An effort is underway to establish an environmentally friendly supply of rare-earth elements (REEs) from waste streams in the U.S. The project, undertaken by American Resources Corp. (Fishers, Ind.; www.americanresourcescorp.com), is focused on re-positioning assets from the coal industry to restore a U.S.-based supply chain for REEs and other critical elements from environmentally problematic, REE-containing waste streams, such as acid-mine drainage and flyash, and end-of-life products, such as used Li-ion batteries and permanent magnets.
So far, the company has made eight acquisitions of legacy coal facilities in Kentucky and West Virginia, and has licensed 16 patents and pieces of university-held intellectual property to capture and purify REEs from waste. Among the key technologies is an electrolysis process developed by Gerardine Botte at Ohio University (now at Texas Tech University) for concentrating REEs from aqueous solutions like acid mine drainage and mining waste. American Resources is currently building a mobile electrolysis facility that can be transported to coal sites to generate a processed concentrate that contains approximately 10% REEs.
Another key technology is a two-stage ligand-assisted displacement (LAD) chromatography process developed at Purdue University that can separate and purify the various types of REEs with the hexadentate ligand EDTA (ethylenediaminetetraacetic acid). American Resources is in the process of selecting sites to assemble a facility to carry out the chromatography.
“Our vision from the outset was to find a viable and efficient way to capitalize on sources of elements that are going to be critical in a future circular economy with renewable energy and an electrified vehicle fleet,” explains Mark LaVerghetta, head of finance and communications at American Resources. “Our process is unique in that it allows us to recycle and reprocess coal-based waste to help create a sustainable supply chain for REEs, while also cleaning up environmental problems from the thermal coal industry.”