SusChEM: Collaborative Research: Coal Ash Wastes as a Resource for Critical and Strategic Elements

1510965(徐金)和1510861(豪尔)该项目旨在量化和表征美国发电厂燃煤残渣中的关键元素，并探索提取方法，以实现高价值材料稀土元素的替代和更可持续的资源。关键和战略要素是指供应中断是消费品制造以及对国家福利和国防至关重要的材料的关切。总体而言，煤炭燃烧残留物是中国最大的工业废物流之一，每年产生超过1亿吨。目前只有不到一半的资金被有益地利用(主要用于建筑、农业和其他部门)。该项目将为利用火山灰作为这些高价值金属的资源提供必要的基本信息。这项研究将产生一个全面的数据库，其中包括来自广泛的美国发电站和煤炭来源的火山灰中的关键金属浓度。研究结果还应有助于人们更好地了解富含这些元素的煤矿和灰烬的类型，以及这些元素在灰烬中的地球化学形态。该项目将系统地探索酸提取和物理化学分离方法，为资源回收提供基础。该项目将研究利用火山灰废料作为稀土元素等关键金属的替代资源的潜力。此前的调查显示，一些煤炭来源及其各自的火山灰副产品中稀土元素的含量达到了与矿场矿藏类似的水平。尽管人们对替代稀土元素来源非常感兴趣，但美国的煤炭和火山灰数据有限。这项研究的具体目标是：1)对从各种煤炭来源和燃烧条件收集的火山灰材料进行调查，并开发一个数据库，其中将包括稀土元素、铂族元素、锗和其他关键金属的浓度。这些数据还将包括火山灰的来源以及地球化学性质和物理性质。2)确定用于资源回收的元素的形态特征，并评估它们如何结合在火山灰材料中。3)评价煤的形态、矿物学和颗粒物理性质对酸提效率的影响，探索从飞灰和底灰中提取和提纯关键元素的分离方法。因此，该项目将满足使供应市场多样化的巨大需求，同时还将固体废物材料(火山灰)用于有益目的。将利用与业界利益攸关方的伙伴关系，为这项工作的传播和反馈提供渠道。教育活动将包括为来自代表性不足群体的K-12学生和本科生提供指导和研究机会。

1510965(Hsu-Kim) & 1510861(Hower)This project aims to quantify and characterize critical elements in coal combustion residues from U.S. power plants and explore methods of extraction that could enable an alternative and more sustainable resource of high value materials, rare earth elements. Critical and strategic elements are those in which disruptions to the supply are a concern for the manufacturing of consumer products and for materials crucial to national welfare and defense. Collectively coal combustion residues represent one of the largest industrial waste streams in the country, with more than 100 million metric tons generated annually. Less than half of the total is currently used beneficially (mostly for construction, agriculture, and other sectors). This project will provide fundamental information that is necessary for the utilization of coal ash as a resource for these high value metals.The research will result in a comprehensive database of critical metals concentrations in ash from a broad array of U.S. power stations and coal sources. The results should also improve the understanding of the types of coal deposits and ashes that are enriched in these elements and the geochemical speciation of these elements in the ash. This project will systematically explore acid extraction and physical-chemical separation methods that will provide a basis for resource recovery. This project will investigate the potential for coal ash wastes to serve as an alternative resource for critical metals such as rare earth elements. Previous surveys have shown that some coal sources and their respective ash by-products are enriched in rare earth elements to levels that are similar to deposits at mining sites. Despite the intense interest in alternative rare earth elements sources, data is limited for coal and coal ash in the U.S. Specific objectives of the research are to: 1) Perform a survey of coal ash materials collected from a wide variety of coal sources and combustion conditions and develop a database that will include concentrations of rare earth elements, platinum group elements, germanium and other critical metals. The data will also include the origins and geochemical and physical properties of the ash. 2) Characterize the speciation of elements identified for resource recovery, and evaluate how they are bound in the coal ash material. 3) Evaluate how speciation, coal mineralogy and particle physical properties influences acid extraction efficiencies and explore separation methods to extract and purify critical elements from fly ash and bottom ash. Thus, this project will address a great need to diversify the supply market while also utilize a solid waste material (coal ash) for beneficial purposes. Partnerships with industry stakeholders will be leveraged to provide avenues for dissemination and feedback of this work. Educational activities will include mentorship and research opportunities for K-12 students and undergraduate students from underrepresented groups.