Structural and temperature sensitivity of the chloride leaching of copper, lead and zinc from a mechanically activated complex sulphide

The hydrometallurgical processing of complex concentrates represents an ecologically attractive alternative with respect to classical pyrometallurgical technologies. The structural and temperature sensitivity of chloride leaching of copper, lead and zinc from a complex CuPbZn sulphide concentrate of Slovak origin which was mechanically activated in an attritor was studied. Mechanical activation influences the leaching kinetics and the recoveries of copper and zinc, but only the leaching kinetics of lead. It has been found that the reaction is sensitive to the increase in surface area and decrease in crystalline phase content of the studied concentrate due to mechanical activation. The demonstration of a linear relationship shows the structural sensitivity of the reaction. For copper and zinc, the reaction temperature sensitivity for the optimum mechanically activated sample in the temperature region 323–363 K showed a change in the rate-determining step at 343 K. Lead showed no change in mechanism over this temperature range. The suggested order of structural sensitivity galena>chalcopyrite>sphalerite is in accordance with their temperature sensitivity.