Transitioning to green energy requires more sustainable rare earth element (REE) production. The current REE supply relies on energy- and chemical-intensive mining, prompting interest in alternative sources like phosphogypsum (PG) waste. However, using conventional solvent extraction to recover REEs in PG is inefficient and environmentally burdensome. This study proposes a treatment train for REE recovery from PG, featuring a bioinspired adsorptive separation, and evaluates its environmental and economic performance using a probabilistic sustainability framework that integrates life cycle assessment (LCA) and techno-economic analysis (TEA). Results show the system achieves an internal rate of return (IRR) above 15% in 87% of simulations, suggesting strong profitability potential. Environmentally, it outperforms conventional REE mining and PG treatment in ecosystem quality and resource depletion but shows higher human health impacts. Scenario analysis reveals profitability at processing capacities over 100 000 kg·h-1 for PG with REE content above 0.5 wt %. However, more dilute sources (0.02-0.1 wt %) are not viable under current conditions due to acid and neutralization costs. This study offers the first in-depth sustainability assessment of REE recovery from PG waste and highlights key areas for future process development to improve access to low-grade sources and enhance environmental outcomes.
Smerigan et al. (Mon,) studied this question.