Comminution in a non-cylindrical roll crusher

Low reduction ratios and high wear rates are the two characteristics most commonly associated with conventional roll crushers. Because of this, roll crushers are not often considered for use in mineral processing circuits, and many of their advantages are being largely overlooked. This paper describes a novel roll crusher that has been developed in order to address these issues. Referred to as the NCRC (Non-Cylindrical Roll Crusher), the new crusher incorporates two rolls comprised of an alternating arrangement of plane and convex or concave surfaces. These unique roll profiles improve the angle of nip, enabling the NCRC to achieve higher reduction ratios than conventional roll crushers. Tests with a model prototype have indicated that, even for very hard ores, reduction ratios exceeding 10:1 can be attained. In addition, since the comminution process in the NCRC combines the actions of roll and jaw crushers there is a possibility that the new profiles may lead to reduced roll wear rates.