Flotation Performance of Low-rank Coal in the Presence of Cetyltrimethyl Ammonium Bromide

Abstract

ABSTRACT The flotation enhancement mechanism and flotation kinetics of low-rank coal in the presence of cetyltrimethyl ammonium bromide (CTAB) were investigated. The contact angle of the coal sample increased by 46.07% and the attachment time between coal particles and a single air bubble decreased by 85.79% with increasing the concentrations of CTAB from 0 to 1 × 10–4 M. Low concentrations of CTAB enhanced the flotation performance of low-rank coal, and the concentrate yield significantly increased by up to 8.59 percentage points with increasing the concentrations of CTAB from 0 to 1 × 10–5 M at the cost of a lower increase in the ash content. However, the selectivity was reduced at high CTAB concentrations (5 × 10–5 M and 10–4 M). Six kinetic flotation models were employed to fit the flotation test data using the 1stOpt analysis software; the flotation rate constant (k), the maximum combustible recovery (ε ∞), the correlation coefficient (R 2) and the modified flotation rate constant (k m) were calculated. Most models showed that the modified rate constant and the maximum combustible recovery of low-rank coal increased with the increasing concentrations of CTAB.