ETUDE DE L’IMPACT DES MELANGES DE DIFFERENTS TYPES DE MAGNESIE SUR LA QUALITE DES HYDROXYDES DE COBALT PRODUITS AUX USINES DE KCC.

The objective of this work is to find a synergistic mixture of two types of magnesia in order to bring out the operating conditions making it possible to obtain, at the same time, a better Cobalt recovery yield and a good quality of the magnesia cake. Cobalt hydroxide produced at the KAMOTO COPPER COMPANY, KCC in acronym, factories, while minimizing the production cost, two series of precipitation tests using different types of magnesia (MgO) and an economic evaluation were carried out for. The orientation tests carried out showed that the synergy between different types of magnesia had a positive effect on the precipitation of Cobalt in the form of hydroxide, thus making it possible to achieve a precipitation yield of 95.1% with the Delta Mag mixture. + QMag at 50-50 proportion, and a content of 39.5% in Cobalt. The optimization tests led to the best results with the mixture of the same types of magnesia, Delta Mag + QMag, in proportions of 25-75, thus giving the following metallurgical results: Cobalt recovery yield: 99.2%; Cobalt content in the cake: 40%; Manganese content: 2.1% and 7.6% for Magnesium. These last two elements being considered as impurities in the Cobalt hydroxide cake obtained. The economic evaluation, for its part, revealed, contrary to the technical consideration, that it is the mixture of the same types of magnesia, Delta Mag and QMag, in proportions of 50-50 which gives the best results, with a production cost of 1,325.94 USD/tonne of Cobalt content produced, the lowest of all; despite a Cobalt recovery yield of 95.1% and a Co content of 39.5%.