IMPROVEMENT OF THE EFFICIENCY OF FINE COAL SLIMES FLOTATION

Abstract

The problems of selective flotation of fine slimes have been analyzed. Different technical solutions aimed at the improvement of the efficiency of flotation of coal containing fine slimes have been considered. As a criterion of the efficiency of separation results in flotation the index of maximum flotation ability has been suggested, which is determined by the method of flotation fractionation as the maximum possible yield of concentrate with a specified ash content. The effect of the degree of fineness of slimes and the influence of interaction of flotation feed grain sizes on the flotation results have been investigated. It has been demonstrated that the maximum possible yield of concentrate with a specified ash content strongly depends on the content of ash units in the less than – 50 μm fraction of the flotation feed that allows for forecasting of the optimal indices of separation by flotation. The indices of maximum flotation ability under conditions of one stage flotation are very difficult to achieve in case of higher content of ash units of – 50 μm size in the flotation feed. The examples have been provided of the optimization of flotation results (obtaining of flotation separation indices close to those for the maximum flotation ability) by selection of reagent regimes (type and consumption of reagents and time of flotation), using of flocculation-flotation method; using of complex flotation flowsheets (rougher, scavenger and cleaner flotation); regulation of aerohydrodynamic parameters in flotation cells.