Supercritical Recovery of Rare Earth Elements from Phosphate Mining Waste

The United States government and private industry are facing significant supply risks as demand for rare earth elements continues to rise. Most rare earth elements are mined, separated, and purified in China, thereby giving significant control of a critical supply chain to a foreign government. This creates uncertainty in securing long-term contracts, and is a threat to our national security. Existing methods to recovery rare earth elements are often high-cost and therefore cannot be applied to small-scale or dilute feedstocks. The Company, in partnership with the nation’s leading phosphate research institute, seeks to develop supercritical fluid extraction as a low-cost method to recover rare earth elements. Materials to be recovered include Neodymium, Praseodymium, and Dysprosium for the domestic permanent magnet industry, and yttrium for the advanced ceramics industry. The feedstock will be existing waste streams from phosphate ore mining in Florida, which are currently used for low-value applications or stockpiled. The purpose of the Phase I project will be to develop an economical and efficient process to recover the target materials from the feedstock. This will include pre-treatment of the phosphate mining wastes at a phosphate research institute, to recover residual phosphoric acid from the mining wastes, and generate an intermediate product to be shipped to the Company, who will develop a process utilizing supercritical carbon dioxide as a medium to extract and separate rare earth elements at high purity from each other, and from contamination and less valuable metals and minerals. The commercial application is domestic recovery of critical metals and residual phosphoric acid from an existing waste stream. Integration with existing phosphate mining and processing operations will allow for efficient on-site recovery. This will provide economic benefits to communities, and national security benefits by bringing steps in a critical supply chain under domestic control. Possible future applications of this technology include rare earth element recovery from other mine wastes, and from post-consumer batteries, magnets, and phosphor light bulbs.