ESTIMATING BREAKAGE OF FINE ORE PARTICLES BY MEDIA IN A SMALL BALL MILL USING DEM

摘要

Most DEM analyses of ball and stirred mills reported to date have considered only media motion andits interaction with the mill lifter configuration. For SAG mills, a large fraction of the feed materialcan already be well represented in DEM models. But for other mill types with much finer feed, thenumber of feed particles has been prohibitive to include them directly in the calculations. The C-MIScode is now sufficiently powerful to allow inclusion of ore particles within a short periodic section ofa small pilot (or large lab) scale mill. This provides the opportunity to better understand the effect ofmedia on the interstitial bed of powder and of the powder on the media.In this paper, the complete pilot mill was first simulated with media only included. A truncatedsize distribution was then used to represent ore particles in a periodic simulation of about one tenthof the mill length. The results allowed for analysis of the effect of rock on the overall flow, and theinfluence of the flow and collisional environment on the fine ore particles. The normal, shear andtotal energy consumptions were also analysed for different powder fill levels.