广西高铁赤泥高值化综合利用途径  

Path analysis of high-value utilization of iron-rich red mud from Guangxi alumina refinery

作　　者：吴小华 李雯霏 WU Xiaohua;LI Wenfei(Guilin University of Technology at Nanning,Nanning 532100,China)

机构地区：[1]桂林理工大学南宁分校,广西南宁532100

出　　处：《中国有色冶金》2023年第2期104-115,共12页China Nonferrous Metallurgy

摘　　要：广西是氧化铝的主要生产基地,年产生赤泥约1500万t,所产赤泥含铁高,且富含“三稀”金属,具有较大资源回收价值。实现赤泥高值化综合利用的4个目标是碱的无害化处理,铁、铝有效分离,富集“三稀”元素,低成本处理。本文综合分析目前赤泥综合利用技术现状,并考虑广西丰富的农林资源,提出采用生物质气还原焙烧高铁赤泥-溶出并磁选的工艺路线。热解气炭联产技术可以将广西丰富的农林废弃物转变为高质量的可燃气体,气化的副产品是生物质炭,可以作为还原剂用于碱还原焙烧工艺,大幅降低了辅料成本。配入碳酸钠的赤泥经过还原焙烧后再湿磨溶出,溶出液主要成分为铝酸钠,回收氢氧化铝和碳酸钠,溶出渣经磁选铁矿后,剩余部分为“三稀”金属富集渣,可以回收钛、钪、稀土等。本文提出的工艺路线达到了铁、铝有效分离及“三稀”元素的富集,而且能够低成本处理,且加入的碱能够循环使用,为广西赤泥的低成本高效利用及“三稀”金属回收提供了一个新路径。Guangxi is the main production base of alumina,with an annual output of about 15 million tons of red mud.The red mud contains high iron,and is rich in rare,dispersed,and rare earth metal elements,which has great resource recovery value.The four goals for achieving high value comprehensive utilization of red mud are harmless treatment of alkali,thorough separation of iron and aluminum,enrichment of“three rare”elements,and low-cost treatment.This paper comprehensively analyzes the current status of comprehensive utilization technology of red mud,and considering the rich agricultural and forestry resources in Guangxi,proposes a process route of using biomass gas reduction roasting high iron red mud-leaching-magnetic separation.Pyrolysis gas carbon cogeneration technology can convert Guangxi's rich agricultural and forestry wastes into high-quality combustible gas.The by-product of gasification is biomass charcoal,which can be used as a reducing agent in the alkali reduction roasting process,significantly reducing the cost of auxiliary materials.The red mud mixed with sodium carbonate is subjected to reduction roasting and then wet grinding for dissolution.The main component of the dissolution liquid is sodium aluminate,and aluminum hydroxide and sodium carbonate are recovered.After magnetic separation of iron ore,the remaining part is the“three rare”enriched slag,which can recover titanium,scandium,rare earth,etc.The proposed process route achieves complete separation of iron and aluminum and enrichment of“three rare”elements,and can be processed at a low cost.The added alkali can be recycled,providing a new path for low-cost and efficient utilization of Guangxi red mud and recovery of“three rare”metals.

关 键 词：高铁赤泥 农林废弃物 碱还原焙烧 生物质热解 高值化综合利用 稀有金属回收 低成本利用 

分 类 号：TF821[冶金工程—有色金属冶金] X758[环境科学与工程—环境工程]