Study on Extracting Vanadium from Stone Coal Calcine by Pressure Alkaline Leaching

Considering that extracting V₂O₅ from coal-stone by "roasting-alkali leaching" process exist some serious problems such as abundant alkali consumption, long leaching time and leaching solution with high impurity content and so on, the experiment of extracting V₂O₅ from stone coal calcine by pressure alkaline leaching was investigated, and effects of dosage of sodium hydroxide, liquid-solid ratio, leaching time, recycle leaching on the vanadium leaching were studied.The results showed that when sodium hydroxide 3.5% of ore calcine weight, the ratio of liquid-solid 1.5:1, leaching temperature 180℃, leaching time 2 h, the leaching rate of vanadium in stone coal is 86%, mass ratio of vanadium and silicon is 0.65, and pH of the leaching solution is 12.1.High-pressure alkaline leaching process with the advantage of high leaching rate of vanadium but low leaching rate of other impurities, provides a new way for extracting V₂O₅ from stone coal.