石灰石中和水解沉铟及二水硫酸钙结晶行为研究

Limestone Neutralization and Hydrolysis of Indium and Crystallization Behavior of CaSO4·2H2O

针对锌浸渣还原浸出液中铟的回收问题,利用石灰石中和还原浸出液中游离的硫酸,调节还原浸出液的pH值使铟发生水解反应进行沉淀。单因素实验分别考察了石灰石中和终点pH值、反应时间以及反应温度对铟沉淀行为的影响。单因素实验结果表明,调节还原浸出液的pH值使铟发生水解反应的最佳实验条件如下:溶液终点pH=4.5、反应时间120 min、反应温度85℃;在该条件下添加晶种5 g·L^-1、搅拌转速400 r·min^-1对锌浸渣还原浸出液开展了综合实验研究,实验结果表明,铟的沉淀率达到了98%,锌的损失率为2.9%。铟在渣中得到了充分的富集,沉铟渣中铟含量达到了3600 g·t^-1。通过电感耦合等离子体-质谱法(ICP-MS)、X射线衍射(XRD)和扫描电子显微镜-能谱分析(SEM-EDS)分析表明,锌浸渣还原浸出液中铟沉淀接近完全,沉铟渣的主要成分为CaSO4·2H2O和In(OH)3,SEM分析表明In(OH)3呈散乱状分布在CaSO4·2H2O的表面。

In view of the problem of indium recovery from leaching solution of zinc leaching residue,the reaction behavior of precipitation of indium by hydrolysis of lime solution pH value was studied.The effects of end point pH,reaction time and reaction temperature on indium precipitation behavior were investigated.The experimental results showed that the optimum reaction conditions were as follows:the end point of solution was pH=4.5,reaction time was 120 min,reaction temperature was 85℃;under this condition,the comprehensive experimental study of zinc leaching residue reduction leaching solution was carried out by adding 5 g·L^-1 crystal seeds and 400 r·min^-1 stirring speed.The experimental results showed that the precipitation rate of indium reached 98%,and the loss rate of zinc was 2.9%.Indium was fully enriched in the residue,and the content of indium in the sediment reached 3600 g·t^-1.The results of inductively coupled plasma-mass spectrometry(ICP-MS),X-ray diffraction(XRD)and scanning electron microscope-energy dispersive spectrometer(SEM-EDS)analysis showed that the precipitation of indium in the reduction leaching solution of zinc leaching residue was nearly completed.The main components of indium precipitation residue were CaSO4·2H2O and In(OH)3.SEM analysis showed that In(OH)3 was scattered on the surface of CaSO4·2H2O.