Gyratory crushers are used as the primary crusher for hightonnage open pit operations with throughputs above 450 t/h (500 tph) because jaw crushers do not have enough capacity.
Below 450 t/h (500 tph), jaw crushers generally are used because of their lower cost. Jaw crushers are also selected for underground crushing plants if the shaft diameter limits the size of equipment that can be handled. For surface installations with over 450 t/h (500 tph), both crushers should be considered.
Some of the differences between jaw and gyratory crushers are as follows:
1. The capacity of a gyratory crusher is much greater than that of a jaw crusher handling the same size of feed.
2. Gyratory crushers can be choke fed by direct dumping from trucks. Jaw crushers cannot be choke fed; they require a scalping grizzly and a feeder .
3. Jaw crushers typically require less maintenance. Since the liners are reversible, the scrap metal loss is usually low.
4. The ratio of full load to idling power is about 2.2 for jaw crushers and 3.3 for gyratory crushers. Therefore, the gyratory that idles more also saves more while idling. In terms of reduction tons, the gyratory does double the work for the same expenditure of energy.
5. A gyratory primary crushing installation will normally cost more than a jaw crusher installation. There are, however, a number of trade-offs, and an engineering estimate is often required.