Oxidation of pure solid CaS with Ar-O2 gas mixture

Abstract

Oxidation behavior of CaS in oxidizing atmosphere has been investigated for the regeneration process of desulfurization slag by oxidation. The temperature range of oxidation of CaS reagent with Ar-21%O2 gas was 973 to 1423 K. The weight gain was observed in the lower temperature range and reached at the maximum value at 1173 K while weight gain turned to decrease when the reaction temperature was higher than 1173 K. It was clarified that CaS was oxidized to CaSO4 under 1173 K or to CaO over 1373 K by the measurement of oxidation rate, XRD and thermodynamic analysis. The results strongly suggested that sulfur removal from the sulfur containing slag may be possible at temperatures of 1223 K or higher by the oxidation of with air.