Production of Barium Sulfide from Low-Grade Barite Ores

The manufacture of barium sulfide or barium salts (BaS, BaCl₂, Ba (OH)₂, among others) requires high-purity barite ores (>90%). In this study, a new method to produce barium sulfide from low-grade barite ores (60% purity) is proposed. The method involves gravitational concentration of barite ore on a shaking table followed by mechanical activation of the barite concentrate with metallurgical coke in a ball mill. The mechanically activated mixture undergoes carbothermic reduction with an argon flow, resulting in the conversion of barite concentrate into barium sulfide. Gravitational concentration studies conducted using a shaking table demonstrated that, upon optimizing key operational parameters—namely, the wash-water flow rate, length, stroke frequency, the splitter positions of the concentrate, middlings, and tailings—a barite concentrate with a purity exceeding 95% BaSO₄ was successfully achieved. Mechanical activation of the barite/coal mixture lowered the initial temperature of the carbothermic reduction from 1100 K to 990 K, enabling complete conversion of barite to BaS, as confirmed by thermogravimetric curves and XRD analysis. Furthermore, the activation energy during the carbothermic reduction ranged from 300 to 500 kJ/mol, suggesting a complex reduction process of barite with metallurgical coke that is difficult to represent by a single reaction.