Optimizing the Extraction of Rare Earth Elements from Char by Combining Physical Beneficiation and Acid Leaching in the Context of Techno-Economic Analysis

The sustainable recovery of rare earth elements (REE-Y) from electronic waste is critical for clean-energy technologies. Yet, the commercial viability of recovering REE-Y from shredder residue char (SR-char) remains unexplored. Because recovery processes are heavily influenced by operational costs, evaluating economic feasibility alongside metallurgical performance is essential. This study assesses a hybrid physical–chemical process using SR-char, integrating particle size classification and dry magnetic separation with optimized hydrochloric acid leaching. A first-order gross-profit screening model was also developed to evaluate the direct reagent economics of the proposed process. This framework calculates Revenue minus Acid and Neutralization Costs only, excluding capital expenditures (CapEx), labor, utilities, downstream separation losses, and the cost of the magnetic separation step. Results show that magnetic separation at 8000 G pre-concentrated REE-Y to >1800 g/t, and subsequent 10 M HCl leaching (60 °C, 3 h) yielded extractions of ~2000 g/t in the 500–1000 µm fraction. However, the profit model showed that maximizing extraction in the presence of high concentrations of other metals, such as Fe, Ca, and Al, results in net financial losses due to excessive reagent and neutralization costs. We conclude that physical pre-concentration to reduce non-target metal content is a critical commercial prerequisite.