Effects of particle size on flotation performance in the separation of copper, gold and lead

Abstract

In order to investigate the effect of particle size on the flotation performance in the separation of copper-gold-lead, froth products of various size fractions were collected as a function of flotation time. The optimum dosage of potassium dichromate (K2Cr2O7) and sodium diethyldithiocarbamate (DDTC) were determined by flotation conditional tests. Six flotation kinetic models were used for fitting the experimental data of copper, gold and lead cumulative recovery using 1stOpt and Origin software. Flotation rate constant (k), the maximum recoveries values (R∞), and the multitude correlation coefficient (R2) of each model, as well as the separation efficiency (SE) and the distribution index (D.I.) were calculated to study the changing trend of flotation parameters for various size fractions. The results demonstrated that the favorable size fraction for the copper-gold-lead separation flotation was −74 + 20 μm. The classical first-order model was considered as the optimum model to adapt to the coppergold-lead separation flotation process in this investigation. The flotation rates of the coarser size fractions were greater than those with relatively finer size fractions, while longer flotation time may contribute to improving the recovery of the fine size fraction, and had little impact on the recovery of coarse-grained. The separation efficiency with respect to intermediate size fractions was greater than both the coarse and ultra-fine size fractions whether it is for copper-lead separation flotation or for gold-lead separation flotation. The most reasonable size fraction for gold enriched in the copper concentrate was −58 + 20 μm, while the coarse size fraction of −100 + 74 μm was found to be against to the selective enrichment of gold.