Kinetics of Carbothermic Reduction of Molybdenite in the Presence of Magnesium Oxide

In this research, the kinetics of carbothermic reduction of molybdenite in the presence of magnesium oxide was studied. Powder samples with a stoichiometric ratio (molybdenite: magnesium oxide: Graphite 1: 2: 2) prepared under simultaneous thermal analysis (STA), with three heating rates of 10, 15 and 20 degrees per minute, respectively. A series of experiments were performed under isothermal argon atmosphere, to determine the intermediate phases formed during the process. The results showed that the process temperature range was 900 ºC to 1400 ºC and with the formation of intermediate phases of molybdenum oxide (MoO2) and magnesium molybdate (MgMoO4) goes. Kinetic investigations were done with the free model methods such as Friedman, Ozawa and Kissinger as well as model fitting method Coats - Redfern. The results of all methods were in good agreement with each other and suggested that the mechanism of the reaction was chemical control and activation energy was about 425 KJ/mol.