The effect of powder filling on selection and breakage functions in batch grinding

Abstract

The effect of powder filling on selection and breakage functions is investigated in this paper. At three levels of powder filling, the selection functions are determined by one-size-fraction tests. The selection function is found to decrease rapidly with increasing powder filling. The breakage functions obtained by direct measurement are studied. When the powder filling is very low, the breakage function appears to be higher. Because of the non-normalization of the breakage function in this work, back-calculation method for determination of the breakage function is applied. It is found that for the non-normalized breakage function, if the selection function is known, it is possible to back-calculate a normalizable breakage function which gives the best simulation results. Finally, the effect of powder filling on product size distribution is studied. It is found that this effect can be totally compensated by adjusting the grinding time.