It was not possible to determine the kinetics for the subsequent oxidation of Cu2O to CuO because of the limited
weight change during this reaction step, but the reaction rate seems to be of the same order of magnitude as for the reaction of Cu2S to Cu2O. It can be concluded that the current experimental results demonstrate that a conversion of copper sulfide to copper oxide, preventing the formation of by-products is possible at temperatures in the range of 550–750 ◦C, oxygen concentrations of 5–10% and that the required contact time is in the order of minutes.