Ballast refers to the coarse sand and gravel used in roads and railways. In the railway transportation system, it is usually used to support the crossties of rails. Before paving crossties and rails, a layer of gravels would be paved on the road base and then pressed tightly. The use of ballast is beneficial to drain water and adjust position of rails. Meanwhile, ballast plays an important part in dispersing the weight of trains and rails so that the noise and vibration brought by running trains can be reduced.
When paving roads and railways, people would use coarse sand and gravel as ballast. The ballast is usually the super-granite which has strong rigidity. As for its crushing technology, very often, the jaw crusher would be used at the first stage of crushing and cone crusher would be used at the second or third stage.