pH值对W-Cu(70g:30g)共沉淀回收率的影响

Effect of pH Value on Co-precipitation Recovery Rates of W-Cu(70g:30g)

用NH4OH把H2WO4转化成(NH4)2WO4,再以CuSO4水溶液和(NH4)2WO4水溶液为反应物,用NH4OH和H2SO4调节pH值,进行W-Cu(70g:30g)共沉淀反应,考察了pH值对W-Cu共沉淀回收率的影响;理论计算了pH值对W-Cu共沉淀回收率的影响。实验结果表明:Cu的回收率随pH值增大而提高,pH值大于6.0时,Cu的回收率有下降的趋势;W的回收率随pH值增大而降低;当pH值为5.2时,W和Cu的回收率相等,且只有一个相等点,此时两者的回收率大于99%,这与理论计算结果相符合。

H2WO4 was transformed to （NH4）2WO4 by NH4OH, then CUSO4·5 H20 solution and （NH4）2WO4 solution were used as reactants, NH4OH and H2SO4 were used to control pH value, the co-precipitation reaction of W-Cu （70 g：30 g） was conducted. The influence ofpH value on co-oprecipitation recovery rates of W-Cu was studied and calculated. It is indicated that the recovery rate of Cu increases with increasing ofpH value; when pH value is greater than 6.0, the recovery rate decreases. The recovery rate of W decreases with increasing of pH value. When pH value equales 5.2 which is unique, the recovery rates of W and Cu are equal to each other, the recovery rates of them are greater than 99% and accordant to the theory calculation result.