Dec 4, 2024
9:30am - 9:45am
Hynes, Level 1, Room 109
Duhan Zhang1
Massachusetts Institute of Technology1
Rare earth elements (REEs) are essential for advanced energy and defense technologies. The U.S. has an estimated 13 million tons of REE ore reserves, but domestic production is limited to a single high-grade mine in Mountain Pass, CA. Although low-grade REE deposits are more plentiful, the scarcity of high-grade deposits in the U.S. presents a challenge. Additionally, REE-containing tailings accumulate, incurring significant economic and environmental costs, with the REE value in tailings such as red mud estimated at $796 per ton. Extracting REEs from these low-grade deposits and tailings is difficult because REEs are often locked within a mineral matrix, typically iron oxide, making mechanical or chemical separation challenging.<br/><br/>We propose a novel process to recover REEs from low-grade deposits and tailings. Our approach involves electro-metallurgically removing iron oxide, hydro-metallurgically extracting aluminum salt, and separating the REEs. This method not only yields refinable REE concentrates but also produces emissions-free iron metal and supplementary cementitious materials, contributing to the decarbonization of the steel and cement industries. By tackling the economic and environmental issues associated with low-grade REE deposits and mining tailings, our electrochemical process provides a sustainable solution for unlocking the potential of domestic rare earth resources. This strategy offers a pathway to utilize mining waste effectively, producing valuable materials while supporting green technology and reducing environmental impact.