The break-up and particle-size reduction of solid materials into smaller particles and fragments by the process of crushing, grinding, pulverization, attrition, impact, or by chemical methods. It is used to break up ores prior to flotation.
Geology and Earth Sciences
The liberation of valuable minerals from their ores by crushing and grinding the ore to a particular grain size so that the residue is a mix of relatively clean particles of ore minerals and waste. Comminution is carried out initially to make excavated material easier to handle and of a specific size. Comminution theory is concerned with the relationships between energy input and particle size from a given feed size.
Geography
Changing rock debris to fine powder via abrasion and attrition. See Hiemstra et al. (2007) Boreas 36, 4 on comminution in subglacial tills.