A clean non-toxic method for leaching of barium tungstate

Abstract Barium tungstate is one of the important components of complex tungsten minerals and is also an intermediate product of hydrometallurgy. Since it is thermodynamically a very stable mineral, most of the current tungsten ore leaching methods are ineffective for its processing. In addition, due to the high toxicity of barium ions, special attention must be paid during the leaching process. In order to solve these problems, a new method of using sodium sulfate to decompose barium tungstate is proposed in this article. A thermodynamic analysis of the Ba2+-SO42–-WO42–-H2O system is carried out, in which the changes of various ions and precipitations at different pH values and different amounts of sodium sulfate were explored. Moreover, this method is theoretically proved to be feasible. Also, the leaching of barium tungstate experiment was carried out. Under optimum conditions with liquid/solid ratio 10:1 mL/g, reaction temperature 75 °C, and Na2SO4 dosage 2.5 -3.0 molar times to BaWO4, the leaching rate of barium tungstate was > 99%. This method has the advantages of simplicity, and high leaching rate, and it is cost effective with no barium toxicity.