低碱高强硅铝聚合材料的研究

Study on Low Alkali Content and High Strength Geopolymer

以煅烧铝土矿选尾矿、矿渣微粉、水玻璃为主要原料,在800℃下煅烧1 h制备得到高强硅铝聚合材料。用XRD和SEM研究了反应产物的相组成和微观结构,并着重比较研究了该材料与特种水泥的抗化学侵蚀性能差异。结果表明:制备得到的胶砂试样,28d抗折、抗压强度分别达到10.2MPa,60.2MPa;试样分别经3%硫酸钠、3%硫酸镁溶液浸泡28 d后,其强度没有下降反而略有上升,在石膏掺量为7%的硫酸盐环境中,其累计膨胀率远远小于中抗硫酸盐硅酸盐水泥的;分别经5%盐酸、5%硫酸溶液浸泡28d后,其质量损失及强度损失均小于铝酸盐水泥和快硬硫铝酸盐水泥的。制备得到的硅铝聚合材料具有优异的抗硫酸盐侵蚀性能、一定的耐稀酸侵蚀性能。

The geopllymer is synthesized from ore-dressing tailings of bauxite calcined at 800℃ for an hour,slag and waterglass as alkali-activator under the condition of normal temperature and low alkali content.The reaction product and its microstructure are investigated by XRD and SEM respectively.The comparison of geopolymer mortar＇s chemical stability with that of special cement is presented as well.The results show that the geopolymer mortar has high strength with 28-day flexural strength of 10.2 MPa and compressive strength of 60.2 MPa.In solution of sodium sulfate of 3% and magnesium sulfate of 3%,the flexural and compressive strength of geoploymer mortar increase both after 28-day immersion.In sulfate environment with 7% gypsum,the cumulative expansion ratio of geopolymer is rather less than that of moderate sulfate resistance Portland cement.The weight loss and strength deterioraion of geopolymer mortar is also less than that of aluminate cement and early stregth sulphoaluminate ecment when exposed to solution of low concentration acid.According to above performance,the geopolymer synthesized from calcined ore-dressing tailings has excellent resistance to sulfate salt and a measure of resistance to low concentration acid.