HOW LEWATIT® ION-EXCHANGE RESINS CAN ADD VALUE TO SOLVENT EXTRACTION CIRCUITS

A complementary ion exchange/solvent extraction process for the recovery of copper from low-grade ores is described, which has successfully been implemented at the Buchim Copper Mine in Macedonia, achieving a maximum copper cathode production of 2400 tons per year. This technology enhances the economic viability of low-grade copper ores by reducing operational and capital expenditures compared to conventional SX/EW operations. The integration of additional Lewatit® ion-exchange installations significantly decreases the volumes of harmful organic substances in the subsequent SX step, thereby minimizing environmental risks and managing chemical handling. Moreover, the reduced liquid quantities required for the SX operation lead to a 50% decrease in the plant's footprint, contributing to further capital expenditure reduction. This paper reviews the main stages of the combined IX/SX process, highlighting its applications in metal recovery and presenting key findings from various projects. A comprehensive technical comparison is also provided, emphasizing the benefits of the combined IX/SX technology as a purification and separation step, aimed at optimizing overall copper recovery and achieving suitable copper concentrations in advanced electrolytes. The implementation of an IX process is found to be advantageous for processing different copper-bearing solutions and in enhancing recovery and cathode quality.