钕
碳酸盐
成核
结晶
热液循环
无定形固体
降水
矿物学
化学工程
材料科学
无机化学
化学
结晶学
有机化学
光学
激光器
物理
工程类
气象学
作者
Zhenjie Cui,Jianwei Guo,Dong Wang,Jianjun Cao,Wang Zhi
标识
DOI:10.1016/j.jcrysgro.2021.126460
摘要
Rare earth carbonates have shown great application value and potential in the process of preparing rare-earth materials. In this work, a non-hydrothermal method of uniform feeding was used to determine the nucleation kinetics of neodymium carbonate. On this basis, the crystallization process and evolution of amorphous phase were studied. For the first time, it is determined the macroscopic crystallization rate of neodymium carbonate follows a zero-order reaction. The primary nucleation activation energy is 36.98 kJ/mol, indicating that the formation of Nd2(CO3)3 is controlled by a mixture of diffusion and chemical reaction. In the initial stage of precipitation, spherical amorphous neodymium carbonate with diameter of 20 nm was formed, with the molecular formula being Nd2(CO3)3·1.87H2O, and subsequently crystallized into tengerite-(Nd) [Nd2(CO3)3·2.5H2O] and lanthanite-(Nd) [Nd2(CO3)3·8H2O]. The stability of the amorphous neodymium carbonate in anhydrous environment and aqueous solution was evaluated, and ion potential was used to judge the stability trend of the rare earth carbonates. During the transition from amorphous phase to crystal, it is found temperature and supersaturation play an important role in the morphology of the final product. The results provide a reference for evaluating the crystallization process and developing large-scale industrial production methods.
科研通智能强力驱动
Strongly Powered by AbleSci AI