气化渣对硅酸盐水泥强度和微观结构的影响研究

Influence of Coal Gasification Slag on Strength and Microstructure of Portland Cement

气化渣是近年来兴起的煤化工工业产生的主要固体废弃物。研究了不同掺量的气化渣粉对普通硅酸盐水泥的凝结时间和抗压强度的影响规律,并采用XRD、FT-IR和SEM微观测试手段分析了气化渣在水泥浆体中的作用机理。结果表明,未反应气化渣在水泥浆体中主要以团聚状态存在,低掺量气化渣(10%)在水泥浆体中能起到成核作用,有利于水泥发生水化反应,提高水泥浆体中水化产物数量,缩短凝结时间,提高水泥浆体抗压强度。气化渣掺量大于30%时,水泥浆体水化产物数量减少,水泥浆体结构松散,凝结时间随气化渣掺量增大显著延长,抗压强度明显降低。

Coal gasification slag is one of the major solid wastes produced by modern coal chemical industry in recent years.In this paper,the setting time and compressive strength of ordinary Portland cement with different contents of coal gasfication slag were studied.The mechanism of the action of the coal gasfication slag in ordinary Portland cement was discussed and analyzed by XRD,FT-IR and SEM techniques.The results show that,in cement stone,the unreacted coal gasification slag mainly exists in forms of aggregate state.Low-content gasification slag(10%)plays the role of nucleation in cement paste,which is favorable to the hydration reaction of cement,resulting in the increasing number of hydration products,the shortening of the setting time of cement paste and the improving of the compressive strength of cement stone.When the content of gasification slag is more than 30%,the amount of the hydration products of cement decreases and the structure of cement stone is loose.With the increase of the content of the coal gasfication slag,the setting time of cement paste is significantly prolonged,and the compressive strength of cement stone decreases markedly.