Carbon Sources as a Factor Determining the Activity of Microbial Oxidation of Sulfide Concentrate at Elevated Temperature

oleh: Aleksandr Bulaev, Anna Boduen

Format: Article
Diterbitkan: MDPI AG 2022-01-01

Deskripsi

The goal of the present work was to evaluate the possibility of improving the efficiency of the stirred tank reactor biooxidation of sulfide gold-bearing concentrate by means of addition of carbon sources required for the constructive metabolism of microorganisms. Biooxidation experiments were performed on gold-bearing pyrite-arsenopyrite concentrate in continuous mode at 45 °C to determine the influence of additional carbon sources (carbon dioxide and molasses) on sulfide mineral oxidation. The use of CO<sub>2</sub> allowed increasing the efficiency of the biooxidation and the extents of sulfide sulfur (Ss) oxidation and gold recovery were 79% and 84%, respectively. Biooxidation in a control experiment (without additional carbon sources) and when using molasses allowed achieving 39% and 66% oxidation of Ss as well as 73% and 81% of gold recovery. Analysis of the microbial populations formed in biooxidation reactors using NGS methods demonstrated that CO<sub>2</sub> application led to an increase in the relative abundance of the genus <i>Sulfobacillus</i>. Thus, it was determined that application of additional carbon source makes it possible to manage the biooxidation process, affecting both sulfide mineral oxidation and microbial population composition.