Coal beneficiation by gas agglomeration
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsThomas D. Wheelock, Shen Meiyu
Life of this patent
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Abstract
Coal beneficiation is achieved by suspending coal fines in a colloidal suspension of microscopic gas bubbles in water under atmospheric conditions to form small agglomerates of the fines adhered by the gas bubbles. The agglomerates are separated, recovered and resuspended in water. Thereafter, the pressure on the suspension is increased above atmospheric to deagglomerate, since the gas bubbles are then re-dissolved in the water. During the deagglomeration step, the mineral matter is dispersed, and when the pressure is released, the coal portion of the deagglomerated gas-saturated water mixture reagglomerates, with the small bubbles now coming out of the solution. The reagglomerate can then be separated to provide purified coal fines without the mineral matter.
Claims20
A process of coal beneficiation by removing mineral impurities from coal fines, comprising:
- suspending coal fines containing mineral impurities in a colloidal suspension of microscopic gas bubbles in water under atmospheric conditions to form small agglomerates comprised of coal fines, gas bubbles and trapped mineral impurities;
- separating the agglomerates from the suspension of unagglomerated mineral impurities;
- resuspending the agglomerates in water and increasing the pressure on the suspension above atmospheric pressure to deagglomerate said small agglomerates;
- releasing the pressure on the deagglomerated suspension of coal fines and gas-saturated water to produce cleaned agglomerates comprised of coal fines, gas bubbles, and a lesser amount of trapped mineral impurities;
- and
- thereafter separating the cleaned coal agglomerates from the suspension of remaining unagglomerated particles.
Dependencies are inferred from the claim text.