氯化铵浸出镁还原渣提钙工艺  

Calcium recovery from ammonium chloride leaching magnesium reduction slag process

作　　者：毛帅东 刘燕 张廷安[1,2] MAO Shuai-dong;LIU Yan;ZHANG Ting-an(Metallurgy School of Northeastern University,Shenyang 110819,China;Key Laboratory of Ecological Metallurgy of Polymetallic Symbiotic Minerals of Ministry of Education,Shenyang 110819,China)

机构地区：[1]东北大学冶金学院,辽宁沈阳110819 [2]多金属共生矿生态化冶金教育部重点实验室,辽宁沈阳110819

出　　处：《中国有色冶金》2022年第2期39-43,49,共6页China Nonferrous Metallurgy

基　　金：国家重点研发计划(2017YFC0210403-04);国家自然科学基金(U1760120);国家重点研发计划(2017YFC0210404)。

摘　　要：皮江法炼镁过程产生大量的镁还原渣,堆存过程中易造成土壤碱化和板结等环境问题,在消纳方面主要用于制备水泥、建筑砖和脱硫剂,综合利用价值低。基于此,提出氯化铵浸出镁还原渣工艺路线,该工艺可以提取和分离镁还原渣中的钙、硅等元素,使镁还原渣成为钙源和硅源,实现镁还原渣的零排放和高值化利用。现针对工艺中的浸出过程,研究在各单因素条件下钙的浸出率及浸出渣物相,得出以下结论:氯化铵能对镁还原渣中钙进行选择性浸出,其浸出率与反应温度、氯化铵浓度、液固体积质量比等密切相关;浸出率随氯化铵浓度、液固体积质量比的增大而增大,随温度的升高先增加后减小;较佳浸出工艺条件为反应温度25℃、氯化铵浓度15%、液固体积质量比40∶1,该条件下,钙的浸出率达到88.7%;浸出渣物相主要为氧化镁、碳酸钙、二氧化硅等物质,通过洗涤工序可以获得较为纯净的含硅原料。Quite a large quantity of magnesium reduction slag is generated in the Pedgeon process of magnesium smelting,during the stockpiling process of the slag,such issues as soil alkalization and hardening,etc.will arise,as for its disposal and consumption,it is mainly used for producing cement,building-use brick and desulfurization agent,with low comprehensive use value.The process route of ammonium chloride leaching of magnesium reduction slag are put forward.The process can be used to extract and separate calcium,silicon and other elements in the magnesium reduction slag,to make the magnesium slag become the calcium source and silicon source,so as to achieve the zero emission and high value utilization of the magnesium slag.In this paper,aiming at the leaching procedure in the process,the calcium leaching efficiency and the phase of leaching residue under various single-factor conditions are studied,and the following conclusions are obtained:the ammonium chloride is able to make selective leaching for the calcium in the magnesium reduction slag,the leaching efficiency is closely related to reacting temperature,ammonium chloride concentration,liquid-solid ratio,etc.;the leaching efficiency increases with the increase of ammonium chloride concentration and liquid-solid ratio,it increases first and then decreases with the rising temperature;the better leaching process conditions are as follows:reacting temperature of 25℃,ammonium chloride concentration of 15%,and liquid-solid ratio of 40∶1,under which,the calcium leaching efficiency can be as high as 88.7%;the phase of the leaching residue is mainly composed of magnesium oxide,calcium carbonate,silicon dioxide and other substances,from which the purer silicon-bearing raw material can be got by scrubbing process.

关 键 词：皮江法炼镁 镁还原渣 综合利用 钙回收 硅回收 氯化铵浸出 

分 类 号：TF822[冶金工程—有色金属冶金] TF827.1