Sulfide and sulfate solid solubility in lime, magnesia, and calcined dolomite: Part I. CaS and CaSO solubility in CaO.

In the present work the solid solubilities of CaS and CaSQ, in burnt lime were investigated by equilibrating lime with CO-CO-SO mixtures at temperatures from 950 to 1300°C. Also, the equilibrium constants for the formation of CaS and CaSO were determined. At high oxy-gen activities, corresponding to a CO/CO ratio >100 in the gas, the sulfur dissolves in lime primarily as sulfate ions. At lower oxygen activities (CO/CO <30), the sulfur goes into so-lution in lime essentially as sulfide ions. Over the temperature range investigated the limit-ing sulfide solubility is within 0.01 to 0.03 pct S, whereas the sulfate solubility is within 0.03 to 0.1 pct S, increasing with increasing temperature. [ABSTRACT FROM AUTHOR]