粉煤灰在饱和Ca(OH)_2溶液中的溶出行为  

Reaction Behavior of Fly Ash in Saturated Calcium Hydroxide Solutions at Room Temperature

作　　者：冯春花[1] 沈振球[2] 李东旭[2] 

机构地区：[1]河南理工大学材料科学与工程学院,焦作454000 [2]南京工业大学材料科学与工程学院,南京210009

出　　处：《材料导报》2014年第4期130-133,共4页Materials Reports

基　　金：国家重点基础研究发展计划(2009CB623104);河南理工大学博士基金(B2013-012)

摘　　要：对在饱和Ca(OH)2溶液中养护至不同龄期的粉煤灰进行测试,对粉煤灰中氧化硅、氧化铝等成分的溶解速率、粉煤灰颗粒表面的微观形貌以及反应产物进行了分析,同时,对SO42-在钙矾石AFt晶体的形成过程中的影响也进行了探讨。结果表明:在饱和Ca(OH)2溶液体系中,粉煤灰中活性SiO2和Al2O3的溶出速率要比粉煤灰水泥浆体中的火山灰反应快;经饱和Ca(OH)2溶液处理后,粉煤灰颗粒表面主要有4种形貌———碱刻蚀现象、结构致密层、疏松的沉积层、颗粒表面形成钙矾石晶体;SO42-的浓度影响钙矾石的成核结晶。The reaction environment in which the pozzolanic reaction of fly ash occurs was simulated in satura- ted calcium hydroxide solutions at room （≈25 ℃） temperature. Different characteristic methods were performed on to determine the reaction behavior in the different maintaining time. The dissolution process of amorphous silicon dioxide and alumina, morphology features of fly ash particles and reaction products were revealed in the experiment, as well as influences of SO4^2- in the formation process of ettringite crystal. The results showed that, amorphous silicon dioxide and alumina were dissolved much faster in saturated calcium hydroxide solutions than the pozzolanic reaction in fly ash cement paste; four main surface morphology features of fly ash particles were revealed-corrosion, compact layer, loose deposition layer, and formation of ettringite crystals; the SO4^2- anions affect the nucleation and growth of the ettringite crystals.

关 键 词：粉煤灰 氢氧化钙 钙矾石晶体 形态特征 

分 类 号：TQ177.3[化学工程—硅酸盐工业]