用浸出工艺回收酸性矿山废水沉淀渣中金属元素

酸性矿山废水沉淀渣的处置一直是废水处理工程面临的难题。以广东省大宝山矿槽对坑尾矿库外排废水处理厂产生的沉淀渣为例，开展沉淀渣中有价金属元素酸浸与回收试验。淀渣铁、锰、铜、锌、镍、铅品位分别为40 919.6，14 320.6，4 681.4，7 557.4，149.3，360.9 g/t，杂质成分主要为石英、方解石。在硫酸浓度为20%、固液比为0.33 g/mL、浸出时间为8 h、浸出温度为30 ℃条件下，铜、锌、镍、铅、锰和铁的浸出率分别为99.49%、21.41%、51.21%、4.45%、55.86%、34.25%。采用硫酸浸出工艺回收沉淀渣中有价金属元素在技术经济上可行，同时可缓解废水处理厂的环保压力。

Recovery of Valuable Metal Elements from Acid Mine Drainage Sludge

The disposition of Acid Mine Drainage ( AMD) sludge has become a serious problem in wastewater treatment industry for a long period. An AMD sludge sample was taken from the wastewater treatment plant of the Duikeng tailings reser-voir,Dabaoshan Mine,Guangdong Province,and an experiment was conducted to recover valuable metals from the sludge by sulfuric acid leaching method. There is 40 919. 6 g/t Fe,14 320. 6 g/t Mn,4 681. 4 g/t Cu,7 557. 4 g/t Zn,149. 3 g/t Ni, 360. 9 g/t Pb,the impurity components are mainly quartz,calcite. In sulfuric acid concentration is 20%,solid-liquid ratio is 0. 33 g/mL,the leaching time of 8 h,leaching temperature 30 ℃,the copper,zinc,nickel,lead,manganese and iron leaching rate were 99. 49%,21. 41%,51. 21%,4. 45%,55. 86% and 34. 25%. Using sulfuric acid leaching process recycling valuable metals element in precipitation slag economically feasible in technology,at the same time,the pressure of the wastewater treat-ment plant of environmental protection was alleviated.