镁钙砂碳酸化反应机理研究  

Carbonation Reaction Mechanism of MgO-CaO Powder

作　　者：吴芸芸[1] 易德莲[1] 梁永和[1] 

机构地区：[1]湖北省耐火材料与高温陶瓷重点实验室(武汉科技大学),湖北武汉430081

出　　处：《武汉科技大学学报》2006年第2期122-125,共4页Journal of Wuhan University of Science and Technology

基　　金：教育部科学技术研究重点资助项目(02097)

摘　　要：采用单一扫描速率（2℃/min）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反应动力学研究提供相关信息.研究结果表明,镁钙砂细粉碳酸化反应初期MgO的碳酸化和CaO碳酸化反应前期机理,可用n=2的Avrami-Erofeev随机成核、随后生长模式函数描述,后期（相对转化率大于33%～38%）则可用Jander或Ginstling-brounshtein三维扩散模式函数描述.同时,MgO碳酸化反应产生的体积效应导致CaO反应前期表观活化能大幅度降低.Carbonation reaction mechanism of MgO-CaO powder in CO2 has been investigated by means of thermogravimetry of single scanning rate of 2℃/min for valuable information relevant to the kinetics of surface carbonation of MgO-CaO coarse particles. The results indicate that the carbonation mechanism of MgO-CaO powder can be described by Avrami-Erofeev model function （ n = 2） of nucleus formation and growth when the fractional conversion rate is smaller than 38%, and by Jander or Ginstling-Brounshtein model function of three-dimension diffusion when the fractional conversion rate is bigger than 33% -38%. And the volume expansion caused by MgO carbonation results in the considerable decrease of the activation energy, of CaO carbonation.

关 键 词：镁钙砂 碳酸化反应 热分析动力学 

分 类 号：TQ175.4[化学工程—硅酸盐工业]