硫铝酸钙-贝利特水泥熟料的低温制备及其水化性能研究

以煤矸石、脱硫石膏、石灰为主要原料,采用水热合成-低温煅烧方法制备了硫铝酸钙-贝利特水泥熟料,通过X射线衍射(XRD)、扫描电镜(SEM)等分析了水热合成物、煅烧试样及水化产物的矿物相,利用等温量热仪测定了水泥早期水化放热随时间的变化,并测定了水泥的力学性能。结果表明:在120℃下水热合成前驱体后再经煅烧,可在1 050℃低温下制成硫铝酸钙-贝利特水泥熟料。与一步法相比,该低温水泥的早期水化放热速率较高。当水泥中的二水石膏掺量为13%(质量分数)时,水泥1d、28d的抗压强度分别为30.2 MPa和57.3 MPa,28d的水化产物主要为长纤维状的AFt。

Study on Low-temperature Preparation and Hydration Properties of Calcium Sulphoaluminate-Belite Cement Clinker

Coal gangue ,desulfurization gypsum and lime were used as main raw materials ,the calcium sulphoaluminate-belite cement clinker was prepared by hydrothermal synthesis and low-temperature calcination . The mineral phases of hydrothermal synthesis products ,calcined samples and their hydration products were measured by XRD (X-ray diffraction) ,SEM (scanning electron microscope) .The change of hydration heat of cement with time was analyzed by isothermal calorimeter ,and the mechanical properties of cement were measured .The results showed that under the premise of hydrothermal synthesis of precursor at 120 ℃ , the calcium sulphoaluminate-belite cement clinker can be completely sintered at 1050 ℃ .The early hydration heat release rate of this low-temperature sintered cement is higher ,compared with that of one-step calcined cement .When gypsum content is 13wt％ in cement ,the 1 d and 28 d compressive strength of cement were 30.2 MPa and 57.3 MPa ,respectively .The hydration product of cement in 28 d was mainly AFt with long fiber .