Sulfidation of manganese in sulfur vapor at low pressure and temperatures between 873 and 1273 K

Abstract

An investigation was carried out on the sulfidation kinetics of manganese plates by thermogravimetry in pure sulfur vapor at low pressures, 4.5×10⁻⁵< p_S2 (atm)<7.2×10⁻⁴, at temperatures between 973 and 1173 K. The reaction kinetics were parabolic and the sulfidation rate constant at 1073 K was proportional to$p_{S_2 }^{{1 \mathord{\left/ {\vphantom {1 n}} \right. \kern-\nulldelimiterspace} n}}$ where n = 6.4±0.8. The activation energy for the sulfidation reaction at$p_{S_2 } = 8.1x10^{ - 5}$ atm was 25,000±3000 cal·mol⁻¹. The α-MnS developed a preferred orientation texture, and grain growth was observed even though the metal exhibited no preferred orientation.