Study of the mechanism of the hydrogen sulfide/dolomite reaction. Quarterly report, January 1978--March 1978

New rate and structure data are presented for the sulfidation of Guelph dolomite. The reaction time for a given conversion is practically independent of reactant gas flow rates, but decreases with increasing temperature or decreasing pellet size. Composition profiles of partially reacted samples, obtained by EDAX, show a diffuse interface separating a product layer from an unreacted core. A kinetic model, intended to represent the reaction behavior at the pellet level, is presented as a basis for the development of a detailed model to describe the reaction behavior at the grain level. Results of the first carbonation experiments are also presented. Both compacted pellets of pure CaS and previously sulfided samples of Guelph dolomite were used. Although no detailed composition profiles have as yet been determined, microscopic examination of polished sections of partially sulfided samples suggests that the reaction proceeds in a topochemical fashion.