粉煤灰制备硅铁合金并富集氧化铝的试验研究  

Carbon thermal reduction is used to enrich alumina from fly ash and prepare ferrosilicon alloy

作　　者：夏文杰 金永丽[1,2,3,4] 张梧祯 张凯悦 Xia Wenjie;Jin Yongli;Zhang Wuzhen;Zhang Kaiyue(College of Rare Earth Industry,Inner Mongolia University of Science and Technology,Baotou 014010,Inner Mongolia,China;Inner Mongolia Key Laboratory of Integrated Exploitation of Bayan-Obo Multi-Metal Resources,Baotou 014010,Inner Mongolia,China;Inner Mongolia Autonomous Region Carbon Neutrality Collaborative Innovation Center,Baotou 014010,Inner Mongolia,China;National and Local Joint Engineering Research Center of Integrated Exploitation of Bayan-Obo Associated Mineral Waste Resources,Baotou 014010,Inner Mongolia,China)

机构地区：[1]内蒙古科技大学稀土产业学院,内蒙古包头014010 [2]内蒙古自治区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]内蒙古自治区碳中和协同创新中心,内蒙古包头014010 [4]白云鄂博共伴生矿废弃物资源综合利用国家地方联合工程研究中心,内蒙古包头014010

出　　处：《钢铁钒钛》2024年第5期108-115,共8页Iron Steel Vanadium Titanium

基　　金：国家自然科学基金项目(52064044);内蒙古自然科学基金项目(2023MS05033);白云鄂博伴生矿战略资源非常规富集技术研发平台内蒙古自治区直属高校基本科研业务费项目(2023RCTD002)。

摘　　要：在实验室条件下对粉煤灰进行了碳热还原制备硅铁合金并富集氧化铝试验,回收粉煤灰中的Si、Fe、Al等元素。研究发现,反应过程中,当温度升高,生成的硅铁合金中硅的含量随之升高。当配碳量增加,粉煤灰中莫来石相的Al-O-Si键更容易分解,还原成氧化铝和二氧化硅。碳热还原时加入Fe_(2)O_(3)不仅能够降低还原温度,而且莫来石相中的二氧化硅更易被还原成硅,并与金属铁结合生成硅铁合金,这为后续硅铁合金和氧化铝的分离创造了条件。该工艺将粉煤灰、Fe_(2)O_(3)和煤粉以5∶4∶2的质量比进行配料,使用电阻炉在1600℃的条件下进行焙烧,保温2 h后随炉冷却,通过破碎、筛分、研磨、磁选处理还原后的物料,得到硅铁合金初级产品及氧化铝含量较高的尾渣,硅的回收率达到76.44%,铝的实际回收率达到93.96%。The comprehensive utilization of fly ash is a solid waste industry with high technical content and application potential,which integrates environmental protection and resource recycling.Ferrosilicon alloy was prepared by carbothermal reduction of fly ash under laboratory conditions and alumina was enriched to recover Si,Fe,Al and other elements in fly ash.It was found that the content of silicon in the ferrosilicon alloy increased with the increase of temperature during the reaction.When the carbon content increases,the Al-O-Si bond of the mullite phase in the fly ash is more easily decomposed and reduced to alumina and silica.The carbothermal reduction is carried out under the condition of adding Fe_(2)O_(3).After adding Fe_(2)O_(3),not only the temperature of carbothermal reduction can be reduced,but also the silicon dioxide in mullite phase is easier to be reduced to silicon,and combined with metal iron to form ferrosilicon alloy,which creates conditions for the subsequent separation of ferrosilicon alloy and alumina.In this process,fly ash,iron oxide and pulverized coal are mixed at a mass ratio of 5∶4∶2,and roasted in a resistance furnace at 1600℃.After holding for two hours,they are cooled with the furnace.After crushing,screening,grinding and magnetic separation,the reduced materials are treated to obtain ferrosilicon alloy primary products and tailings with high alumina content.The desilication rate reaches 76.44%,and the recovery rate of aluminum reaches 93.96%.

关 键 词：硅铁合金 氧化铝 粉煤灰 碳热还原 磁选 

分 类 号：TF645[冶金工程—钢铁冶金] X757[环境科学与工程—环境工程]