Caracteriza？？o química, física e mineralógica do produto granulado de manganês proveniente da Mina do Azul

the manganese ores from azul mine are important raw materials for ferro alloys production. for improvements in the manganese ferro alloys production, azul's lump ore product was characterized. a representative sample from the mine has been obtained and their particle sizes were classified. the size distribution showed that 80% of particles were below 22.6mm and 50% were below 12.5mm. the particles with sizes between 37.5mm and 6.3mm were named lump ore product. the fraction between 37.5mm and 6.3mm was submitted to chemical and mineralogical characterization. the tga tests showed weight losses in 300oc, 500oc, 700oc, 900oc and 1000oc due, mainly, the high manganese oxides decompositions. the mn, fe and sio2 contents were, respectively, 47.68%; 3.59% and 3.16%. azul's lump product has cryptomelane[kmn8o16] and pyrolusite[mno2] as main mineralogical constituents. todorokite[(na,ca,k)2mn6 o12？3-4.5(h2o)], magnetite[fe3o4] and gibbsite[al(oh)3] appear as minor constituents (pyrolusite, magnetite e gibbsite were identified by optical microscopy).