Manganese Ores used for Production of High Carbon Ferromanganese: Studies on properties and reduction of manganese ores-I

To study on the reducibility of some manganese ores which are used for ferromanganese production, we investigated their properties in the first place. We obtained the following results of X-ray diffraction, differential thermal analysis and thermal balance analysis. (1) Foreign ores are mostly MnO2 ores, and their attendant minerals are MnO·OH, 3Mn2O3·MnSiO3, hydrated Mn oxide, SiO2, etc. MnO2 ores have α-, β-, γ- and/or δ-phases and most of them are these mixtures. (2) In every MnO2 ore, γ- and δ-phases are incompletely crystalline, and they are reduced to Mn2O3 or Mn3O4 easily at comparative low temperature. Ghana ore, which is γ-MnO2, belongs to the above group, and is expected to have high reducibility. (3) Domestic ores are mostly manganese carbonate ores or silicate ores, and mineral compositions of burnt ores represent variations in the burning temperature and atmosphere. (4) Quantitative studies on such mineral compositions will be continued futhermore.