Enhancing Barite Carbothermal Reduction with Brown Coal by Compaction of the Charge

Abstract

Barium sulfide is an important intermediate in the manufacture of ceramics, glass, plastics, and pharmaceutical products. This substance is traditionally obtained by carbothermal reduction of barite (barium sulfate) in the presence of a carbon-containing reducing agent, mainly coal. Herein, it is demonstrated that compaction of the charge before the carbothermal reduction significantly enhances the conversion of barium sulfate to sulfide due to an increase in the contact time of carbon monoxide with barite in a compact sample in comparison with a powder sample. In the presence of NaOH as a catalyst, the degree of conversion of barium sulfate in a compact sample was 0.95–0.97 upon roasting at 1150 °C for 65 min, while in a powder sample this value did not exceed 0.6. Furthermore, charge compaction reduced the conversion activation energy (136 vs. 264 kJ mol−1), which could be a tool for reducing the energy intensity of obtaining barium sulfide from its sulfate.