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

该第一阶段小企业创新研究（SBIR）项目更广泛的影响/商业潜力是通过从燃煤副产品（即粉煤灰）中收获稀土元素，实现无需采矿的稀土元素（REE）生产。美国每年通过燃煤发电产生超过1亿公吨的粉煤灰，全国各地的储存池中有超过20亿公吨的粉煤灰，估计可满足美国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，其中稀土用于高性能风力涡轮机和电动汽车。目前，美国缺乏稳定的国内稀土供应，并依赖于缺乏类似劳动力和环境保护的外国的采矿努力。这种依赖是一种战略弱点。从煤灰中回收稀土元素将建立一个可持续的、多样化的、有弹性的材料供应链，以支持清洁能源转型，同时创造新的就业机会，并为公用事业提供一条经济途径，以更好地利用煤灰和清空现有的灰池。SBIR一期项目将优化一种新型的基于离子液体的回收工艺，从粉煤灰中回收稀土元素（REEs）。所讨论的离子液体对稀土元素具有高的结合亲和力，并且还显示出独特的热变形行为：加热时，水和离子液体形成单一液相，并且稀土元素通过质子交换机制从粉煤灰中浸出。在冷却时，水和IL分离，并且浸出的元素在两相之间分配。该回收策略以一种代表突破性技术的新方法利用了这种行为：离子液体可以直接从固体灰分中提取稀土元素，而无需消化并将稀土元素与散装元素分离。这大大降低了化学品的消耗和废物的产生，并简化了昂贵的下游加工。在该项目的第一阶段，努力的重点是提高离子液体阶段的稀土浓度，开发从离子液体浓缩物中纯化稀土的新工艺，并验证各种煤灰样品的工艺。该项目的产出预计将得到全面的测试和验证的恢复过程准备缩放。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.