Mined ore, coal, building stone and other mineral raw materials are composed of different size particles. Before using or further processing, these materials often need to be divided into several levels according to size, this job is called classification.
According to different material characteristics and size, grading operations often takes a different approach. For fine-grained materials, often using hydraulic classification or air classification.
For the larger particle size materials,general 3-300mm material,the sieve surface classification of screening machine is available. The particle size that less than the sieve size,through the sieve mesh of the sieve surface fall to the bottom of the screen surface, these materials are known as the under sieve material. The particle size that is larger than the mesh size and remained in the sieve surface, is known as the sieve material. This grading operations are known as screening.