GEO-CM:A systematic investigation of sorption mechanisms of light REEs on iron oxides: roles of mineral morphology, crystallinity, and surface sites

GEO-CM：轻稀土在氧化铁上的吸附机制的系统研究：矿物形态、结晶度和表面位点的作用

• 批准号: 2327527
• 负责人: Tingying Xu
• 金额: $ 29.69万
• 依托单位: Oklahoma State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2327527&HistoricalAwards=false
• 关键词: GEO; CM; systematic; investigation; sorption

Rare-earth elements (REEs) are critical materials to many leading-edge technologies that underlie clean energy transportation, energy generation and storage, communication, and computing. The availability of REEs is of special concern due to the lack of adequate U.S. domestic production. REEs enrichment in minerals in highly weathered environments represents a promising opportunity for future exploration. However, major knowledge gaps exist in our understanding of the fundamental geochemical controls on REEs accumulation in secondary minerals like clays and iron/aluminum (hydr)oxides (common products of rock weathering), especially the mechanisms of how REEs bind to and are mobilized from mineral surfaces. This project seeks to obtain the foundational scientific knowledge on REEs interactions with oxide minerals, which is required to accurately predict the occurrence and formation of REEs deposits via rock weathering and could be informative in new ways to extract these critical materials. Of equal importance will be the direct involvement and training of students at multiple levels from high school to graduate students to attract the potential next generation of scientists into STEM disciplines.The effects of oxide mineralogy on the sorption mechanisms of REEs could play important roles in controlling REE fate in weathering environments but are poorly understood. This project will reveal these previously unrecognized factors using iron oxides as the model system. The overall goal is to elucidate how mineral structure, crystallinity, morphology, and interfacial structure dynamics could affect REEs sorption reactions at mineral-water interfaces. Light REEs will be used as the probing elements and an integrated series of laboratory wet chemistry experiments and synchrotron-based X-ray techniques will be employed on both iron oxide particles and hematite single crystals to accomplish the research objectives. The proposed study will obtain insight into fundamental geochemical processes controlling the formation of these critical element deposits during rock weathering processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

稀土元素是许多前沿技术的关键材料，这些技术是清洁能源运输、能源发电和储存、通信和计算的基础。由于美国国内缺乏足够的产量，稀土的可获得性尤其令人担忧。在高度风化的环境中，稀土在矿物中的富集性代表着未来勘探的一个很有希望的机会。然而，对于稀土在次生矿物如粘土和铁铝氧化物(岩石风化的常见产物)中积累的基本地球化学控制，尤其是稀土如何与矿物表面结合和从矿物表面活化的机制，我们存在着重大的认识空白。该项目寻求获得稀土与氧化物矿物相互作用的基础科学知识，这是通过岩石风化准确预测稀土矿床的发生和形成所必需的，并可能在提取这些关键物质的新方法方面提供信息。同样重要的是从高中到研究生的多个层次的学生的直接参与和培训，以吸引潜在的下一代科学家进入STEM学科。氧化物矿物学对稀土吸附机制的影响可能在控制风化环境中稀土的命运方面发挥重要作用，但人们对此知之甚少。该项目将使用氧化铁作为模型系统来揭示这些以前未被认识到的因素。总体目标是阐明矿物结构、结晶度、形态和界面结构动力学如何影响稀土在矿物-水界面的吸附反应。将使用轻稀土作为探测元素，并将对氧化铁颗粒和赤铁矿单晶进行一系列综合的实验室湿化学实验和基于同步辐射的X射线技术，以完成研究目标。这项拟议的研究将深入了解在岩石风化过程中控制这些关键元素矿床形成的基本地球化学过程。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。