轻稀土水合硝酸盐的热分解

STUDY ON THERMOLYSIS PROCESS OF CERIUM-GROUP RARE EARTH NITRATE HYDRATES

用TG-DTG法研究轻稀土La、Ce、Pr、Nd、Sm的13种水合硝酸盐热分解过程,通过IR对反应物、中间产物和最终产物进行鉴别。发现中间产物均有低水合物、无水盐和碱式盐(铈除外),最终产物都是氧化物。提出它们的热分解机理。另外,用Kissinger法计算了一些脱水过程的表观活化能。

The thermal decomposition of 13 nitrate hydrates of cerium-group rare earth has been studied with TG-DTG. The reactants, intermediates and end-products have also been characterized by IR. It was found that the reactants underwent a series of decomposition stages, all the intermediates were lower hydrates, anhydrous and basic nitrate (except for cerium nitrate hydrate) respectively, and the end-products were the oxide. The thermal decomposition mechanism of Ln(NO_3)_3·nH_2O(Ln=La,Ce,n=6,4; Ln=Pr, n=6,4,2; Ln=Nd,Sm,n=6,5,4) have been presented. In addition, the apparent active energy values of dehydration were calculated with Kissinger method.