The carbothermic reduction of zinc sulfide ill the presence of sodium carbonate has been studied using X-ray diffractometry (XRD), thermogravimetric analysis system (TGA). atomic absorption spectrometry (AAS), inductively coupled plasma-mass spectrometry (ICP-MS). elemental analyzer (EA) and scanning electron microscopy (SEM). Experimental results of AAS indicated that the reduction ill the presence of sodium carbonate proceeded Significantly faster than ill the presence of calcium carbonate and its sulfur fixation efficiency was acceptable. The results of XRD revealed that zinc Sulfide vas first transformed from beta-type to alpha-type, then reduced to zinc vapor. The sequence of the variation of sodium containing material was found to be Na(2)CO(3)(s,gamma)-> Na(2)CO(3)(s,alpha -> Na(2)CO(3)(l)-> Na(2)O(l)-> Na(2)S(l)-> Na(2)SO(4)(l). A reaction mechanism is proposed to interpret the overall reaction. Results of kinetic study indicated that the rate of reduction could be increased by increasing the reaction temperature, the initial molar ration of C/ZnS, or the initial molar ratio of Na(2)CO(3)/ZnS. The rate was also found to be increased with a decrease in sample height, size of C aggregate, size of Na(2)CO(3) aggregate or the initial bulk density. The reduction rate, however, was found not to be influenced.(c) 2008 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.