Crusher used in mining industry is also known as stone crusher, which stands the every crushing machinery that can product the compound particle with its size greater than three millimeters and the output more than 50% of the total discharge quantity after crushing. Stone crusher used in mining industry was first invented by the British. Crushing operations are often classified by the size of its output, which including coarse crushing, medium crushing and subtle crushing. Gravel equipment have many kinds such as jaw crusher, impact crusher, compound crusher, single stage hammer crusher, vertical crusher, gyratory crusher, cone crusher, roll