Coal preparation at coke plants often involves selective flotation of coal slurries to accelerate the clarification of process waters. This is usually done under static conditions in radial or pyramid thickeners or in outdoor settling basins. In order to intensify this process, Kharkov Polytechnical Institute and Kharkov Coal Chemistry Institute developed a centrifugal ftocculation method of classifying (concentrating) coals. The process was studied at the coal preparation departments of Yasinovka Coke Plant (in a hydrocyclone) and Makeevka Coke Plant (in a centrifugal classifier), where the coal aggregates of slurry particles are classified and separated in continuous operations [1]. When a selectively flocculated coal slurry is classified in a centrifugal field, the fioc is subjected to greater dynamic action from the flow of liquid phase, compared with settling under static conditions (in a radial thickener). Moreover, in continuously operating centrifugal classifiers, the solid grains are subjected to the additional factor of hydrodynamic perturbations that occur in the internal currents of the hydro-cyclone and in the rotor of the centrifugal classifier and which depend on the speed of these flows; i.e., on the operating capacity of the equipment.
展开▼
