关键词: 砂质煤矸石, 热活化, 蚀变剂, 胶凝材料

Abstract:

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.

Key words: 砂质煤矸石, 热活化, 蚀变剂, 胶凝材料