1. The wolframite is crushed to 320 mesh by the alkaline hydrolysis method of tungsten ore, and 30% caustic soda is added to the reactor for alkaline hydrolysis. After alkaline hydrolysis, it is reacted with calcium chloride to synthesize calcium tungstate, and calcium tungstate reacts with hydrochloric acid to generate tungstic acid. Then react with caustic soda to generate sodium tungstate, which is evaporated, crystallized, centrifuged and dried to obtain the finished product of sodium tungstate.
2In industry, the raw mineral wolframite is extracted with sodium hydroxide aqueous solution to make crude sodium tungstate, and then the crude product is made into WO3·2H2O with acid, and then Na2WO4·2H2O is made with sodium hydroxide again. The purification method can be recrystallized with water. When a purer product is required, the aqueous solution is added to hot concentrated hydrochloric acid to precipitate tungsten oxide monohydrate WO3·H2O. The precipitate was washed repeatedly,…