Minimisation of Cobalt Coprecipitation During the Removal of Iron, Aluminium, and Manganese in the Cobalt Circuit (FAM) by Oxidising the Bath with Hydrogen Peroxide, Case Study: The METALKOL Hydrometallurgical Plant in the Democratic Republic of Congo

The removal of impurities from cobalt-bearing solutions is an important step in the processing of cobalt to obtain a high-quality product. The main problem at this stage is the loss of cobalt that occurs through coprecipitation. A sample of cobalt-rich solution was taken from the feed to the Iron, Aluminium and Manganese (IAM) circuit at the Metalkol hydrometallurgical plant in the Democratic Republic of Congo. The pH and potential were the parameters studied to assess their effect on the overall process. After contact with 20 ml of a 30 g/l concentrated hydrogen peroxide solution and 27.3 g of calcium carbonate, the results showed a significant reduction in cobalt loss and a high level of impurity removal, with the exception of manganese, which could not be removed.