Abstract:Although the existing copper electrolyte purification method can remove arsenic, but there are still problems such as environmental pollution, high energy consumption, and high content of antimony and bismuth.In this paper, based on the mechanism of Ti—As—O chemical bond bonding, a process of titanium-based precipitant removing arsenic, arsenic-containing slag alkali leaching regeneration, regenerated precipitant acidification removing sodium, preparing metal arsenic was investigated.The better process parameters of arsenic removal process are as follows: the addition amount of titanium oxysulfate-sulfuric acid hydrate is 1.2 times of the total arsenic mass, the reaction temperature is 40℃, and the reaction time is 8h. Under this condition, the initial arsenic removal rate reaches about 60%.The optimum process parameters of alkali leaching regeneration process of arsenic sediment are as follows: liquid-solid ratio 20∶1, NaOH concentration 25g/L, reaction temperature 80℃, reaction time 1.5h. Under these conditions, the leaching rate of arsenic is 65.3%, and the arsenic removal rate reaches 50.6% in one cycle. The optimum process parameters for acidizing removing sodium of regenerated precipitant are as follows: liquid-solid ratio 2∶1, end-point pH=3.0, room temperature, reaction time 1h. Under these conditions, the sodium content in the acidized liquid is 926mg/L, and the titanium content is 0.21mg/L. The optimum process parameters for the preparation of metal arsenic are as follows: hydrazine hydrate excess coefficient 3 times, dilution multiple 5 times, reaction temperature 80℃, solution pH=7.0, reaction time 2h. Under these conditions, the reduction rate of arsenic is about 75%, and the purity of metal arsenic is about 93%.The process is simple in operation and has high selectivity for the removal of arsenic and antimony; the solution after arsenic removal can be returned to the copper electrolysis system; the arsenic-containing alkaline leaching solution can be reduced to prepare metal arsenic.The multiple cycle arsenic removal rate is maintained at about 50%, which does not cause the loss of valuable metals such as copper. Further screening of arsenic precipitation agents and reducing agents is needed to reduce the cost of agents.
