Bioleaching kinetics of copper from copper smelters dust

The smelting factory of Sarcheshmeh Copper Complex in Iran produces about 50 tons per day of copper dust containing 36% Cu, 22.2% Fe and 12.2% S. The dust is currently recycled to the smelters. This method is not desirable in terms of operation, and energy consumption. A mixed culture of mesophilic bacteria was used to examine the bioleaching of copper from the dust. The effect of various parameters such as pulp density, nutrients, temperature, and the amount of pyrite added to the bioleaching media were examined in the dust bioleaching tests. It was shown that the bacteria contributed effectively in the leaching of copper from the dust. The collected data showed that at pH 1.8 and the pulp density less than 7%, the dissolution of copper followed shrinking core kinetic model and the process was limited by diffusion of lixiviant. With the pulp density of 7%, however, the process showed to be reaction limited.