Hydrometallurgical recovery of zinc and lead from electric arc furnace dust using mononitrilotriacetate anion and hexahydrated ferric chloride.
Hydrometallurgical recovery of zinc and lead from electric arc furnace dust using mononitrilotriacetate anion and hexahydrated ferric chloride.
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DOI：
10.1016/s0304-3894(01)00394-6
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发表时间：
2002-04
影响因子：
13.6
通讯作者：
Nathalie Leclerc;Eric Meux;J. Lecuire
中科院分区：
文献类型：
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作者：
Nathalie Leclerc;Eric Meux;J. Lecuire
这项工作的目的是研究处理电弧炉粉尘（EAFD）的新湿法冶金工艺在实验室规模的可行性。所提出的工艺旨在从 EAFD 中提取锌和铅，而不破坏铁氧化物基质。因此，这种材料可以被钢铁行业回收利用。与样品的来源无关，这些废物中存在的主要矿物形态是 Fe3O4、ZnO、ZnFe2O4 和 PbOHCl。拟议的工艺包括基于锌和铅选择性浸出的废物湿法冶金处理。最初，利用螯合剂次氮基三乙酸根阴离子 (NTA3-) 作为质子化形式 HNTA2- 进行浸出。在室温下用试剂摩尔溶液处理五个 EAFD 样品一小时，导致 ZnO 完全浸出。在所有情况下，溶解的铁不超过 3wt.%。锌和铅的回收是通过用 Na2S4 四硫化钠 2M 溶液沉淀金属硫化物来进行的。这些金属硫化物可作为冶金原料，螯合剂经pH调节后可在工艺中重复使用。对浸出残渣进行归一化浸出试验AFNOR X31-210，结果显示所有样品均符合危险废物填埋验收标准。然而，残渣中含有大量的锌（ZnFe2O4）。提取锌元素需要破坏铁素体结构。在此过程中，ZnFe2O4经FeCl3·6H2O处理。该反应包括颗粒 O2−/Cl− 交换，从而将锌回收为 ZnCl2，将铁回收为赤铁矿 Fe2O3。这些产物的分离是通过简单的水浸来完成的。在 150°C 下处理 8 小时，摩尔比为 FeCl3·6H2O/ZnFe2O4 等于 10 时，所有的锌都被提取出来。最终的固体残留物已浓缩为铁，可用于钢铁工业。
The purpose of this work was to study the feasibility at laboratory-scale of a new hydrometallurgical process for treating electric arc furnace dusts (EAFD). The proposed process is intended to extract zinc and lead from EAFD without destroying the iron oxides matrix. So, this material can be recycled by the steel industry. Independently of the origin of the samples, major mineralogical forms present in these wastes are Fe3O4, ZnO, ZnFe2O4and PbOHCl. The proposed process consists of a hydrometallurgical treatment of wastes based on selective leaching of zinc and lead. Initially, a leaching is carried out utilizing a chelating agent, nitrilotriacetate anion (NTA3−), as the protonated form HNTA2−. Treatment of five EAFD samples for an hour at room temperature with a molar solution of reagent results in total leaching of the ZnO. In all cases the solubilized iron does not exceed 3wt.%. The recovery of zinc and lead is performed by precipitation of metallic sulfides with a solution of Na2S4sodium tetrasulfide 2M. These metallic sulfides can be used as metallurgical raw materials and the chelating reagent can be reused in the process after pH adjustment. The results of the normalized leaching test AFNOR X31-210 conducted on the leaching residues, shows that all the samples meet acceptance thresholds for hazardous wastes landfill. However, the residues contain a considerable amount of zinc as ZnFe2O4. The extraction of the zinc element requires the destruction of the ferrite structure. In this process, ZnFe2O4is treated by FeCl3·6H2O. The reaction consists in a particle O2−/Cl−exchange allowing the recovery of zinc as ZnCl2and iron as hematite Fe2O3. The separation of these products is accomplished by simple aqueous leaching. All of the zinc is extracted in a 8h treatment at 150°C with a molar ratio FeCl3·6H2O/ZnFe2O4equal to 10. Ultimate solid residues, which have been concentrated in iron, can be oriented towards the steel industry.