The Taguchi method has been used to determine the optimum conditions of dissolution of copper in converter slag with chlorine gas in aqueous media. After the parameters were determined to be efficient on the extraction efficiency, the experiments were begun. The chosen experimental parameters and their ranges were: (i) chlorine gas flow rate (ml min(-1)); 180-220, (ii) solid-to-liquid ratio (g ml(-1)); 0.1-0.166, (iii) stirring speed (rpm); 350-750, (vi) reaction time (min); 90-210. The optimum conditions were found to be as follows: chlorine gas flow rate (ml min(-1)); 220, solid-to-liquid ratio (g ml(-1)); 0.1, stirring speed (rpm); 550, reaction time (min); 90. Under these optimum conditions, copper, iron and zinc extraction efficiency from converter slag were 98.35, 8.97 and 25.17%, respectively.