Rare earth elements from waste

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 degrees C, similar to 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 similar to 2x increase in leachability and high recovery yields using diluted acid (e.g., 0.1 M HCI). 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.

Automated summary

Rare earth elements (REEs) are critical materials in electronics and clean technologies. Researchers have developed an ultrafast electrothermal process to improve the extractability of REEs by activating waste materials. This process is energy-efficient and applicable to various types of waste.