Leaching of nickel-molybdenum sulfide ores with Metallosphaera sedula

The bioleaching of nickel-molybdenum sulfide ores with the thermophilic and acidophilic lithotroph, Metallosphaera sedula, with shaking flasks was studied in order to probe a more efficient and sustainable biometallurgical way. The result shows that the leaching rate of Ni with MetaUosphaera sedula was all more than 91%, but that in the groups without Metallosphaera sedula was 77.64%. The leaching rates of Ni and Mo in the groups with adapted Metallosphaera sedula cultured with Fe²⁺ were 96.56% and 65.43%, those in the groups with unadapted Metallosphaera sedula 94.37% and 60.20%, respectively. The leaching rates of Ni and Mo in the groups when the initial pH was 2 were 97.55% and 62.97% respectively. The leaching rates of Ni in the groups with the sizes less than 0.048 mm and 0.077 mm were 97.58% and 95.37%, while the leaching rates of Mo were 64.46% and 59.54%. The leaching rates of Ni and Mo in the groups with an ore mass concentration of 5 g· L^-1 were higher than the more ore content and reached 98.67% and 81.87% respectively. In the groups with 0.5 g· L^-1 Fe³⁺ added and the contrast group without Metallosphaera sedula, the leaching rates of Ni were 91.19% and 77.64% respectively, while those of Mo were 52.25% and 50.19%. The leaching rates of Ni and Mo in the dialyzing group were lower than those of the undialyaing group. The leaching rates of Ni and Mo in the groups with Metallosphaera sedula were 94.01% and 64,74% respectively, while just 67.77% of Ni and 38.16% of Mo were leached out in the groups with Acidthiobacillus ferrooxidans.