Collaborative Research: Experimental Determination of REE-Chloride Complex Stability Constants and Monazite Solubilities in Hydrothermal Solutions

合作研究：稀土-氯化物络合物稳定性常数和独居石在热液中溶解度的实验测定

• 批准号: 9705661
• 负责人: Scott Wood
• 金额: $ 7.08万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-06-15 至 2000-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9705661&HistoricalAwards=false
• 关键词: Collaborative; Research; Experimental; Determination; REE

9705661 Wood Knowledge of the behavior of the rare earth elements (REE) in high temperature water solutions is required in the following areas: 1) geochronology (i.e., rock dating); 2) REE ore deposit geology; and 3) remediation and safe storage of nuclear waste . Unfortunately, there is a lack of the relevant data required for a better understanding od REE geochemistry. It is expected that the REE will form a dissolved complex with the chloride ion in many natural solutions, and it is known that REE phosphate phases (monazite, xenotime, rhabdophane) are common REE minerals. Thus, the objectives of this proposal are to: 1) determine the solubility of monazite/xenotime in hydrothermal solutions up to 350(C; 2) determine the stoichiometries and stabilities of REE chloride complexes up to 350(C; and 3) apply our experimental data to problems related to the mobility of REE during water-rock interaction. The data obtained in this study will resolve discrepant theoretical estimates in the literature, provide one of the first experimentally derived sets of thermodynamic data for REE complexes at elevated temperatures, permit quantitative modeling of the role of REE chloride complexes in REE mobility, and serve as a basis for improved theoretical predictions of stability constants for other REE complexes for use until additional experimental data become available. During the course of this project, one graduate and one undergraduate student will be trained in hydrothermal experimental techniques, a number of modern analytical methods, and various aspects of aqueous geochemistry relevant to studies in economic geology and environmental geochemistry. In addition, a new experimental geochemistry laboratory will be set up at Montana Tech.

9705661在以下区域需要在高温水溶液中对稀土元素（REE）行为的木材知识：1）地年代学（即岩石约会）； 2）REE矿石存款地质； 3）核废料的修复和安全存储。不幸的是，缺乏更好地理解OD REE地球化学所需的相关数据。可以预期，REE将在许多天然溶液中与氯离子形成溶解的复合物，并且众所周知，REE磷酸盐阶段（独居石，异种，黄脂蛋白）是常见的REE矿物质。因此，该提案的目标是：1）确定在高达350（c; 2）的水热溶液中独居石/异种的溶解度，确定REE氯化物复合物的石化液和稳定性，最多350（c;和3）应用我们实验数据与与REE相互作用期间REE的迁移率有关的问题。这项研究中获得的数据将解决文献中的差异理论估计值，它为REE温度下的REE复合物提供了第一批实验衍生的热力学数据集之一，允许对REE氯化物在REE竞争中的作用进行定量建模，并用作REE在REE迁移率中的作用。改进其他REE复合物稳定性常数的理论预测的基础，直到获得其他实验数据为止。在该项目的过程中，一名研究生和一名本科生将接受水热实验技术的培训，许多现代分析方法以及与经济地质和环境地球化学研究相关的水域地球化学的各个方面。此外，将在蒙大拿州理工学院设立一个新的实验地球化学实验室。