高碱性拜耳法赤泥碳酸化脱碱及其机理研究  

Research on Dealkalization and Mechanism of High-alkaline Bayer Process Red Mud by Carbonation

作　　者：苏泽林 王东波 黄纤晴 李想 余昕 黄莹 冯庆革 柏秀奎 SU Zelin;WANG Dongbo;HUANG Xianqing;LI Xiang;YU Xin;HUANG Ying;FENG Qingge;BAI Xiukui(Guangxi Cooperative Innovation Centre for Calcium-based Materials, School of Resources, Environment and Materials,Guangxi University, Nanning 530004, China)

机构地区：[1]广西大学资源环境与材料学院,广西钙基材料协同创新中心,南宁530004

出　　处：《硅酸盐通报》2020年第5期1547-1552,共6页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(51762004);广西自然科学基金(2017GXNSFAA198205);广西创新驱动项目(桂科AA17204066);广西钙基材料协同创新研究(GJZX2020-6)。

摘　　要：利用二氧化碳对高碱性拜耳法赤泥进行碳酸化脱碱实验,研究了反应体系压力、时间、温度和液固比对赤泥脱碱效果的影响,并对其反应机理进行探讨。结果表明,室温下,在反应压力为0.6 MPa,反应时间为60 min,液固比为7的反应条件下,碱溶出率为6.99%。拜耳法赤泥中的碱主要以两种形式存在,一是以NaOH、NaCO3为主的游离态碱,二是以钙霞石为主的结合态碱。其脱碱机理主要是通过碳酸化作用脱除赤泥中的游离态碱,部分钙霞石与碳酸反应生成可溶性钠盐。The carbonation and dealkalization experiments of high-alkaline Bayer process red mud were carried out with carbon dioxide.The effects of reaction pressure,time,temperature and liquid-solid ratio on the dealkalization of the red mud were studied,and the reaction mechanism was also discussed.The results show that under the conditions of pressure of 0.6 MPa,reaction time of 60 min,room temperature and liquid-solid ratio of 7,the alkali dissolution rate is 6.99%.There are mainly two forms of alkali in Bayer process red mud,one is the free state base dominated by NaOH and NaCO3,the other is the combination state base formed by bauxite and strong alkali solution.The mechanism of carbonation and dealkalization of highly alkaline Bayer process red mud is to remove free alkali in red mud through carbonation,and some cancrinite reacts with carbonation to form soluble sodium salt.

关 键 词：二氧化碳 赤泥 碳酸化 脱碱 钙霞石 

分 类 号：X756[环境科学与工程—环境工程]