Dual roll crushers, how they functionRolls crushers are effectively used in minerals crushing where the ores are not too abrasive and they are also used in smaller scale production mining of more abrasive metal ores, such as gold. Coal is probably the largest user of roll crushers, currently, though. Coal plants will use roll crushers, either single roll or double.coal roll crusher plant,Roll Crusher - 911 MetallurgistFeb 24, 2018 . Crushing rolls might, logically, include roll crushers of the sledging type, the name, by popular usage, is restricted to the double-roll machine (with either smooth or ... Both single and double-roll crushers have been extensively developed for crushing coal, coke, shale and similar soft and friable materials.