Caifang Cao

Separation of macro amounts of tungsten and molybdenum by precipitation with ferrous salt

Abstract In order to develop a low-cost approach for separating macro amounts of Mo and W, the effects of parameters on the separation using FeSO 4 as precipitation reagent were studied. The results show that the optimum reaction temperature is 10°C, and the separation factor does not further improve after a reaction time of 7 h. Moreover, slow dropping speed of the precipitation reagent is beneficial for improving the separation efficiency. When the H + /W molar ratio is below 1/1, the addition of acid to a neutral solution is favorable to the separation. For the solution with an ammonium concentration below 3 mol/L, the separation factor is high due to the high W-precipitation rate. Furthermore, the method is also effective when it is applied to industrial solution containing some other impurities. All these indicate the ferrous salts have great potential for removing W from Mo on a commercial scale.