Crushing is necessary for mineral processing plant, and there are 2 kinds of crushing process. The one is two stages crushing, and the other one is three stages crushing. Two stages crushing is divided into two stages closed-circuit crushing and two stages open- circuit crushing, the same division of three stages crushing.Xinhai simply analyzed the applications of these crushing flows as follow:Two stages crushingTwo stages crushing is suitable for underground mining method of small size mines, and the total reduction ratio is small, generally about 15-25%; the crushing capacity is not large, less than 1000t/d. The two stages closed-circuit crushing is composed by two stages crushers and checking screen into a closed circuit. The main objective of this crushing flow is to ensure product size to meet the requirements, and not to affect the next grinding operation.For example, the crude ore is less than 300mm; after the first prescreening, the ore less than 75mm does not need to go through the first stage crushing, only 75-300mm ore on the screen enters the crusher for crushing and screening operations for the first time; and then the ore from the first prescreening and the ore from the first crushing enter into the screening; the ore 15-75mm enters into the second crushing.Three stages crushingThere will be pre-screening in three stage crushing process. The three stages open circuit crushing process is rarely used, mainly because the crushing granularity cannot reach the requirements of particle size; the three stages closed-circuit crushing is the most common crushing process, and it is mainly suitable for the large, medium-sized ore dressing plant. The total reduction ratio is large, about 25-200mm. The max. feeding particle size is up to 1000mm.