Theoretical analysis and experimental study on metal separation of tungsten-containing systems

Based on the leaching solution of tungsten secondary resource, the metal separation properties of tungsten-containing systems such as the W-Mg-Si-H2O, the W-Al-H2O, the W-Fe-Mo-H2O and the W-Ca-V-H2O, were investigated by theoretical E-pH diagrams and experiments. The results demonstrated that the precipitation rates of Si and W were 99% and 2.4% respectively at pH = 9 in W-Mg-Si-H2O system; the precipitation rates of Al and W were 99.8% and 3.0% respectively at pH = 7 in W-Al-H2O system; the precipitation rates of W and Mo were 95% and 24% respectively at pH = 7 in W-Fe-Mo-H2O system; the precipitation rates of V and W were 91.2% and 4.3% respectively at pH = 13 with Ca:V = 3:1 in V-Ca-W-H2O system. The theoretical predictions were in good agreement with the experimental results. The metal separation for a tungsten-containing polymetallic solution of W, Mo, V, Si and Al, was designed and the parameters were optimized through the orthogonal experiments. The metals of (Si/Al), V, W and Mo were separated step by step with the precipitation rates exceeding 92%. This study provided a reference to metal comprehensive separation and recovery for the tungsten secondary resources.