湿法炼锌溶液中镁的水热结晶行为  

Hydrothermal crystallization of magnesium in zinc hydrometallurgical process

作　　者：熊甲成 李存兄[1] 张利波[1] 李世伟[1] 夏力 吴远桂 吉文斌 林晓坦 XIONG Jia-cheng;LI Cun-xiong;ZHANG Li-bo;LI Shi-wei;XIA Li;WU Yuan-gui;JI Wen-bin;LIN Xiao-tan(Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学冶金与能源工程学院,昆明650093

出　　处：《中国有色金属学报》2021年第6期1601-1610,共10页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(52064034,51664038,51474117);云南省重点研发计划资助项目(2018BA078)。

摘　　要：利用高温下金属硫酸盐易结晶沉淀的化学原理,开展了水热结晶脱镁行为研究,研究了初始Zn^(2+)浓度、反应温度、反应时间、初始SO_(4)^(2-)浓度、初始硫酸浓度对水热结晶脱镁过程的影响规律。结果表明:在初始Zn^(2+)和Mg^(2+)浓度分别为120 g/L和25 g/L、反应温度为200℃、反应时间3 h、初始SO_(4)^(2-)浓度为145g/L、初始硫酸浓度为5×10^(-4)g/L的条件下,镁以Mg SO_(4)·6H_(2)O的形式结晶析出,其脱出率可达到94.42%。升高反应温度以及初始SO_(4)^(2-)和Mg^(2+)的浓度、延长结晶时间均有利于提高镁的结晶脱出率。受同离子效应影响,当Zn^(2+)浓度由0增大至120 g/L可有效降低Mg^(2+)的结晶析出温度,并使Mg^(2+)的结晶脱出率增大40%以上,相近的ZnSO_(4)·x H_(2)O和Mg SO_(4)·x H_(2)O微观结构抑制了水热条件下Mg SO_(4)·6H_(2)O向Mg SO_(4)·H_(2)O的转变。受初始硫酸浓度及溶液中HSO_(4)-电离平衡引起SO_(4)^(2-)和H+浓度变化的影响,Mg^(2+)的结晶析出率随初始硫酸浓度的升高先增大后减小。水热结晶除镁法可实现湿法炼锌含镁硫酸锌溶液中Mg^(2+)的清洁高效脱出。The hydrothermal crystallization of magnesium sulfate was studied by using the chemical principle of easy crystallization precipitation of metal sulfate in high temperature.The effect of initial concentration of Zn^(2+),reaction temperature,reaction time,initial concentration of SO_(4)^(2-) and initial concentration of sulfuric acid on hydrothermal crystallization process of de-magnesia was studied.The results show that,under the conditions of initial Zn^(2+) and Mg^(2+) concentrations of 120 g/L and 25 g/L,reaction temperature of 200℃,reaction time of 3 h,and initial SO_(4)^(2-) concentration of 145 g/L,magnesium is crystallized out in the form of MgSO_(4)·6 H_(2)O,with release rate of 94.42%.Increasing the reaction temperature and the initial concentration of SO_(4)^(2-) and Mg^(2+),and prolonging the crystallization time are beneficial to improving the crystallization rate of magnesium.Under the influence of the same ion effect,when the concentration of Zn^(2+)increases from 0 to 120 g/L,the crystallization temperature of Mg^(2+) can be effectively reduced and the crystallization rate of Mg^(2+)increases by more than 40%.The similar microstructures of ZnSO_(4)·x H_(2)O and Mg SO_(4)·x H_(2)O prevent the transformation of MgSO_(4)·6 H_(2)O into Mg SO_(4)·H_(2)O under hydrothermal conditions.Under the influence of the initial sulfuric acid concentration and the concentration changes of SO_(4)^(2-) and H+caused by the equilibrium of HSO_(4)-ionization in the solution,the crystallization rate of Mg^(2+)first increases and then decreases with the increase of the initial sulfuric acid concentration.The hydrothermal crystallization method of magnesium removal can realize the clean and efficient removal of Mg^(2+) from zinc sulphate solution containing magnesium.

关 键 词：湿法炼锌 水热法 除镁 结晶 结晶脱出率 

分 类 号：TF813[冶金工程—有色金属冶金]