Sulfur-Phosphorus Mixed Acid Decomposition Extraction Method
The sulfur-phosphorus mixed acid decomposition extraction method is adopted, so that tungsten enters the solution in the form of phosphotungstic heteropolyacid, and calcium precipitates into the solid phase in the form of calcium sulfate, so as to achieve stable and efficient decomposition of scheelite.
An acidic organic extractant is used to obtain a tungsten-loaded organic solvent, and then ammonia water is added for substitution to obtain a crude ammonium tungstate solution. The solution is then subjected to ion exchange to remove impurities to obtain a pure ammonium tungstate solution.
Sulfur-Phosphorus Mixed Acid Decomposition Extraction Method Process Flow Chart