Manganese sulfidation in H₂S-H₂ mixtures in the temperature range 673–1223 K

Abstract

Pure manganese was sulfidized in H₂S−H₂ mixtures at temperatures between 673 and 1223 K, under a sulfur partial pressure in the range 2.2 × 10⁻⁵−3.4 Pa. The large temperature range investigated must be partitioned into three domains, in which kinetics, sulfide scale morphology, and texture are strongly linked. In the higher-temperature domain, experimental results were in accordance with literature data concerning manganese sulfidation carried out in pure sulfur vapor, with respect to parabolic kinetics and the morphological point of view. In the lower-temperature domain, kinetics were linear for the major duration of an experiment. They began with a period of decreasing rate, followed by a period of a few hours during which no weight gain was detected. Scale texture and morphology were unusual in this environment. Between these two domains, an intermediate one was observed wherein some characteristics of the two previous ones were mixed.