Pressure Leaching of Chalcopyrite Concentrate with Oxygen and Kinetic Study on the Process in Sulfuric Acid Solution

摘要

In this research work, the pressure leaching of chalcopyrite concentrate with oxygen was studied. Experiments were carried out under conditions of the solid-liquid ratio of 0.1, agitation speed of 750 rpm, and sulfuric acid concentration of 2 M in a stainless-steel autoclave system under 0.6 to 1 MPa oxygen gas. Central composite design was used to design experiments, and three factors of temperature, time, and oxygen pressure were selected as the design variables. A linear model for %Cu and a quadratic model for %Fe were proposed by Minitab Software. The results showed that temperature is the most effective factor in chalcopyrite leaching. Under optimal conditions, 93.08% of copper with the aim of maximum dissolution was extracted. The kinetic study illustrated that the diffusion of the passive layer, produced during chalcopyrite leaching, controls the rate of the process. It can be represented by the 1-23 alpha-(1-alpha)23=kdt equation. The activation energy was calculated to be 14.19 kJ mol(-1).