荷电高岭石界面水合稀土离子吸附/解吸双电层模型的分子动力学研究

离子吸附型稀土矿是世界中重稀土的主要来源，针对其浸矿生产中因缺乏科学浸取理论模型指导而造成稀土回收率低、浸出周期长和环境污染大的问题，本项目从离子吸附型稀土矿浸出过程本质规律入手，以稀土离子和高岭石为研究对象，采用密度泛函理论和从头算分子动力学方法研究稀土离子水化效应，明晰水体中稀土离子的微观赋存形态；利用分子动力学方法构建水合稀土离子在荷电高岭石界面吸附平衡的双电层模型，采用稀土吸附过程的微量热法测试进行模型验证；采用分子动力学方法构建单一及复合浸取剂溶液体系中荷电高岭石界面水合稀土离子的解吸平衡双电层模型，开展离子吸附型稀土矿柱浸试验进行模型验证，建立浸取剂性能评价体系，明晰浸取剂解吸稀土离子过程的离子特异性效应和协同作用机理。研究成果可为浸取参数优化、高效环保浸取剂和复合强化浸出工艺研发提供理论指导，对离子吸附型稀土矿的绿色高效开发具有重要的理论价值和实践意义。

Ion-adsorbed rare earth ore is the main source of medium and heavy rare earth in the world. In view of the problems of low rare earth recovery rate, long leaching cycle and large environmental pollution caused by the lack of scientific leaching theoretical model guidance in its leaching production, this project starts with the essential law of the leaching process of Ion-adsorbed rare earth ore, taking rare earth ions and kaolinite as research object, the hydration effect of rare earth ions was studied by using density functional theory and car-parrinello molecular dynamics methods, and the microscopic occurrence form of rare earth ions in water was clarified. An electric double layer model of adsorption equilibrium of hydrated rare earth ions at the charged kaolinite interface was established using molecular dynamics methods, and was verified by using microcalorimetry test of rare earth ions adsorption process. The desorption equilibrium double electric layer model of hydrated rare earth ions at the interface of the charged kaolinite in the single and composite leaching agent solution system was established by using molecular dynamics method, and verification tests of ionic rare earth column-leaching were carried out, to establish a performance evaluation system for the leaching agent, clarify the ion-specific effect and synergistic mechanism of the rare earth ions desorption process by leaching agent. The research results can provide theoretical guidance for the optimization of the leaching parameters, the development of high-efficiency environmental protection leaching agent and compound enhanced leaching process of ion-adsorbed rare earth ores, and have important theoretical value and practical significance for the green and efficient development of ion-adsorbed rare earth ores.