Sethurajan Manivannan, Huguenot David, Lens Piet N L, Horn Heinrich A, Figueiredo Luiz H A, van Hullebusch Eric D
Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454, Marne-la-Vallée, France; UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands; Universidade Federal de Minas Gerais, NGqA-CPMTC, Instituto de Geociências, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454, Marne-la-Vallée, France.
J Environ Manage. 2016 Jul 15;177:26-35. doi: 10.1016/j.jenvman.2016.03.041. Epub 2016 Apr 10.
Zinc plant purification residue (ZPR), a typical Zn-hydrometallurgical waste, was collected from the Três Marias Zn plant (MG, Brazil). ZPR was characterized for its metal content and fractionation, mineralogy, toxicity and leachability. Toxicity characteristics leaching procedure (TCLP) and European Community Bureau of Reference (BCR) sequential extraction results revealed that this ZPR displays high percentages of metals (Cd, Cu, Zn and Pb) in the highly mobilizable fractions, increasing its hazardous potential. Bulk chemical analysis, pH dependent leaching and acid (H2SO4) leaching studies confirm that the ZPR is polymetallic, rich in Cd, Cu and Zn. The sulfuric acid concentration (1 M), agitation speed (450 rpm), temperature (40 °C) and pulp density (20 g L(-1)) were optimized to leach the maximum amount of heavy metals (Cd, Cu and Zn). Under optimum conditions, more than 50%, 70% and 60% of the total Cd, Cu and Zn present in the ZPR can be leached, respectively. The metals in the acid leachates were investigated for metal sulfide precipitation with an emphasis on selective Cu recovery. Metal sulfide precipitation process parameters such as initial pH and Cu to sulfide ratio were optimized as pH 1.5 and 1:0.5 (Cu:sulfide) mass ratio, respectively. Under optimum conditions, more than 95% of Cu can be selectively recovered from the polymetallic ZPR leachates. The Cu precipitates characterization studies reveal that they are approximately 0.1 μm in diameter and mainly consist of Cu and S. XRD analysis showed covellite (CuS), chalcanthite (CuSO4·5H2O) and natrochalcite (NaCu2(SO4)2(OH)·H2O) as the mineral phases. ZPRs can thus be considered as an alternative resource for copper production.
锌厂净化残渣（ZPR）是一种典型的湿法炼锌废物，取自巴西米纳斯吉拉斯州的特雷斯玛丽亚斯锌厂。对ZPR进行了金属含量与分级、矿物学、毒性和浸出性等方面的表征。毒性特征浸出程序（TCLP）和欧洲共同体标准局（BCR）连续萃取结果表明，这种ZPR在高迁移性组分中显示出高比例的金属（镉、铜、锌和铅），增加了其潜在危害性。全化学分析、pH依赖性浸出和酸（硫酸）浸出研究证实，ZPR是多金属的，富含镉、铜和锌。对硫酸浓度（1M）、搅拌速度（450转/分钟）、温度（40℃）和矿浆密度（20克/升）进行了优化，以浸出最大量的重金属（镉、铜和锌）。在最佳条件下，ZPR中分别有超过50%、70%和60%的总镉、铜和锌可以被浸出。对酸浸出液中的金属进行了金属硫化物沉淀研究，重点是选择性回收铜。优化了金属硫化物沉淀工艺参数，如初始pH值和铜与硫化物的比例，分别为pH 1.5和1:0.5（铜:硫化物）质量比。在最佳条件下，超过95%的铜可以从多金属ZPR浸出液中选择性回收。铜沉淀物的表征研究表明，它们的直径约为0.1μm，主要由铜和硫组成。X射线衍射分析显示，矿物相为辉铜矿（CuS）、胆矾（CuSO4·5H2O）和水绿铜矾（NaCu2(SO4)2(OH)·H2O）。因此，ZPR可被视为铜生产的替代资源。
