HK1191364A - Methods and compositions for drying coal - Google Patents

Description

Method and composition for drying coal

Background

Many current coal mining methods use water to extract pulverized coal particles (also known as coal fines). These particles may typically have a diameter of about 100 to 800 microns, although the coal fines may have a smaller diameter, for example on the order of 50 microns or less. Conventional methods of drying coal particles, including centrifugation and heating techniques, can easily dry these coal "fines" to approximately 30% moisture. In addition, the method of drying the pulverized coal generally employs a blower and a heater, which require capital-intensive investment, require the use of a large amount of energy, and create environmental problems and hazards from energy use and aerosolization of the pulverized coal.

SUMMARY

Embodiments of the present disclosure provide methods and compositions for drying wet coal fines by employing water-collecting materials (e.g., molecular sieves, water-adsorbing polymeric reagents, desiccants, etc.) that are readily separated from the coal fines (e.g., by sieving or screening). These materials may remove all or a portion of the water from the wet coal fines by physical and/or chemical action. For example, the water-collecting material may draw water from wet coal fines by sorption (e.g., absorption or adsorption). In embodiments of the methods and compositions herein, the material used to collect water from the coal fines may be recycled and/or reused, thereby drying more coal fines after some or all of the water is removed from the water-collecting material.

Brief Description of Drawings

Fig. 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 sieve is determined after drying each batch of coal fines and is weighed periodically at the specified time throughout the drying process

Detailed Description

Embodiments described herein utilize water-collecting materials, such as adsorbents and absorbents, that can collect moisture from wet coal fines. Advantageously, these materials may effectively collect water from the coal fines and may subsequently be separated from the coal fines in order to reduce the amount of water associated with the coal fines. In some embodiments, the water-collecting material may then be dried separately from the coal fines. The methods may provide one or more desirable benefits, such as one or more of reduced time, energy, cost, and/or adverse environmental impact, as compared to other methods of drying wet pulverized coal. In addition, embodiments of the present disclosure may substantially reduce the generation of coal dust fumes from hair dryers that may pose health, fire, and explosion hazards.

Although the embodiments described herein do not require drying and re-use of these water-collecting materials, many of these materials can be effectively dried separately from the coal fines and re-used one or more times. The embodiments described herein thus employ drying and re-use of water-collecting materials, such as absorbents and adsorbents. In other embodiments, all or a portion of the water-collecting material may be discarded, such as when the absorbent degrades and cannot be effectively separated from the coal fines. In one embodiment, the particles of water-collecting material are separated by sieving or screening to remove degraded particles that may be larger than the particles of coal fines but smaller than desired for processing wet coal fines. In other embodiments, some or all of the sorbent materials used in removing moisture from the coal fines may be biodegradable.

The water-collecting material may also combine with water to cause the water to associate with the material rather than the coal fines.

1.0 removal of Water from coal dust

The coal fines may be separated from the bulk water used in the mining/recovery process (over the water associated with the coal fines as they settle or are filtered or centrifuged out of the aqueous suspension solution) by any one or more known techniques. These techniques include, but are not limited to, one or more of filtration (e.g., gravity-based filtration or centrifugal force, pressure or vacuum assisted filtration), sedimentation, centrifugation, and the like, which can be used alone or in combination. Other amounts of water may optionally be removed from the coal fines by a second round of such treatment.

After one or more separation steps to remove the bulk of the water, the wet coal fines are then mixed with particles of water-collecting material or a combination of different types of water-collecting materials (e.g., particles of absorbents or adsorbents) to further reduce the amount of water associated with the fines. In one embodiment, the water-collecting material particles are large enough to be separated from the coal fines by size (e.g., screening with a suitably sized screen or sieve). In various embodiments, to aid in drying thereof, the wet coal fines are mixed with one or more types of water-collecting materials, including but not limited to molecular sieves, hydratable polymer particles (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 present in the coal fines may be affected by temperature. Each type of water-collecting material may have a different optimum temperature for their rate of water accumulation from the coal fines. In some cases, heating/warming the molecular sieve with or immediately before mixing the molecular sieve with the coal fines, like the molecular sieve, may increase the rate at which water becomes associated with the molecular sieve. In other embodiments, a material such as alumina particles may accumulate water from coal fines at a suitable rate at room temperature (e.g., about 20-25 ℃). The water-collecting material, which contains water originally associated with the coal fines, can then be removed from the coal fines in a number of ways.

1.1 use of molecular sieves as adsorbents to reduce the water content of coal fines

Molecular sieves are materials containing small pores of precise and uniform size (typically about 3 to about 10 angstroms in pore diameter) that are used as adsorbents for gases and liquids. Without wishing to be bound by any theory, generally molecules small enough to pass through the pores are adsorbed while large molecules cannot enter the pores. Molecular sieves differ from conventional filters in that they operate at the molecular level. For example, water molecules may be insufficiently small to pass through while smaller molecules in the gas pass through. Thus, they tend to act as desiccants. Some molecular sieves can adsorb up to 22% of their dry weight of water. Molecular sieves tend to be composed of aluminosilicate minerals, clays, porous glasses, microporous carbons, zeolites, activated carbons (activated charcoal or activated carbon), or synthetic compounds having an open structure through which small molecules (such as nitrogen and water) can diffuse or enter. In some embodiments, the molecular sieve is an aluminosilicate mineral (e.g., andalusite, kyanite, sillimanite, or mullite). In other embodiments, the molecular sieve comprises about 10%, 20%, 30%, 40%, 50%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99% or more (on a weight basis) aluminosilicate mineral. In some embodiments, including those in which the molecular sieve comprises aluminosilicate minerals, the molecular sieve particles may contain other minerals, such zirconium or titanium oxides may enhance properties such as strength and attrition resistance (e.g., zirconia-reinforced aluminosilicates or alumina-titanate-mullite composites). In some embodiments, the molecular sieve is a 3 angstrom molecular sieve (e.g., an MS3a4825 molecular sieve from Delta Enterprises, Roselle, Illinois having a 2.5-4.5mm bead size and a 14lb crush strength) or A4 angstrom molecular sieve (e.g., an MS4a4810 molecular sieve from Delta Enterprises, Roselle, Illinois having a 2.5-4.5mm bead size and an 18lb crush strength).

A variety of molecular sieves can be used alone or in combination to remove water or moisture from the coal fines. In one embodiment, the molecular sieve may be selected from aluminosilicate minerals, clays, porous glasses, microporous carbons, zeolites, activated carbons, or synthetic compounds having an open structure through which small molecules (such as nitrogen and water) may diffuse or enter. In other embodiments, the molecular sieve may be selected from aluminosilicate minerals, clays, porous glasses, or zeolites.

Molecular sieves having pores large enough to attract water molecules but small enough to prevent any coal fines from entering the molecular sieve particles may be advantageously employed. Hardened molecular sieves or those having particularly hard shells are useful in the processes described herein because these molecular sieves do not easily wear off and can be reused after removal of moisture.

In some embodiments, the molecular sieve particles have a diameter greater than 1, 1.25, 1.5, 1.75, 2.0, 2.25, or 2.5mm and less than about 5mm or 10 mm. In other embodiments, the molecular sieve particles have a diameter greater than about 12, 14, 16, 18, 20, 22, 24, or 26mm and less than about 28, 30, or 32 mm. When mixed with wet coal fines having excess moisture (wet coal fines), the molecular sieve quickly draws moisture from the coal fines. Because the sieve is larger than the coal fines (e.g., more than one millimeter in diameter), the mixture of sieve and coal fines can bounce gently on the fine mesh grid where the dry coal fines can be separated from the molecular sieve. The separated molecular sieve may be somewhat dusty and may carry a very small amount of coal fines after it has absorbed water. Once separated, the molecular sieve can be passed through a heater (where it is dried) and enough water removed to allow it to be reused if desired. Thus, the molecular sieves can be employed in a closed loop system where they are mixed with coal fines, separated from the coal fines after they have removed water/moisture (drying) and passed through a heater and reused. A minimum amount of agitation is required during drying of the molecular sieve.

1.2 use of hydratable polymeric materials to reduce the water content of coal fines

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

In one embodiment, the hydratable polymeric material is a polyacrylate (e.g., a sodium salt of polyacrylic acid). Polyacrylate polymers are superabsorbents employed in a variety of commercial products, such as baby diapers, because they absorb up to 400% of their weight in water. Polyacrylates are commercially available as translucent gels or snow-white particles. Suitable amounts of polyacrylic acid polymers (polyacrylates) are sufficient to adsorb the desired amount of water from the coal fines that can be mixed with the coal fines, thereby rapidly drying the coal. The polyacrylate (swollen into particles or "pellets") can be separated from the coal fines on a suitably sized filter or screen. The particles or "pellets" may be discarded or used in a drying cycle by using any suitable method (direct heating, heating by exposure to microwave energy, etc.).

The characteristics of the hydratable polymer (including polyacrylate polymers) may vary depending on the characteristics of the process used to dry the coal fines. One skilled in the art will recognize that the properties (gel strength, water absorption capacity, biodegradability, etc.) are controlled to a considerable degree by the type and degree of crosslinking employed in preparing the hydratable polymer. One skilled in the art will also recognize that it may be desirable to match the degree of crosslinking to the mechanical strength of the method of drying the coal fines and, if present, the number of times the particles are intended to be reused in a batch of dried coal fines. The use of more crosslinked polymer (which is generally mechanically more stable/rigid) will generally allow its use in more mechanically robust processes and more reuse of the particles.

In 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). These compositions or other superabsorbent hydratable polymers can be used to remove water from coal fines in a manner similar to the molecular sieve or polyacrylate polymer compositions described above.

1.3 use of desiccants to reduce the moisture content of coal fines

In other embodiments, a desiccant is used as the water-collecting material to dry the coal fines. Various desiccants may be employed to reduce the moisture content of the coal fines, including but not limited to silica, alumina, and calcium sulfate (Drierite, w.a. hammond Drierite Col Ltd xenon, OH) and similar materials. Similar to the above-described compositions, desiccants may be used to remove water from coal fines in a manner similar to the molecular sieve or polyacrylate polymer compositions described above.

In some embodiments, the desiccant material is comprised of activated alumina, a material that is effective to absorb water. Without wishing to be bound by any theory, the efficiency of activated alumina as a desiccant is based on the large and highly hydrophilic surface area of activated alumina (in the order of 200 m)²/g) and attraction (binding) of water to the activated alumina surface. Other materials with high hydrophilic surface areas are contemplated, e.g. with hydrophilic surfaces and greater than 50m²/g、100m²G or 150m²Material per g of surface area. In some embodiments, the desiccant comprises about 10%, 20%, 30%, 40%, 50%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99% or more (on a weight basis) alumina.

Activated alumina is a very hard, durable ceramic that can withstand significant wear, however, the wear resistance and mechanical properties of activated alumina can be improved by incorporating other materials into the water-collecting material particles comprising alumina. In some embodiments, the desiccant 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 minerals that the zirconium or titanium oxides may enhance such properties as strength and wear resistance (e.g., zirconia alumina or zirconia reinforced alumina ZTA).

1.4 Water-collecting Material particles

As noted above, a variety of water-collecting materials may be employed in the system to remove water from wet (or wet) coal fines. These water-collecting materials include those that absorb water, those that adsorb water, and those that bind or react with water. Generally the water-collecting material is in the form of particles which may have any shape suitable to form a mixture with wet (or moist) coal fines and which can be recovered. The particles may be irregularly shaped or have a regular shape. When the particles are irregularly shaped, they can be of virtually any shape. In one embodiment, generally or substantially spherical or generally or substantially oblate spheroidal or prolate particles may be employed. In addition to regular polygons, such as icosahedral particles, cubic particles, and the like, suitable particle shapes also include cylindrical or conical particles. During use and re-use, the particles may become worn and change their shape.

The particles used in the methods and systems for removing water (e.g., reducing water content) from coal fines described herein may have a variety of sizes. In one embodiment, where the water-collecting material is in the form of particles, the average size of the particles 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, typically in the range of 100 to 800 microns. In one embodiment, the difference in size is based on the difference in average size of the largest dimension of the particles and coal fines.

The particles of water-collecting material (including those that are spherical or substantially spherical) may have an average diameter (or largest dimension) of 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 2.5mm, or at least 4mm, wherein the average diameter (or largest dimension) is less than about 5mm, 7.5mm, 10mm, or 15 mm. In another embodiment, the system may employ particles having an average diameter (or largest dimension) greater than about 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, or 26mm and less than about 28, 30, or 32 mm.

In embodiments where the particles have an irregular shape or are not spherical or substantially spherical, their largest dimension may be 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 2.5mm, or at least 4mm and less than about 5mm, 7.5mm, 10mm, or 15 mm. In another embodiment, the methods and systems described herein may employ irregular or non-spherical particles having a largest dimension greater than about one of 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, or 26mm and less than about one of 28, 30, or 32 mm.

In one embodiment, the water-collecting material is a desiccant, such as an activated alumina desiccant, which is manufactured in various forms. In some embodiments, the desiccant particles (which may be spherical or substantially spherical) for the water-collecting material have a diameter greater than about 1, 1.25, 1.5, 1.75, 2.0, 2.25, or 2.5mm and less than about 5mm or 10 mm. In other embodiments, the desiccant particles have an average diameter or largest dimension greater than about 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, or 26mm and less than about 28, 30, or 32 mm. In one set of embodiments, the desiccant particles are spheres (or substantially spheres) having a diameter (e.g., average diameter) in those size ranges. In other embodiments, the desiccant particles are spheres (or substantially spherical) up to or about 6mm in diameter size. In other embodiments, the desiccant is spherical or substantially spherical particles composed of alumina having a size in a range selected from the group consisting of about 2mm to about 4mm, about 4mm to about 8mm, about 8mm to about 16mm, about 16mm to about 32mm, about 5mm to about 10mm, about 8mm to about 20mm, and about 16mm to about 26 mm. In yet other embodiments, the water-collecting material is 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 separation by size and/or magnetic means

The water-collecting material may be separated from the coal fines by any suitable technique including filtration, sieving or screening or the use of a gas stream to entrain coal fines from larger and/or heavier particulate water-collecting materials.

Where the water-collecting material comprises a material that is capable of being attracted to or sensitive to magnetic attraction, separation of all types of water-collecting materials (e.g., molecular sieves, desiccants, or hydratable polymers) can also be accomplished using magnetic separation devices. Materials that cause the water-collecting material to become attracted to the magnet include magnetic materials and ferromagnetic materials (e.g., iron, steel, or neodymium-iron-boron). The water-collecting material need only contain sufficient magnetic material to allow it to be separated from the coal fines. The amount of magnetic material employed to allow separation of water-collecting particles from the coal fines will vary depending on, among other things, the strength of the magnets, the size of the particles, and the depth of the bed of coal fines in 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 dry weight of the water-collecting material. In some embodiments, the magnetic material is iron or a ferrous material, such as steel.

Regardless of the magnetic material employed to render the water-collecting material susceptible to magnetic collection, the magnetic material may be disposed within the water-collecting material as a solid core or dispersed particles or layers within the water-collecting material. When dispersed particles are employed, they can be uniformly distributed throughout the water-collecting material. In one embodiment, the magnetic material comprises iron-containing particles mixed with a water-collecting material (such as alumina or mullite) prior to forming a pellet of the ceramic type material to be fired. In still other embodiments, the water-collecting material may contain a layer of material (e.g., iron or steel) that renders the particles susceptible to attraction by a magnet. Examples of magnetic alumina particles that may be used as water-collecting materials may be found in U.S. patent No. 4,438,161 entitled Iron-containing recovery beads for recovering oil scales issued to Pollock.

3.0 separation System and method

The present disclosure also includes and provides systems and methods for removing water from wet coal fines. The systems and methods described herein may employ any of the above-described water-collecting materials or water-collecting material particles for removing water from coal fines. As noted above, the water-collecting material may comprise a molecular sieve, a hydratable polymer, or a desiccant. Also as noted above, regardless of the type, size, and shape of the water-collecting material particles, the particles may also include materials that render the particles susceptible to magnetic attraction to facilitate magnetic separation of the particles from the coal fines.

In one embodiment, these systems and methods include:

a first location where the wet coal fines are mixed with at least one water-collecting material to form a mixture of wet coal fines and the water-collecting material, an

A second location in which at least a portion of the water-collecting material is removed from the mixture.

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

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

The system and method for collecting water from coal fines may further include a third location in which at least a portion of the water is removed from the water-collecting material. Additionally, the system may further comprise means for transporting at least a portion of the water-collecting material obtained from the third location back to the first location for mixing with wet coal fines. These delivery systems may also include magnetic delivery devices when particles having materials sensitive to magnetic attraction are used.

In one embodiment, at least 25% of the water (by weight) in the composition is associated with the water-collecting material after the step of forming a mixture of coal fines and water-collecting material. In other embodiments, the amount of water 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% by weight.

Example 1

Coal fines (15g) having a moisture content of 30 wt% were dried to a moisture content of < 5 wt% by mixing with a molecular sieve having a pore size of 3 angstroms (15g, MS3A48252.5-4.5 mm bead size from Delta Adsorbents, a division of Delta Enterprises, Inc., Roselle, Ill.) for about 60 minutes. After the coal fines were separated from the molecular sieves by sieving, the molecular sieves were weighed and dried in an oven at 100 ℃. The coal fines were weighed periodically to determine the length of time required to drive off the water absorbed from the coal fines. The data for the first batch of coal fines is plotted in fig. 1. The second through sixth batches of coal fines repeat the process using the same molecular sieve. The graph in fig. 1 shows the results of the weight measurement of the molecular sieve throughout the drying process after drying the first to sixth batches of pulverized coal. Figure 1 demonstrates that the molecular sieve can be effectively reused.

Example 2

Coal powder (15g) having a water content of 30 wt% was mixed with a polyacrylate polymer (0.5g of online Science Mall, Birmingham, Alabama) for about 1 minute to dry the coal powder to a moisture content of < 5 wt%. After the mixture was gently screened to separate the coal fines from the polymer, the molecular polyacrylate polymer particles were recovered for reuse after drying.

Example 3

Coal fines (100g) having a moisture content of 21 wt% were mixed with activated alumina beads (6mm diameter, AGM contact Controls, Inc, Tucson, AZ) for about 10 minutes to dry the coal fines to a moisture content of about 7 wt%. After gently sieving the mixture to separate the coal fines from the polymer, the activated alumina beads were recovered for reuse after drying.

The invention, which is defined by the appended claims, is 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 are therefore considered to be within the scope of the appended claims.

Claims (70)

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

2. The method of claim 1, wherein the water-collecting material collects water by absorption and/or adsorption.

3. The method of claim 1, wherein the water chemically reacts with the water-collecting material.

4. A method according to any one of claims 1-3, wherein prior to the step of contacting the wet coal fines with the water-collecting material, the coal fines are in an aqueous mixture that is subjected to an early treatment to remove water.

5. The method of claim 4, wherein the early treatment is by one or more treatments selected from the group consisting of treatment with air or other gas, filtration, sedimentation, and centrifugation.

6. The method of claim 5, wherein the early treatment is by a filtration treatment selected from the group consisting of gravity-based filtration, centrifugal force-assisted filtration, pressure-assisted filtration, and vacuum-assisted filtration.

7. The method of any one of claims 1-6, wherein the water-collecting material is in the form of particles.

8. The method of claim 7, wherein the average size of the particles is at least: 2. 3, 4, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, or 30 times.

9. The method of any one of claims 7-8, wherein the particles have an average diameter of 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 2.5mm, and less than about 5mm or 10 mm.

10. The method of claim 7, wherein the particles have an average diameter of greater than about 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, or 26 mm.

11. The method of claim 10, wherein the average diameter is less than about 28, 30, or 32 mm.

12. The method of any one of claims 1-11, wherein the water-collecting material comprises a material selected from the group consisting of molecular sieves, hydratable polymers, and desiccants.

13. The method of any one of claims 1-12, wherein the water-collecting material comprises a hydratable polymeric material selected from the group consisting of polyacrylates and carboxymethylcellulose.

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

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

16. The method of claim 15, wherein the separating comprises size-based separating.

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

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

19. A method as in claim 18 wherein after said removing at least a portion of said water from said water-collecting material, said water-collecting material is reused to collect water from wet coal fines.

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

21. A method according to any one of claims 1-20, wherein the amount of water associated with the coal fines after collection of water by the water-collecting material 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% by weight.

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

23. A composition according to claim 22, wherein the amount of water associated with the water-collecting material by weight 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. The composition of any one of claims 22 and 23, wherein the water-collecting material comprises a material that absorbs water.

25. The composition of any one of claims 22-24, wherein the 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 said water-collecting material.

27. The composition of any one of claims 22-26, wherein the 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 having an average size that is at least 2, 3, 4, 6, 7, 8, 9, 10, 121416, 18, 20, 25, or 30 times greater than the average size of said coal fines.

29. The composition of any one of claims 27 and 28, wherein the particles have an average diameter of 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 2.5mm, and less than about 5mm or 10 mm.

30. The composition of any one of claims 27-28, wherein the particles have an average diameter of greater than about 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, or 26 mm.

31. The composition of claim 29, wherein the average diameter is less than about 28, 30, or 32 mm.

32. The composition of any one of claims 22-31, wherein the water-collecting material comprises a material selected from the group consisting of molecular sieves, hydratable polymers, and desiccants.

33. The composition of any one of claims 22-32, wherein the water-collecting material comprises a hydratable polymeric material selected from the group consisting of polyacrylates and carboxymethylcellulose.

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

35. A combination comprising

The composition of any one of claims 22-34, and

a device for separating at least a portion of the water-collecting material from the composition.

36. The combination of claim 35, wherein the device is a device configured to separate the water-collecting material from the coal fines by a size-based separation process.

37. The combination of claim 36, wherein the device is configured to provide at least one treatment selected from the group consisting of filtration, sieving or sifting and the use of a gas stream 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 where the wet coal fines are mixed with at least one water-collecting material to form a mixture of wet coal fines and the water-collecting material, an

A second location in which at least a portion of the water-collecting material is removed from the mixture.

39. A system as set forth in claim 38 wherein at least 25% of the water (by weight) in the composition is associated with the water-collecting material after the step of forming the mixture.

40. A system according to claim 39, wherein the amount of water associated with the water-collecting material by weight 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. The system of any one of claims 38-40, wherein the water-collecting material comprises a material that absorbs water.

42. The system of any one of claims 38-41, wherein the water-collecting material comprises a material that adsorbs water.

43. The system of any one of claims 38-42, wherein the water-collecting material comprises a material that binds to the water.

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

45. A system according to any of claims 38-44, wherein water-collecting material is in the form of particles having an average size that is at least 2, 3, 4, 6, 7, 8, 9, 10, 121416, 18, 20, 25, or 30 times larger than the average size of the coal fines.

46. The system of claim 44, wherein the particles have an average diameter with an average size of 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 2.5mm, and less than about 5mm or 10 mm.

47. The system of claim 44, wherein the particles have an average diameter of greater than about 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, or 26 mm.

48. The system of claim 47, wherein the average diameter is less than about 28, 30, or 32 mm.

49. The system of any one of claims 38-48, wherein said water-collecting material comprises a material selected from the group consisting of molecular sieves, hydratable polymers, and desiccants.

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

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

52. The system of any one of claims 38-51, wherein the second position is configured to provide size-based separation.

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

54. The system of any one of claims 38-53, further comprising a third location in which at least a portion of the water is removed from the water-collecting material.

55. A system as defined in claim 54, further comprising means for conveying at least a portion of the water-collecting material obtained from the third location back to the first location for mixing with wet coal fines.

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

57. A method as in claim 56, wherein after said contacting, said method further comprises separating, wherein at least a portion of said water-collecting material is separated from said coal fines by magnetic separation alone or in combination with size-based separation applied to said particles before or after said magnetic separation.

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

59. A 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

The composition of claim 58 or 59, and

a device for separating at least a portion of the water-collecting material from the composition;

wherein the apparatus is configured to separate the water-collecting material from the coal fines by a magnetic-based separation process used alone or in combination with size-based separation.

61. A system for removing water from wet coal fines comprising

A first location in which said wet coal fines are mixed with at least one water-collecting material sensitive to magnetic attraction to form a mixture of wet coal fines and said water-collecting material, and

a second location in which at least a portion of the water-collecting material is removed from the mixture using magnetic separation alone or in combination with size-based separation applied to the particles before or after the magnetic separation.

62. A system in accordance with claim 61, wherein at least 25% of the water (by weight) in the composition is associated with the water-collecting material after the step of forming the mixture.

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

64. The system of claim 61 claim 62, wherein the particles have an average diameter with an average size of 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 2.5mm, and less than about 5mm or 10 mm.

65. The system of claim 61 or claim 62, wherein the particles have an average diameter greater than about 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, or 26 mm.

66. The system of claim 65, wherein the average diameter is less than about 28, 30, or 32 mm.

67. The system according to any one of claims 61 to 66, wherein said water-collecting material comprises a material selected from the group consisting of molecular sieves, hydratable polymers, and desiccants.

68. The system according to any one of claims 61-67, 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 one of claims 61-68, wherein said second location is configured to provide magnetic separation of said water-collecting material from said coal fines alone or in combination with size-based separation of said water-collecting material from said coal fines.

70. The system of any one of claims 61-69, further comprising a third location in which at least a portion of the water is removed from the water-collecting material; the system further includes a conveyor containing water-collecting material for conveying at least a portion of the water-collecting material obtained from the third location back to the first location for mixing with wet coal fines.