The mechanisms of conversion to elemental sulfur, sulphites, sulfates and others; they are diverse, leading to the formation of sulfuric acid and therefore, to the acidification of the medium. Based on these characteristics, acidophilic bacteria are considered as sulfur chemolytotrophs, since they obtain their energy from the conversion of sulfur compounds and, in most cases, the final product is sulfate. The acid formed by these bacteria that oxidize sulfides is sulfuric acid. Similarly, bacteria isolated from acid drains, during their metabolic action, generate a decrease in pH. The Thiobacillus genus is relevant among the others for its ability to oxidize sulfur compounds, producing elemental sulfur extracellularly. The energy required to carry out its functions is derived from the oxidation of one or more reduced sulfur compounds including sulfide and thiosulfate. In the study of the...

The mechanisms of conversion to elemental sulfur, sulphites, sulfates and others; they are diverse, leading to the formation of sulfuric acid and therefore, to the acidification of the medium. Based on these characteristics, acidophilic bacteria are considered as sulfur chemolytotrophs, since they obtain their energy from the conversion of sulfur compounds and, in most cases, the final product is sulfate. The acid formed by these bacteria that oxidize sulfides is sulfuric acid. Similarly, bacteria isolated from acid drains, during their metabolic action, generate a decrease in pH. The Thiobacillus genus is relevant among the others for its ability to oxidize sulfur compounds, producing elemental sulfur extracellularly. The energy required to carry out its functions is derived from the oxidation of one or more reduced sulfur compounds including sulfide and thiosulfate. In the study of the...

The study was carried out with isolated strains of acid drainage and consisted of processing of highly mineralized copper sulphides that mainly contained 45.30% pyrite and 13.12% arsenopyrite. Bioleaching was carried out in 500 ml flasks, where 300 ml of 9k medium, 30 ml of bacterial inoculum (10% V / V) of 7.05x107 Cell / ml and various amounts of FeSO4.7H2O were added. The pH was regulated to 1.8 and they were subjected to platform agitation with 150 RPM at ambient temperature of 20 ° C on average. The tests were carried out in three successive stages at different concentrations of ferrous salt. In the first stage, 72.64% copper was obtained with 6 g / l of FeSO4.7H2O in 22 days. In the second stage, 85.6% of copper was achieved in the absence of the ferrous salt. Greater bacterial growth was also achieved with 15 g / l FeSO4.7H2O and 25.62% copper recovery in 24 days of leaching; In ...

The study was carried out with isolated strains of acid drainage and consisted of processing of highly mineralized copper sulphides that mainly contained 45.30% pyrite and 13.12% arsenopyrite. Bioleaching was carried out in 500 ml flasks, where 300 ml of 9k medium, 30 ml of bacterial inoculum (10% V / V) of 7.05x107 Cell / ml and various amounts of FeSO4.7H2O were added. The pH was regulated to 1.8 and they were subjected to platform agitation with 150 RPM at ambient temperature of 20 ° C on average. The tests were carried out in three successive stages at different concentrations of ferrous salt. In the first stage, 72.64% copper was obtained with 6 g / l of FeSO4.7H2O in 22 days. In the second stage, 85.6% of copper was achieved in the absence of the ferrous salt. Greater bacterial growth was also achieved with 15 g / l FeSO4.7H2O and 25.62% copper recovery in 24 days of leaching; In ...