In general, the raw ore, which is sent into the mineral processing equipment, is of very big block. The size of some raw ore is 1500mm. But the particle size of the material, ready to be separated, is small. The crushers and ball mills in existence can not, at a time, turn a huge block of ore into the particles of the required particle size. Thus, the ore crushing line should be phased gradually. The crushing machine and the ball mill are the major equipment in the crushing line. According to the particle sizes of the materials, the crushing line can be divided into the coarse crushing process, the secondary crushing process, and the fine crushing process. And the ore grinding line can be divided into the coarse grinding process and the fine grinding process. These processes are divided by the particle sizes of the materials, which are ready to be handled, or by the times for which the material has gotten through the crushing machines and ball mills. In different crushing and grinding processes, different machines are adopted. For example, in the coarse crushing process, the jaw crusher is adopted. In the secondary process, the standard hammer crusher is used. The cone crusher is used in the fine crushing process. In the coarse grinding process, the grid-type ball mill can be used. And the overflow-type ball mill can be used in the fine grinding process. However, in the actual production line, the required processes should be determined by the property of the ore and the particle size of the finished product.
The crushing machine is often equipped with screening equipment, in order to control the particle sizes of the finished products of the the crushing machine and the ball mill. In this way, the crushed ores, which can meet the requirement, can be separated from the others in advance, which can reduce unnecessary crushing times to make the crushing machine and the ball mill be in operation more efficiently. The crushing machine is often equipped with the screening equipment. And the ball mill is often equipped with the classification equipment. In a word, different kinds of configurations of them form a variety of crushing and grinding processes.