摘要
高镍锍是重要的铜镍冶炼中间产品。为了剖析其氧化过程的界面反应机理,本文研究了高镍锍在氨性溶液中的浸出原理及氧化行为。利用XRD、SEM、EDS等表征手段对高镍锍样品进行矿相识别,检测到含有六方硫化镍(Ni_(3)S_(2))、辉铜矿(Cu_(2)S)、磁铁矿(Fe_(3)O_(4))和镍铁合金(Ni_(3)Fe)。研究了暴露空气中和阳极极化条件下的高镍锍在氨性溶液中的浸出行为,采用金相显微镜观察高镍锍表面浸出前后的变化,利用XPS分析了浸出产物的组成。浸出结果显示Ni_(3)S_(2)、Cu_(2)S先后发生氧化,在原物相表面形成氧化层。利用工作界面对单矿相的锥形电极和多矿相电极进行阳极极化对比实验,Ni_(3)S_(2)在0 V(vs.SCE)附近开始发生氧化,先分解成NiS_(2)、Ni^(2+)和S^(0),NiS_(2)又进一步分解为Ni^(2+)和S^(0)。Cu_(2)S在0.3 V(vs.SCE)附近发生氧化,生成CuS和Cu_(2)O,在提高电位后进一步氧化生成Cu_(2)O、Cu(OH)_(2)、S^(0)。
High-grade nickel matte is an important intermediate product in copper-nickel smelting.In order to reveal the interfacial reaction mechanism in the oxidation process,the leaching principles and oxidation behaviors of highgrade nickel matte in ammoniacal solution were investigated.Heazlewoodite(Ni_(3)S_(2)),chalcocite(Cu_(2)S),magnetite(Fe_(3)O_(4))and ferronickel(Ni_(3)Fe)were detected after identifying the high-grade nickel matte samples by XRD,SEM and EDS.The leaching behavior of high-grade nickel matte in an ammoniacal solution was studied under exposure to air and anodic polarization conditions.The changes in high-grade nickel matte surfaces before and after the leaching process were observed by a metallographic microscope,and the composition of the leaching products was analyzed by XPS.The leaching results show that Ni_(3)S_(2) and Cu_(2)S are oxidized successively,forming an oxide layer on the surface of the initial phase.The contrast experiments of anode polarization between the conical electrode with the working interface of single mineral phase and the multi-phase electrode show that Ni_(3)S_(2) begins to oxidize near 0 V(vs.SCE),decomposing into NiS_(2),Ni^(2+)and S^(0),among which NiS_(2) further decomposes into Ni^(2+)and S^(0).Meanwhile,Cu_(2)S Oxidation occurs near 0.3 V(vs.SCE)to generate CuS and Cu_(2)O,and further oxidation to generate Cu_(2)O,Cu(OH)_(2) and S^(0) after increasing the potential.
作者
华晓鸣
朱纯成
许茜
HUA Xiaoming;ZHU Chuncheng*;XU Qian(Jiangsu Vocational College of Information Technology,School of Automobile and Intelligent Traffic,Wuxi 214153,Jiangsu,China;State Key Laboratory of Advanced Special Steel&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)
出处
《有色金属科学与工程》
CAS
北大核心
2024年第5期675-683,共9页
Nonferrous Metals Science and Engineering
基金
国家自然科学基金联合基金重点资助项目(U2002214)。
关键词
高镍锍
浸出
电化学
氧化机理
high-grade nickel matte
leaching
electrochemistry
oxidation mechanisms
