氯化铵焙烧氯化氧化钕及其动力学研究

Kinetic and Chloridizing Roasting Conditions of Nd_2O_3(s) Through Ammonium Chloride

研究了氯化铵焙烧氯化氧化钕的热力学、反应过程、适宜条件和动力学.结果表明:氯化铵焙烧氯化氧化钕在热力学上是可行的;氯化反应自发进行的最低温度为425 K,反应进行完全(K≥10~5)的理论温度为456 K;氯化铵首先与氧化钕反应生成2NH_4Cl·NdCl_3(s)中间复合物,而后2NH_4Cl·Nd Cl_3(s)受热分解为NdCl_3(s);氯化反应的适宜条件为n_(NH_4Cl)∶n_(Nd_2O_3)=12∶1、氯化温度320~340℃、氯化时间30 min,氯化率100%;过量的氯化铵是提高氯化率的关键;氯化反应的表观活化能Ea为52.73 k J·mol^(-1),频率因子A0为7.9×103.

NdCl3（s）is prepared in this work with roasting NH4Cl（s）and Nd2O3（s）. The reaction thermodynamics and its optional reaction condition as well as the reaction kinetics are investigated in this work. Initial temperature of chlorination reaction is 425 K and chlorination reaction is basically completed in the theory about 456 K. During the process,a intermediate of 2NH4Cl ·NdCl3（s）is produced,subsequently,the intermediate is decomposed after roasting at 320-340℃after 30 min to produce NdCl3（s）,and the best ratio is nNH4Cl∶nNd2O3=12∶1. The experimental results indicate that excess NH4Cl（s）is the key role to ensure the reaction yield,with the optional reaction ratio, the yields is nearly 100%. Kinetic results indicate that the activation energy is 52.73 kJ · mol^-1 and frequency factor A0 is 7.9×10^3.