METHOD OF DRY BENEFICIATION OF HIGH-ASH COAL Russian patent published in 2018 - IPC B07B9/00 

FIELD: mining.

SUBSTANCE: invention relates to coal industry and can be used for dry beneficiation of hard-cleaning coals, namely high-ash coals. Method for beneficiating the high-ash coal includes processing steps carried out in the following sequence: the initial coal of less than 120 mm size is subjected to grinding to a size of less than 5 mm and to simultaneous drying in a grinding unit with a controlled atmosphere, the ground product is subjected to dedusting by air sizing, after which electrostatic separation is performed to partially remove the ash fraction, then the ore concentrate obtained by electrostatic separation is subjected to medium-temperature pyrolysis by heating in a controlled atmosphere, the resulting char is subjected to a dry magnetic separation to remove the ash fraction. Temperature of the material unloaded from the grinding unit is maintained at 120–250 °C, and the oxygen content in the controlled atmosphere of the grinding unit is maintained below 10 %. Dedusting is carried out with a particle size of less than 0.1 mm. Isolated dust fraction is burned in the furnace, the produced flue gas is used as a heat transfer fluid at drying. Pyrolysis is carried out at a temperature of 475–550 °C.

EFFECT: increase in the coal content of the produced ore concentrate.

4 cl, 2 dwg, 2 tbl, 6 ex