Coal treatment process
AssigneeMicroFuels, Inc.
InventorDavid W. Taylor
Life of this patent
Estimating the term…
Abstract
A process and apparatus for treating coal to produce micron-size coal particles having high surface reactivity and a low level of ash-forming impurities. The process involves grinding the coal in a substantially air tight fluid energy attrition mill to form a hydrophobic coal-fraction and a hydrophilic impurities-fraction, and separating the fractions by virtue of the impurities-fraction's affinity for water.
Claims22
An apparatus for treating coal to reduce the level of ash-forming impurities contained therein comprising, in combination:
- a substantially air tight grinding mill for reducing said coal to particles comprising a hydrophobic coal-fraction and a hydrophilic impurities-fractions, a major portion of said particles having a size less than about 40 microns, injector means for introducing an air-free fluid carrier medium into said mill, inlet means for introducing raw coal into said carrier medium, and outlet means for withdrawing from said mill at least a portion of said coal-fraction and impurities-fraction entrained in said carrier medium;
- a feed conduit for supplying raw coal to said mill for size reduction said conduit having means for excluding air from said conduit and said mill;
- means for cooling said withdrawn coal-fraction and impurities-fraction thereby causing wetting of the particles constituting the impurities fraction, but leaving the particles constituting the coal-fraction substantially dry;
- a separator for separating said hydrophobic coal-fraction from said wetted impurities-fraction;
- and
- means for transferring said carrier medium with said unagglomerated coal-fraction and said impurities-fraction entrained therein from said mill to said separator.
A process for treating coal to reduce the level of ash-forming impurities contained therein comprising:
- a. grinding raw coal to a particle size of less than about 40 microns in a substantially air free environment to form a hydrophobic coal fraction and a hydrophilic impurities fraction;
- b. contacting said fractions with an aqueous liquid whereby the particles constituting the impurities fraction are wetted, but the particles constituting the coal fraction are left substantially dry;
- c. separating the impurities particles from the coal particles.
A process for treating coal to reduce the level of ash-forming impurities contained therein comprising:
- a. deaerating raw coal;
- b. grinding said coal to a particle size of less than about 40 microns in a substantially air free environment to form a hydrophobic coal-fraction and a hydrophilic impurities-fraction;
- c. contacting said fraction with an aqueous liquid whereby the particles constituting the impurities-fraction are wetted but the particles constituting the coal fraction are left substantially unagglomerated;
- d. separating the impurities particles from the coal particles.
A process for beneficiating coal to reduce the level of ash-forming impurities contained therein comprising:
- a. heating raw coal to reduce the moisture content thereof;
- b. deaerating said coal;
- c. grinding said coal to a particle size of less than about 40 microns in a substantially air free environment to form a hydrophobic coal-fraction and a hydrophilic impurities-fraction;
- d. contacting said fractions with an aqueous liquid whereby the particles constituting the impurities fraction are wetted but the particles constituting the coal fraction are left substantially dry;
- e. separating the impurities particles from the coal particles;
- and
- f. recovering the separated coal particles.
Dependencies are inferred from the claim text.