Analysis of the compositions of manganese ores and charges for the production of agglomerate from the position of phase structure diagrams of manganese-containing systems

Abstract

This paper studies the phase formation processes during the agglomeration of manganese ores of the "Tur" deposit. When introducing dolomite into the composition of the agglomeration batch from the position of thermodynamic-diagram analysis MgO-MnO-CaO-Al₂O₃-SiO₂, it is shown that the phase composition of the substance’s changes in a certain sequence with entry into one or another pentatope and depends on the completeness of the interaction of dolomite with manganese ore. Adding dolomite to the agglomeration batch leads to the formation of refractory compounds due to the latter's interaction with low-melting manganese compounds. The most low-melting compound in the spessartite system (t_melt=1205 ºС), present in the screenings of manganese ores, when interacting with dolomite, will form more refractory compounds of forsterite Mg₂S (t_melt=1860 ºС) and diopside CMS₂ (t_melt=1391.5 ºС). As a result, the addition of dolomite to the sinter batch of more than 8.4% leads to the transition of the agglomerate composition from pentatope No. 4 (M₃AS₃-CAS₂-M₂S-Mg₂S-S) to pentatope No. 3 (СMS₂-CAS₂-M₂S-Mg₂S-S), in which spessartite M₃AS₃ is absent.