METHOD OF DRY COAL CONVERSION Russian patent published in 2006 - IPC B07B9/00 

FIELD: coal industry; conversion of difficultly enriched coals.

SUBSTANCE: proposed method includes preliminary crushing at separation of 0-25 mm class, selective grinding, treatment on pneumatic classifier at separation of 0-1 mm class and sieving remaining class of 1-35 mm on sieve. Size of mesh of previous sieve relative to subsequent one is equal to 1.7-2.0 for obtaining respective classes at ratio of larger particles to smaller ones within 1.7-2.0; then, each class is fed to conveyer with belt made from screen and provided with nozzles having rarefaction of 300-800 mm of water column. First nozzle (in way of motion of conveyer) whose shear is mounted at maximum distance from belt is used for removal of material at density of 1250-1350 kg/m³ at ash content of A^d=8-11% which is just coal-concentrate; second nozzle whose shear in mounted at lesser distance from belt as compared with first nozzle is used for removal of material having density of 1350-1600 kg/m³ (A^d=11-25%) and third nozzle whose shear is mounted at minimum distance from belt is used for removal of material at density of 1600-1800 kg/m³ (A^d=25-45%). Material remaining on belt having density of 1800-2500 kg/m³ at ash content of A^d=70-80% goes to the dump and material of classes of +25 mm remaining after screening is subjected to selective grinding to size of 0-25 mm and classification at separation of class of 0-1 mm followed by separation in sieves and conveyer as described above.

EFFECT: enhanced efficiency of conversion of coals used as solid fuel.

2 dwg, 1 ex