低钙钢渣中钙、铁分离及回收利用  

Separation and recovery of calcium and iron from low calcium steel slag

作　　者：赵树海 金永丽[1,2,3,4] 郭嘉诚 张凯旋 蒋锦韬 ZHAO Shuhai;JJIN Yongli;GUO Jiacheng;ZHANG Kaixuan;JIANG Jintao(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,Nei Mongol,China;Key Laboratory of Integrated Exploitation of Bayan-Obo Multi-Metal Resources,Inner Mongolia University of Science and Technology,Baotou 014010,Nei Mongol,China;Inner Mongolia Autonomous Region Carbon Neutrality Collaborative Innovation Center,Inner Mongolia University of Science and Technology,Baotou 014010,Nei Mongol,China;Collaborative Innovation Center of Integrated Exploitation of Bayan-Obo Multi-Metal Resources,Inner Mongolia University of Science and Technology,Baotou 014010,Nei Mongol,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]内蒙古科技大学白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014010 [3]内蒙古科技大学内蒙古自治区碳中和协同创新中心,内蒙古包头014010 [4]内蒙古科技大学白云鄂博共伴生矿资源高效综合利用省部共建协同创新中心,内蒙古包头014010

出　　处：《中国冶金》2023年第10期125-132,共8页China Metallurgy

基　　金：国家自然科学基金资助项目(52064044);省部科技重大专项资助项目(2021ZD0016);内蒙古自治区自然科学基金资助项目(2023MS05033)。

摘　　要：针对中国钢铁行业所面临的钢渣综合利用和CO_(2)减排这两大迫切需求,研究了以低钙钢渣为原料、醋酸为提取剂浸出钙离子的方法。使钙、铁分离后,再利用钙浸出液碳酸化固定CO_(2)制备轻质碳酸钙,并磁选回收浸出渣中的铁元素。借助ICP、XRD、XRF、TG-DSC等手段,对钢渣中钙和铁元素浸出效果、浸出渣磁选效果以及沉淀CaCO_(3)的纯度进行表征。结果表明,在钢渣粒径为[58,74]μm、浸出时间为1 h、固液比为1∶10、酸浓度为2 mol/L、浸出温度为40℃的条件下,钙铁分离的效果最佳。浸出液改性后通入模拟烟气,每t转炉渣能固定103.72 kg CO_(2),可回收240.1 kg CaCO_(3),CaCO_(3)纯度可达到98.18%。在0.14 T的磁场强度下浸出渣的磁选效果最好,富铁矿物回收量可达每t钢渣201 kg,同时铁品位也能达到57.3%。固碳产物碳酸钙可以作为填充剂用于橡胶、塑料行业,富铁矿物可返回钢铁生产流程。研究结果可为钢渣的有效利用提供参考。Aiming at the urgent needs for comprehensive utilization of steel slag and emission reduction of CO_(2) faced by the iron and steel industry of China,calcium ions leaching was studied by choosing low calcium steel slag as raw material and acetic acid as extraction agent.After calcium and iron separation,calcium leaching solution was used to carbonate fixed CO_(2) to produce light calcium carbonate,and magnetic separation of iron from the leaching slag.By means of ICP,XRD,XRF,TG-DSC and other means,the leaching effect of calcium and iron in steel slag,the magnetic separation effect of leaching slag and the purity of precipitated CaCO_(3) were characterized.The results show that under the conditions of particle size[58,74]μm,leaching time 1 h,solid-liquid ratio 1∶10,acid concentration 2 mol/L and leaching temperature 40℃,the separation effect of calcium and iron is the best.After the leaching solution is modified,simulated flue gas is introduced,and 103.72 kg CO_(2) can be fixed per ton of converter slag,240.1 kg CaCO_(3) can be recovered,and the purity of CaCO_(3) can reach 98.18%.Under the magnetic field intensity of 0.14 T,the magnetic separation effect of leaching slag is the best.The recovery amount of rich iron minerals can reach 201 kg per ton of steel slag,and the iron grade can also reach 57.3%.Calcium carbonate,a product of carbon fixation,can be used as filler in rubber and plastic industries,and iron rich minerals return to the steel production process,which can provid a reference for the effective utilization of steel slag.

关 键 词：低钙钢渣 钙、铁分离 铁元素回收 固碳 沉淀碳酸钙 

分 类 号：TF56[冶金工程—钢铁冶金] TQ132.32[化学工程—无机化工] X757[环境科学与工程—环境工程]