OXIDATION PROCESS IN IRON ORE MATERIALS AT LOW TEMPERATURES

Using methods of physico-chemical analysis (differentially– thermal and mineralogical) helped to study the oxidation process of magnetite (titanium magnetite) on samples from Olhovsk magnetite and Kachkanar titanium magnetite concentrates at low temperatures (200 –400 °C). Kinetic curves for the studied materials were obtained at different temperatures; they are typical for topochemical processes. Meanings of specific speeds of oxidation of magnetite various size at different temperatures were calculated and sizes of apparent energy of activation of the process were defined. The influence of partial pressure on kinetics of oxidation in gas phase was studied to expose the limiting point of the process of oxidation of magnetite and titanium magnetite. The order of oxidation reaction on oxygen at definite temperatures and the oxidation degree was calculated using graphical methods. The influence of titanium inclusions in magnetite on kinetics of phase change of magnetite–hematite was examined at the temperature interval of 200 –400 °C, it happens in mixed operational parameters. Then the process comes to diffusive operational parameters. Kinetic principles and the character of oxidation of the studied materials in nonisothermical conditions were defined at different speeds of heating. These results are of some interest and can be used to optimize the low temperature oxidation regimes of iron ore materials on a conveyor roasting machine. 

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