Coal plants will use roll crushers, either single roll or double roll, as primary. Single Roll Crushers - Mineral Processing & Extractive Metallurgy Mar 31, 2016 . 1 Crushing Action; 2 Discharge Product; 3 Feed Size; 4 Capacity; 5 Applications . the single-roll crusher the following stages may be observed: first, there is a . of contact on the face of the roll where the teeth can get a full bite on the rock. .