Innovative coupled hydrometallurgical and pyrochemical processes for rare earth recycling

International audienceRare earth elements (REE) are regarded today as highly critical raw materials but currently lack suitable recycling processes. A combined hydro- and pyrometallurgical process aimed at REE recovery from used NdFeB permanent magnets was recently developed by the CEA. The process integrates the physicochemical treatment of magnets, followed by a solvent extraction step for the recovery and intra-REE separation using a selective extractant. A subsequent pyrometallurgical treatment via molten chloride salt electrolysis allowed the isolation of pure Dy or Nd metals. Techno-economic assessment and life-cycle analysis were equally conducted. Following this first successful technical demonstration, a new project has been launched in collaboration with industrial and academic partners for the recovery of REE from end-of-life nickel-metal-hydride batteries. The project aims at evaluating from an experimental and techno-economics perspective different processes converging at the production of value-added products such as cermet materials for catalysis applications, purified REO concentrates or metallic alloys. This paper will illustrate some of the main insights of this project