Rare earth elements from waste

Abstract

Rare earth elements (REEs) are critical materials in electronics and clean technologies. With the diminishing of easily accessible minerals for mining, the REE recovery from waste is an alternative toward a circular economy. Present methods for REE recovery suffer from lengthy purifications, low extractability, and high wastewater streams. Here, we report an ultrafast electrothermal process (~3000°C, ~1 s) based on flash Joule heating (FJH) for activating wastes to improve REE extractability. FJH thermally degrades or reduces the hard-to-dissolve REE species to components with high thermodynamic solubility, leading to ~2× increase in leachability and high recovery yields using diluted acid (e.g., 0.1 M HCl). The activation strategy is feasible for various wastes including coal fly ash, bauxite residue, and electronic waste. The rapid FJH process is energy-efficient with a low electrical energy consumption of 600 kWh ton −1 . The potential for this route to be rapidly scaled is outlined.

Current Applications and Future Potential of Rare Earth Oxides in Sustainable Nuclear, Radiation, and Energy Devices: A Review

“…Furthermore, innovative technology to extract REOs from waste materials is suggested by Deng et al (2022) . The ultrafast electrothermal technique based on flash Joule heating was proposed resulting in a two-fold increase in leachability and a high yield recovery rate.…”

“…Furthermore, innovative technology to extract REOs from waste materials is suggested by Deng et al (2022). 59 The ultrafast electrothermal technique based on flash Joule heating was proposed resulting in a two-fold increase in leachability and a high yield recovery rate. Hence, REOs may contribute to developing cost-effective and long-term solutions for ensuring both energy and environmental safety in the future.…”

Scandium Recovery from Aqueous Solution by Adsorption Processes in Low-Temperature-Activated Alumina Products

“…Occupational safety and public health risks related to rare metals must be addressed and analysed for every metal in all the process stages: mining, transportation, processing and disposal, storage of waste and decommissioning of the equipment and production units. Many research papers targeting these issues recommend recovery instead of opening new mining operation units and the rapid return, as much as possible, toward a circular economy [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. Scandium is one of the most valuable metals in the rare metals category.…”

Tailoring a bio-based adsorbent for sequestration of late transition and rare earth elements

“…In that regard, recycling the existing REE-containing materials such as common REE-based magnets needs to be promoted. [8][9][10] However, both mining and recycling require the use of extraction and separation techniques involving large amounts of hazardous reagents and solvents. 5,7,11 The most common technology for REE separation is acidic leaching with various acidic leaching agents, using several precipitation steps to remove unwanted components, after which the product can be calcined and re-dissolved.…”