高铝粉煤灰两步碱水热法浸出氧化铝工艺研究  

Technical study of leaching alumina from high-alumina coal fly ash by pre-desilication two-step alkali hydrothermal process

作　　者：李会泉[1,2] 许德华[1,2] 王晨晔[1] 回俊博[1,2] 包炜军[1] 孙振华[1] Li Huiquan Xu Dehua Wang Chenye Hui Junbo Bao Weijun Sun Zhenhua(Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院过程工程研究所绿色过程与工程重点实验室,湿法冶金清洁生产技术国家工程实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《轻金属》2016年第12期5-10,共6页Light Metals

基　　金：国家重点基础研究发展计划(973计划,No.2013CB632605);内蒙古自治区科学技术项目计划(No.201501059)

摘　　要：本文以高铝粉煤灰为研究对象,提出了预脱硅-两步碱水热法提取氧化铝工艺,分别对第一、二步碱水热过程进行了详细研究。结果表明,预脱硅后,非晶态氧化硅得到有效脱除,铝硅比从1.2提高到1.8。第一步碱水热过程优化工艺条件为:反应温度220℃,液固比8,反应时间为1 h,苛性比14;第二步碱水热过程优化工艺条件为:反应温度260℃,液固比8,钙硅比1.0,反应时间为0.75 h。基于两步碱水热法的优化工艺条件,将两步反应耦合,氧化铝的总提取率达94.9%,提取液中氧化铝的浓度为78.8 g/L,苛性比从一步碱水热法的11.5降低到7.2,实现了苛性比的大幅降低,为碱水热法提取氧化铝开辟了新路线。An approach to leach alumina from high - alumina coal fly ash （CFA） by using pre - desilication two - step alkali hydrothermal process was proposed and the technical process was investigated systematically. Results showed that the amorphous silica was removed effectively and the alumina - sil- ica ratio of CFA increased from 1.2 to 1.8. The optimal conditions of the first step alkali hydrothermal process were temperature of 220℃, liquid - solid ratio of 8, time of 1 h and caustic ratio of 14. Meanwhile, the optimal conditions of the second step alkali hydrethermal process were temperature of 260%, liquid - solid ratio of 8, calcium - silica ratio of 1.0 and time of 0.75 h. Based on the optimal conditions above, the alumina leaching ratio can reach 94. 9% and the concentration of the leaching solution of alumina can reach 78.8g/L by coupling the two steps. Comparing with one - step alkali hydrothermal process, the caustic ratio had a significant decline from 11.5 to 7.2, indicating that the two - step alkali hydrothermal process provided a novel method of leaching alumina from high - alumina coal fly ash.

关 键 词：高铝粉煤灰 两步碱水热法 氧化铝 

分 类 号：TQ133.1[化学工程—无机化工]