石膏溶解特性对无水硫铝酸钙水化进程的影响  

Effects of Dissolution Characteristics of Gypsum on Hydration Process of Anhydrous Calcium Sulfoaluminate

作　　者：黄炳银 崔素萍[1] 王亚丽[1] 陈智丰 王剑锋[1] HUANG Bingyin;CUI Suping;WANG Yali;CHEN Zhifeng;WANG Jianfeng(Materials and Manufacturing Department,Beijing University of Technology,Beijing 100124,China;Tangshan Polar Bear Building Materials Co.,Ltd.,Tangshan 063705,China)

机构地区：[1]北京工业大学材料与制造学部,北京100124 [2]唐山北极熊建材有限公司,唐山063705

出　　处：《硅酸盐通报》2023年第5期1804-1813,共10页Bulletin of the Chinese Ceramic Society

基　　金：北京市科技计划(Z221100007522002);北京市自然科学基金-市教委联合资助项目(KZ202010005013)。

摘　　要：石膏的溶解度和溶解速率等特性对无水硫铝酸钙水化及性能有重要的影响。本文采用等温量热仪、XRD、TG-DTG等多种测试方法,研究了半水石膏、二水石膏、硬石膏溶解特性及其对无水硫铝酸钙水化进程的影响,并基于Krstulovic-Dabic和Kondo模型,计算了水化反应各阶段的动力学参数。结果表明,半水石膏、二水石膏、硬石膏在纯水中的溶解度分别为2.74、2.30、2.38 g/L,半水石膏的溶解速率最大,其次是二水石膏,硬石膏的最小(1 h的溶解度为1.19 g/L)。石膏的加入缩短了无水硫铝酸钙水化诱导期进而加快了水化进程,其中半水石膏表现最为显著,水化热曲线几乎不存在诱导期,二水石膏次之,硬石膏对诱导期的影响最小;加速期初期的水化反应速率常数从小到大为硬石膏体系、二水石膏体系、半水石膏体系。石膏溶解速率和溶解度影响钙矾石的形成过程,溶解速率大的石膏促使水化早期钙矾石沉淀出现,生成量快速达到最大值;且在相同时间内,溶解度高的石膏体系钙矾石生成量大,在水化1 h时,半水石膏体系中钙矾石生成量约占试样总量的15.77%(质量分数),二水石膏体系中钙矾石生成量占13.28%(质量分数),硬石膏体系中钙矾石生成量仅占3.60%(质量分数)。The solubility and dissolution rate of gypsum have important effects on the hydration and properties of anhydrous calcium sulfoaluminate.In this paper,isothermal calorimeter,XRD,TG-DTG and other test methods were used to study the dissolution characteristics of hemihydrate gypsum,dihydrate gypsum and anhydrite and their effects on the hydration process of anhydrous calcium sulfoaluminate.Based on Krstulovic-Dabic and Kondo model,the kinetic parameters of each stage of hydration reaction were calculated.The results show that the solubility of hemihydrate gypsum,dihydrate gypsum and anhydrite in pure water is 2.74,2.30,2.38 g/L,respectively.The dissolution rate of hemihydrate gypsum is the maximum,followed by dihydrate gypsum,and the minimum is anhydrite(1 h solubility is 1.19 g/L).The addition of gypsum shortens the induction period of hydration of anhydrous calcium sulfoaluminate and accelerates the process of hydration,where hemihydrate behaves most significantly,with the hydration heat curve having almost no induction period,followed by dihydrate,and anhydrite having the least effect on the induction period.At the beginning of the acceleration period,the hydration rate constant from small to large is anhydrite system,dihydrate system,hemihydrate system.The dissolution rate and solubility of gypsum affect the formation process of ettringite.The gypsum with large dissolution rate prompts the appearance of ettringite precipitation at the early stage of hydration and the amount reaches the maximum value quickly.And in the same time,the system with the addition of gypsum with high solubility has a large amount of ettringite production.At 1 h of hydration,the amount of ettringite produced in the hemihydrate system is about 15.77%(mass fraction)of the total sample,13.28%(mass fraction)in the dihydrate system and only 3.60%(mass fraction)in the anhydrite system.

关 键 词：石膏 无水硫铝酸钙 溶解特性 水化进程 钙矾石 水化动力学 

分 类 号：TQ172.1[化学工程—水泥工业]