Yang Youming, Zhang Xiaolin, Li Liu, Wei Tingmin, Li Kaizhong
Institute of Engineering Research and School of Metallurgical and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou, Jiangxi 341000, China.
ACS Omega. 2019 May 23;4(5):9160-9168. doi: 10.1021/acsomega.9b00453. eCollection 2019 May 31.
The carbonate solution-dissolved rare earth showed some metastable chemical characteristics. In this paper, the systematic investigation of metastable dissolution regularity of Nd in NaCO solution was carried out. The results showed that Nd has an instantaneous saturated solubility in NaCO solution. When the amount of the dissolution Nd did not reach the instantaneous saturated solubility, the solution was in a stable-state period. Once the concentration of Nd exceeded the instantaneous saturated solubility, the solution was no longer in the metastable state and generated the neodymium double salt of carbonate precipitates rapidly. The molecular dynamics simulation of the solution in the metastable state was carried out. In high concentration NaCO solution, dissolved Nd had a coordination reaction with the CO . Also, there was a stronger interaction between Na and CO , which caused the effective concentration of free CO which could react with Nd to become lower. Thus, these reasons make the solution exhibit a metastable state. In that metastable period, the dissolved Nd becomes steady and hard to generate the neodymium double salt of carbonate precipitates.
碳酸盐溶液溶解的稀土表现出一些亚稳化学特性。本文对钕在碳酸钠溶液中的亚稳溶解规律进行了系统研究。结果表明，钕在碳酸钠溶液中有一个瞬时饱和溶解度。当溶解的钕量未达到瞬时饱和溶解度时，溶液处于稳定状态期。一旦钕的浓度超过瞬时饱和溶解度，溶液就不再处于亚稳状态，并迅速生成碳酸钕复盐沉淀。对处于亚稳状态的溶液进行了分子动力学模拟。在高浓度碳酸钠溶液中，溶解的钕与碳酸根发生配位反应。此外，钠离子与碳酸根之间存在较强的相互作用，这使得能够与钕反应的游离碳酸根的有效浓度降低。因此，这些原因使得溶液呈现出亚稳状态。在那个亚稳期，溶解的钕变得稳定，难以生成碳酸钕复盐沉淀。
