St. Petersburg Mining University (St. Petersburg, Russia):

Saltykova S. N., Associate Professor, Candidate of Engineering Sciences, saltykova_sn@spmi.ru
Nazarenko M. Yu., Assistant, Candidate of Engineering Sciences, max.nazarenko@mail.ru

Research into the role of microorganisms in the destruction of silicates is gaining momentum due to the development of a new area based on the use of bacteria in mineral processing technologies. The aim of this work was to study the effect of preliminary biological treatment of copper-molybdenum off-balance ores on their further processing. Head and biologically treated copper-molybdenum ore was studied. The samples were placed in a muffle furnace and heat-treated. The calcination was performed at 400, 450, 500, 550, 600 and 650 °C. The calcination and leaching studies conducted for off-balance refractory copper-molybdenum ore, as well as a comparison of the results of these processes in the presence of preliminary biotreatment, have shown that biotreatment facilitates the liberation of copper minerals and improves copper recovery into the solution both with and without calcination before leaching. This is explained by the destruction of the crystalline structure in the ore materials and by the facilitation of access to copper-containing minerals for oxygen (in calcination) and chemicals (in leaching). Preliminary biotreatment allows separating the maximum amount (up to 12 % of the sample weight) of the magnetic fraction already at 400 °С, which will positively affect the subsequent leaching process. When the proposed process flow is applied for the processing of off-balance copper-molybdenum ore, two by-products are generated: the magnetic fraction and the leaching residue. The former may be used in ferrous metallurgy as a flux in the production of pig iron and steel, and the latter may be applied in the manufacture of building materials.

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