Quartzite particles,as a bed material,are used in the high density fluidized bed.However,in the operation,a great amount of fines,due to the attrition of quartzite particles,were elutriated,which would result in the decrease of bed material and bed pressure drop,and herein have an impact on the normal fluidization in the fluidized bed.In view of the attrition of quartzite particles,a mathematic model was established based on the Fleischer’s system energy balance theory about the friction attrition mechanism.The condition that the fine particles were separated from the parent particles was based on the least energy principle of material dynamic failure.The particle’s operation characteristics in the fluidized bed and the particle’s physical properties were also considered in the model.This model could explain some factors of the particle’s attrition.Moreover,the predicted value from the model was close to the experimental value.Therefore,this study would be beneficial to the engineering application of the high density fluidized bed.