LEACHING OF A Cu-Co ORE FROM CONGO USING SULPHURIC ACID-HYDROGEN PEROXIDE LEACHANTS

This study investigates the leachability of copper (Cu) and cobalt (Co) from a Cu-Co ore sourced from Katinga Province, Republic of Congo, characterized by 1.5% Co and 1.6% Cu, utilizing a mixture of sulphuric acid and hydrogen peroxide under various conditions. The objective was to optimize extraction rates for both metals. Experimental conditions varied acid concentrations from 0.36 to 1.1M, assessing modifications with hydrogen peroxide at concentrations between 0.008 and 0.042M. Results indicated that without hydrogen peroxide, maximum copper extraction reached approximately 80%, whereas cobalt extraction was approximately 15%. The addition of hydrogen peroxide enhanced copper recovery to ~90%, and cobalt recovery to ~90% at 20°C with a 0.36M sulphuric acid and 0.025M hydrogen peroxide solution after 3 hours. The rate of cobalt extraction accelerated to less than 2 hours at 30°C. Stabcal modeling demonstrates the role of hydrogen peroxide as a significant reductant, confirmed by Eh measurements indicating a potential decrease of 300-350 mV. Kinetics of the leaching process followed the shrinking core model, indicating a linear relationship with hydrogen peroxide concentration. The activation energy for the leaching process was determined to be 72.3 kJ/mol.