Mineral decomposition process of vanadium recovery from stone coal by low temperature sulphating roasting

The new mineral decomposition process of vanadium recovery from stone coal by low temperature sulphating roasting was proposed, which overcomes the shortages of high energy consumption and long working cycle existing in stone coal decomposition with sulfuric acid solution under normal atmosphere. Using the stone coal obtained from Kaili of Guizhou Province, China, as raw material, the process parameters, such as roasting time, roasting temperature, sulfuric acid addition volume and the leaching with water for the calcine, were investigated. The results show that when the stone coal is firstly treated by low temperature sulphating roasting, then the obtained calcine is leached in water with liquid-to-solid ratio of 1.2 mL/g at 100 ℃ for 2 h, the leaching rate of vanadium is 78.2%. However, when the stone coal is leached with the same sulfuric acid addition and the same liquid-to-solid ratio under normal atmosphere at 100 ℃ for 48 h, the leaching rate of vanadium is only 67.8%. The process of low temperature sulphating roasting can effectively enhance the mineral decomposition of stone coal, which shortens the working cycle of vanadium recovery from stone coal and increases the utilization ratio of sulfuric acid and vanadium leaching rate.