Large caliber cyclone for coarse slime recovery
At present, most adopt the three-stage (that is, increase coarse slime separation) coal preparation mode. The advanced nature of the three-stage coal preparation process needs to be manifested by superior performance sorting equipment. At present, the large-diameter heavy medium cyclone has the characteristics of large processing capacity, wide feed particle size range, good separation effect, strong adaptability to coal type and selectivity, and is used as ideal equipment for coarse coal separation. The cyclonic micro-bubble flotation column has the characteristics of good selectivity and high separation accuracy for fine-grained coal and ultra-fine-grained coal as the best choice for fine-grained coal separation equipment.
(1) Definition of coarse slime: The particle size is close to that of slime, usually above 0.3-0.5mm, and it is not suitable to use flotation particles. In recent years, with the focus on coarse slime separation technology, the coal preparation industry has more often defined slime with a particle size of 0.3-2.0 mm as coarse slime.
(2) The characteristics of coarse slime: The particle size is near the lower limit of the separation. The ash content is 2% to 4% higher than the ash content of the refined coal. The dissociation of coal and minerals is relatively sufficient and it is easier to select.
(3) Sources of coarse slime in coal washing plant: The sources of coarse slime in coal preparation plant are mainly divided into two situations: one is the selection method of desilting before selection. Currently, 2mm (3mm) desilting sieve is used to remove sludge and slime water It must contain 0.5 ~ 2mm coarse slime; the second is the non-sludge selection method, due to the uneven sieve of the degumming sieve or the desilting sieve, when the wear is serious, the content of> 0.5mm in the slime water will increase. In order to ensure the floating particle size, the slime water needs to be classified to recover the coarse slime.
(4) Main separation equipment for coarse slime: The coarse slime separation mainly adopts the slime heavy medium cyclone, spiral sorter and interference bed sorter (TBS) for separation.