There was however a difference
in the average grain size with the dry milling producing a smaller
d50 grain size than wet milling. The crushing technique however made no difference to the average grain size for BMS’s.Different
trends were observed for the PGMs. The cone crusher followed
by dry milling (CC–DM–MS) produced a greater percentage
liberation than the cone crusher sample followed by wet milling
(CC–WM–SS and CC–WM–MS). The HPGR sample however showed
little difference in liberation between wet and dry milling although
in PGM liberation the percentage values were greater than for the
equivalent cone crusher samples. The PGM grain size generated
was slightly smaller for the dry milled samples. There was little difference in liberation and grain size between the mild steel and
stainless steel samples.