AOD不锈钢渣中Ca高效浸出及其间接碳酸化  

Efficient leaching and indirect carbonation of Ca from AOD stainless steel slag

作　　者：秦松 李俊国 王亚军 张建宝 彭丽杰 高爱民 QIN Song;LI Junguo;WANG Yajun;ZHANG Jianbao;PENG Lijie;GAO Aimin(College of Metallurgy and Energy,North China University Science and Technology,Tangshan 063210,Hebei,China)

机构地区：[1]华北理工大学冶金与能源学院,河北唐山063210

出　　处：《钢铁》2024年第8期200-209,共10页Iron and Steel

基　　金：中央引导地方科技发展资金资助项目(236Z3803G);河北省自然科学基金创新研究群体资助项目(E2022209093);唐山市科技计划资助项目(23130205E)。

摘　　要：钢渣中钙含量较高,利用钢渣替代天然矿石作为钙源进行碳酸化反应固存CO_(2)是一种前景广阔的固废利用与碳减排方法。采用间接湿法碳酸化,不仅能显著提高固碳效率,还可实现制备高纯度、高附加值的碳酸钙产品。以AOD不锈钢渣(AOD渣)为材料,首先对其进行化学分析和矿相分析,确定其具有较高的固碳潜力;然后基于间接湿法加速碳酸化过程,探究AOD渣中钙的高效浸出规律,采用正交试验和单因素试验探究浸出温度、盐酸物质的量浓度、液固比和搅拌转速对钙浸出效率的影响;最后进行碳酸化反应并利用X射线衍射仪(XRD)、扫描电子显微镜(SEM-EDS)和热重分析仪(TG-DTG)研究钙离子转化率、碳酸钙纯度和微观形貌。试验结果表明,盐酸物质的量浓度和液固比是影响钢渣中钙浸出的主要因素;随着浸出反应进行,硅基团溶解生成的硅酸胶体会阻碍AOD渣内部元素进一步溶出;升温和提高酸浓度可有效消除硅酸胶体的影响,促进钙溶出。以1.5 mol/L盐酸为浸出剂,在85℃、液固比为50 m L/g、搅拌速度为600 r/min的浸出条件下,AOD渣中钙的浸出率可达90.51%,通过热重试验分析,经间接碳酸化后制备的CaCO_(3)产物纯度为96.04%,钙的转化率达到83.96%。研究结果可为利用钢渣钙碳酸化固碳并协同制备高附加值CaCO_(3)产物的冶金固废高效资源化利用提供试验和理论基础。The Ca content in steel slag is relatively high.Utilizing steel slag as a substitute for natural ore as a Ca source for carbonation reactions to sequester CO_(2)is a promising method for both solid waste utilization and carbon reduction.The use of indirect wet carbonation not only significantly improves carbon fixation efficiency but also enables the production of high-purity,high-value-added calcium carbonate products.In this study,AOD stainless steel slag(AOD slag)was chosen as the material.Firstly,chemical analysis and mineralogical analysis were conducted to confirm its high carbon fixation potential.Subsequently,based on the indirect wet method to accelerate the carbonation process,the efficient leaching behavior of Ca from AOD slag was investigated.Orthogonal experiments and single-factor experiments were employed to explore the effects of leaching temperature,hydrochloric acid concentration,liquid-to-solid ratio,and stirring speed on Ca leaching efficiency.Finally,the carbonation reaction was carried out,and the transformation ratio of calcium ions,purity of calcium carbonate,and microstructure were studied using XRD,SEM-EDS,and TG-DTG.The results indicated that hydrochloric acid concentration and liquid-to-solid ratio were the main factors influencing Ca leaching from AOD slag.As the leaching reaction proceeded,the silicate colloids formed by the dissolution of Si-based groups hindered the further leaching of elements within AOD slag.Increasing temperature and acid concentration effectively eliminated the impact of silicate colloids,promoting Ca leaching.Under the conditions of leaching with 1.5 mol/L HCl at 85℃,a liquid-to-solid ratio of 50 mL/g,and a stirring speed of 600 r/min,the leaching ratio of Ca from AOD slag could reach 90.51%.Through thermogravimetric analysis,the purity of the CaCO_(3)product prepared after indirect carbonation was 96.04%,and the conversion ratio of Ca reached 83.96%.The results provide experimental and theoretical foundations for the efficient resource utilization of metall

关 键 词：AOD渣 钙 浸出 间接碳酸化 碳酸钙 

分 类 号：X757[环境科学与工程—环境工程]