C₂S和中间相前导矿物对熟料中C₃S形成动力学影响

【作者】 栗潮；

【导师】 管宗甫；

【作者基本信息】 郑州大学 ， 材料学， 2009， 硕士

【摘要】 Alite是水泥熟料中最重要矿物,其含量和活性的提高,必将赋予熟料高的胶凝性。因此,如何提高水泥熟料中Alite的含量,进而提高水泥熟料质量是水泥行业研究的主要方向。但是Alite是水泥熟料矿物中生成温度最高的矿物,提高水泥熟料中Alite含量会给生产一定得困难。现有的研究认为在液相出现以前alite不会大量形成。到达最低共熔温度后,开始出现液相,在高温液相作用下,水泥熟料逐渐烧结,同时,硅酸二钙与游离氧化钙都逐步溶解于液相中,以Ca²⁺离子扩散与硅酸根离子、硅酸二钙反应,形成硅酸盐水泥的主要矿物硅酸三钙。对C₂S和中间相在C₃S的生成动力学过程中的具体作用和影响的研究,对水泥熟料的生产,提高水泥熟料质量有着重要意义。本文设计了以C₂S为起点研究C₃S的形成动力学参数。通过先合成C₂S前导物和中间相前导物,再对C₂S前导物补足CaCO₃、Fe₂O₃、Al₂O₃;对中间相前导物补足CaCO₃、SiO₂,在不同温度下煅烧得到水泥熟料。为剔除水泥熟料中其他矿物对C₃S形成动力学过程的影响,依据水泥熟料矿物组成和配料方式提出了四种CaO转化率公式,可以计算出CaO反应生成C₃S的量,排除其他因素的干扰。通过计算出CaO反应生成C₃S的转化率,采用金斯特林格和Arrhenius公式计算了熟料中C₃S形成的表观活化能。研究结果表明:设计以C₂S为起点研究C₃S的形成动力学参数,方法可行,计算所得活化能更为接近C₃S真实活化能;提出的CaO转化率的计算公式,可以有效剔除熟料中其他矿物对C₃S生成活化能的影响,可以有效的评价不同前导物对C₃S形成活化能的影响;导物可以有效降低熟料中C₃S的形成活化能。C₂S的生成反应在C₃S形成动力学过程中可能是关键反应,制约着C₃S生成速度。中间相则为这个过程提供了良好的扩散环境,加速了硅酸盐矿物形成的扩散过程。更多还原

【Abstract】 Alite is the most important mineral in cement clinker, the increase of content and activity of which endow the clinker high cementitious properties. Therefore, it has become one of the primary research direction of cement by increasing the content of alite to improve the quality of clinker. However, it will bring some difficulties in practical production, because the formation temperature of alite is the highest in clinker. Present researches have indicated that, alite would not form until the occurring of liquid phase with high temperature, which happened after the reach of lowest eutectic point, and it could promote the sintering of clinker. Simutaneously, dicalcium silicate （C₂S） and free calcium oxide （f-CaO） melted into the liquid phase and diffused in the form of Ca²⁺ to react with SiO₄^2- and C₂S to produce tricalcium silicate （C₃S）-the principal mineral in clinker. Therefore, it is very meaningful to research the specific function and influence of C₂S and mesophase in the formation kinetics process of C₃S, which will have significant effect on improving the quality of clinker.The formation kinetics parameters of C₃S were investigated based on the formation of C₂S in this study. Firstly, the C₂S former body and mesophase former body were prepared, and then cement clinkers were produced by calcining at different temperatures by adding supernumerary CaCO₃、Fe₂O₃、Al₂O₃ for C₂S former body and CaCO₃、SiO₂ for mesophase former body, respectively. Four conversion rate equations of CaO were proposed to calculate the formation content of C₃S by CaO, and in order to reject the affect of other minerals, equations were proposed according to the cement clinker mineral composition and blending way. The apparent activation energy of C₃S in clinker were calculated through the calculation of conversion rate of C₃S reacted by CaO, according to Kuenstlinger and Arrhenius equations.Results showed that: It is practicable to investigate the formation kinetics parameters of C₃S based on the formation of C₂S, and the calculated activation energy of C₃S is close to its real activation energy. The influence of other minerals on the formation activation energy of C₃S can be rejected efficiently, according to the conversion rate equations of CaO proposed in this study, and at the time it can evaluate efficiently the influene of different former body on the formation activation energy of C₃S. The formation activation energy of C₃S in the clinker system can be decreased efficiently by both C₂S former body and mesophase former body. In the formation kinetics process of C₃S, the formation reaction of C₂S may be the key reaction, which restricts the formation rate of C₃S, and the mesophase provides favorable diffusional environment for this process to accelerate the diffusion of formation of silicate minerals.更多还原