磷石膏炭热分解的热动力学研究  

Thermal and Kinetic Study on Decomposition of Phosphogypsum by Carbon

作　　者：徐悦[1] 林强[2,3] 李建锡[2] 宁平[2] 阚黎黎[4] 

机构地区：[1]昆明理工大学建筑工程学院,昆明650500 [2]昆明理工大学环境科学与工程学院,昆明650500 [3]海南师范大学化学与化工学院,海口571158 [4]上海理工大学环境与建筑学院,上海200093

出　　处：《硅酸盐通报》2017年第3期839-845,共7页Bulletin of the Chinese Ceramic Society

基　　金：云南省应用基础研究基金面上项目(2013FB023)

摘　　要：在活性炭掺量为10%~15%,煅烧温度为1100~1250℃条件下,从动力学和热力学角度对磷石膏分解煅烧制胶凝材的可行性进行了研究。在该温度范围内,通过等温热分析法确定了磷石膏分解体系的表观活化能为299.88~382.85 k J·mol^(-1),指前因子ln A为18.64~25.61 s^(-1),分解动力学方程为受三维扩散控制的Z-L-T方程。经Factsage软件计算和SEM、EDS、XRD等微观检测发现,煅烧过程中,不仅发生了硫酸钙的分解,还伴随着分解产物CaO和杂质SiO_2的合成反应。根据CaO-SiO_2-CaSO_4相图的理论计算结果表明,适量补充硅铝质改性组分,调节生料的配比范围,有使磷石膏基水硬性复合胶凝材料强度提升的潜能。From the kinetic and thermodynamic point of view,the feasibility of phosphogypsum（ PG）decomposition making cementitious material at low temperature was studied. The decomposition kinetics of PG with 10%-15% activated carbon（ AC） were investigated at 1100-1250 ℃. The results show that the apparent activation energy of PG decomposition system is 299. 88-382. 85 k J · mol^-1,the preexponential factor is 18. 64-25. 61 s^-1 and the most possible decomposition mechanism is Z-L-T function.The synthesis reaction of Ca O and SiO2 was processing along with the decomposition during the calcination was confirmed by the thermodynamic calculation and microstructural analysis. According to the phase diagram of CaO-SiO2-CaSO4 system,adding some appropriate silicon aluminum modified components and adjusting the scope of raw material proportion have the potentiality to improve the compressive strength of cementitious material made from PG.

关 键 词：磷石膏 硫酸钙 活性炭 分解动力学 热力学计算 胶凝材料 

分 类 号：TQ170.2[化学工程—硅酸盐工业]