氧压酸浸工艺从烧结镍合金中选择性浸出镍和钴  

Selective leaching of nickel and cobalt from sintered nickel alloy by oxygen pressure acid leaching process

作　　者：王勇伟 常雪洁 程雨荷 覃文庆 韩俊伟 WANG Yong-wei;CHANG Xue-jie;CHENG Yu-he;QIN Wen-qing;HAN Jun-wei(School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China;Wanhua Chemical Group Co.,Ltd.,Yantai 265500,China)

机构地区：[1]School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China [2]Wanhua Chemical Group Co.,Ltd.,Yantai 265500,China

出　　处：《Journal of Central South University》2023年第12期4004-4020,共17页中南大学学报（英文版）

基　　金：Projects(52374293,52174269)supported by the National Natural Science Foundation of China;Projects(2022RC1123,2022GK4058)supported by the Science and Technology Innovation Program of Hunan Province,China;Project(2021JJ20062)supported by the Natural Science Foundation of Hunan Province,China。

摘　　要：本研究采用氧压酸浸工艺来提高烧结镍合金中有价金属的浸出率。技术分析表明,样品中的NiO和被Ni_(2)O_(3)包裹的NiO阻碍了常压酸浸过程中镍的进一步溶解。氧压酸浸工艺可将镍的氧化物转化为可溶性的硫酸镍。热力学分析表明,在pH<6.26、温度>146℃和电位>0.20 V的体系中,烧结镍合金中的大部分镍和钴能以离子的形式溶解在溶液中,而大部分铁则水解形成Fe_(2)O_(3)进入浸出渣。优化浸出条件为:H_(2)SO_(4)浓度150 g/L,温度180℃,氧分压2 MPa,液固比10 mL/g,搅拌速度400 r/min,时间150 min。在此条件下,Ni、Co和Fe的浸出率分别为97.42%、96.30%和10.05%。反应动力学研究表明,镍的浸出过程受表面化学控制模型支配,表观活化能为43.73 kJ/mol。这项工作为从烧结镍合金中高效浸出镍提供了一种可行且环保的方法。In this work,oxygen pressure acid leaching is implemented to augment the leaching efficiency of valuable metals from sintered nickel alloy.Techniques investigation shows that NiO in the sample and NiO coated by Ni_(2)O_(3)impede the ongoing dissolution of nickel during atmospheric acid leaching.The nickel oxides undergo conversion into soluble nickel sulfate via oxygen pressure acid leaching.Thermodynamic analysis indicates that in the system of pH<6.26,temperature>146℃and potential>0.20 V,a substantial portion of both nickel and cobalt dissolved into the solution as metal ions,while most of the iron is hydrolyzed to Fe_(2)O_(3)in residue.The optimized leaching conditions are:H_(2)SO_(4)concentration of 150 g/L,leaching temperature of 180℃,oxygen partial pressure of 2 MPa,liquid-to-solid ratio of 10 mL/g,stirring rate of 400 r/min,and time of 150 min.Given these circumstances,the leaching efficiencies of Ni,Co and Fe were 97.42%,96.30%and 10.05%,correspondingly.Reaction kinetics studies indicate that the leaching process of nickel was dictated by a controlled model of surface chemistry,featuring an apparent activation energy of 43.73 kJ/mol.This study offers a viable and environmentally-friendly methodology for the leaching of nickel from sintered nickel alloy.

关 键 词：镍浸出 氧压酸浸 表面钝化 热力学分析 XPS分析 

分 类 号：TF815[冶金工程—有色金属冶金] TF816