In 2017, Kamoto CopperCopper Company (KCC) upgraded its refinery plant, transitioning from oxide concentrate processingProcessing to treating oxide ore using the Whole Ore LeachWhole ore leach method. This transformation included implementing a counter-current decantation (CCD) plant to remove water from the ore using low-grade (LG) raffinate as a wash solution. This approach optimized sulfuric acidAcid recyclingRecycling, thus significantly reducing quicklime and acid consumptionAcid consumption. However, subsequent efforts to ramp up productionProductions to achieve 300,000 tonnes of copperCopper cathode annually introduced new challenges. The acidAcid content in the LG raffinate began prematurely leachingLeaching copperCopper. The excess copperCopper inadvertently transported to the cobalt plantCobalt plant affected the iron, aluminum, manganese, and copperCopper (FAM-Cu) precipitates, which were recycled upstream to recover residual copperCopper. This led to a volumetric imbalance and reduced the residence time at FAM-Cu precipitationPrecipitation stages, which increased lime consumptionLime consumption triggering urgent plant upgradesUpgrade to fulfil the high lime demandDemand. These new changes resulted in disrupting quicklime slaking reaction further increasing quicklime consumption. To address all these issues, KCC and Glencore’s metallurgical teams implemented a comprehensive mitigation strategy. Key actions involved understanding the complex factors influencing quicklime consumption, enhancing ore quality control, improving laboratory practices, upgrading flowsheetFlowsheet by replacing LG raffinate reporting to the pre-leach plant with LG pregnant leach solution, and optimizing slaking conditions with stricter control. In parallel, a new control philosophy for the CCD circuit was introduced, focusing on optimizing thickener densities. These efforts resulted in substantial reductions in quicklime and acidAcid use, improved process stability, and increased cobalt recoveryCobalt recovery from 60 to 76%.