摘要
采用单一扫描速率法对镁钙砂细粉的碳酸化反应进行了热分析动力学研究,为镁钙砂颗粒表面碳酸化改性动力学研究提供相关信息。结果表明:镁钙砂中的MgO仅发生轻微碳酸化,因其碳酸化温度较低、反应量较小,且反应产物MgCO3在400℃后即开始分解,因此不会对镁钙砂中CaO的碳酸化反应产生太大影响;镁钙砂中CaO碳酸化反应的最大转化速率出现在700℃左右,碳酸化反应前期(相对转化率约小于38%)机理可用n=2的Avrami-Erofeev成核生长模式(机理)函数描述,后期(相对转化率约大于38%)则可用Ginstling-Brounshtein三维扩散模式(机理)函数描述。
Carbonation kinetics of MgO -CaO powder in CO2 was investigated by means of thermogravimetry of gle scanning rate of 2℃· min^-1 for some information available to the kinetics research of surface carbonation of MgO - CaO coarse particles. The results showed that the main carbonation in MgO - CaO powder is the carbonation of CaO and the maximum conversion rate appeared at about 700℃. Since the amour MgCO3 converted from MgO was small and it decomposed at above 400 ℃ so that the carbonation of MgO would have little effect on carbonation of CaO. The carbonation mechanism of CaO in MgO - CaO powder could be described by Avrami - Erofeev model function （ n =2） of nucleus formation and growth when fractional conversion rate was less than 38% ,and by Ginstling - Brounshtein model function of three-dinsion diffusion when the fractional conversion rate was more than 38%.
出处
《耐火材料》
EI
CAS
北大核心
2005年第5期371-375,共5页
Refractories
基金
教育部科学技术研究重点项目(02097)。
