The sequence of solid phase reduction of elements from ferromanganese ores with hydrogen

The main problem of ferroalloy production in Russia is its dependence on imported ore raw materials, despite the presence of its own mineral resource base. This is due to the use of outdated technologies for smelting ferroalloys and obtaining standard, but not always high-quality products by world standards. Russian manganese-containing raw materials are usually of low quality. Therefore, physical and chemical studies and new technologies are needed. This paper presents the results of solid-phase reduction of ferromanganese ore components with hydrogen. Ferromanganese ore from the Keregetas deposit (Kazakhstan) with a high content of iron and arsenic was used as the initial samples. According to the results of the study of the distribution of elements in the original ore, oxides of Si, Mn and Fe are present, in addition, complex phases are found in which several elements Mn, Si, Al are present. The distribution of arsenic is not detected, which is apparently due to its low concentration. The experiments on reduction were carried out in a laboratory furnace of the company RB Automazione MM 6000 at a temperature of 700–1100°C, holding time of 60 minutes and hydrogen consumption of 0.5 l/min. It was found that at a temperature of 700–800°C only iron and arsenic are reduced, with an increase in temperature to 900–1000°C a small part (from 2.8 to 4.4 at.%) of manganese passes into the metal, the oxide phase consists of oxides of active metals that were not reduced under the experimental conditions - manganese, silicon, barium and aluminum. The reduced metal and oxides can be easily separated by melting. The results of the work can be used in the development of theoretical and technological foundations for the processing of substandard ferromanganese ores, which are not processed by existing technologies.