Comparison of the Flotation Performance between Wide and Narrow Particle Size Ranges of Coal

Abstract

The flotation completion degree τ and an energy parameter E were proposed to compare the flotation effect for wide and narrow particle size ranges. Flotation rate tests were conducted at different agitation speeds in a laboratory flotation cell on different particle-sized coal. The results showed that the particle constitution of the sample was unimodal and that the yields of the middle particle size (−250 µm to +75 µm) and middle density (1.40 g/cm3 to 1.60 g/cm3) were high. Optimal flotation recovery for the various sizes occurred at the lower speeds (1500 rpm or 1800 rpm). During flotation, the τ value initially increased and then decreased. Compared with the narrow particle size, the wide particle size exhibited a better flotation effect, less ash in clean coal, and higher recovery.