OA18527A - Methods and Compositions for Drying Coal - Google Patents

Abstract

The present disclosure provides methods, compositions and systems for drying coal fines.

Description

Many current methods of coal mining use water to extract fine coal particles (also called coal fines). Such particles typically can hâve with diameters from approximately 100 to 800 microns in diameter, although coal fines may hâve smaller diameters, e.g., on the order of 50 microns or less. Traditional methods of drying the coal particles, including centrifugation and heating technologies, can readily dry these coal “fines to approximately 30% moisture. Methods of drying coal fines beyond this point typically employ blowers and heaters which require capital intensive investment, require substantial energy use, and create environmental problems and hazards both from energy use and from aerosolization of the coal fines.

Summary

Embodiments of this disclosure provide methods and compositions for drying wet coal fines by employing water-collecting materials such as molecular sieves, water adsorbing polymeric agents, desiccants, and the like that are easily separated from the coal fines, for example by sieving or sifting. Such materials may remove ail or a portion of the water from the wet fines by physical and/or chemical action. For example, the water-collecting materials may draw water from the wet fines by sorption, e.g., absorption or adsorption. ln embodiments of the methods and compositions herein, the materials used for collecting water from the coal fines can be recycled and/or reused to dry more coal fines after removing some or ail of the water from the watercollecting materials.

Brief Description of the Drawing

Figure 1 shows the weight of a batch of molecular sieves used to adsorb water from six batches of coal fines. The weight of the molecular sieves are determined after drying each batch of coal fines and at the indicated time throughout the drying process weighed periodically

Detailed Description

Embodiments described herein utilize water-collecting materials such as adsorbents and absorbents that can collect moisture from wet coal fines. Advantageously, such materials can efficiently collect the moisture from the coal fines, and then can be separated from the fines, so as to reduce the amount of water associated with the coal fines. In some embodiments, the watercollecting materials then can be dried separately from the coal fines. The process may provide one or more désirable benefits such as a réduction in one or more of time, energy, cost, and/or adverse environmental impact, as compared to other processes of drying wet coal fines. Moreover, embodiments of this disclosure can substantially reduce the aerosolization of coal fines by blowers, which can pose health, fire and explosion hazards.

Although embodiments described herein do not require the drying and reuse of such watercollecting materials, many such materials can be efficiently dried separately from the coal fines and reused one or more times. Embodiments described herein thus employ the drying and reuse water-collecting materials such as absorbents and adsorbents. In other embodiments ail or a portion ofthe water-collecting material can be discarded, e.g., where an absorbent is degraded and cannot be effectively separated from the coal fines. In one embodiment, particles of watercollecting materials are separated by sieving or sifting to remove degraded particles which may be larger than particles of coal fine, but are smaller than désirable for processîng wet coal fines. In other embodiments, some or ail of the absorbent materials employed for use in removing moisture from coal fines may be biodégradable.

The water-collecting material also may bond with the water to cause the water to be associated with the material instead of the coal fines.

1.0 Removing Moisture from Coal Fines

Coal fines may separated from the bulk water (water in excess of that which is associated with coal fines when they settle, or are filtered or centrifuged out aqueous suspension) used in the mining /recovery process by any one or more of a variety of known techniques. Such techniques include, but are not limited to one or more of, filtration (e.g., gravity based filtration, or filtration assisted by centrifugal force, pressure or vacuum), settling, centrifugation and the like, which can used singly or in combination. Further amounts of water may optionally be removed from the coal fines by a second round of such treatments.

After one or more séparation steps to removal bulk water, the wet coal fines are then mixed with particles of a water-collecting material or combination of different types of water-collecting materials, e.g., particles of absorbent or adsorbent, to further reduce the amount of water associated with the fines. In one embodiment, the particles of water-collecting material are large enough to be separated from the coal fines by size (e.g., sifting with an appropriate size screen or mesh). In various embodiments, to facilitate their drying, the wet coal fines are mixed with one or more types of water-collecting materials including, but not limited to, molecular sieves, particles of hydratable polymers (e.g., polyacrylate or carboxymethyl cellulose/polyester particles), or desiccants (e.g., silicates). The rate at which various water-collecting materials adsorb, absorb, or react with water présent in coal fines may be affected by température. Each type of watercollecting material may hâve different optimum températures for the rate at which they will accumulate water from the coal fines. In some instances, as with molecular sieves, heating/warming the molecular sieves with the coal fines, or heating/warming molecular sieves immediately prior to mixing them with coal fines, may increase the rate at which water becomes associated with the molecular sieves. In other embodiments, materials such as alumina particles may accumulate water at suitable rate from coal fines at room température (e.g., about 20-25 °C). Water-collecting materials containing water formerly associated with the coal fines can subsequently be removed from the coal fines a variety of means.

1.1 The Use of Molecular Sleves as Adsorbents to Reduce the Moisture Content of Coal Fines

Molecular sieves are materials containing pores ofa précisé and uniform size (pore sizes are typically from about 3 to about 10 Angstroms) that are used as an adsorbent for gases and liquids. Without wishing to be bound by any theory, generally molécules small enough to pass through the pores are adsorbed while larger molécules cannot enter the pores. Molecular sieves are different from a common filter in that they operate on a molecular level. For instance, a water molécule may not be small enough to pass through while the smaller molécules in the gas pass through. Because ofthis, they often function as a desiccant. Some molecular sieves can adsorb water up to 22% of their dry weight. Molecular sieves often they consist of aluminosilicate minerais, clays, porous glasses, microporous charcoals, zeolites, active carbons (activated charcoal or activated carbon), or synthetic compounds that hâve open structures through or into which small molécules, such as nitrogen and water can diffuse. In some embodiments, the molecular sieves are an aluminosilicate minerai (e.g., andalusite, kyanite, sillimanite, or mullite). ln other embodiments, the molecular sieves comprise about 10%, 20%, 30%, 40%, 50%, 60%, 65%,70%, 75%, 80%, 85%, 90%, 95%, 98%, 99% or greater (on a weigh basis) of an aluminosilicate minerai. In some embodiments, including those embodiments where the molecular sieves comprise an aluminosilicate minerai, the particles of molecular sieves may contain other minerais, such oxides of zirconium or titanium to enhance properties such as strength and wear (e.g., zirconia toughened aluminosilicates or alumina-titanate-mullite composites), ln some embodiments the molecular sieves are 3 angstrom molecular sieves (e.g., MS3A4825 molecular sieves with 2.5 - 4.5 mm bead size and 14 lb crush strength from Delta Enterprises, Roselle, Illinois) or 4 angstrom molecular sieves (e.g., MS4A4810 molecular sieves with 2.5 - 4.5 mm bead size and 18 lb crush strength from Delta Enterprises, Roselle, Illinois).

A variety of molecular sieves can be employed alone or in combination to remove water or moisture from coal fines. In one embodiment, molecular sieves may be selected from aluminosilicate minerais, clays, porous glasses, microporous charcoals, zeolites, active carbons, or synthetic compounds that hâve open structures through or into which small molécules, such as nitrogen and water can diffuse. In other embodiments, molecular sieves may be selected from aluminosilicate minerais, clays, porous glasses, or zeolites.

Molecular sieves with pores large enough to draw in water molécules, but small enough to prevent any of the coal fines from entering the sieve particles, can be advantageously employed. Hardened molecular sieves or molecular sieves, or those with an especially hard shell, are useful in the methods described herein as such sieves will not be readily worn down and can be reused after removal of moisture.

ln some embodiments molecular sieve particles are greater than 1, 1.25, 1.5, 1.75, 2.0, 2.25 or 2.5 mm in diameter and less than about 5 mm or 10 mm. ln other embodiments the molecular sieve particles are greater than about 12, 14, 16, 18, 20, 22, 24 or 26 mm in diameter and less than about 28, 30 or 32 mm in diameter. When mixed with the wet coal fines having excess moisture (wet coal fines), the molecular sieves quickly draw the moisture from the coal fines. As the sieves are larger than the coal fines (e.g., over a millimeter in diameter), the mixture of sieves and coal fines can be lightly bounced on a fine mesh grid, where the dry coal fines can be separated from the molecular sieves. The separated molecular sieves can be a bit dusty and can carry a minute amount of coal fines with them after they hâve absorbed the water. Once separated, the molecular sieves can be passed to a heater where they can be dried and sufficient moisture is removed to permit their reuse if desired. Thus, the molecular sieves can be employed in a close-loop system, where they are mixed with the coal fines, and after removing water/ moisture (drying) they are separated from the coal fines and passed through a heater and reused. Minimal agitation is required during dry the sieves.

1.2 The Use of Hydratable Polymeric Materials to Reduce the Moisture Content of Coal Fines

Hydratable polymeric materials or compositions comprising one or more hydratable polymers may be employed to reduce the moisture content of coal fines (e.g., polyacrylate or carboxymethyl cellulose/polyester particles/beads).

ln one embodiment the hydratable polymeric materials is polyacrylate (e.g., a sodium sait of polyacrylic acid). Polyacrylate polymers are the superabsorbents employed in a variety of commercial products such as in baby’s diapers, because of their ability to absorb up to 400% of their weight in water. Polyacrylates can be purchased as a corne a translucent gel or in a snowy white particulate form. Suitable amounts of polyacrylic acid polymers (polyacrylates) sufficient to adsorb the desired amounts of water from coal fines can be mixed with the fines, to quickly dry coal. The polyacrylate, which swells into particles or “bails,” may be separated from the coal fines on suitable size filters or sieves. The particles or “bails can either be discarded or recycled by drying using any suitable method (direct heating, heating by exposure to microwave energy, and the like).

The properties of hydrateable polymers, including polyacrylate polymers, may be varied depending on the spécifies of the process being employed to dry the coal fines. A skilled artisan will recognize that the properties (gel strength, ability to absorb water, biodegradability etc.) are controlled to a large degree by the type and extent of the cross-linking that is employed in the preparation of hydratable polymers. A skilled artisan will also recognize that it may be désirable to match the degree of cross-linking with the mechanical vigorofthe process being used dry the coal fines and the number of times, if any, that the particles are intended to be reused in drying batches of coal fines. Typically, the use of more cross-linked polymers, which are typically mechanically more stable/rigid, will permit their use in more mechanically vigorous processes and the potential reuse of the particles.

ln another embodiment the hydratable polymer composition employed is a combination of carboxymethylcellulose (CMC) and polyester (e.g., CMC gum available from Texas Terra Ceramic Supply, Mount Vernon, TX). Such compositions, or other super adsorbent hydratable polymeric substances, can be used to remove water from coal fines in a manner similar to that described above for molecular sieves or polyacrylate polymer compositions.

1.3 The Use of Desiccants to Reduce the Moisture Content of Coal Fines

In other embodiments, desiccants are used as water-collecting materials to dry coal fines. A variety of desiccation agents (desiccants) may be employed to reduce the moisture content of coal fines including, but not limited to, silica, alumina, and calcium sulfate (Drierite, W.A. Hammond Drierite Col Ltd Xenia, OH) and similar materials. Desiccants, like the compositions described above can be used to remove water from coal fines in a manner similar to that described above for molecular sieves or polyacrylate polymer compositions.

ln some embodiments, the desiccant material is comprised of activated alumina, a material that is effective in absorbing water. Without wishing to be bound by any theory, activated alumina's efficiency as a desiccant is based on the large and highly hydrophilic surface area of activated alumina (on the order of 200 m^z/g) and water's attraction (binding) to the activated alumina surface. Other materials having high-surface areas that are hydrophilic are contemplated, e.g., materials that hâve hydrophilic surfaces and surface areas greater than 50 m²/g, 100 m²/g or 150 m²/g. ln some embodiments the desiccant comprises about 10%, 20%, 30%, 40%, 50%, 60%, 65%,70%, 75%, 80%, 85%, 90%, 95%, 98%, 99% or greater (on a weigh basis) of alumina.

Activated alumina is a very hard, durable ceramic capable of withstanding significant abrasion and wear, however, the wear résistance and mechanical properties of activated alumina may be enhanced by introducing other materials into particles of water-collecting materials that comprise alumina. In some embodiments, desiccants comprising alumina may contain about 0.5%,

1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% or more of other minerais, such oxides of zirconium or titanium to enhance properties such as strength and wear (e.g., zirconia alumina or zirconia toughened alumina ZTA).

1.4 Particles of Water Collecting Materials

As described above, a variety of water-collecting materials may be employed in Systems for removing water from wet (or moist) coal fines. Such water-collecting materials include those that absorb water, those that adsorbs water, and those that bonds or react with water. Typically the water-collecting materials will be in the form of particles that can be of any shape suitable for forming an admixture with the wet (or moist) coal fines and that are capable of being recovered. Such particles may be irregular in shape, or hâve a regular shape. Where particles are not irregular in shape they may be of virtually any shape. In one embodiment, particles that are generally or substantially spherical, or generally or substantially oblate, or prolate may be employed. Suitable particle shapes also include cylindrical or conical particles, in addition to regular polygons such as icosahedral particles, cubic particles and the like. During use and reuse the particles may become abraded altering their shape.

Particles for use in the methods and Systems for removing water (e.g., reducing the moisture content) of from coal fines described herein can be of a variety of sizes. In one embodiment, where the water-collecting materials are in the form of particles, the particles hâve an average size that is at least: 2, 3, 4, 6, 7, 8; 9, 10,12,14,16, 18, 20, 25, or 30 times greater than the average size of the coal fines, which are typically in the range of 100 to 800 microns. In one embodiment the différence in size is based upon the différence in the average size ofthe largest dimension of the particles and coal fines.

Particles of water-collecting materials, including those that are spherical or substantially spherical, may hâve an average diameter (or largest dimension) that is at least: 1, at least 1.25, at least 1.5, at least 1.75, at least 2.0, at least 2.25, at least 2.5 mm, or at least 4 mm where the average diameter (or largest dimension) is less than about 5 mm, 7.5mm, 10mm or 15 mm. ln another embodiment, the Systems may employ particles that hâve an average diameter (or largest dimension) that is greater than about 4, 5, 6, 8, 10, 12,14,16, 18, 20, 22, 24 or 26 mm and less than about 28, 30 or 32 mm.

ln embodiments where particles hâve an irregular shape, or are not spherical or substantially spherical, they may hâve a largest dimension that is at least: 1, at least 1.25, at least 1.5, at least 1.75, at least 2.0, at least 2.25, at least 2.5 mm, or at least 4 mm, and less than about 5 mm, 7.5 mm, 10mm or 15 mm. ln another embodiment, the methods and Systems described herein may employ irregular or non-spherical particles that hâve a largest dimension that is greater than about one of 4, 5, 6, 8, 10,12,14, 16, 18, 20, 22, 24 or 26 mm and less than about one of 28, 30 or 32 mm.

In one embodiment the water-collecting materials are desiccants, such as activated alumina desiccants, which are manufactured in multiple forms. In some embodiments the desiccants particles used for water-collecting materials, which may be spherical or substantially spherical, are greater than about 1, 1.25, 1.5, 1.75, 2.0, 2.25 or 2.5 mm in diameter and less than about 5 mm or 10 mm in diameter. In other embodiments the desiccant particles hâve an average diameter or greatest dimension that is greater than about 4, 5, 6, 8,10, 12, 14, 16,18, 20, 22, 24 or 26 mm in and less than about 28, 30 or 32 mm. In one set of embodiments the desiccant particles are spheres (or substantially spherical) with diameters (e.g., average diameters) in those size ranges. In other embodiments, the desiccant particles are spheres (or substantially spherical) in sizes up to or about 6mm in diameter. In other embodiments the desiccants are spherical or substantially spherical particles comprised of alumina having a size in a range selected from: about 2mm to about 4 mm, about 4 mm to about 8 mm, about 8 mm to about 16 mm, about 16 mm to about 32 mm, about 5 mm to about 10 mm, about 8 mm to about 20 mm, and about 16 mm to about 26 mm. In still other embodiments, the water collecting materials are spherical or substantially spherical alumina particles having an average diameter of about: 4, 6, 8,10, 12, 14,16, 18, 20, 22, 24, 26, 28, 30, or 32 mm.

2.0 Séparation by Size and/or Magnetic Means

Water-collecting materials may be separated from coal fines by any suitable technique including filtering, sieving or sifting, or the use of a stream of gas to carry coal fines away from larger and/or heavier particles water-collecting materials.

The séparation of ail types of water-collecting materials (e.g., molecular sieves, desiccants, or hydratable polymers) may also be accomplished using magnetic séparation equipment where the water-collecting materials comprise material capable of, or susceptible to, being attracted by a magnet. Materials that render water-collecting materials capable of being attracted by a magnet include magnetic material and ferromagnetic material (e.g., iron, steel, or neodymium-iron-boron). Water-collecting materials need only comprise sufficient magnetic materials to permit their séparation from coal fines. The amount of magnetic material employed permit the séparation of water-collecting particles from coal fines will vary depending on, among other things, the strength of the magnet, the size of the particles, and the depth of the bed of coal fines from which the particles are to be collected. The amount of magnetic material may be greater than about 10%, 20%, 30%, 40%, 50%, 60%, 65%, 70%, 75%, 80%, 85%, or 90% of the total weight of the water-collecting material on a dry weight basis. In some embodiments the magnetic materials will be iron or an iron containing material such as steel.

Regardless of the magnetic material employed to render water-collecting materials susceptible to magnetic collection, the magnetic materials may be arranged in the water-collecting material as a solid core or as dispersed particles or layers within the water-collecting materials. Where dispersed particles employed are employed, they may be spread uniformly throughout the water-collecting material. In one embodiment the magnetic material is comprises iron containing particles that are admixed with water-collecting materials such as alumina or mullite prior to forming into pellets that will fired into a ceramic type of material. In still other embodiments the watercollecting materials may contain layers of materials that render the particles susceptible to attraction by a magnet (e.g. iron or steel). Examples of magnetic alumina particles that may be used as water-collecting materials may be found in US Patent No. 4,438,161 issued to Pollock titled Iron-containing refractory balls for retorting oil shale.

3.0 Séparation Systems and Methods

The présent disclosure also includes and provides for Systems and methods for removing water from wet coal fines. The Systems and methods described herein may employ any of the above-described water-collection materials or particles of water collecting materials for removing water from coal fines. As described above the water-collecting materials may comprise molecular sieve, a hydratable polymers or desiccants. And as also described above, regardless of the type, size and shape of particles of water-collecting material, the particles also may include materials that render the particles susceptible to attraction by a magnet to facilitate magnetic séparation of the particles from coal fines.

In one embodiment such Systems and methods comprise:

a first location in which the wet coal fines are admixed with at least one water-collecting material to form an admixture of wet coal fines and said water-collecting material, and a second location where at least a portion of said water-collecting material is removed from said admixture.

In one embodiment the second location is configured to provide size-based séparation. In another embodiment, the second location is configured to provide a treatment selected from the group consisting of filtering, sieving or sifting, and the use of a stream of gas to carry coal fines away from larger and/or heavier water-collecting materials.

The second location may also be configured to provide magnetic séparation of watercollecting materials from the coal fines. Magnetic séparation may be employed alone or in combination with any one or more of filtering, sieving or sifting, and the use of a stream of gas to separate coal fines from particles of water-collecting materials.

Systems and methods for collecting water from coal fines may further comprise a third location where at least a portion of the water is removed from the water-collecting material. In addition, the Systems may further comprising a transporter for transporting at least a portion of the water-collecting material obtained from the third location back to the first location for admixture with 5 wet coal fines. Where particles having materials that are susceptible to attraction by a magnetic are used, such transport Systems also may include magnetic transport equipment.

In one embodiment, following the step of forming an admixture of the coal fines with the water-collecting material, at least 25% of the water (by weight) in the composition is associated with the water-collecting material. In other embodiments, the amount of water by weight that is associated with the water-collecting material is at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, or at least 90%.

Example 1

Coal fines (15 g) with a moisture content of 30% by weight are mixed with molecular sieves 15 having a pore sizes of 3 angstroms (15 g, product MS3A4825 2.5-4.5 mm bead size from Delta

Adsorbents, which is a division of Delta Enterprises, Inc., Roselle, Illinois) for about 60 minutes thereby drying the coal fines to <5% moisture by weight. After separating the coal fines from the sieves by sifting, the molecular sieves were weighed and dried în a 100° C oven. The coal fines were weighed periodically to détermine the length of time necessary to drive off the water absorbed 20 from the coal. The data is plotted in Figure 1 for the first batch of coal. The process is repeated using the same molecular sieves with a second through sixth batch of coal fines. The graph in Figure 1 shows the weight measurements for the molecular sieves throughout the drying process after drying the first through sixth batches of coal fines. Figure 1 demonstrates that the molecular sieves can be effectively reused.

Example 2

Coal fines (15 g) with a moisture content of 30% by weight are mixed with a poîyacrylate polymer (0.5 g Online Science Mail, Birmingham, Alabama) for about 1 minute thereby drying the coal fines to <5% moisture by weight. After separating the coal fines from the polymer gently sifting the mix, the molecular poîyacrylate polymer particles are recovered for reuse after drying.

Example 3

Coal fines (100g) with a moisture content of 21% by weight are mixed with activated alumina beads (6mm diameter, AGM Container Controls, Inc, Tucson, AZ) for about 10 minutes, thereby drying the coal fines to about 7% moisture by weight. After separating the coal fines from the polymer gently sifting the mix, the activated alumina beads are recovered for reuse after drying.

The invention(s) as defined by the appended claims is/are not to be limited in scope by the embodiments disclosed herein. Indeed, various modifications of the embodiments shown and described herein will become apparent to those skilled in the art from the foregoing description and thus should be deemed to fall within the scope of the appended claims.

Claims (15)

1. A method of reducing the water associated with wet coal fines comprising contacting said wet coai fines with at least one water-collecting material, wherein at least a portion of the water présent in the mixture becomes associated with the water-collecting material.

2, 3, 4, 6, 7, 8; 9,10,12,14, 16, 18, 20, 25, or 30 times greater than the average size of said coal fines.

2. A method according to claim 1, wherein said water-collecting material collects water by absorption and/or absorption.

3. A method according to claim 1 wherein said water chemically reacts with the water-

4. A method according to any of claims 1-3, wherein prior to the step of contacting said wet coal fines with said water-collecting material, the coal fines are in a mixture comprising water that is subjected to an earlier treatment for removing water.

5 comprises a material selected from the group consisting of a molecular sieve, a hydratable polymer and a desiccant.

68. A system according to any of claims 61 to 67, wherein said water-collecting material comprises a desiccant selected from the group consisting of silica, alumina, and calcium sulfate.

69. A System according to any of claims 61 -68, wherein said second location is configured to provide magnetic séparation of said water-collecting material from said coal fines, either alone or in combination with a size-based séparation of said water-collecting material from said coal fines.

5. A method according to claim 4, wherein said earlier treatment is carried out by one or more treatments selected from the group consisting of treatment with air or other gas, filtration, settling, and centrifugation.

20

6. A method according to claim 5, wherein said earlier treatment is carried out by a filtration treatment that is selected from the group consisting of gravity-based filtration, filtration assisted by centrifugal force, pressure-assisted filtration and vacuum-assisted filtration.

7. A method according to any of claims 1-6, wherein said water-collecting material is in the

25 form of particles.

8. A method according to claim 7, wherein said particles hâve an average size that is at least:

9. A method according to any of claims 7-8, wherein said particles hâve an average diameter that is at least 1, at least 1.25, at least 1.5, at least 1.75, at least 2.0, at least 2.25 and at least 2.5 mm, and less than about 5 mm or 10 mm.

10. A method according to claim 7, wherein said particles hâve an average diameter that is greater than about 4, 5, 6, 8, 10, 12, 14,16, 18, 20, 22, 24 or 26 mm.

10 collecting material.

11. A method according to claim 10, wherein said average diameter is less than about 28, 30 or 32 mm.

12. A method according to any of claims 1-11, wherein said water-collecting material comprises a material selected from the group consisting of a molecular sieve, a hydratable polymer and a desiccant.

13 A method according to any of claims 1-12, wherein said water-collecting material comprises a hydratable polymeric material selected the group consisting of a polyacrylate and a carboxymethyl cellulose.

14. A method according to any of claims 1-13, wherein said water-collecting material comprises a desiccant selected from the group consisting of silica, alumina, and calcium sulfate.

15. A method according to any of claims 1-14, wherein following said contacting, the method further comprises a séparation in which at least a portion of said water-collecting material is separated from said coal fines.

16. A method according to claim 15, wherein said séparation comprises size-based séparation.

17. A method according to claim 16, wherein said size-based séparation comprises one or more procedures selected from the group consisting of, filtering, sieving or sifting, and the use of a stream of gas to carry coal fines away from larger and/or heavier water-collecting materials.

18. A method according to any of claims 16-17, wherein following said séparation, the method further comprises removing at least a portion of the water formerly associated with said coal fines from the water-collecting material.

19. A method according to claim 18, wherein following said removal of at least a portion ofthe water from the water-collecting material, said water-collecting material is re-used to collect water from wet coal fines.

20. A method according to any of claims 1-19, wherein said wet coal fines comprise an amount of water by weight selected from the group consisting of from about 10% to about 15%, from about 15% to about 20%, from about 20% to about 25%, from about 25 to about 30%, from about 30% to about 35%, and greater than 35%.

21. A method according to any of claims 1-20, wherein, following the collection of water by the water-collecting material, the amount of water associated with the coal fines by weight is selected from the group consisting of less than about 10%, less than about 8%, less than about 6%, less than about 5% and less than about 4%.

22 A composition comprising wet coal fines, and at least one water-collecting materials, wherein at least 25% of the water (by weight) in the composition is associated with the watercollecting material.

23. A composition according to claim 22, wherein the amount of water by weight that is associated with the water-collecting material is selected from the group consisting of at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, and at least 90%.

24. A composition according to any of claims 22 and 23, wherein said water-collecting material comprises a material that absorbs water.

25. A composition according to any of claims 22-24, wherein said water-collecting material comprises a material that adsorbs water.

26. A composition according to any of claims 22-25, wherein said water-collecting material comprises a material that chemically reacts with the water-collecting material.

27. A composition according to any of claims 22-26, wherein said water-collecting material is in the form of particles.

28. A composition according to any of claims 22-27, wherein said water-collecting material is in the form of particles with an average size that is at least: 2; 3; 4; 6; 7; 8; 9,10,12 14 16,18, 20, 25, or 30 times greater than the average size of the coal fines.

29. A composition according to any of claims 27 and 28, wherein said particles hâve an average diameter that is at least 1, at least 1.25, at least 1.5, at least 1.75, at least 2.0, at least 2.25 and at least 2.5 mm, and less than about 5 mm or 10 mm.

30. A composition according to any of claims 27-28, wherein particles hâve an average diameter that is greater than about 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 or 26 mm.

31. A composition according to claim 29, wherein said average diameter is less than about 28, 30 or 32 mm.

32. A composition according to any of claims 22-31, wherein said water-collecting material comprises a material selected from the group consisting of a molecular sieve, a hydratable polymer and a desiccant.

33. A composition according to any of claims 22-32, wherein said water-collecting material comprises a hydratable polymeric material selected the group consisting of a polyacrylate and a carboxymethyl cellulose.

34. A composition according to any of claims 22-33, wherein said water-collecting material comprises a desiccant selected from the group consisting of silica, alumina and calcium sulfate.

35. A combination comprising a composition according to any of claims 22-34, and an apparatus for separating at least a portion of said water-collecting material from said composition.

36. A combination according to claim 35, wherein said apparatus is an apparatus that is configured to separate said water-collecting materials from said coal fines by a size-based séparation process.

37. An combination according to claim 36, wherein said apparatus is configured to provide at least one treatment selected from the group consisting of filtering, sieving or sifting, and the use of a stream of gas to carry coal fines away from larger and heavier water-collecting materials.

38. A system for removing water from wet coal fines comprising a first location in which the wet coal fines are admixed with at least one water-collecting material to form an admixture of wet coal fines and said water-collecting material, and a second location where at least a portion of said water-collecting material is removed from said admixture.

39. A system according to claim 38, wherein following the step of forming said admixture, at least 25% ofthe water (by weight) in the composition is associated with the water-collecting material.

40. A system according to claim 39, wherein the amount of water by weight that is associated with the water-collecting material is selected from the group consisting of at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, and at least 90%.

41. A system according to any of claims 38-40, wherein said water-collecting material comprises a material that absorbs water.

42. A System according to any of claims 38-41, wherein said water-collecting material comprises a material that adsorbs water.

43. A system according to any of claims 38-42, wherein said water-collecting material comprises a material that bonds with the water.

44. A system to any of claims 38-43, wherein said water-collecting material is in the form of particles.

45. A system to any of claims 38-44, wherein water-collecting material is in the form of particles that hâve an average size that is at least: 2, 3, 4, 6, 7, 8; 9,10, 12 14 16, 18, 20, 25, or 30 times greater than the average size of the coal fines.

46. A system according to claim 44, wherein the average size of said particles hâve an average diameter that is at least: 1, at least 1.25, at least 1.5, at least 1.75, at least 2.0, at least 2.25 and at least 2.5 mm, and less than about 5 mm or 10 mm.

47. A system according to claim 44, wherein said particles hâve an average diameter that is greater than about 4, 5, 6, 8, 10, 12,14,16, 18, 20, 22, 24 or 26 mm.

48. A system according to claim 47, wherein the average diameter is less than about 28, 30 or 32 mm.

49. A system according to any of claims 38-48, wherein said water-collecting material comprises a material selected from the group consisting of a molecular sieve, a hydratable polymer and a desiccant.

50. A system according to any of claims 38-49, wherein said water-collecting material comprises a hydratable polymeric material selected the group consisting of a polyacrylate and a carboxymethyl cellulose.

51. A system according to any of claims 38-50, wherein said water-collecting material comprises a desiccant selected from the group consisting of silica, alumina, and calcium sulfate.

52. A system according to any of claims 38-51, wherein said second location is configured to provide size-based séparation.

53. A system according to claim 52, wherein said second location is configured to provide a treatment selected from the group consisting of filtering, sieving or sifting, and the use of a stream of gas to carry coal fines away from larger and/or heavier water-collecting materials.

54. A system according to any of claims 38-53, further comprising a third location where at least a portion of the water is removed from the water-collecting material.

55. A system according to claim 54, further comprising a transporter for transporting at least a portion of the water-collecting material obtained from the third location back to the first location for admixture with wet coal fines.

56. A method of reducing the water associated with wet coal fines comprising contacting said wet coal fines with at least one water-collecting material, wherein at least a portion of the water présent in the mixture becomes associated with the water-collecting material; wherein said watercollecting material is in the form of particles that are susceptible to attraction by a magnet.

57. The method of claim 56, wherein following said contacting, the method further comprises a séparation in which at least a portion of said water-collecting material is separated from said coal fines by magnetic séparation alone or in combination with size based séparation applied to said particles either before or after said magnetic séparation.

58. A composition comprising coal fines and particles of at least one water-collecting material that is susceptible to attraction by a magnet.

59. The composition according to claim 58, wherein at least 25% of the water (by weight) in the composition is associated with the water-collecting material.

60. A combination comprising a composition according to claim 58 or 59, and an apparatus for separating at least a portion of said water-collecting material from said composition;

wherein said apparatus is configured to separate said water-collecting materials from said coal fines by a magnetic-based séparation process used alone or in combination with a sîze-based séparation.

61. A system for removing water from wet coal fines comprising a first location in which the wet coal fines are admixed with at least one water-collecting material that is susceptible to attraction by a magnet to form an admixture of wet coal fines and said water-collecting material, and a second location where at least a portion of said water-collecting material is removed from said admixture using magnetic séparation alone or in combination with size based séparation applied to said particles either before or after said magnetic séparation.

62. A system according to claim 61, wherein following the step of forming said admixture, at least 25% of the water (by weight) in the composition is associated with the water-collecting material.

63. A system according claim 61 or claim 62, wherein water-collecting material is in the form of particles that hâve an average size that is at least: 2, 3, 4, 6, 7, 8, 9,10, 12, 14,16,18, 20, 25, or 30 times greater than the average size of the coal fines.

64. A system according claim 61 or claim 62, wherein the average size of said particles hâve an average diameter that is at least: 1, at least 1.25, at least 1.5, at least 1.75, at least 2.0, at least 2.25 and at least 2.5 mm, and less than about 5 mm or 10 mm.

65. A system according claim 61 or claim 62, wherein said particles hâve an average diameter that is greater than about 4, 5, 6, 8,10,12, 14, 16,18, 20, 22, 24 or 26 mm.

66. A system according to claim 65, wherein the average diameter is less than about 28, 30 or 32 mm.

67. A system according to any of claims 61 to 66, wherein said water-collecting material

15 70. A system according to any of claims 61-69, further comprising a third location where at least a portion of the water is removed from the water-collecting material; said system further comprising a transporter comprising a magnet for transporting at least a portion of the water-collecting material obtained from the third location back to the first location for admixture with wet coal fines.