激发剂对天然硬石膏水化作用的影响

The influence of the activator on the hydration property of natural anhydrite

以安徽省含山县天然硬石膏(Ⅱ型无水石膏)为主要原料,研究了5种化学激发剂(K2SO4、FeSO4.7H2O、CaO、Na2C2O4、煅烧明矾)对天然硬石膏水化作用的影响。采用重量法测定了不同掺量时硬石膏的水化率,用X射线粉末衍射和扫描电子显微镜分析了硬石膏水化产物组成及其微观结构,探讨了天然硬石膏水化活性的激发机理。研究结果表明,激发剂可以明显提高硬石膏的水化率,且水化硬化体的微观结构也有显著改善;掺加5.0%的煅烧明矾时,硬石膏的水化效果最好,28d后,水化率可达74.32%。

China has very rich resources of anhydrite,and anhydrite resources only in Hanshan of Anhui Province has reached 60 million tons.The development of natural anhydrite as a binding material has important research value in developing low carbon economy and energy conservation.The composition,structure and hydration hardening performance of natural anhydrite were analyzed in this paper.The activity and improvement of the activity of natural anhydrite by adding different activators were studied.Hydrous mechanisms of natural anhydrite were also analyzed.Taking natural anhydrite（Ⅱ type anhydrous gypsum）produced by Hanshan County of Anhui Province as the major raw material,the influences of five kinds of chemical activators（K2SO4,FeSO4·7 H2O,CaO,Na2C2O4 and calcined alum）on the hydration property of natural anhydrite were investigated.The hydration rates of anhydrite with different contents were detected using the gravimetric method.The composition and microstructure of hydrated products of natural anhydrite were characterized by XRD and SEM.The activated mechanism of hydration activity of natural anhydrite was further discussed.The experimental results indicate that the chemical activator the authors used could obviously promote the hydration rate of natural anhydrite,and the crystal microstructure of the hydration and hardened body was also notably improved after doping activator.The natural anhydrate mixed with 5.0% calcined alum had very good activating action on hydraion.28 days later,the hydration rate reached 74.32%.