降低高酸高铟预中和石膏渣含铟量的工艺研究  

Study on the Process of Reducing Indium Content in High Acid and High Indium Pre-neutralization Gypsum Slag

作　　者：陶家荣 潘辉 刘洪嶂 陆开臣 张泽林 TAO Jiarong;PAN Hui;LIU Hongzhang;LU Kaichen;ZHANG Zelin

机构地区：[1]云锡文山锌铟冶炼有限公司,云南文山663700

出　　处：《绿色矿冶》2023年第4期18-21,30,共5页Sustainable Mining and Metallurgy

摘　　要：湿法炼锌赤铁矿法回收铟的主要工艺流程为利用二氧化硫还原浸出低酸浸出渣中的铟,还原浸出后液酸度约30 g/L,需要预先中和使酸度降至10 g/L,然后加入碳酸钙中和沉铟、富集铟,沉铟渣经浸出、净化、萃取等工艺流程回收铟。预中和过程中产生的石膏渣会夹带部分铟,造成铟的损失。本文通过进行单因素试验,研究预中和液中Fe^(3+)浓度、终点酸度及反应时间等试验条件变化对预中和石膏渣含铟量、石膏渣沉降及过滤性能的影响。试验结果表明,由于In^(3+)与Fe^(3+)性质相似,在黄钠铁矾形成过程中,In^(3+)可部分取代Fe^(3+)形成晶间化合物进入渣中,因此Fe^(3+)含量越高,预中和石膏渣含铟量越高;终点酸度小于10 g/L时,溶液中的Al、Si易生成胶状物,与Ca化合生成钙铝黄长石沉淀,影响矿浆沉降性能及过滤性能,终点酸越低,石膏渣含铟量越高,过滤性能越差;随着反应时间的延长,溶液中Fe^(2+)氧化成Fe^(3+)的量越多,石膏渣含铟量逐渐增加。The main process of recovering indium by wet zinc smelting hematite method is to use sulfur dioxide to reduce and leach indium from low acid leaching residue.The acidity of the solution after reduction leaching is about 30 g/L,which needs to be neutralized in advance to reduce the acidity to 10 g/L,and then calcium carbonate is added to neutralize the precipitation of indium and enrich indium.The precipitation of indium residue is recovered by leaching,purification and extraction.The gypsum slag produced in the pre-neutralization process will entrain part of indium,resulting in the loss of indium.In this paper,the effects of Fe^(3+)concentration,end-point acidity and reaction time on the indium content,settlement and filtration performance of gypsum slag were studied by single factor test.The results show that,due to the similar properties of In^(3+)and Fe^(3+),In^(3+)can partially replace Fe^(3+)to form intergranular compounds and stably enter the slag during the formation of sodium jarosite.Therefore,the higher the content of Fe^(3+),the higher the indium content of pre-neutralized gypsum slag.When the end-point acidity is less than 10 g/L,Al and Si in the solution are easy to form gel,which react with Ca to form gehlenite precipitation,affecting the sedimentation performance and filtration performance of the slurry.The lower the end-point acidity is,the higher the indium content of gypsum slag is,and the worse the filtration performance is.With the extension of reaction time,the more Fe^(2+)is oxidized to Fe^(3+)in the solution,the more indium is contained in the gypsum slag.

关 键 词：湿法炼锌 赤铁矿法 碳酸钙 预中和 铟 石膏渣 

分 类 号：TF813[冶金工程—有色金属冶金] TF843.1