Evaluation of Mesophilic Species Performance in Extraction of Cobalt and Manganese from Hot Filter Cake of Zinc Processing Plant

Cobalt, recognized as one of the scarcest industrial metals, is typically discarded during the zinc production process in the high-temperature refining section, along with manganese. This waste product is colloquially referred to as 'hot cake.' The present study endeavored to segregate cobalt and manganese from the hot cake and transition them into the liquid phase via bioleaching, a method that is both economically and environmentally superior to pyrometallurgical techniques. In the hot cake, cobalt exists as Co (III) and manganese as Mn (IV). Given their oxidized states, both cobalt and manganese are insoluble in acid and necessitate reduction for dissolution. The study employed Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans bacteria to create an environment conducive to the reduction of cobalt and manganese. Under optimal conditions, this biotechnological approach facilitated the recovery of 62.8% of cobalt and 91.6% of manganese. Subsequently, a model was developed to predict the optimal method for processing cobalt from hot cake, based on the recovery rates of cobalt and manganese. This research contributes to the broader goal of resource recovery and waste minimization in the metal industry.