Multiple-pass High Pressure Grinding Rolls Circuits

HPGR in series can be used to grind a large proportion of the feed to product size but efficiency reduces after the second pass.

.. Smaller-diameter HPGR rolls can increase the breakage of coarse particles in multi-pass circuits.

.. Smaller top-size, steeper size distribution

.. Coarsest particles are not broken efficiently in a thick bed of fine particles