自燃煤矸石胶凝材料中钙矾石形成研究

Research on the Ettringite Formation in Cementitious Material of Spontaneous Combustion Coal Gangue

采用 XRD 分析了自燃煤矸石胶凝材料中活性 Al_2O_3在不同因素影响下水化形成钙矾石的情况。研究结果表明,在相同条件下芒硝存在,时自燃煤矸石中活性 Al_2O_3水化生成钙矾石,而含等量硫的石膏存在时水化浆体中不但有水化产物钙矾石还有未反应的石膏;胶凝体系中不含熟石灰时,活性 Al_2O_3水化首先生成石膏,随着水化的进行再转化成钙矾石,而在有熟石灰时水化则直接生成钙矾石;矿渣促进了自燃煤矸石中 Al_2O_3水化形成钙矾石。

The ettringite formation of active Al2O3 in the spontaneous combustion coal gangue cementitious material is analyzed by XRD. The results show that active Al2O3 hydrates with sodium sulfate to form ettringite. However, in the same condition when the same content sulfate comes from gypsum there is ettringite and unhydrated gypsum in the hydration pastes. When it hydrates with sodium sulfate and no white lime, at first the gypsum is formed and with the process of hydration the gypsum transfers into ettringite. At the same time, when the hydration goes with white lime, the ettringite is formed directly. The slag promotes the hydration of active Al2O3 in spontaneous combustion coal gangue to form ettringite.