In present study, the effect of extrusion process on kinetic of carbothermal reduction of barite was investigated. In order to improve the gasification rate potassium carbonate was doped on coke as catalyst. The mixture of barite and coke powder was shaped by a laboratory extruder and the reduction process was isothermally carried out at four temperatures, ranging 850-1000 degrees C. The effect of extrusion process on conversion of barite was evaluated by iodometry method. Also, a modified kinetic model was used to analyze the conversion data. The experimental results revealed that the extrusion process can effectively promote the rate constant both in catalytic and non-catalytic runs. It was proved that the rate of reaction is controlled by active site density in the presence of potassium carbonate and the extrusion process reduces activation energy approximately, 20 kJ/mol. Finally the reduction time was optimized to achieve the maximum conversion in the absence and presence of catalyst. (C) 2010 Elsevier B.V. All rights reserved.