Technoeconomic Analysis of the Supercritical Fluid Extraction Process for the Extraction of Rare Earth Elements from Ores

This study investigates the technoeconomic feasibility of utilizing supercritical fluid extraction (SCFE) with supercritical CO2 and a tributyl phosphate–nitric acid (TBP-HNO3) adduct for recovering rare earth elements (REEs) from the complex zircon-rich mineral concentrate. A detailed technoeconomic analysis (TEA) framework is employed, integrating mass and energy balance calculations, economic modeling, scenario evaluation, and sensitivity analysis. The research aims to establish the economic viability and scalability of SCFE technology as a sustainable alternative to conventional extraction methods. The study focused on an industrial-scale facility in Ontario, Canada, equipped with a 4000 L SCFE reactors. Key findings included first-year operational expenditures approaching 3 million USD and total capital expenditures of 13.7 million to 14.6 million USD. Revenue from the extracted REEs varied, with the highest returns associated with high-value elements such as terbium and dysprosium. Sensitivity analysis highlights that the profitability of the process is most sensitive to REE prices, particularly for Nd2O3, Dy2O3, and Tb4O7, followed by reagent costs and utility expenses. Payback periods ranged from 6.9 years in the optimal scenario to 12.8 years in less favorable configurations. This study demonstrates the potential of SCFE as a viable technology for REE recovery, emphasizing the importance of feedstock optimization, cost-effective reagent usage, and scalability.