Leaching of Low- Grade Nickel Ores by Fungi Metabolic Acids

This study was designed to investigate the nature of nickel and cobalt dissolution from limonite and weathered saprolite ores. Chemical leaching was conducted using 1 to 3M of citric, lactic and malic acids. These tests aimed to mimic metal dissolution achieved using heterotrophic or fungi organism and their corresponding metabolic products. The results in this study was able to demonstrate the effect of secondary reaction or adsorption, pulp density and the potential hampering effect of acid neutralizing minerals and acid activity or strength on metal dissolution. Nickel and cobalt dissolution were also found to be dependent on the nature of the host minerals and amenability of these gangue minerals to dehydroxylate as a result of acid attack