含镁铝尖晶石的铝酸盐水泥的制备及其抗侵蚀性

以白云石和工业Al2O3为原料,采用烧结法制备了含镁铝尖晶石的铝酸盐新型水泥,利用X射线衍射检测了合成产物的物相组成,采用扫描电子显微镜观察了新型铝酸盐水泥中各物相的形貌和能谱分析了成分分布,测量了这种铝酸盐水泥的凝结时间、耐火度以及其所结合的高铝矾土制成的耐火浇注料的早期强度.选择静态坩埚法进行抗渣性实验,对比了新型铝酸盐水泥和纯铝酸钙水泥结合刚玉浇注料的抗渣性差异.结果表明:这种水泥的物相组成为镁铝尖晶石、一铝酸钙和二铝酸钙;物相分布较为均匀.与纯铝酸钙水泥比较,凝结时间正常,新型铝酸盐水泥结合刚玉浇注料与纯铝酸钙水泥结合刚玉浇注料的抗弯强度相当,耐火度较高和抗侵蚀性较好,其原因在于水泥中存在镁铝尖晶石相,而镁铝尖晶石有较高的熔点和抗熔渣侵蚀能力.

PREPARATION AND CORROSION RESISTANCE OF ALUMINOUS CEMENT CONTAINING MAGNESIUM ALUMINATE SPINEL

A new type of aluminous cement containing magnesium aluminate (MA) spinel was prepared from mixtures of dolomite and alumina by a sintering process. The microstructures and phase constituents of the synthesized product were inspected by X-ray diffraction and scanning electron microscope with energy dispersive X-ray spectrometry. The setting time, refractoriness and bonding strength of the new type of aluminous cement were measured by means of standard methods. The corrosion resistance property was also investigated by static crucible method. The experimental results show that the new type of aluminous cement consists of MA spinel, calcium monoaluminate and calcium dialuminate phases. Compared with aluminous cement, the prepared cement with more uniform phase distribution has a reasonable setting time, and the cement containing MA spinel bonded castables with bauxite as an aggregate have considerable bonding strength, higher refractoriness and better corrosion resistance. This is due to the introduction of MA spinel, which has a high melting point and prevents slag from penetrating.