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US 4,461,627 AGranted
Upgrading method of low-rank coal
AssigneeHitachi, Ltd.
InventorsHiroshi Yokoyama, Toshio Kuge, Shunsuke Nogita, Yoichi Nakamura
Life of this patent
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Abstract
A coal is finely pulverized. The finely pulverized coal is subjected to dry distillation. A tar obtained by the dry distillation is added to an aqueous slurry together with the dry-distilled coal to effect the submerged granulation.
Claims8
An upgrading method for low-rank coal comprising the steps of:
- (a) finely pulverizing the coal to provide an amount of coal particles having particle sizes of up to 74.mu. between 20 and 75 weight %,
- (b) subjecting the finely pulverized coal to dry distillation at a temperature of from 200.degree. to 600.degree. C. to obtain water, tar and dry-distilled coal,
- (c) mixing the dry-distilled coal with water to obtain an aqueous slurry,
- (d) adding the tar obtained by the dry distillation to the slurry to agglomerate coal particles, and
- (e) separating the agglomerated coal particles from water.
2 more elements
An upgrading method for low-rank coal comprising the steps of:
- (a) finely pulverizing the coal to provide an amount of coal particles having particle sizes of up to 74.mu. between 20 and 75 weight %,
- (b) subjecting part of the finely pulverized coal to dry distillation at a temperature of from 200.degree. 600.degree. C. to obtain water, tar and dry-distilled coal,
- (c) subjecting the balance of the finely pulverized coal to a non-evaporating heating treatment at a temperature of from 180.degree. to 350.degree. C. to reduce its water content and to distill tar,
- (d) mixing the dry-distilled coal and the non-evaporatingly heated coal with water to obtain an aqueous slurry,
- (e) adding the tar obtained by the dry distillation and the non-evaporating heating treatment to the slurry for agglomerating coal particles, and
- (f) separating the agglomerated coal particles from water.
3 more elements
Dependencies are inferred from the claim text.