Optimization of copper recovery from copper converted slag. Part I: Pyrometallurgical aspects

In this study, roasting and leaching of copper converter slag was carried out and the effects of their significant parameters were investigated. Minitab programing was put to use in design and analysis of these experiments. In roasting experiments the results show that roasting temperature has the greatest influence on solubility of Copper, while roasting time and grain size are in second and third place. Roasting slag with 237μ average grain size in 600 ° C with duration of 90 minutes was the best case of roasting. It resulted in 75.3% Copper recovery after leaching. Then in second stage, for obtaining optimum leaching parameters, all samples were prepared under previously mentioned roasting parameters and then went through leaching as its parameters were being manipulated. Best case was achieved when leached in boiling 150 gr/L acid, with L/S=10 and leaching time of 45 minutes which leads to Copper recovery of 92.2%