SBIR Phase I: Sustainable Rare Earth Element Production from Coal Combustion Byproducts

这个第一阶段小型企业创新研究(SBIR)项目的更广泛的影响/商业潜力是，通过从燃煤副产品(即煤飞灰)中提取稀土，实现在不开采的情况下生产稀土元素(REE)。美国每年通过燃煤发电产生超过1亿公吨的煤飞灰，全国各地有超过20亿公吨的储存池，估计可以容纳美国长达100年的稀土需求。缺少的是一种可持续、可扩展和经济的分离方法。稀土元素在许多不同的技术中发挥着关键作用，从国防应用到制造和消费电子产品，再到医疗保健等等。一个特别重要的行业是清洁技术，稀土用于高性能风力涡轮机和电动汽车。目前，美国国内缺乏稳定的稀土供应，依赖于缺乏类似劳动力和环境保护的外国的采矿努力。这种依赖是一个战略上的弱点。从火山灰中提取稀土元素将建立一个可持续、多样化和有弹性的材料供应链，以支持清洁能源转型，并创造新的就业机会，为公用事业公司提供一条更好地利用火山灰和清空现有灰池的经济途径。这个SBIR第一阶段项目将优化一种新的基于离子液体的回收工艺，以从煤炭飞灰中提取稀土元素(REE)。所讨论的离子液体对稀土元素具有很高的结合亲和力，并且还表现出独特的热形态行为：加热时，水和离子液体形成单一液体相，稀土元素通过质子交换机制从煤飞灰中浸出。冷却后，水和IL分离，浸出的元素在两相之间分配。回收策略以一种代表突破性技术的新方法利用了这一行为：离子液体可以直接从固体火山灰中提取稀土，而不需要消化，并将稀土从大宗元素中分离出来。这大大降低了化学品消耗和废物产生，并简化了昂贵的下游加工。在该项目的第一阶段，工作重点是提高IL阶段的稀土浓度，开发从离子液体浓缩物中提纯稀土的新工艺，并对各种火山灰样品验证该工艺。该项目的产出预计将经过全面测试和验证的恢复过程，为扩大规模做好准备。该奖项反映了NSF的法定使命，并已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。

The broader impact/commercial potential of this Phase I Small Business Innovation Research (SBIR) project is to enable rare earth element (REE) production without mining, by harvesting REEs from coal combustion byproducts, namely coal fly ash. The U.S. produces over 100 million metric tons of coal fly ash each year through burning coal for power and has more than two billion metric tons in storage ponds across the country, estimated to contain up to 100 years’ worth of U.S. demand of REEs. What is missing is a sustainable, scalable, and economic method of separation. REEs play critical roles in many different technologies, ranging from national defense applications to manufacturing and consumer electronics, to healthcare treatments, and much more. One particularly important industry is clean tech, where REEs are used in high-performance wind turbines and electric vehicles. Currently, the U.S. lacks a stable domestic supply of REEs and is reliant on mining efforts in foreign nations that lack similar labor and environmental protections. This dependence is a strategic vulnerability. Harvesting REEs from coal ash would build a sustainable, diverse, and resilient supply chain of materials needed to support the clean energy transition, as well as create new jobs and provide utilities with an economic pathway to better utilize ash and empty existing ash ponds.This SBIR Phase I project will optimize a novel ionic-liquid-based recovery process to harvest rare earth elements (REEs) from coal fly ash. The ionic liquid in question has a high binding affinity for REEs and additionally displays unique thermomorphic behavior: upon heating, water and the ionic liquid form a single liquid phase, and REEs are leached from coal fly ash via a proton-exchange mechanism. Upon cooling, the water and IL separate, and leached elements partition between the two phases. The recovery strategy exploits this behavior in a new method that represents a breakthrough technology: the ionic liquid can extract the REEs directly from the solid ash without the need for digestion and separate the REEs from bulk elements. This dramatically lowers chemical consumption and waste generation and simplifies costly downstream processing. In Phase I of the project, efforts are focused on improving REE concentration in the IL phase, developing new processes for purifying REEs from ionic liquid concentrate, and validating the process for a variety of coal ash samples. The output of this project is expected to be comprehensively tested and validated recovery process ready for scaling.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.