Reductive kinetics of the reaction between a natural ilmenite and carbon

摘要

The reductive degree and rate of Bama ilmenite concentrate by graphite under argon atmosphere were measured by using thermogravimetric analysis system at the temperatures from 850 deg C to 1400 deg C. The reduction degree of the ilmenite increased with temperature rise, the case similar to reaction rate. The higher the temperature was, the faster the reaction rate was. The phases before and after reduction and the morphology of reduced samples were identified by using X-ray diffraction and optical microscopy analysis, respectively. The reduction degree of the ilmenite decreased due to the presence of impurities. Manganese and magnesium oxide-rich zones formed which prevented complete reduction of Fe~(2+). In general, the reaction products were iron, Ti_3O_5, reduced rutiles and pseudobrookite solid solution. The kinetics was also discussed and it was found that the rate-controlling steps were different in the different temperature ranges.