铅锌选矿废水净化处理与循环回用试验研究

针对四川某铅锌多金属矿选矿废水开展了水质调研、混凝沉降试验、除钙试验、活性炭吸附以及处理水回用试验研究。结果表明，针对该选矿废水特性，选用“Na₂CO₃+PAC+PAM+活性炭”工艺处理混合水样，在Na₂CO₃用量100 mg/L、PAC用量50 mg/L、PAM用量1.5 mg/L、活性炭用量25 mg/L条件下，处理后出水澄清无色，处理水pH值8.31，COD_Cr降至38.05 mg/L，各污染物去除效果显著，各项指标均达到GB 25466-2010(直接排放)要求且符合选矿回用水质要求。在原矿含铅0.6%、含锌2.17%的情况下，处理水回用闭路试验获得了铅品位46.61%、含锌1.85%、铅回收率83.81%的铅精矿以及锌品位56.20%、含铅0.59%、锌回收率92.04%的锌精矿，选矿指标良好，且与新鲜水闭路试验指标无明显差异，实现了选矿废水全部回用，提高了选矿厂经济效益。

Purification and Recycling of Wastewater from Lead-Zinc Ore Dressing Process

The quality of ore dressing wastewater from a lead-zinc polymetallic ore in Sichuan Province was evaluated, and a series of tests were performed for coagulation settlement, calcium removal, activated carbon adsorption and water recycling. The results show that according to the characteristics of the wastewater, a “Na₂CO₃ + PAC + PAM + C” approach was adopted to treat some mixed water samples. After treated using 100 mg/L Na₂CO3, 50 mg/L PAC, 1.5 mg/L PAM and 25 mg/L active carbon, the water was clear and colorless. The pH of the treated water was 8.31, COD_Cr was reduced to 38.05 mg/L, and a pollutant removal effect was significant. It is shown that all the indexes meet the standard (GB 25466-2010) for direct discharge, and the water quality meets the reuse requirements for mineral dressing. The treated water was recycled in a closed-circuit test to process the raw ore containing 0.6% Pb and 2.17% Zn, producing a lead concentrate grading 46.61% Pb, 1.85% Zn with Pb recovery of 83.81% and a zinc concentrate grading 56.20% Zn and 0.59% Pb, with Zn recovery of 92.04%. The beneficiation index is good and there is no obvious difference comparing with the index from closed-circuit with fresh water. It realizes the recycling of dressing wastewater and improves the economic benefit of the concentrator.