Since metallurgical processes take place at high temperatures and pressures, aspects of thermodynamic
processes occupy a special place. In particular, when smelting grades of manganese alloys in ferroalloy production, high losses of manganese with the slag and gas phase are directly related to the reduction process. This article presents thermodynamic comparative calculations of the processes of reduction of margene oxide with carbon, silicon and aluminum, which occur during the melting of various grades of ferromanganese. As shown by the results of calculations, it is proved that the oxidation of manganese by the carbothermic method occurs at high temperatures, and by the metallothermic method-at correspondingly low temperatures, that is, aluminosilicates are formed. In addition, it was
found that the reduction reactions in the presence of silicon and aluminum proceed in the forward direction in the studied temperature ranges of 298.15-2773 K. According to the results of the studies, the value of the Gibbs energy change in the temperature range 298.15-2773 K was calculated for the reduction reactions of manganese silicon and aluminum. As practice shows, the metallothermic method (silicon and aluminum) has an optimal effect on the oxidation process, i.e. increases the technical and economic indicator of melting (increases the supply of basic elements, reduces electricity losses). As reducing agents containing silicon and aluminum, an aluminum-silm-manganese alloy can be used to reduce manganese.

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