Jaw crushers are typically used as primary crushers, or the first step in the process of reducing rock. They typically crush using compression. The rock is dropped between two rigid pieces of metal, one of which then move inwards towards the rock, and the rock is crushed because it has a lower breaking point than the opposing metal piece.

Jaw crusher movement is obtained by using a pivot point located at one end of the “swing jaw”, and an eccentric motion located at the opposite end.

JAW CRUSHER GOOD PRACTICE :

• Jaw crushers should be fed a consistent rate of feed that will result in the crushing chamber being kept full at all times.
• Deep-chambered jaw crushers will have more rock-on-rock crushing while the feed is passing through, and a better nip-angle.
• Deep-chambered jaw crushers will typically produce more cubical product and have a longer wear life from the manganese per ton processed
• A jaw crusher should not be sized to the maximum size rock that might pass through it. It will result in buying a jaw crusher that will be under-utilized, difficult to keep choke-fed, cost more than necessary, and have a much higher operating cost.
• A jaw crusher should be sized to handle 95-98% of the raw feed material, with the larger sizes being removed prior by using a grizzly.
• Do not feed a jaw crusher with rock larger than its capacity, nor with rock that is smaller than the closed-side setting. This will prevent damage to the jaw, plugging, increase the total plant production, and extend the wear life of the manganese.