碱激发化学结合陶瓷的反应机理

Reaction Mechanism of Chemically Bonded Ceramics Activated by Alkali

采用水玻璃激发高炉粒化矿渣,制备出了强度等级达到水泥52.5的化学结合陶瓷,并研究其反应机理。X射线衍射分析及扫描电镜分析表明,主要反应产物有C-S-H无定形凝胶、水化钙铝黄长石、水化铝酸钙、钠长石等,其中C-S-H与硅酸盐水泥相比,不仅C/S低,而且碱含量较高。结合体系pH值与反应热的测定分析认为:水玻璃的掺入,OH-离子迅速从高炉粒化矿渣表面产生激发作用,打破高炉粒化矿渣玻璃体的Si-O及Al-O键,加速Si4+、Al3+、Ca2+离子的溶解,反应过程通过诱导前期、诱导期、加速期、稳定期、2次加速期、2次稳定期等阶段完成。

Activated by sodium glass, chemically bonded ceramics were produced with water-hardened slag grains from blast furnace, and the strength grade could be the same as Grade 52.5 cement. The reaction mechanism was studied. The analysis of XRD diffraction and electric lens scanning shows that the main reaction products are formless gelatin C-S-H, hydrate calcium aluminates feldspar, calcium aluminates hydrate and albite etc. Among them C-S-H has lower C/S and higher alkali content compared with Portland cement. Based on measurements of system PH value and reaction heat, the paper pointed out that admixture of sodium glass made ion OH active on the slag surface rapidly and disrupt bonds of Si-O and Al-O of the slag glass. Those accelerate the dissolution of Si^4＋, Al^3＋ and Ca^2＋. The whole reaction process include early induction phase, induction phase, acceleration phase, stabilization phase, the second acceleration phase and the second stabilization phase.