房山砂质煤矸石热活化的影响因素分析

Factors influencing thermal-activation of Fangshan sandy gangue

为提高房山砂质煤矸石的胶凝活性,用于制备胶凝材料,采用XRD分析、DSC-TG分析、胶砂试块强度测试和SEM分析等多种方法,分析了房山煤矸石的热活化机理,研究了煅烧温度、冷却方式以及蚀变剂等因素对煤矸石活性的影响。结果表明:使房山砂质煤矸石有效活化的煅烧温度在800℃左右,蚀变物料出炉后于自然风中冷却;在煅烧过程中添加适量的蚀变剂可以侵蚀石英、长石类晶体表面,使其化学键发生断裂,结构发生解体,产生活性的SiO2,从而提高房山煤矸石的活性。

A huge amount of coal gangue is piled in Beijing,especially in Fangshan District.The best method to utilize it is the transformation of them for producing cement.Because Fangshan gangue is a kind of sandy one,whose mineralogical composition contains clay minerals such as kaolinite,muscovite and chlorite,quartz,calciclase and carbon,etc,it is difficult to improve its activity.In order to explore a way of utilizing it,in this paper,XRD analysis and DSC-TG analysis were used to research the activation mechanism of the gangue.Some major factors affecting the thermal activation of the gangue,such as temperature,cooling way and content of the alteration agent,were investigated,strength test of cement mortar and SEM were employed.The results showed that,the strength of cementitious materials obtained by the thermal activation of coal gangue was significantly improved.The activity of Fangshan gangue could be obviously increased when the mixture of powder and bulk gangues were heated to 800℃ for 5 h.The surface of quartz and feldspar crystals was eroded and their chemical bond was broken by adding alteration agent.Fangshan gangue could be highly activated with proper amount of alteration agent during the thermal activation process,so that it could be used as hydraulic binders.