Cobalt Alloy Re-Melting and Recovery as Cobalt-Rich Slag: A Position Paper

The rise in cobalt prices and demand is significantly driven by the increasing needs of the electronics and electric vehicle industries. Konkola Copper Mines has a cobalt-to-copper ratio of 1:10 in its ore, which is processed in a concentrator and subsequently recovered as an alloy containing 70% copper and 4%-7% cobalt. The processing of this cobalt alloy presents challenges due to the limited number of plants capable of treating it, thereby creating marketing difficulties. This study aims to enhance the cobalt alloy by producing cobalt-rich slag that is simpler to handle in further processes. The methodology involved re-melting the cobalt alloy containing 3.60% cobalt in a copper bath that was four times its mass, followed by the addition of silica and lime to facilitate phase separation. Fire refining was carried out at a temperature of 1200°C, resulting in the skimming of cobalt-rich slag and casting blister copper into anodes for electrorefining. The findings indicate that this innovative approach not only eases processing challenges but also potentially strengthens the marketability of cobalt products in the context of burgeoning global demand.