CA1256601A - Method for recovering fine granulated coal by flotation - Google Patents
Method for recovering fine granulated coal by flotationInfo
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- CA1256601A CA1256601A CA000453572A CA453572A CA1256601A CA 1256601 A CA1256601 A CA 1256601A CA 000453572 A CA000453572 A CA 000453572A CA 453572 A CA453572 A CA 453572A CA 1256601 A CA1256601 A CA 1256601A
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- coal
- fine
- frother
- flotation
- fine granulated
- Prior art date
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Abstract
ABSTRACT
The present invention provides a method for flotation and recovery of fine granulated coal.
The water slurry of fine powder coal with 5 - 20% by weight of a binder added, based on the pure coal matter, is stirred to manufacture the water slurry of fine granulated coal having a particle size of 100 - 250 µm.
100 - 200 ppm of a frother or a flotation agent with a frother base, based on the fine granulated coal, is added to the above-mentioned water slurry of fine granulated coal to recover the fine granulated coal by flotation.
The present invention provides a method for flotation and recovery of fine granulated coal.
The water slurry of fine powder coal with 5 - 20% by weight of a binder added, based on the pure coal matter, is stirred to manufacture the water slurry of fine granulated coal having a particle size of 100 - 250 µm.
100 - 200 ppm of a frother or a flotation agent with a frother base, based on the fine granulated coal, is added to the above-mentioned water slurry of fine granulated coal to recover the fine granulated coal by flotation.
Description
~;2S6~
METHOD FOR RECOVERING
FINE GR~NULATED COAL BY FLOTATION
Background of the Invention The present invention xelates to a method for recovering fine granulated coal and more particularly to a method for forming a water slurry of fine granulated coal from a water slurry of fine powder coal containing mineral matter and then recovering the fine granulated coal from its water slurry by flotation.
The art of dressing coal from mineral matter by flotation has been commercially completed for example in the technology of dressing coal of a high coalification degree for coke making, for example coking coal.
With so-called steam coal of a low coalification degree in comparison to coking coal such as bituminous coal of low rank, sub-bituminous coal, brown coal and lignite~ the flotation method is incom-plate technologically for the following reason: With such coal, their hydrophillic properties increase with a lowering in their coalification degrees, so that the coal has the defects that a recovering efficiency for it by flotation lowers and also inclusion of mineral matter by froth more increases. As coal-dressing technologies by flotation for fine powder-shaped steam coal having a ;66~
particle si~e of about 80~ by weight of powder passing through 200 meshes, there exist considerably the ones on the course of development and such ones as may become extinct in a short period of time after appearance, but there are not yet existent comple~ed flotation technologies for the steam coal that are free from the above-mentioned defects.
On the other hand, as a coal-dressing technology for fine powder~shaped steam coal, there can be cited a so-called OA (Oil Agglomeration) method when an economical efficiency is not taken into account. The OA metnod is a method for agglomerating fine powder coal to manufacture granulated coal, using as a binder at least 20% by weight of hydrocarbon oil based on pure coal weight with the amount of the hydrocarbon oil varying with the quality of coal. Granulated coal of size of 0.5 - 3 mm is obtained by the OA method and separation of the granulated coal from the slurry mother liquid and removal of mineral matter from the granulated coal are both good. The OA method, however, can be said to be lacking in economical efficiency today when hydrocarbon oil is expensive, for it uses a large amount of hydrocarbon oil expensive as compared with steam coal as the binder.
~L~566~
If an attempt to raise the economical efficiency of the OA method is carried out by reducing the amount of binder used to 10 - 15% by weight based on the pure coal, only granulated coal of a size of about 100 - 200 ~m is obtained, so that problems arise that the granulated coal cannot be separated or the separation efficiency is only extremely low with use of a vibration screen or screen-based type centrifugal mechanical dryers utilized in the OA method.
Summar~ of the Invention The first object of the present invention is to provide a method for recovering fine granulated coal by flotation.
The second object of the present invention is to provide a method for recovering fine granulated coal with good separation properties, using a reduced amount of binder used.
The third object of the present invention is to provide a method having an improved economical efficiency in separation and recovery of fine granuiated coal.
The fourth object of the present invention is to provide a method for recovering fine granulated coal that is applicable independent of the kind of coal.
3L%56~
Such objects of the present invention are achieved by stirring the water slurry of fine powder coal with 5 20% by weight of a binder added based on the weight of coal to manufacture the water slurry of fine granulated coal of size of 100 - 250 ~m and then adding 100 - 200 ppm of a frother or a flotation agent with a frother base based on the weight of the above-mentioned fine granulated coal to the water slurry of the fine granulated coal to recover the granulated coal by flotation.
Drawings The drawings is a flow sheet showing an example of the present invention.
The Preferred Embod _ nts The present invention is described on the basis of the flow sheet shown in the drawing hereinafter.
In the present invention, first, raw coal (1) is pulverized with a mill (2) to manufacture fine powder coal (3). As raw coal, bituminous coal, sub-bituminous coal, brown coal and lignite can all be used independent of the kind of coal.
Besides the raw coal, coal, coke, petroleum coke and the like scattered on floors and devices (which are termed coal to be swept hereinafter) are collected for example with a dust collector and can be used for the ~25Ei6(~
present invention. Conventionally, the coal to be swept, when collected, has simply been discarded as waste, disadvantageGusly. According to the present invention, however, the coal to be swept is put into u~e, usually after nails, iron pieces and the like included have been removed away with a magnet or the like.
The fine powder coal (3) is usuall~ pulverized so as to have a particle size of 70 - 80% by weight of coal powder passing through 200 meshes. If the raw coal has such particle size as a result of pulverization which may take place not mechanically but naturally during the coal preparation or coal to be swept already has such a particle size, it is unnecessary to further operate pulverization.
The mill (2) is not specially restricted so far as the resulting fine powder coal (3) has a particle size within the above-mentioned range, and the mill (2) may be a dry mill or a wet mill.
Next, in this process, the resultin~ fine powder coal (3) is fed into a mixing tank (4) to form a water slurry of the fine powder coal with a binder (5) added. An order for adding water (6) and a binder (5) is not specially restricted. For example, water (6) is first added to the fine powder coal (3) to form a water slurry of the fine powder coal and then a binder (5) may ~2S~6~L
be added to the slurry. In contrast to this, after a binder (5) has been added to the fine powder coal, water (6) may be added to the fine powder coal.
As binder (5), normally use is made of hydrocarbon oils, more specifically, petroleum-containing oils such as crude oil, heavy oil and light oil, frac-tions corresponding to the above-mentioned petroleum-containing oils in liquid fractions resulting from hydrogenation lique~action of coal, and vegetable oils such as bean oils and cottonseed oils. Besides such hydrocarbon oils, also ~seful are hydrophobic s~nthetic polymers having a hydrophilic functional group, for example polypropyleneglycol monomethyl ether, various other oils such as lubricating oils and working oils for hydraulic devices in factories, thermal power stations and iron mills, and waste oils from factories.
Further, according to the present invention, it is also possible to add a dispersing agent as an auxiliary member to the above binder (5).
~he dispersing agent may be any of such as alkanol amide type nonion (polyethyleneglycolether or ester) surface active agent, sulfuric acid ester type anion surface active agent and quaternary ammonium type cation surface active agent, and the amount to be added of the dispersing agent is preferably within the range ~2~6601 of 200 to 800 ppm or, more preferably, 200 to 300 ppm based on the weight of the pure coal in the fine powder coal (3) A
The dispersing agent has a function to increase the specific surface area of the binder (5).
The concentration of fine powder coal in a water slurry (7) of the coal is 20 - 40% by weight and may be appropriately selected within the range of concent-ration.
Further, the amount of a binder (5) added is 5 - 20% by weight based on the amount of pure coal in raw coal (1), and it is preferably 5 - 15% by weight if an economical efficiency is taken into account. With an amount to be added of the binder (5) less than 5% by weight based on the amount of pure coal, the efficiency is adver-sely affected of the separation of coal matter from mineral matters in the slurry, and when the amount in reference exceeds 20~ by weight, the economical efficiency is lowered particularly when a hydrocarbon oil is used as the binder, so that an amount of binder used exceeding 20% by weight is not desirable.
Next, the water slurry (7) of fine powder coal with a binder added is fed into a granulator (8) and is stirred to granulate the fine powder coal, and thus the water slurry (9) offine granulated coal is formed.
5~6C~1 As a granulator (8), the one used in the conventional OA method can be adopted and, for example, a horizontal cylindrical granulator having stirring blades on its longitudinal shaft can be cited.
By this granulation opexation, fine powder coal containing a binder agglomerates to form fine granulated coal, and, on the other hand, since mineral matter in fine powder coal is hydrophillic as compared with coal matter, mineral matter transfers intowater, and thus most of mineral matter is removed from coal. The amount of a binder added in the present invention is less than in the conventional OA method, so that the particle size of the resulting granulated coal in the present invention is usually 100 - 250 ~m and preferably 100 - 200 ~m.
The fine granulated coal has a muddy state in the water slurry, in which the coal is suspended, and when the slurry is let stand for a long time, the granulated coal will precipitate with mineral matter.
Further, water (11) is preferably added to the water slurry (9) of fine granulated coal to adjust the concentration of the fine granulated coal in the slurry at 10 - 15~ by weight. The concentration adjustment is for facilitating the flotation of the fine granulated coal that is to be mentioned later and it is not always necessary. Such a concentration adjustment can be 125~i60~
g carried out after feeding the slurry (9) of fine granula-ted coal into a tank, e.g., a conditioner (10) for concentration adjustment.
Subsequently, a frother or a flotation agent (12) with a frother base is added to the water slurry of fine granulated coal having a concentration adjusted.
The function of the frother used in the present invention is to froth the water slurry of the fine granulated coal, and as the frother there can be cited higher alcohols, e.g. methylisobutyl carbinol, octanol, pine oil, terpineol, polyoxypropylene alkyl ether, and the like.
The flotation agent with a frother base means a mixed agent of such a frother as mentioned above with an auxiliary such as kerosine or a mixed agent of a frother with a froth stabilizer such as alkylol amide.
The function of the auxiliary is to agglomerate the fine granulated coal, and the function of the froth stabilizer is to stabilize the fro~h. It is appropriately determined according to the qualLty and ash content of raw coal and to the particle size of fine granulated coal that which should be used, a frother or a flotation agent with a frother base. Further, those frother or flotation agents are all available on the market.
The amount of such a frother or a flotation agent with a frother base used in the present invention -- 10 ~
is 100 - 200 ppm based on the weight of fine granulated coal, and the amount of an auxiliary or a froth stabilizer in the flotation agent with a frother base is 20 - 30% by weight based on the weight of the frother.
When the amount of a frother or a flotation agent with a frother base used is less than 100 ppm of the weight of fine granulated coal, frothing is insufficient and the flotation and recovery of the fine granulated coal become incomplete.
When the above-mentioned use amount exceeds 200 ppm, there is no difference in frothing and in the efficiency of flotation and recovery of fine granulated coal due to the use amount and also the economical efficiency comes into question. Therefore, such a use amount is not desired.
Such a frother or a flotation agent is usually added to the water slurry of fine granulated coal in a tank, e.g., a conditioner (10) used for adjustment of the slurry concentration.
Finally, the water slurry of fine granulated coal with a frother or a flotation agent added is fed into a flotation machine (13) to separate and recover the fine granulated coal by flotation.
The fine granulated coal (14) with a binder added is more hydrophobic than the original powder coal, ~:5~ V~
so that the coal (14) is raised by air bubbles resulting from the frother or flotation agent and floats on the water surface. On the other hand, as the mineral matter tl5) in fine granulated coal is more hydrophillic than the granulated coal (14), it does not float but precipitates.
When the thus floating fine granulated coal (14) is collected by the same method as in a conventional flotation method, fine granulated coal (14) having a small mineral matter content can be obtained. ~he thus obtained fine granulated coal is suitable as a fuel in boilers, thermal power stations and the like.
As mentioned above, according to the present invention, fine granulated coal is formed using a small amount of a binder as compared with a conventional OA
method and then the coal is separated and recovered by flotation, so that the use amount of a hydrocarbon oil binder expensive as compared with coal can be substan-tially reduced, thus allowing the economical efficiency
METHOD FOR RECOVERING
FINE GR~NULATED COAL BY FLOTATION
Background of the Invention The present invention xelates to a method for recovering fine granulated coal and more particularly to a method for forming a water slurry of fine granulated coal from a water slurry of fine powder coal containing mineral matter and then recovering the fine granulated coal from its water slurry by flotation.
The art of dressing coal from mineral matter by flotation has been commercially completed for example in the technology of dressing coal of a high coalification degree for coke making, for example coking coal.
With so-called steam coal of a low coalification degree in comparison to coking coal such as bituminous coal of low rank, sub-bituminous coal, brown coal and lignite~ the flotation method is incom-plate technologically for the following reason: With such coal, their hydrophillic properties increase with a lowering in their coalification degrees, so that the coal has the defects that a recovering efficiency for it by flotation lowers and also inclusion of mineral matter by froth more increases. As coal-dressing technologies by flotation for fine powder-shaped steam coal having a ;66~
particle si~e of about 80~ by weight of powder passing through 200 meshes, there exist considerably the ones on the course of development and such ones as may become extinct in a short period of time after appearance, but there are not yet existent comple~ed flotation technologies for the steam coal that are free from the above-mentioned defects.
On the other hand, as a coal-dressing technology for fine powder~shaped steam coal, there can be cited a so-called OA (Oil Agglomeration) method when an economical efficiency is not taken into account. The OA metnod is a method for agglomerating fine powder coal to manufacture granulated coal, using as a binder at least 20% by weight of hydrocarbon oil based on pure coal weight with the amount of the hydrocarbon oil varying with the quality of coal. Granulated coal of size of 0.5 - 3 mm is obtained by the OA method and separation of the granulated coal from the slurry mother liquid and removal of mineral matter from the granulated coal are both good. The OA method, however, can be said to be lacking in economical efficiency today when hydrocarbon oil is expensive, for it uses a large amount of hydrocarbon oil expensive as compared with steam coal as the binder.
~L~566~
If an attempt to raise the economical efficiency of the OA method is carried out by reducing the amount of binder used to 10 - 15% by weight based on the pure coal, only granulated coal of a size of about 100 - 200 ~m is obtained, so that problems arise that the granulated coal cannot be separated or the separation efficiency is only extremely low with use of a vibration screen or screen-based type centrifugal mechanical dryers utilized in the OA method.
Summar~ of the Invention The first object of the present invention is to provide a method for recovering fine granulated coal by flotation.
The second object of the present invention is to provide a method for recovering fine granulated coal with good separation properties, using a reduced amount of binder used.
The third object of the present invention is to provide a method having an improved economical efficiency in separation and recovery of fine granuiated coal.
The fourth object of the present invention is to provide a method for recovering fine granulated coal that is applicable independent of the kind of coal.
3L%56~
Such objects of the present invention are achieved by stirring the water slurry of fine powder coal with 5 20% by weight of a binder added based on the weight of coal to manufacture the water slurry of fine granulated coal of size of 100 - 250 ~m and then adding 100 - 200 ppm of a frother or a flotation agent with a frother base based on the weight of the above-mentioned fine granulated coal to the water slurry of the fine granulated coal to recover the granulated coal by flotation.
Drawings The drawings is a flow sheet showing an example of the present invention.
The Preferred Embod _ nts The present invention is described on the basis of the flow sheet shown in the drawing hereinafter.
In the present invention, first, raw coal (1) is pulverized with a mill (2) to manufacture fine powder coal (3). As raw coal, bituminous coal, sub-bituminous coal, brown coal and lignite can all be used independent of the kind of coal.
Besides the raw coal, coal, coke, petroleum coke and the like scattered on floors and devices (which are termed coal to be swept hereinafter) are collected for example with a dust collector and can be used for the ~25Ei6(~
present invention. Conventionally, the coal to be swept, when collected, has simply been discarded as waste, disadvantageGusly. According to the present invention, however, the coal to be swept is put into u~e, usually after nails, iron pieces and the like included have been removed away with a magnet or the like.
The fine powder coal (3) is usuall~ pulverized so as to have a particle size of 70 - 80% by weight of coal powder passing through 200 meshes. If the raw coal has such particle size as a result of pulverization which may take place not mechanically but naturally during the coal preparation or coal to be swept already has such a particle size, it is unnecessary to further operate pulverization.
The mill (2) is not specially restricted so far as the resulting fine powder coal (3) has a particle size within the above-mentioned range, and the mill (2) may be a dry mill or a wet mill.
Next, in this process, the resultin~ fine powder coal (3) is fed into a mixing tank (4) to form a water slurry of the fine powder coal with a binder (5) added. An order for adding water (6) and a binder (5) is not specially restricted. For example, water (6) is first added to the fine powder coal (3) to form a water slurry of the fine powder coal and then a binder (5) may ~2S~6~L
be added to the slurry. In contrast to this, after a binder (5) has been added to the fine powder coal, water (6) may be added to the fine powder coal.
As binder (5), normally use is made of hydrocarbon oils, more specifically, petroleum-containing oils such as crude oil, heavy oil and light oil, frac-tions corresponding to the above-mentioned petroleum-containing oils in liquid fractions resulting from hydrogenation lique~action of coal, and vegetable oils such as bean oils and cottonseed oils. Besides such hydrocarbon oils, also ~seful are hydrophobic s~nthetic polymers having a hydrophilic functional group, for example polypropyleneglycol monomethyl ether, various other oils such as lubricating oils and working oils for hydraulic devices in factories, thermal power stations and iron mills, and waste oils from factories.
Further, according to the present invention, it is also possible to add a dispersing agent as an auxiliary member to the above binder (5).
~he dispersing agent may be any of such as alkanol amide type nonion (polyethyleneglycolether or ester) surface active agent, sulfuric acid ester type anion surface active agent and quaternary ammonium type cation surface active agent, and the amount to be added of the dispersing agent is preferably within the range ~2~6601 of 200 to 800 ppm or, more preferably, 200 to 300 ppm based on the weight of the pure coal in the fine powder coal (3) A
The dispersing agent has a function to increase the specific surface area of the binder (5).
The concentration of fine powder coal in a water slurry (7) of the coal is 20 - 40% by weight and may be appropriately selected within the range of concent-ration.
Further, the amount of a binder (5) added is 5 - 20% by weight based on the amount of pure coal in raw coal (1), and it is preferably 5 - 15% by weight if an economical efficiency is taken into account. With an amount to be added of the binder (5) less than 5% by weight based on the amount of pure coal, the efficiency is adver-sely affected of the separation of coal matter from mineral matters in the slurry, and when the amount in reference exceeds 20~ by weight, the economical efficiency is lowered particularly when a hydrocarbon oil is used as the binder, so that an amount of binder used exceeding 20% by weight is not desirable.
Next, the water slurry (7) of fine powder coal with a binder added is fed into a granulator (8) and is stirred to granulate the fine powder coal, and thus the water slurry (9) offine granulated coal is formed.
5~6C~1 As a granulator (8), the one used in the conventional OA method can be adopted and, for example, a horizontal cylindrical granulator having stirring blades on its longitudinal shaft can be cited.
By this granulation opexation, fine powder coal containing a binder agglomerates to form fine granulated coal, and, on the other hand, since mineral matter in fine powder coal is hydrophillic as compared with coal matter, mineral matter transfers intowater, and thus most of mineral matter is removed from coal. The amount of a binder added in the present invention is less than in the conventional OA method, so that the particle size of the resulting granulated coal in the present invention is usually 100 - 250 ~m and preferably 100 - 200 ~m.
The fine granulated coal has a muddy state in the water slurry, in which the coal is suspended, and when the slurry is let stand for a long time, the granulated coal will precipitate with mineral matter.
Further, water (11) is preferably added to the water slurry (9) of fine granulated coal to adjust the concentration of the fine granulated coal in the slurry at 10 - 15~ by weight. The concentration adjustment is for facilitating the flotation of the fine granulated coal that is to be mentioned later and it is not always necessary. Such a concentration adjustment can be 125~i60~
g carried out after feeding the slurry (9) of fine granula-ted coal into a tank, e.g., a conditioner (10) for concentration adjustment.
Subsequently, a frother or a flotation agent (12) with a frother base is added to the water slurry of fine granulated coal having a concentration adjusted.
The function of the frother used in the present invention is to froth the water slurry of the fine granulated coal, and as the frother there can be cited higher alcohols, e.g. methylisobutyl carbinol, octanol, pine oil, terpineol, polyoxypropylene alkyl ether, and the like.
The flotation agent with a frother base means a mixed agent of such a frother as mentioned above with an auxiliary such as kerosine or a mixed agent of a frother with a froth stabilizer such as alkylol amide.
The function of the auxiliary is to agglomerate the fine granulated coal, and the function of the froth stabilizer is to stabilize the fro~h. It is appropriately determined according to the qualLty and ash content of raw coal and to the particle size of fine granulated coal that which should be used, a frother or a flotation agent with a frother base. Further, those frother or flotation agents are all available on the market.
The amount of such a frother or a flotation agent with a frother base used in the present invention -- 10 ~
is 100 - 200 ppm based on the weight of fine granulated coal, and the amount of an auxiliary or a froth stabilizer in the flotation agent with a frother base is 20 - 30% by weight based on the weight of the frother.
When the amount of a frother or a flotation agent with a frother base used is less than 100 ppm of the weight of fine granulated coal, frothing is insufficient and the flotation and recovery of the fine granulated coal become incomplete.
When the above-mentioned use amount exceeds 200 ppm, there is no difference in frothing and in the efficiency of flotation and recovery of fine granulated coal due to the use amount and also the economical efficiency comes into question. Therefore, such a use amount is not desired.
Such a frother or a flotation agent is usually added to the water slurry of fine granulated coal in a tank, e.g., a conditioner (10) used for adjustment of the slurry concentration.
Finally, the water slurry of fine granulated coal with a frother or a flotation agent added is fed into a flotation machine (13) to separate and recover the fine granulated coal by flotation.
The fine granulated coal (14) with a binder added is more hydrophobic than the original powder coal, ~:5~ V~
so that the coal (14) is raised by air bubbles resulting from the frother or flotation agent and floats on the water surface. On the other hand, as the mineral matter tl5) in fine granulated coal is more hydrophillic than the granulated coal (14), it does not float but precipitates.
When the thus floating fine granulated coal (14) is collected by the same method as in a conventional flotation method, fine granulated coal (14) having a small mineral matter content can be obtained. ~he thus obtained fine granulated coal is suitable as a fuel in boilers, thermal power stations and the like.
As mentioned above, according to the present invention, fine granulated coal is formed using a small amount of a binder as compared with a conventional OA
method and then the coal is separated and recovered by flotation, so that the use amount of a hydrocarbon oil binder expensive as compared with coal can be substan-tially reduced, thus allowing the economical efficiency
2~ of the resulting fine granulated coal to be raised markedly.
Further, the method of the present invention can treat all kinds of coal and even coal to be swept that has been wasted so far. In the conventional OA
method, even when a large amount o~ 20 - 30~ by weight ~2~;6~
of a binder, based on the pure coal matter of sub-bituminous coal, brown coal or lignite, is used, only granulated coal having a perticle size of about 500 ~m at ut~ost can be obtained, so that the granulated coal can hardly be separated by screeningu In the method of the present invention, however, the fine granulated coal of all kinds of coal can be floated and recovered as in the cases of coal of a high coalification degree for coke making such as coking coal, independent of the kind of coal.
Further, the method of the present invention does not require special devices for recovering of fine granulated coal, but granulators and flotation machines having been used from the past can be used without alteration, so that the method of the present invention has an extremely large industrial value.
The following describes the example of the present invention.
EXAMPLE
Sub-bituminous coal having an ash content of 28% by weight was pulverized so as to have a particle size of 80% by weight of powder coal passing through 200 meshes.
Next, 7% by weight of heavy oil C, based on the amount of pure coal of the fine powder coal was added to
Further, the method of the present invention can treat all kinds of coal and even coal to be swept that has been wasted so far. In the conventional OA
method, even when a large amount o~ 20 - 30~ by weight ~2~;6~
of a binder, based on the pure coal matter of sub-bituminous coal, brown coal or lignite, is used, only granulated coal having a perticle size of about 500 ~m at ut~ost can be obtained, so that the granulated coal can hardly be separated by screeningu In the method of the present invention, however, the fine granulated coal of all kinds of coal can be floated and recovered as in the cases of coal of a high coalification degree for coke making such as coking coal, independent of the kind of coal.
Further, the method of the present invention does not require special devices for recovering of fine granulated coal, but granulators and flotation machines having been used from the past can be used without alteration, so that the method of the present invention has an extremely large industrial value.
The following describes the example of the present invention.
EXAMPLE
Sub-bituminous coal having an ash content of 28% by weight was pulverized so as to have a particle size of 80% by weight of powder coal passing through 200 meshes.
Next, 7% by weight of heavy oil C, based on the amount of pure coal of the fine powder coal was added to
3~Z5~6 the fine powder coal and then water was added to form the water slurry of the fine powder coal having a concentration of 31% by weight.
The water slurry was fed into a vertical cylindrical granulator to agglomerate the fine particles of coal and the water slurry of fine granulated coal was manufactured. The fine granulated coal had a particle size of 105 - 149 ~m.
The water slurry of the fine granulated coal was fed into a conditioner and then water was further added to adjust the concentration of the fine granulated coal at 14% by welght.
Next, 150 ppm of a higher alcohol (octanol) was added to the water slurry of the fine granulated coal, which was fed into a flotatlon machlne, and then the fine granulated coal was recovered by flotation.
The recovery ratio of combus-tible matter of the resulting fine granulated coal was 96% and the ash content of the coal was 8.3% by weight.
The water slurry was fed into a vertical cylindrical granulator to agglomerate the fine particles of coal and the water slurry of fine granulated coal was manufactured. The fine granulated coal had a particle size of 105 - 149 ~m.
The water slurry of the fine granulated coal was fed into a conditioner and then water was further added to adjust the concentration of the fine granulated coal at 14% by welght.
Next, 150 ppm of a higher alcohol (octanol) was added to the water slurry of the fine granulated coal, which was fed into a flotatlon machlne, and then the fine granulated coal was recovered by flotation.
The recovery ratio of combus-tible matter of the resulting fine granulated coal was 96% and the ash content of the coal was 8.3% by weight.
Claims (15)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for flotation and recovery of fine granulated coal, characterized by stirring a water slurry of fine powder coal with 5 to 20% by weight of a binder and 200 to 800 ppm of alkanol amide type dispersing agent added, based in the weight of pure coal matter, to manufacture a water slurry of fine granulated coal of a particle size of 100 to 250 µm and by adding to the resulting water slurry of fine granulated coal 100 to 200 ppm of a frother or a flotation agent with a frother base, based on the fine granulated coal, to the water slurry of fine granulated coal to recover the fine granulated coal by flotation.
2. A method as claimed in claim 1, wherein the fine powder coal has a particle size of 70 - 80% by weight of powder coal passing through 200 meshes.
3. A method as claimed in claim 1, wherein the amount of a binder added is 5 - 15% by weight based on the pure coal matter.
4. A method as claimed in claim 1, wherein the concentration of fine powder coal in the water slurry of the fine powder coal is 20 - 40% by weight.
5. A method as claimed in claim 1, wherein the fine powder coal is bituminous coal, sub-bituminous coal, brown coal or lignite.
6. A method as claimed in claim 1, wherein the fine powder coal is coal to be swept.
7. A method as claimed in claim 1, wherein the fine granulated coal has a particle size of 100 - 200 µm.
8. A method as claimed in claim 1, wherein water is added to the water slurry of the fine granulated coal to adjust the concentration of fine granulated coal to 10 -15% by weight.
9. A method as claimed in claim 1, wherein the binder is a hydrocarbon oil.
10. A method as claimed in claim 1, wherein the binder is a lubricating oil.
11. A method as claimed in claim 1, wherein the binder is a hydraulic working oil.
12. A method as claimed in claim 1, wherein the binder is a waste oil from factory.
13. A method as claimed in claim 1, wherein the frother is one compound selected from a group comprising higher alcohols, pine oil, terpineol and polyoxypropylene alkyl ether.
14. A method as claimed in claim 1, wherein the flotation agent with a frother base is a mixed agent of the frother with an auxiliary.
15. A method as claimed in claim 1, wherein the flotation agent with a frother base is a mixed agent of the frother with a froth stabilizer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58228529A JPS60122065A (en) | 1983-12-05 | 1983-12-05 | Method for recovering fine granulated coal by floatation |
| JP58-228529 | 1983-12-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1256601A true CA1256601A (en) | 1989-06-27 |
Family
ID=16877837
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000453572A Expired CA1256601A (en) | 1983-12-05 | 1984-05-04 | Method for recovering fine granulated coal by flotation |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS60122065A (en) |
| AU (1) | AU573584B2 (en) |
| CA (1) | CA1256601A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4605420A (en) * | 1984-07-02 | 1986-08-12 | Sohio Alternate Energy Development Company | Method for the beneficiation of oxidized coal |
| JPS61103992A (en) * | 1984-10-26 | 1986-05-22 | Tokyo Electric Power Co Inc:The | Deashing recovery of coal |
| CN102773153B (en) * | 2012-07-16 | 2013-08-21 | 中国矿业大学 | Lignite separation process |
| CN104815748B (en) * | 2015-04-26 | 2017-06-20 | 中国矿业大学 | The broken mill floatation process of two sections of coal in a kind of coking |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4270926A (en) * | 1979-06-19 | 1981-06-02 | Atlantic Richfield Company | Process for removal of sulfur and ash from coal |
| US4340467A (en) * | 1980-03-20 | 1982-07-20 | American Cyanamid Company | Flotation of coal with latex emulsions of hydrocarbon animal or vegetable based oil |
| JPS5785891A (en) * | 1980-11-18 | 1982-05-28 | Hitachi Ltd | Method for deashing coal |
| AU542958B2 (en) * | 1981-12-04 | 1985-03-28 | Dow Chemical Company, The | Froth flotation of coal |
| JPS59127660A (en) * | 1983-01-07 | 1984-07-23 | Kawasaki Heavy Ind Ltd | Treatment of coal ash and low grade coal |
-
1983
- 1983-12-05 JP JP58228529A patent/JPS60122065A/en active Granted
-
1984
- 1984-05-02 AU AU27599/84A patent/AU573584B2/en not_active Expired
- 1984-05-04 CA CA000453572A patent/CA1256601A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60122065A (en) | 1985-06-29 |
| AU573584B2 (en) | 1988-06-16 |
| JPH044032B2 (en) | 1992-01-27 |
| AU2759984A (en) | 1985-06-13 |
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| MKEX | Expiry |