Testing of a Prototype of Equipment for Classification of Coal Slurries

摘要

The run-of-mine (ROM) coals that are to be subjected to hydraulic beneficiation in jigging machines contain a considerable amount of high-ash small, fine and ultrafine size fractions. Moreover, in water-slurry circuits of coal preparation plants there are again formed secondary slurries due to wetting and pulverization of coal-mineral grains in circulating streams (1, 2). As is known, under industrial conditions, for the concentration of coal slurries of fineness 0.5-0.01 mm a method of froth flotation is used (3, 4); in order to separate a coal-containing product of < 0.01 mm, the workers of the Ukrainian Institute of Coal Chemistry (UKhIN) have developed and implemented a method of selective flotation with the use of a reagent BS-30F (5, 6).For the beneficiation of a coarse-grain slurry of 3(6)-0.5 mm at coal preparation plants use is made of the following equipment: concentrating tables, water-only hydrocyclones, heavy-media hydrocyclones, steeply inclined and spiral separators, froth separation machines, band vacuum filters and slurry hydraulic jigging machines. However, because of the insufficient specific capacity and operational unreliability of concentrating tables, insufficient efficiency of concentration in water-only hydrocyclones, steeply inclined and spiral separators, the high cost of the concentration process in heavy-media hydrocyclones, froth separation and in slurry jigging machines and also because of the shortcomings in the operation of preliminary classifying equipment, the necessary technological indices are not provided with the equipment employed (7). It is for this reason that the coarse-grain slurry is practically not subjected to concentration in coal beneficiation plants of Ministry of the Coal Industry and in coal preparation sections of Ukrainian byproduct coke plants.