Percolation bacterial leaching of low-grade chalcopyrite using acidophilic microorganisms

Abstract

Bioleaching studies were carried out in percolation columns using low-grade copper containing rock (granite). The lixiviant consisted of acidified ferric sulfate containing acidophilic microorganisms. The iron oxidizing strain was isolated from Malanjkhand mine water and after adaptation the iron oxidation observed to be 500 mg/L/h. Leaching parameters studied were lixiviant flow rate, particle size and bed height. It was observed that leaching efficiency increased with decrease of particle size and lixiviant flow rate. The precipitation of iron during leaching observed to be low as pH was maintained at 2. Based on the leaching kinetics, a unified rate equation was developed and shown as r alpha (d(p))(-0.61) (F)(-0.76) (H-b)(0.97).