Tungsten and arsenic substance flow analysis of a hydrometallurgical process for tungsten extracting from wolframite

In this study, the metabolism of a hydrometallurgical process for tungsten extracting from wolframite was studied through substance flow analysis. The mass balance accounts, substance flow charts of tungsten and arsenic were established to evaluate the metabolism efficiency of the investigated system. The results showed that, the total tungsten resource efficiency of the system was 97.56%, and the tungsten recovery of unit process autoclaved alkali leaching, ion exchange, Mo removing, concentration and crystallization was 98.16%, 98.94%, 99.71%, 99.89%, respectively. Meanwhile, for extracting 1 ton of tungsten into the qualified ammonium paratungstate, 10.0414 kg of arsenic was carried into the system, with the generation of 7.2801 kg of arsenic in alkali leaching residue, 1.5067 kg of tungsten in arsenic waste residue, and 1.2312 kg of tungsten in Mo residue. Besides, 7.9 g of arsenic was discharged into nature environment with waste water, 15.5g of arsenic was entrained into the final APT. The distribution and transformation behaviors of arsenic during production were analyzed through phases change analysis, and some recommendations for improving the resource efficiency of tungsten and pollution control during production were also proposed based on the substance flow analysis in this study.