The question you posed about trying to control product size is well understood by mineral milling specialist around the world.

First, the product strength properties must be identified by laboratory experimental analysis to define the Breakage Function (B) dependent on size et al. Second, the incomming particle size distribution needs to be know. Third, the comminution process needs to be quantified to determine the Selection Function (S). Once B and S are known, using Population Balance Modeling (PBM), the product size distribution can be determined or altered to suit other comminution equipment. Changes in incomming size can produce more or less the same product specifications by altering the manner of feed, et al. The same product size may be attainable with different incomming product properties. The process can be modeled using DEM (discrete element method) or DSG (discrete grain breakage).

See the available input from SAG2001 in Vancouver.

I would be glad to give more input if this sounds of interest. We have the expertise to do the above and to look directly a modeling particle fracture during comminution as introduced on our web site: (being revised today)

Lawrence Nordell
Conveyor Dynamics, Inc.
1111 West Holly St
Bellingham, WA 98225 USA
ph 360/671-2200
fx 360/671-8450