Abstract

FARIA, G. L; REIS, E. L; JANOTTI JR., N.  and  ARAUJO, F. G. S.. Chemical, physical and mineralogical characterization of Azul Mine manganese lump product. Matéria (Rio J.) [online]. 2012, vol.17, n.1, pp. 901-908. ISSN 1517-7076.  http://dx.doi.org/10.1590/S1517-70762012000100003.

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).

Keywords : Manganese ore; lump product; characterization; Azul Mine.