A geometallurgical comparison between lump ore and pellets of manganese ore

• Pioneer study about geometallurgical characteristics of manganese ore pellets
• Methodology that characterizes and compares pellets and manganese lump ore
• Characterization of a strategic manganese lump ore and of a product from its fines
• Correlation between mineralogical aspects and the geometallurgical characteristics
• Influences of heat decomposition on the particle disintegration phenomena

Manganese lump ores are still the main raw material used in the manufacture of manganese ferroalloys, but the processing of the ore to the beneficiation point generates fines. So an alternative to be studied is making pellets. This work compares the main geometallurgical characteristics of the lump ore from the Azul Mine and the pellets made from fines generated during beneficiation of this lump ore on a small scale. The characteristics assessed were: the chemical composition, mineralogical constitution, hot and cold particle disintegration, thermal decomposition and solid state reduction. It can be observed that the pellets contain a greater proportion of manganese oxides than the lump ore and they are also richer in Mn. In the pellets the hot and cold particle disintegration phenomena are minimal when compared with those found in lump ore. Lump ore can be efficiently reduced in the solid state, while most of the manganese minerals in the pellets have already been reduced to MnO. The conclusion is that manufacturing pellets in order to take advantage of the manganese ore fines is a path that must be studied further, since the pellets can be used as a viable source of manganese and act as agents that contribute to the increase in permeability of the charge. But possible reductions in the temperature of the granular zone during solid state reduction need to be considered.