In this study, Carbothermic reduction of Molybdenite in the presence of Magnesium oxide and calcined Dolomite has been thermodynamically studied. Also the effect of Mechanical activation on structural evolution and reduction behavior of Molybdenite with carbon in two mixtures of MoS2-C-MgO and MoS2-C-CaxMg1-xO has been investigated. It was found that the reaction proceeds through direct oxidation of MoS2 by CaO and MgO to form intermediate molybdenum oxidized species, MoO2, MgMoO4 and CaMoO4. The results showed that the Reduction of oxidized species leads to the formation of Mo, Mo2C, MoC or MgO and CaO products. Also the results showed that the gaseous phase was mainly composed of CO. Mechanical activation was performed on the mixtures (molybdenite: Graphite: Magnesium oxide =1:2:2 and molybdenite: Graphite: calcined Dolomite =1:2:2) in argon atmosphere for different time periods (0-50 hours), using a planetary ball mill. Structural and phase changes in the powder mixtures were investigated by X-ray diffraction (XRD). The Results showed that no reaction occurred in the mill to produce new phases in the mixtures. Changes in Molybdenite crystallite size and structural micro strain were studied based on integral breadth analysis of obtained XRD patterns. However by mechanical activation the grain size and structural strain of Molybdenite were decreased and increased, respectively. The Parameters (?/d) and ?/tan? were introduced for evaluation of the degree of mechanical activation in different mixtures.The Results showed that the activation i MoS2-C-MgO mixture was lower than MoS2-C-CaxMg1-xO. More over Scanning electron microscopy (SEM) was carried out in order to investigate the morphological changes in the structure due to milling. SEM observations revealed that mechanical milling produces a compacted composite structure of particles. The effects of Mechanical activation on the reduction of different samples were thoroughly investigated by simultaneous Thermal Analysis (STA). The samples were heated in argon atmosphere with the linear heating rates of 10, 15, 20 ?C/min. the plots of process conversion degrees versus temperature showed that by mechanical activation for 50 hours, the starting reduction temperature of reduction in two mixtures (molybdenite, Graphite, Magnesium oxide) and (molybdenite, Graphite, calcined Dolomite) decreased 190?C and 240 ?C, respectively. Kinetics of Molybdenite carbothermic reduction in non-isothermal conditions were studied by model- fitting (Coats-Redfern) and model-free (Ozawa, Friedman, Kessinger) methods. It's was found that the Boudouard reaction was the controlling step in the carbothermic reduction of Molybdenite in . The
