Comminution is an essential part of mineral processing which involves the breakage of ore to
achieve size reduction. Its aim is to increase the likelihood of separation and liberation of
valuable minerals from gangue in subsequent processing stages (Napier-Munn et al. 1996
Fuerstenau 2003 Wills and Napier-Munn 2015). Ore breakage in comminution occurs in three
forms namely blasting crushing and grinding (Kapur et al. 1997 Le Pham 2011 Yahyaei et
al. 2016). During blasting ore breakage occurs by means of explosive devices. In crushing it
occurs via mechanical compression of ore against hard surfaces (Unland and Szczelina 2004). In
the case of grinding ore breakage takes places through a combination of two or more of: impact
(ores drop against a rigid body or media drop against ores) abrasion (ores of similar size
shear against each other) and attrition (relatively big ores grind smaller materials) (Austin
2002 Le Pham 2011 Wills and Napier-Munn 2015).Comminution is well known to be highly
energy-intensive. Previous studies have shown that comminution typically accounts for 50% of
the energy consumption in a mineral processing circuit and globally comminution activity
accounts for about 0.2% of the world's electricity supply (Napier-Munn et al. 1999 Ballantyne
and Powell 2014). In addition the process has been shown to be inefficient in that a small
fraction of the energy supplied is directly utilised for rock breakage (Tromas 2008). The
remaining energy is either lost as heat (Radziszewski 2013) carbon dioxide (CO2) emissions
(Norgate and Haque 2010) or absorbed by the comminution equipment causing wear and degradation
(Weerasekara et al. 2013).
