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.
出处
《过程工程学报》
CAS
CSCD
北大核心
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)
关键词
高铝粉煤灰
氧化铝
氧化硅
脱硅
碱溶
反应机理
high aluminum fly ash
alumina
silica
desilification
alkali dissolution
reaction mechanism
