Complex copper sulfide concentrates normally contain As, Sb, Bi, Zn, Pb, as the main impurities.Conventional smelters do not treat concentrates with high levels of impurities; therefore, oxidizing roasting is normally used to remove the unwanted impurities, a process where arsenic is removed effectively but antimony and bismuth removal is deficient. Because of the poor removal of antimony in oxidizing roasting, an alternative chloridizing roasting of stibnite and complex MH copper concentrate (Ministro Hales, CODELCO, Chile) has been studied. The roasting was done with CaCl2 in oxidizing atmosphere. In roasting at 500 - 650 °C, temperature and oxygen concentration affected significantly the Sb volatilization from Sb2S3-CaCl2 sample. At 600 °C and 10 % oxygen, antimony volatilization was 60% in 30 min. In roasting the MH concentrate at 600 °C and 5% oxygen, arsenic can be eliminated in less than 20 min probably as a mixture of arsenic trichloride and trioxide.