High-Temperature Oxidation Behavior of Vanadium, Titanium-Bearing Magnetite Pellet

By means of isothermal oxidation and chemical analysis, great importance was attached to the parameters that made effects on the oxidation degree of vanadium, titanium-bearing magnetite pellet in high-temperature processing (1 073 - 1 323 K). Based on the experimental data, oxidation kinetics of pellet was analyzed according to shrinking unreacted-core model subsequently. Experiment results display that the oxidation degree of pellet increases with increasing of oxidation time, oxidation temperature and oxygen content, as well as shrinking of pellet diameter. Under the condition of oxidation time 20 min, oxidation temperature 1 223 K, oxygen content 15%, and pellet diameter 12 mm, oxidation degree of pellet reaches 92. 92%. The analysis of oxidation kinetics indicates that oxidation process of pellet is controlled by chemical reaction with activation energy 68. 64 kJ/mol at a relatively lower temperature (1 073 - 1 173 K). Oxidation process of pellet is mixed-controlled by chemistry reaction and diffusion with activation energy 39. 66 kJ/mol in the temperature range of 1 173 - 1 273 K. When oxidation temperature is higher than 1 273 K, the limited link of oxidation reaction is the diffusion control with the activation energy 20. 85 kJ/mol. These results can serve as a reference to the production of vanadium, titanium-bearing magnetite pellet.