Crusher - an overview | ScienceDirect Topics
A. Gupta, D.S. Yan, in Mineral Processing Design and Operation, 2006 6.1.3 Roll Crusher Circuit Design. Roll crushers are generally not used as primary crushers for hard ores. Even for softer ores, like chalcocite and chalcopyrite they have been used as secondary crushers. Choke feeding is not advisable as it tends to produce particles of irregular size.