Experimental Study on Vanadium Extraction from Refractory Vanadium Ore

The vanadium ore of Gansu was difficult to treat with flotation process for the complex composition and superfine dissemination size. Experiments of acid direct leaching vanadiferous, roasting-acidic leaching, roasting-alkali leaching and roasting-immersion were taken to research this refractory vanadium ore. The results showed that the roasting-acidic leaching process had better effect, and the pregnant solution with vanadium leaching rate 93.36% could be achieved, under optimal conditions of raw ore grinding fineness -0.074 mm 70%, Φ8～20 mm granulation, 1.5 h roasting time, 800℃ rosting temperature, -0.074 mm 60% of baked ore, 12% sulfate, 1.2:1 of liquid-solid ratio, 1 h leaching , 30℃ of reaction temperature. The adopted process technology route has solved the technical problems such as low vanadium leaching rate and large consumption of sulfuric acid in the conventional wet vanadium extraction process for the refractory vanadium ore, and laid a solid technical foundation for realizing the efficient utilization of resources and ensuring the safety of national energy resources.