高铝粉煤灰碱溶脱硅过程反应机理  

Reaction Mechanism of Desilification Process of High Aluminum Fly Ash by Alkali Solution

作　　者：杜淄川[1] 李会泉[2] 包炜军[2] 李少鹏[2] 蔡卫权[1] 

机构地区：[1]武汉理工大学化学工程学院,湖北武汉430070 [2]中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室,北京100190

出　　处：《过程工程学报》2011年第3期442-447,共6页The Chinese Journal of Process Engineering

基　　金：国家"十一五"科技支撑计划基金资助项目(编号:2009BAB49B04)

摘　　要：采用多种检测技术分析了高铝粉煤灰中主要矿物组成和含量,并结合热力学稳定性分析,考察了反应时间与反应温度对碱溶脱硅反应前后高铝粉煤灰的物相、形貌和表面化学成分的影响,并分析了反应机理.结果表明,高铝粉煤灰中Al2O3,SiO2及Ga含量分别高达42.20%,42.28%和0.0062%,且非晶态SiO2占总SiO2一半以上,采用碱溶脱硅有利于提取非晶态SiO2,但反应温度的影响较大,在130℃、反应2h的条件下,SiO2溶出率高达42.5%,Al2O3溶出率仅为1.83%,高于130℃时,莫来石和刚玉发生反应同时加剧方钠石的形成,导致脱硅效率降低.The main mineral components and their contents in high aluminum fly ash, and the effects of reaction time and reaction temperature on the phase, morphology and surface chemical composition of fly ash before and after desilification were analyzed with several analytical instruments combined with thermodynamic stability analysis, and the reaction mechanism of desilification process discussed. The results show that the contents of Al2O3, SiO2 and Ga are 42.20%, 42.28% and 0.0062% separately, content of amorphous SiO2 is more than half of the total SiO2, desilification process by alkali dissolution can extract amorphous SiO2 in fly ash, and reaction temperature has an great influence on desilification, the extraction efficiency of SiO2 and Al2O3 amounts to 42.5% and 1.83% respectively under the conditions of 130℃ and 2 h. The desilification reaction at the temperature below 130℃ is between glass phase and NaOH, increasing temperature accelerates the dissolution of amorphous SiO2 and Al2O3 in glass phase. When temperature is above 130℃, increasing temperature causes the dissolution of mullite and corundum, but aggravates the formation of sodalite.

关 键 词：高铝粉煤灰 氧化铝 氧化硅 脱硅 碱溶 反应机理 

分 类 号：TD982[矿业工程—选矿]