Kinetic Analysis of Copper Sulfide (Chalcopyrite) Dissolution by Moderately Thermophilic Bacteria

Abstract

ABSTRACTThe objective of this study was to improve the basic understanding of copper sulfide minerals dissolution during bioleaching of flotation concentrate and to analyze the dissolution kinetic. The results show that the sulfide mineral dissolution kinetic changes with operation time. Both surface reaction and diffusion through product layer were found to be effective parameters for the rate of reaction with various degrees of influence. In other words, the whole dissolution process can be divided into two intervals. At the beginning, the effect of surface reaction on the reaction rate is obvious. With increasing operation time and formation of layer on the surface of copper sulfides, the influence of diffusion through the layers increases. However, the dissolution rate depends also on the particle size distribution index (d80) and pulp density. With decreasing particle size and pulp density, the influence of surface reaction on the dissolution rate is increasing more than that of diffusion through layers.