Recovery of alkali and alumina from Bayer red mud by the calcification–carbonation method  

作　　者：xiao-feng zhu ting-an zhang yan-xiu wang guo-zhi lü wei-guang zhang 

机构地区：[1]Key Laboratory of Ecological Utilization of Multi-metal Intergrown Ores of the Ministry of Education,School of Materials and Metallurgy,Northeastern University,Shenyang 110819,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2016年第3期257-268,共12页矿物冶金与材料学报（英文版）

基　　金：financially supported by the Joint Funds of the National Natural Science Foundation of China(No.U1202274);the National Natural Science Foundation of China(No.51204040);the Research Fund for the Doctoral Program of Higher Education of China(No.20120042110011);the Fundamental Research Funds for the Central Universities(No.N140204015)

摘　　要：Red mud produced in the Bayer process is a hazardous solid waste because of its high alkalinity; however, it is rich in valuable components such as titanium, iron, and aluminum. In this study, a novel calcification-carbonation method was developed to recover alkali and alumina from Bayer red mud under mild reaction conditions. Batch experiments were performed to evaluate the potential effects of im- portant parameters such as temperature, amount of CaO added, and CO2 partial pressure on the recovery of alkali and alumina. The results showed that 95.2% alkali and 75.0% alumina were recovered from red mud with decreases in the mass ratios of Na2O to Fe2O3 and of Al2O3 to Fe2O3 from 0.42 and 0.89 to 0.02 and 0.22, respectively. The processed red mud with less than 0.5wt% Na2O can potentially be used as a construction material.Red mud produced in the Bayer process is a hazardous solid waste because of its high alkalinity; however, it is rich in valuable components such as titanium, iron, and aluminum. In this study, a novel calcification-carbonation method was developed to recover alkali and alumina from Bayer red mud under mild reaction conditions. Batch experiments were performed to evaluate the potential effects of im- portant parameters such as temperature, amount of CaO added, and CO2 partial pressure on the recovery of alkali and alumina. The results showed that 95.2% alkali and 75.0% alumina were recovered from red mud with decreases in the mass ratios of Na2O to Fe2O3 and of Al2O3 to Fe2O3 from 0.42 and 0.89 to 0.02 and 0.22, respectively. The processed red mud with less than 0.5wt% Na2O can potentially be used as a construction material.

关 键 词：waste utilization red mud CALCIFICATION CARBONATION ALUMINA ALKALI RECOVERY 

分 类 号：X758[环境科学与工程—环境工程]