Hydrometallurgical extraction of zinc from CaO treated EAF dust in ammonium chloride solution
Hydrometallurgical extraction of zinc from CaO treated EAF dust in ammonium chloride solution
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DOI：
10.1016/j.jhazmat.2015.09.020
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发表时间：
2016-01-25
影响因子：
13.6
通讯作者：
Nagasaka, Tetsuya
中科院分区：
文献类型：
--
作者：
Miki, Takahiro;Chairaksa-Fujimoto, Romchat;Nagasaka, Tetsuya
电弧炉烟尘和电弧炉烟尘中的锌主要以锌铁和氧化锌的形式存在。虽然氧化锌可以简单地溶解在酸性或碱性溶液中，但很难溶解锌铁(2)O4。在我们之前的工作中，我们介绍了一种名为“CaO处理”的工艺，这是一种初步的火法冶金工艺，旨在将电炉粉尘中的锌铁(2)O4转化为氧化锌和Ca2Fe2O5。在CaO处理过程中，卤素和其他重金属被有利地蒸发，锌和铁没有必要的蒸发损失，CaO处理后的粉尘主要由氧化锌和Ca2Fe2O5组成，没有问题的ZnFe2O4化合物。在本工作中，研究了氧化钙处理后的粉尘中锌对铁和钙的选择性浸出。考察了温度、反应时间和NH4Cl浓度对溶解行为的影响。CaO处理后的粉尘中的大部分锌在70℃下用2M Na4Cl浸取2 h后，只有约20%的钙在NH4Cl溶液中被浸出。然而，铁没有溶解，在残渣中以Ca2Fe2O5的形式存在。证实了用NH4Cl溶液可以有效地回收锌。(C)2015爱思唯尔B.V.保留所有权利。
Zinc in Electric Arc Furnace dust or EAF dust mainly exists as ZnFe(2)O4 and ZnO. While ZnO can be simply dissolved into either an acidic or alkaline solution, it is difficult to dissolve ZnFe(2)O4. In our previous work, we introduced a process called "CaO treatment", a preliminary pyrometallurgical process designed to transform the ZnFe(2)O4 in the EAF dust into ZnO and Ca2Fe2O5. The halogens and others heavy metals were favorably vaporized during CaO treatment with no essential evaporation loss of zinc and iron, leaving CaO treated dust which consisted mainly of ZnO and Ca2Fe2O5 and no problematic ZnFe2O4 compound. In this work, the selective leaching of zinc over iron and calcium in the CaO treated dust was investigated using an NR4Cl solution. The effects of temperature, reaction time and NH4Cl concentration on dissolution behavior were examined. While most of the zinc in the CaO treated dust was extracted after 2 h at 70 degrees C with 2 M Na4Cl, only about 20% of calcium was leached in NH4Cl solution. However, the iron did not dissolve and remained as Ca2Fe2O5 in residue. It was confirmed that zinc can be effectively recovered using NH4Cl solution. (C) 2015 Elsevier B.V. All rights reserved.