Alternative processes for rare-earth extraction from primary and secondary sources

A.F. Bouarab, P. Hajiani
INNORD - Geomega Resources,

Keywords: rare earth elements (REE), cleaner production, hydrometallurgy, recycling, waste valorization


Although there is an abundance of rare-earth elements (REE) resources in North America, there are challenges to their exploitation, namely their relatively low grade compared to profitably mined deposits. A lower REE grade increases the operating costs per ton of rare earth product as well as the environmental impacts of ore processing. Moreover, the volatility of REEs prices makes REE projects risky in terms of capital investment. It is therefore important to have a disruptive REE processing technology to develop an economically robust REE production project that is profitable based on REE bottom prices and sustainable in a Western context, which implies lowering operating costs, while limiting environmental impacts by minimizing residues and effluents. One approach is to reduce the net acid/base consumption by regenerating and recirculating the main reagents within the process which has the advantages of reducing the operating costs and minimizing neutralization effluents. Innord is developing innovative processes for the extraction of REE and other critical minerals contained in various primary and secondary sources (extracted ores, mineral concentrates, mining, and industrial waste streams), which may not be economically, technologically, or environmentally feasible today. The main features of these processes are decreasing volume of residues by valorizing waste as marketable by-products and recycling the main reagents associated to them. For instance, iron being generally a major component of many ores, tailings, and metallic scraps, is an important acid consumer in hydrometallurgical processes. Iron recovery as a marketable product allows to decrease the volume of residues and to provide additional revenues from a traditional and well-established commodity to a rare-earth project. This principle and know-how is currently being applied to various sources of REE and other critical and strategic minerals such as bastnaesite-bearing ores, rare-earth magnet scrap, and bauxite residues.