铅锌矿选矿废水的处理及循环利用

Treating and recycling of wastewater from lead-zinc mineral processing plant

采用聚合硫酸铁(PFS)和PFS-FeSO4复合混凝剂处理铅锌矿选矿废水。结果表明:采用PFS处理选矿废水,当剂量(以铁计)为56 mg.L-1时,Cu,Pb和浊度去除率分别可达90.63%,99.97%和100%,但Cr去除率仅为24.98%;采用PFS-FeSO4复合混凝剂处理选矿废水,当剂量(以铁计)分别为42和780 mg.L-1时,Cu和Pb去除率分别为81.25%和99.97%,Cr去除率达到88.74%,但浊度去除率下降至86.06%;当剂量(以铁计)为84 mg.L-1,并在0.5 L废水中加入0.5 g Na2S时,Cu,Pb,Cr和浊度去除率分别为84.69%,99.97%,98.9%和99.14%,去除Cr效果显著增加,处理后选矿废水中的Cu,Pb,Zn和Cr含量低于国家污水综合排放标准(GB8978-1996)。工业放大实验结果表明,处理后废水可循环利用。

Lead-zinc mineral processing wastewater was treated by polymeric ferric sulfate （PFS） and a complex coagulant of PFS-FeSO4. The results show that after the wastewater is treated by PFS and the dosage of total iron is 56 mg·L^-1, the removal rates of Cu, Pb and turbidity are up to 90.63%, 99.97% and 100%, respectively, while the removal rate of Cr is only 24.98%. After the wastewater is treated by PFS-FeSO4 and the dosages of total iron of PFS and FeSO4 are separately 42 and 780 mg·L^-1, the removal rates of Cu and Pb are 81.25% and 99.97%, and the removal rate of Cr is up to 88.74%, but the removal rate of turbidity is down to 86.06%. After the wastewater is treated by PFS-FeSO4, and 0.5 g sodium sulfide（Na2S） is added into 0.5 L wastewater and the dosage of total iron is 84 mg·L^-1, the removal rates of Cu, Pb, Cr and turbidity are up to 84.69%, 99.97%, 98.9% and 99.14%, respectively. The surplus concentrations of Cu, Pb, Zn and Cr of the wastewater treated by the complex coagulant of PFS-FeSO4 and Na2S are under the Chinese standards of wastewater discharge （GB8978-1996）. The industrial experimental proves that the treated wastewater can be recycled.