一种低品质湿排粉煤灰的激发及性能研究

Research on Performance and Activation Technology of Wet-Discharged Fly Ash

本文采用机械湿磨与化学激发剂的复合激发技术,制备得到高活性湿排粉煤灰料浆,并研究了不同化学激发剂、干磨和湿磨粉磨方式对湿排粉煤灰活性激发的影响以及水化产物(SEM)的变化。研究表明,复合化学激发剂Na2SO4+Ca(OH)2具有良好的活性激发效果,SEM显示7d改性湿排粉煤灰已参与二次水化反应,而激发剂Na(OH)+Ca(OH)2,水化生成大量的Ca(OH)2,对强度不利。湿磨比干磨具有更好的粉磨及活性激发效果,且湿磨对混凝土的坍落度损失影响小。通过复合激发的湿排粉煤灰料浆活性高于普通Ⅱ粉煤灰。

In this paper, a kind of high - activated wet - discharged fly ash slurry was prepared, adopting a composite activating technology of wet mechanical grinding and chemical activation. The research about the activation effect of different chemical activator and SEM appearance of hydrated product were carried on. And it also investigated the influence of grinding treatment about wet - grinding and dry - grinding. The results indicated that： the composite chemical ac-tivator Na2SO4 ＋ Ca（ OH）2 has a good activated effect, and the modified wet fly ash has involved in the secondary hydration reaction examined by SEM. How-ever too many alkaline activator is detrimental to the development of cement strength. The wet grinding of wet - discharged fly ash has a better grinding and ac-tivity effect than dry grinding, and it has less affect on the slump loss of concrete. The activation of composite modified wet -discharged fly ash slurry is higher than ordinary Ⅱ fly ash.