A Study on Mineral and Sulfur Rejection from Coal Using a Small-Scale Floatation Column

Abstract

Floatability of three kinds of coal, Datong, Ensham and Illinois No.6, was investigated with various superficial gas velocities and additive concentrations in a small-scale flotation column. The orders of both carbonaceous materials recovery and ash rejection were found to be Datong > Ensham > Illinois No.6. Distribution of hyd-rophobicity of coal particles was evaluated by means of the film flotation method. The order of the strength of hydrophobicity determined by the film floatation method was in consistent with that of carbonaceous materials recovery and thereby it was confirmed that this method is useful for evaluating floatability of coal qualitatively. It was found that inorganic sulfur can be rejected by column flotation, indicating that a column floata-tion process can be applied for simultaneous demineralization and desulphurization of coal. The order of pyrite rejection was Ensham > Datong > Illinois No.6, being different from that of ash rejection.