用热重-差热(TG-DTA)技术,在不同升温速率条件下,研究了十水草酸镧在空气气氛下的热分解过程.分别采用Ozawa-Flynm-Wall法、Kissinger法、Crane法和同步热分析法确定其热分解动力学参数.TG-DTA曲线表明:十水草酸镧分解为四个阶段,前两个阶段为脱水过程,后两个阶段为La2(C2O4)3的分解过程.实验计算得出四步反应表观活化能E分别为83.92、76.04、136.26、162.61kJ?mol-1左右;指前因子A分别为4.92×1010、6.1×107、2.1×109、8.46×106s-1左右;反应级数n均为1左右, 并用Coats-Redfem积分法得出第三步分解机理受F1控制.
Thermal decomposition behavior of lanthanum oxalate was studied by the simultaneous thermal analysis technique TG-DTA in an air atmosphere.The thermal decomposition kinetics parameters of La2(C2O4)3?10H2O was determined by using Ozawa-Flynm-Wall method、Kissinger method、Crane method and simultaneous thermal analysis method.Curve of TG showed : the thermal decomposition of La2(C2O4)3?10H2O has 4 stages, the first two stages are the dehydration process, the succedent two stages are the thermal decomposition of La2(C2O4)3.The four stages' apparent activation energies are 83.92、76.04、136.26、162.61 kJ?mol-1, the exponential factors are about 4.92×1010、6.1×107、2.1×109、8.46×106 s-1 respectively, the reaction order is about one,and the decomposition mechanism of the third step is controlled by F1 according to Coats-Redfem method.
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