电解锰阳极泥有机还原浸出回收锰和铅的研究

Recovery of Manganese and Lead from Manganese Electrowinning Anode Slime by Reduction Leaching with Organic Reductants

选用玉米秆、木薯淀粉、甘蔗渣和废糖蜜4种有机还原剂对某电解锰阳极泥进行了还原浸出试验研究,并对有机还原剂浸出锰阳极泥的机理进行了探讨。结果表明,在获得相同锰浸出率条件下,还原剂用量排序如下:淀粉<玉米秆<废糖蜜<甘蔗渣(水解)。玉米秆用量虽比淀粉大,但其来源广价格低,在适宜水解和浸出条件下,阳极泥锰浸出率可达97.01%。浸出液经除杂后,净化液锰含量达40.96 g/L,锰回收率92.29%。净化液经碳化结晶可制得碳酸锰产品,产品达到行业标准,锰回收率92.10%。浸出渣经浸出除杂处理,铅品位可提高到60.79%,达到三级铅精矿要求,铅回收率为82.52%。

Four kinds of organic reductants, including cornstalk, tapioca starch, bagasse and molasses were selected, respectively, for tests on reduction leaching of manganese electrowinning anode slime, and its corresponding mechanism was also investigated. Test results showed that in order to get the same leaching rate of Mn, the dosages of four reductants were in the following ascending order： tapioca starch〈cornstalk〈discarded molasse〈bagasse. Although with more dosage than tapioca starch, cornstalk is characterized by low cost and wide availability. Using cornstalk as organic reductant, with an optimized hydrolysis and leaching conditions, the leaching rate of manganese from anode slime can reach 97.01%. Purification of the resulted leachate can produce a solution containing 40.96 g/L Mn, leading to the Mn recovery up to 92.29%. Then, carbonization of the purified solution produces MnCO3（ industrial grade） with Mn recovery of 92.10%. And further removal of impurities from the reduction leaching residue can result in 82.52% Pb recovery to a third-grade Pb concentrate grading 60.79% Pb.