The dehydration kinetics of Sebinkarahisar (Gedehor) alunite ore in a fluidized bed was investigated. It was observed that the dehydration reaction rate increased with increasing temperature and decreasing water vapor pressure. However, the particle size and air flow rate did not have a significant influence on the dehydration rate. On the basis of these conversion-time relations, the dehydration process was assumed to be controlled by chemical reaction. By nonlinear regression analysis, the Avrami model was found to fit the kinetic data best. n similar to 1, the high activation energy value (209 M mol(-1)), and scanning electron microscopic photographs of the calcined ore supported this control mechanism.