Resources Recycling ISSN:2765-3439(Print) 2765-3447(Online) 자원리싸이클링

This study analyzes the cost structure of rare earth element (REE) processing plants based on their feasibility assessment data from 6 overseas REE mining projects. REE metallurgical processing involves the production of high-purity REE mixtures through a series of unit operations such as leaching, precipitation, and filtration following physical concentration. Significant expenditures are required for REE processing plants, which are broadly categorized into capital expenditures (CAPEX) and operational expenditures (OPEX). The cost analysis revealed that, for projects with a final production capacity ranging from 6 to 50 tons per day, total direct CAPEX ranged from USD 130 million to 720 million. Of this, the direct CAPEX attributable to the processing plant alone was approximately USD 30 million to 250 million. Meanwhile, the total OPEX ranged from USD 12 to 31 per kilogram, with the processing plant-specific OPEX falling between USD 6.1 and 15.1 per kilogram. An analysis of the correlation between final production capacity and CAPEX for the surveyed mining projects indicated that both total direct costs and processing plant CAPEX followed a nonlinear curve with an exponent of approximately 0.7 to 0.9 (R² > 0.9) as production increased. This suggests that the unit investment cost for REE processing plants may converge toward a stable value as production capacity increases. Furthermore, while the total OPEX per kilogram showed a gentle nonlinear decline with an exponent of -0.23 as final production increased, the processing plant-specific OPEX did not exhibit a similar trend. The findings from this cost analysis of REE processing plants must be validated through future studies involving actual field performance and detailed cost breakdowns. In addition, reasonable evaluation of economic feasibility will require careful consideration of the composition of various REEs in the final product and corresponding price fluctuations.