle size per density for compressive breakage to a top size of 6.7 mn with 2 minutes attritioning (Run 23).
Table C. 81: Particle size per density for compressive breakage to a top size of 6.7 mn with 2 minutes attritioning (Run 23).
Table C. 82: Particle size per density for compressive breakage to a top size of 6.7 mn with 5 minutes attritioning (Run 24).
Table C. 82: Particle size per density for compressive breakage to a top size of 6.7 mn with 5 minutes attritioning (Run 24).
Figure C. 39: Particle size per density graph for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Figure C. 39: Particle size per density graph for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Figure C. 41: Particle size per density graph for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Figure C. 41: Particle size per density graph for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Figure C. 43: Particle size per density graph for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Figure C. 43: Particle size per density graph for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Figure C. 45: Particle size per density graph for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Figure C. 45: Particle size per density graph for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Figure C. 47: Particle size per density graph for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Figure C. 47: Particle size per density graph for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Figure C. 49: Particle size per density graph for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Figure C. 49: Particle size per density graph for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Figure C. 51: Particle size per density graph for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Figure C. 51: Particle size per density graph for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Figure C. 53: Particle size per density graph for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Figure C. 53: Particle size per density graph for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 83: Density per particle size for raw ROM coal. that specific particle size interval. Thus the total mass fraction at that specific size interval will add
Table C. 83: Density per particle size for raw ROM coal. that specific particle size interval. Thus the total mass fraction at that specific size interval will add
Table C. 84: Density per particle size for impact breakage to a top size of 13.2 mm with nc attritioning (Run 1-3 average).
Table C. 84: Density per particle size for impact breakage to a top size of 13.2 mm with nc attritioning (Run 1-3 average).
Table C. 85: Density per particle size for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 85: Density per particle size for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 86: Density per particle size for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 86: Density per particle size for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 87: Density per particle size for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 87: Density per particle size for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 88: Density per particle size for impact breakage to a top size of 6.7 mm with ne attritioning (Run 7-9 average).
Table C. 88: Density per particle size for impact breakage to a top size of 6.7 mm with ne attritioning (Run 7-9 average).
Table C. 89: Density per particle size for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 89: Density per particle size for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 90: Density per particle size for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 90: Density per particle size for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
‘able C. 91: Density per particle size for impact breakage to a top size of 6.7 mm with £ minutes attritioning (Run 12).
‘able C. 91: Density per particle size for impact breakage to a top size of 6.7 mm with £ minutes attritioning (Run 12).
Table C. 92: Density per particle size for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 92: Density per particle size for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 93: Density per particle size for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 93: Density per particle size for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 94: Density per particle size for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 94: Density per particle size for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 95: Density per particle size for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 95: Density per particle size for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 96: Density per particle size for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 96: Density per particle size for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 97: Density per particle size for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 97: Density per particle size for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 98: Density per particle size for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 98: Density per particle size for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 99: Density per particle size for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 99: Density per particle size for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Figure C. 55: Density per particle size graph for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Figure C. 55: Density per particle size graph for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Figure C. 57: Density per particle size graph for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Figure C. 57: Density per particle size graph for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Figure C. 59: Density per particle size graph for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Figure C. 59: Density per particle size graph for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Figure C. 61: Density per particle size graph for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Figure C. 61: Density per particle size graph for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Figure C. 63: Density per particle size graph for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Figure C. 63: Density per particle size graph for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Figure C. 65: Density per particle size graph for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Figure C. 65: Density per particle size graph for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Figure C. 67: Density per particle size graph for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Figure C. 67: Density per particle size graph for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Figure C. 69: Density per particle size graph for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Figure C. 69: Density per particle size graph for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 100: Float ash per particle size for raw ROM coal.
Table C. 100: Float ash per particle size for raw ROM coal.
Table C. 101: Float ash per particle size for impact breakage to 13.2 mm with no attritioning (Run 1-3 average).
Table C. 101: Float ash per particle size for impact breakage to 13.2 mm with no attritioning (Run 1-3 average).
Table C. 102: Float ash per particle size for impact breakage to 13.2 mm with 1 minute attritioning (Run 4).
Table C. 102: Float ash per particle size for impact breakage to 13.2 mm with 1 minute attritioning (Run 4).
Table C. 103: Float ash per particle size for impact breakage to 13.2 mm with 2 minute attritioning (Run 5).
Table C. 103: Float ash per particle size for impact breakage to 13.2 mm with 2 minute attritioning (Run 5).
Table C. 104: Float ash per particle size for impact breakage to 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 104: Float ash per particle size for impact breakage to 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 105: Float ash per particle size for impact breakage to 6.7 mm with no attritioning (Run 7-9 average).
Table C. 105: Float ash per particle size for impact breakage to 6.7 mm with no attritioning (Run 7-9 average).
Table C. 106: Float ash per particle size for impact breakage to 6.7 mm with 1 minute attritioning (Run 10).
Table C. 106: Float ash per particle size for impact breakage to 6.7 mm with 1 minute attritioning (Run 10).
‘able C. 107: Float ash per particle size for impact breakage to 6.7 mm with 2 minute: attritioning (Run 11).
‘able C. 107: Float ash per particle size for impact breakage to 6.7 mm with 2 minute: attritioning (Run 11).
Table C. 108: Float ash per particle size for impact breakage to 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 108: Float ash per particle size for impact breakage to 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 109: Float ash per particle size for compressive breakage to 13.2 mm with no attritioning (Run 13-15 average).
Table C. 109: Float ash per particle size for compressive breakage to 13.2 mm with no attritioning (Run 13-15 average).
Table C. 110: Float ash per particle size for compressive breakage to 13.2 mm with 1 minute attritioning (Run 16).
Table C. 110: Float ash per particle size for compressive breakage to 13.2 mm with 1 minute attritioning (Run 16).
Table C. 111: Float ash per particle size for compressive breakage to 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 111: Float ash per particle size for compressive breakage to 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 112: Float ash per particle size for compressive breakage to 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 112: Float ash per particle size for compressive breakage to 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 113: Float ash per particle size for compressive breakage to 6.7 mm with no attritioning (Run 19-21 average).
Table C. 113: Float ash per particle size for compressive breakage to 6.7 mm with no attritioning (Run 19-21 average).
Table C. 114: Float ash per particle size for compressive breakage to 6.7 mm with 1 minute attritioning (Run 22).
Table C. 114: Float ash per particle size for compressive breakage to 6.7 mm with 1 minute attritioning (Run 22).
Table C. 115: Float ash per particle size for compressive breakage to 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 115: Float ash per particle size for compressive breakage to 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 116: Float ash per particle size for compressive breakage to 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 116: Float ash per particle size for compressive breakage to 6.7 mm with 5 minutes attritioning (Run 24).
Figure C. 72: Float ash per particle size graph for impact breakage to 13.2 mm with no attritioning (Run 1-3 average).
Figure C. 72: Float ash per particle size graph for impact breakage to 13.2 mm with no attritioning (Run 1-3 average).
Figure C. 74: Float ash per particle size graph for impact breakage to 13.2 mm with 2 minutes attritioning (Run 5).
Figure C. 74: Float ash per particle size graph for impact breakage to 13.2 mm with 2 minutes attritioning (Run 5).
Figure C. 76: Float ash per particle size graph for impact breakage to 6.7 mm with no attritioning (Run 7-9 average).
Figure C. 76: Float ash per particle size graph for impact breakage to 6.7 mm with no attritioning (Run 7-9 average).
1 minute attritioning is presented as Figure 4.18. Figure C. 77: Float ash per particle size graph for impact breakage to 6.7 mm with 2 minutes attritioning (Run 11).
1 minute attritioning is presented as Figure 4.18. Figure C. 77: Float ash per particle size graph for impact breakage to 6.7 mm with 2 minutes attritioning (Run 11).
Figure C. 78: Float ash per particle size graph for impact breakage to 6.7 mm with 5 minutes attritioning (Run 12).
Figure C. 78: Float ash per particle size graph for impact breakage to 6.7 mm with 5 minutes attritioning (Run 12).
Figure C. 80: Float ash per particle size graph for compressive breakage to 13.2 mm with 1 minute attritioning (Run 16).
Figure C. 80: Float ash per particle size graph for compressive breakage to 13.2 mm with 1 minute attritioning (Run 16).
Figure C. 82: Float ash per particle size graph for compressive breakage to 13.2 mm with 5 minutes attritioning (Run 18).
Figure C. 82: Float ash per particle size graph for compressive breakage to 13.2 mm with 5 minutes attritioning (Run 18).
Figure C. 84: Float ash per particle size graph for compressive breakage to 6.7 mm with 1 minute attritioning (Run 22).
Figure C. 84: Float ash per particle size graph for compressive breakage to 6.7 mm with 1 minute attritioning (Run 22).
Figure C. 86: Float ash per particle size graph for compressive breakage to 6.7 mm with 5 minutes attritioning (Run 24). Overall washability:
Figure C. 86: Float ash per particle size graph for compressive breakage to 6.7 mm with 5 minutes attritioning (Run 24). Overall washability:
Table C. 117: Overall washability for raw ROM coal. Table C. 118: Overall washability for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average). The overall washability of each sample was analysed by using the float yield and the float ash. The float yield and the float ash for each sample was calculated by using Equation D- 14 and Equation D- 15, and are presented in Table C. 117 to Table C. 133. The cumulative float yield was calculated by cumulatively adding the total fractional mass yield at each RD interval to give a total cumulative float yield of 100% at S1.8.
Table C. 117: Overall washability for raw ROM coal. Table C. 118: Overall washability for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average). The overall washability of each sample was analysed by using the float yield and the float ash. The float yield and the float ash for each sample was calculated by using Equation D- 14 and Equation D- 15, and are presented in Table C. 117 to Table C. 133. The cumulative float yield was calculated by cumulatively adding the total fractional mass yield at each RD interval to give a total cumulative float yield of 100% at S1.8.
Table C. 119: Overall washability for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 119: Overall washability for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 120: Overall washability for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 120: Overall washability for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 121: Overall washability for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 121: Overall washability for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 122: Overall washability for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 122: Overall washability for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 123: Overall washability for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 123: Overall washability for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 124: Overall washability for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 124: Overall washability for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 125: Overall washability for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 125: Overall washability for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 126: Overall washability for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 126: Overall washability for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 127: Overall washability for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 127: Overall washability for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 128: Overall washability for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 128: Overall washability for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 129: Overall washability for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 129: Overall washability for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 130: Overall washability for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 130: Overall washability for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 131: Overall washability for compressive breakage to a top size of 6.7 mm with minute attritioning (Run 22).
Table C. 131: Overall washability for compressive breakage to a top size of 6.7 mm with minute attritioning (Run 22).
Table C. 132: Overall washability for compressive breakage to a top size of 6.7 mm with ; minutes attritioning (Run 23).
Table C. 132: Overall washability for compressive breakage to a top size of 6.7 mm with ; minutes attritioning (Run 23).
Table C. 133: Overall washability for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 133: Overall washability for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Figure C. 88: Ash curve for compressive breakage to a top size of 13.2 mm.
Figure C. 88: Ash curve for compressive breakage to a top size of 13.2 mm.
Table C. 134: Liberation curve for raw ROM coal. material refers to the material with a relative density higher than 1.4.
Table C. 134: Liberation curve for raw ROM coal. material refers to the material with a relative density higher than 1.4.
Table C. 135: Liberation curve for impact breakage to a top size of 13.2 mm with nc attritioning (Run 1-3 average).
Table C. 135: Liberation curve for impact breakage to a top size of 13.2 mm with nc attritioning (Run 1-3 average).
Table C. 136: Liberation curve for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 136: Liberation curve for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 137: Liberation curve for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 137: Liberation curve for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 138: Liberation curve for impact breakage to a top size of 13.2 mm with £ minutes attritioning (Run 6).
Table C. 138: Liberation curve for impact breakage to a top size of 13.2 mm with £ minutes attritioning (Run 6).
Table C. 140: Liberation curve for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 140: Liberation curve for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 141: Liberation curve for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 141: Liberation curve for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 142: Liberation curve for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 142: Liberation curve for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 143: Liberation curve for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 143: Liberation curve for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 144: Liberation curve for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 144: Liberation curve for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 145: Liberation curve for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 145: Liberation curve for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 146: Liberation curve for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 146: Liberation curve for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 147: Liberation curve for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 147: Liberation curve for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 149: Liberation curve for compressive breakage to a top size of 6.7 mm with ; minutes attritioning (Run 23).
Table C. 149: Liberation curve for compressive breakage to a top size of 6.7 mm with ; minutes attritioning (Run 23).
Figure C. 89: Liberation curve (RD<1.4) for raw ROM coal.
Figure C. 89: Liberation curve (RD<1.4) for raw ROM coal.
fable C. 151: Overall hypothetical ash for raw ROM coal (continue on next page).
fable C. 151: Overall hypothetical ash for raw ROM coal (continue on next page).
Table C. 152: Overall hypothetical ash for raw ROM coal (continued from previous page).
Table C. 152: Overall hypothetical ash for raw ROM coal (continued from previous page).
Table C. 153: Overall hypothetical ash for impact breakage to a top size of 13.2 mm with no attrition (Run 1-3 average).
Table C. 153: Overall hypothetical ash for impact breakage to a top size of 13.2 mm with no attrition (Run 1-3 average).
Table C. 154: Overall hypothetical ash for impact breakage to a top size of 13.2 mm with 1 minute attrition (Run 4).
Table C. 154: Overall hypothetical ash for impact breakage to a top size of 13.2 mm with 1 minute attrition (Run 4).
Table C. 155: Overall hypothetical ash for impact breakage to a top size of 13.2 mm with 2 minutes attrition (Run 5).
Table C. 155: Overall hypothetical ash for impact breakage to a top size of 13.2 mm with 2 minutes attrition (Run 5).
Table C. 156: Overall hypothetical ash for impact breakage to a top size of 13.2 mm with 5 minutes attrition (Run 6).
Table C. 156: Overall hypothetical ash for impact breakage to a top size of 13.2 mm with 5 minutes attrition (Run 6).
Table C. 157: Overall hypothetical ash for impact breakage to a top size of 6.7 mm with no attrition (Run 7-9 average).
Table C. 157: Overall hypothetical ash for impact breakage to a top size of 6.7 mm with no attrition (Run 7-9 average).
Table C. 158: Overall hypothetical ash for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 158: Overall hypothetical ash for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 159: Overall hypothetical ash for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 159: Overall hypothetical ash for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 160: Overall hypothetical ash for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 160: Overall hypothetical ash for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 162: Overall hypothetical ash for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 162: Overall hypothetical ash for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 166: Overall hypothetical ash for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 166: Overall hypothetical ash for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 167: Overall hypothetical ash for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 167: Overall hypothetical ash for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 170: Projected float yield and according particle size distributions for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Table C. 170: Projected float yield and according particle size distributions for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Table C. 171: Projected float yield and according particle size distributions for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 171: Projected float yield and according particle size distributions for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 172: Projected float yield and according particle size distributions for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 172: Projected float yield and according particle size distributions for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 173: Projected float yield and according particle size distributions for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 173: Projected float yield and according particle size distributions for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 174: Projected float yield and according particle size distributions for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 174: Projected float yield and according particle size distributions for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 175: Projected float yield and according particle size distributions for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 175: Projected float yield and according particle size distributions for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 176: Projected float yield and according particle size distributions for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 176: Projected float yield and according particle size distributions for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 177: Projected float yield and according particle size distributions for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 177: Projected float yield and according particle size distributions for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 178: Projected float yield and according particle size distributions for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average)
Table C. 178: Projected float yield and according particle size distributions for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average)
Table C. 179: Projected float yield and according particle size distributions for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 179: Projected float yield and according particle size distributions for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 180: Projected float yield and according particle size distributions for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17)
Table C. 180: Projected float yield and according particle size distributions for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17)
Table C. 181: Projected float yield and according particle size distributions for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 181: Projected float yield and according particle size distributions for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 182: Projected float yield and according particle size distributions for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average)
Table C. 182: Projected float yield and according particle size distributions for compressive breakage to a top size of 6.7 mm with no attritioning (Run 19-21 average)
Table C. 183: Projected float yield and according particle size distributions for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 183: Projected float yield and according particle size distributions for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 184: Projected float yield and according particle size distributions for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 184: Projected float yield and according particle size distributions for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 185: Projected float yield and according particle size distributions for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 185: Projected float yield and according particle size distributions for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 187: Cumulative feed PSD and float PSD for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Table C. 187: Cumulative feed PSD and float PSD for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Table C. 188: Cumulative feed PSD and float PSD for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 188: Cumulative feed PSD and float PSD for impact breakage to a top size of 13.2 mm with 1 minute attritioning (Run 4).
Table C. 189: Cumulative feed PSD and float PSD for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 189: Cumulative feed PSD and float PSD for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Table C. 190: Cumulative feed PSD and float PSD for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 190: Cumulative feed PSD and float PSD for impact breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 6).
Table C. 191: Cumulative feed PSD and float PSD for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 191: Cumulative feed PSD and float PSD for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Table C. 192: Cumulative feed PSD and float PSD for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 192: Cumulative feed PSD and float PSD for impact breakage to a top size of 6.7 mm with 1 minute attritioning (Run 10).
Table C. 193: Cumulative feed PSD and float PSD for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 193: Cumulative feed PSD and float PSD for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Table C. 194: Cumulative feed PSD and float PSD for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 194: Cumulative feed PSD and float PSD for impact breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 12).
Table C. 195: Cumulative feed PSD and float PSD for compressive breakage to a top siz of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 195: Cumulative feed PSD and float PSD for compressive breakage to a top siz of 13.2 mm with no attritioning (Run 13-15 average).
Table C. 196: Cumulative feed PSD and float PSD for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 196: Cumulative feed PSD and float PSD for compressive breakage to a top size of 13.2 mm with 1 minute attritioning (Run 16).
Table C. 197: Cumulative feed PSD and float PSD for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 197: Cumulative feed PSD and float PSD for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Table C. 198: Cumulative feed PSD and float PSD for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 198: Cumulative feed PSD and float PSD for compressive breakage to a top size of 13.2 mm with 5 minutes attritioning (Run 18).
Table C. 199: Cumulative feed PSD and float PSD for compressive breakage to a top siz of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 199: Cumulative feed PSD and float PSD for compressive breakage to a top siz of 6.7 mm with no attritioning (Run 19-21 average).
Table C. 200: Cumulative feed PSD and float PSD for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 200: Cumulative feed PSD and float PSD for compressive breakage to a top size of 6.7 mm with 1 minute attritioning (Run 22).
Table C. 201: Cumulative feed PSD and float PSD for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 201: Cumulative feed PSD and float PSD for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 202: Cumulative feed PSD and float PSD for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Table C. 202: Cumulative feed PSD and float PSD for compressive breakage to a top size of 6.7 mm with 5 minutes attritioning (Run 24).
Figure C. 92: Hypothetical density wash curve for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Figure C. 92: Hypothetical density wash curve for impact breakage to a top size of 13.2 mm with no attritioning (Run 1-3 average).
Figure C. 94: Hypothetical density wash curve for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Figure C. 94: Hypothetical density wash curve for impact breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 5).
Figure C. 96: Hypothetical density wash curve for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Figure C. 96: Hypothetical density wash curve for impact breakage to a top size of 6.7 mm with no attritioning (Run 7-9 average).
Figure C. 98: Hypothetical density wash curve for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Figure C. 98: Hypothetical density wash curve for impact breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 11).
Figure C. 100: Hypothetical density wash curve for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Figure C. 100: Hypothetical density wash curve for compressive breakage to a top size of 13.2 mm with no attritioning (Run 13-15 average).
Figure C. 102: Hypothetical density wash curve for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Figure C. 102: Hypothetical density wash curve for compressive breakage to a top size of 13.2 mm with 2 minutes attritioning (Run 17).
Figure C. 104: Hypothetical density wash curve for compressive breakage to a top size ot 6.7 mm with no attritioning (Run 19-21 average).
Figure C. 104: Hypothetical density wash curve for compressive breakage to a top size ot 6.7 mm with no attritioning (Run 19-21 average).
Figure C. 106: Hypothetical density wash curve for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Figure C. 106: Hypothetical density wash curve for compressive breakage to a top size of 6.7 mm with 2 minutes attritioning (Run 23).
Table C. 203: Standard deviation on fractional mass yield for impact breakage to top size of 13.2 mm with no attrition (Runs 1-3).
Table C. 203: Standard deviation on fractional mass yield for impact breakage to top size of 13.2 mm with no attrition (Runs 1-3).
Table C. 204: Standard deviation on fractional mass yield for impact breakage to top size of 6.7 mm with no attrition (Runs 7-9).
Table C. 204: Standard deviation on fractional mass yield for impact breakage to top size of 6.7 mm with no attrition (Runs 7-9).
Table C. 205: Standard deviation on fractional mass yield for compressive breakage to top size of 13.2 mm with no attrition (Runs 13-15).
Table C. 205: Standard deviation on fractional mass yield for compressive breakage to top size of 13.2 mm with no attrition (Runs 13-15).
Table C. 206: Standard deviation on fractional mass yield for compressive breakage to top size of 6.7 mm with no attrition (Runs 19-21).
Table C. 206: Standard deviation on fractional mass yield for compressive breakage to top size of 6.7 mm with no attrition (Runs 19-21).
Table C. 207: Experimental error on fractional mass yield for impact breakage to top size of 13.2 mm with no attrition (Run 1-3).
Table C. 207: Experimental error on fractional mass yield for impact breakage to top size of 13.2 mm with no attrition (Run 1-3).
Table C. 208: Experimental error on fractional mass yield for impact breakage to top size of 6.7 mm with no attrition (Run 7-9).
Table C. 208: Experimental error on fractional mass yield for impact breakage to top size of 6.7 mm with no attrition (Run 7-9).
Table C. 209: Experimental error on fractional mass yield for compressive breakage to top size of 13.2 mm with no attrition (Run 13-15).
Table C. 209: Experimental error on fractional mass yield for compressive breakage to top size of 13.2 mm with no attrition (Run 13-15).
Table C. 210: Experimental error on fractional mass yield for compressive breakage to top size of 6.7 mm with no attrition (Run 19-21).
Table C. 210: Experimental error on fractional mass yield for compressive breakage to top size of 6.7 mm with no attrition (Run 19-21).
Table C. 211: Repeatability and experimental error on fractional mass yield of attritioning.
Table C. 211: Repeatability and experimental error on fractional mass yield of attritioning.
Table C. 212: Averages for proximate, calorific value and swelling index analysis results expressed on a dry basis (average of 0.0-1.0 mm and 1.0-13.2 mm results).
Table C. 212: Averages for proximate, calorific value and swelling index analysis results expressed on a dry basis (average of 0.0-1.0 mm and 1.0-13.2 mm results).
Table C. 213: Averages for proximate, calorific value and swelling index analysis results expressed on an air dry basis.
Table C. 213: Averages for proximate, calorific value and swelling index analysis results expressed on an air dry basis.
Table C. 214: Standard deviation for proximate, calorific value and swelling index analysis results expressed on an air dry basis.
Table C. 214: Standard deviation for proximate, calorific value and swelling index analysis results expressed on an air dry basis.
Table C. 215: Experimental errors for proximate, calorific value and swelling index analysis results expressed on an air dry basis.
Table C. 215: Experimental errors for proximate, calorific value and swelling index analysis results expressed on an air dry basis.
Table C. 217: Absolute difference between values for proximate, calorific value and swelling index analysis results expressed on an air dry basis.
Table C. 217: Absolute difference between values for proximate, calorific value and swelling index analysis results expressed on an air dry basis.
Table C. 218: Accuracy check for proximate, calorific value and swelling index analysis results expressed on an air dry basis (“Outside accepted limits according to SANS 5725-6:2009).
Table C. 218: Accuracy check for proximate, calorific value and swelling index analysis results expressed on an air dry basis (“Outside accepted limits according to SANS 5725-6:2009).

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Some experiments in-situ and in laboratory to determine the physico-mechanical properties of coal
Ezzeddin Bakhtavar

A number of simple field and laboratory studies and tests were carried out to visualize the nature and variation extent of mechanical properties with emphasis on cuttability across C1 coal seam in Parvade1 mine of Tabas located in east of Iran. Selection of the suitable coal winning machines and of the most effective and fitness bits for it and their arrangement on cutter head have a special relation to reach maximum productivity with minimum energy consumption. The effect of physico-mechanical properties on cuttability were studied in the laboratory and field for the C1 coal seam to identify the relevant parameters affecting the specific energy of coal cuttability. Field studies were also in-situ cuttability along with conducted over a number of active mechanized coal faces to study the geo-mining conditions of the site. The field and the laboratory data of coal cuttability was estimated due to the achieved results of uni-axial, shear, and tensile strength tests, as well as, Impact strength index, expanding bolt, and M.R.E. penetration tests on C1 coal seam.

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Importance of Coal Characteristics for Effective Utilization of Coal
Environmental Science Archives

Environmental Science Archives, 2024

Coal is a heterogeneous rock with complex characteristics. Composition varies even in centimeters. Origin influences the composition of coal deposits, both organic and inorganic materials. The concentration of vitrinite or inertinite is determined by the nature and origin of the coal during the formation. Fluctuation and rates of down-warping or up-warping influence the accumulation of inorganic materials. The rank of the coal is determined by the thermal treatment undergone by the coal deposits over the period. Internal Moisture content depends upon the rank of the coal. Surface moisture content is based on the size of mined and crushed coal. Beneficiation of coal is a process of reducing the inorganic materials.

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Investigation of breakage characteristics of low rank coals in a laboratory swing hammer mill
Heechan Cho Cho

Powder Technology, 2014

The breakage characteristics of low rank coals were tested in a laboratory using ECO coal from an Indonesian mine as the feed material. The grinding test results were used to fit the parameters of the breakage functions of an existing continuous hammer mill model. The mill holdup , specific energy and projection rate to the screen were analyzed to observe the effects of operating conditions. The results indicate that for each underscreen aperture there exists a characteristic threshold point of the feed rate above which over-grinding occurs. This threshold point can be used to determine the optimal operating conditions of the breakage process. Additionally, a scale-up model of the hammer mill is established based on the energy-size relationship to predict the mill capacity as a function of the mill design and the operating parameters. A comparison between the prediction from the model and the manufacturer's data illustrates that the model based on Rittinger's theory fits the breakage characteristics of the hammer mill better than the models based on Bond's and Kick's theories. The established scale-up model agrees well with the manufacturer's test data within an acceptable degree of accuracy.

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Handbook of coal Analysis (1)
Amin farajivand
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Devolatilization and Cracking Characteristics of Australian Lumpy Coals
Byongchul Kim

Energy &amp; Fuels, 2008

An experimental study was conducted to investigate the devolatilization characteristics of five Australian coals in a thermogravimetric analysis (TGA) reactor by varying the coal lump size and the temperature. The swelling ratio was measured after thermal treatment of coal lumps in a horizontal tube furnace at 1273 K while the cracks generated in the lumpy char samples were examined using scanning electron microscopy (SEM). Physical and chemical properties of coal and char samples were measured using CO 2 gas adsorption, Hg porosimetry, X-ray fluorescence (XRF) and X-ray diffraction (XRD). Under all the tested conditions, the total volatile yield of lumpy coals was found to be not influenced by either the temperature or particle size and was similar to that indicated in proximate coal analysis. However, as expected, the devolatilization rates were found to increase with increasing temperature as well as the increasing amount of volatiles present in the coal. The study further demonstrated that the effect of coal properties on the devolatilization rates of lumpy coals may not be significant as the rates decrease with increasing lump size, such that coal lumps with sizes more than 10 mm indicated similar orders of reaction rates. The apparent activation energy of coal lumps indicated a linear correlation with the stack height of the carbon crystallite of coals. The study demonstrated that the cracking and swelling behavior of coals was influenced by physical as well as chemical properties, particularly their modification during devolatilization conditions. The study showed that coals with low volatiles indicated high cracking which would increase further with increasing lump size in accordance with the size effect. The cracking tendency of coals appeared to have a reciprocal association with swelling tendency such that less swelling coals are more vulnerable to cracking.

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Leonard, Joseph W., III Eds. Coal Preparation
Fabio Vanzeloti
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Coal Industry
Emily J . Haas

2015

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Handbook of coal Analysis
Alejandro Bonilla
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Proceedings of the 2010 Coal Operators\u27 Conference
Naj Aziz

2010

Proceedings of the 2010 Coal Operators\u27 Conference. All papers in these proceedings are peer reviewed in accordance with the AUSIMM publication standard

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