Modeling of the Bioleaching of Process Silver Pulp

Modeling of the bioleaching process applied to the system silver-manganese (Ag-Mn) was carried out. The two-moving-fronts model was used to describe the main stages of the process. Bioleaching involves a catalytic process carried out by bacteria to dissolve the mineral ores. Initially, the bacteria interact with the mineral to dissolve manganese, leading to the precipitation of silver. The Ag-Mn compound is dissolved by the bacteria in two stages. First, the bacteria dissolve the manganese and form a biofilm composed mostly of exopolysaccharides. In the second stage, the biofilm is consumed by the bacteria, ending up in dissolved manganese and silver precipitation. At 48 h, the viscosity of the pulp reaches a maximum attributed to the maximum concentration of extracellular polysaccharides in the medium. Predictions describe the basic issues of the bioleaching process in this system. A new model for the bioleaching process of silver is used to theoretically describe available experimental data. The model is based on the two-moving-front description of mineral bioleaching. The model quantitatively predicts the evolution of the silver mass fraction and the minimum in the biofilm mass fraction, related to the maximum in the rheological properties. image

Automated summary

This study models and describes the bioleaching process in the silver-manganese (Ag-Mn) system, revealing its main stages and basic issues. The results show that bacteria dissolve manganese and form biofilms in two stages to dissolve and precipitate silver and manganese. The maximum concentration of extracellular polysaccharides and the viscosity of the pulp are positively correlated.