Cheng Benjun, Feng Hao, Armia Erbolat, Guo Hongli, Zhang Shaowei, Zhang Haijun
School of Energy Science and Engineering, Central South University, Changsha 410083, China.
Sinosteel Group Luoyang Refractories Research Institute Co., Ltd., Luoyang 471039, China.
Materials (Basel). 2023 Apr 16;16(8):3141. doi: 10.3390/ma16083141.
In this paper, the effect of a sodium tripolyphosphate (STPP) addition on the dispersion and hydration of pure calcium aluminate cement (PCAC) was investigated, and the corresponding mechanism of effect was studied. The effects of STPP on the dispersion, rheology, and hydration processes of PCAC and its adsorption capacity on the surface of cement particles were analysed by measuring the 𝜁-potential on the surface of cement particles, the changes in the concentrations of elemental P and Ca ions in a solution at different STPP additions. The experimental results show that STPP easily complexes with Ca ions to produce the complex [CaPO] adsorbed on the surface of cement particles, which changes the potential on the surface of cement particles and increases the electrostatic repulsive force between cement particles, thus improving the dispersion and rheology of cement. At the same time, the contact area between cement particles and water is reduced, which hinders the hydration process and makes the time of hydration process longer. A comprehensive analysis shows that the best effect of STPP on pure calcium aluminate cements is achieved when the addition of STPP is 0.2%. This study can provide a reference for the addition of water-reducing agents in refractory castables as well as improving the quality of refractory materials.
本文研究了添加三聚磷酸钠（STPP）对纯铝酸钙水泥（PCAC）分散性和水化的影响，并研究了相应的作用机理。通过测量水泥颗粒表面的ζ电位、不同STPP添加量下溶液中元素P和Ca离子浓度的变化，分析了STPP对PCAC分散性、流变学和水化过程及其在水泥颗粒表面吸附能力的影响。实验结果表明，STPP易与Ca离子络合生成吸附在水泥颗粒表面的络合物[CaPO]，改变了水泥颗粒表面的电位，增加了水泥颗粒间的静电斥力，从而改善了水泥的分散性和流变学性能。同时，水泥颗粒与水的接触面积减小，阻碍了水化过程，并使水化过程时间延长。综合分析表明，当STPP添加量为0.2%时，其对纯铝酸钙水泥的效果最佳。本研究可为耐火浇注料中减水剂的添加以及提高耐火材料质量提供参考。
