An experimental study of stibnite solubility in gaseous hydrogen sulphide from 200 to 320 degrees C

The solubility of stibnite in gaseous hydrogen sulphide was investigated ex perimentally in the systems Sb2S3-S-H2S and Sb2S3-H2S at temperatures betwe en 200 and 320 degreesC (pressures of up to 200 bars). The concentrations o btained are several orders of magnitude higher than those calculated for H2 S-free systems and display a prograde dependence on temperature in the rang e of 200 to 290 degreesC. Concentrations of Sb2S3 are relatively constant a t temperatures ranging from 290 to 320 degreesC with a proposed solubility maximum at 300 degreesC. In order to be able to describe stibnite solubilit y in the gas phase a simple solvation model was used, namely: Sb2S3cryst. + H2Sgas = Sb2S3 . (H2S)(gas). Equilibrium constant fur this solvation reaction varied from 10(-6.76) to 1 0(-5.77) over the temperature range from 200 to 320 degreesC. Copyright (C) 2001 Elsevier Science Ltd.