The hammer crushing circuit of dressing plant is varied. Their common characteristics show below: crushing proceeds in sections; crusher is usually used with griddle; section is the fundamental unit of crushing circuit, it divides into three groups: coarse crushing section, intermediate crushing section, fine crushing section and superfine crushing section. And they also divide into one-section crushing, two-section crushing, three-section crushing and four-section crushing. All crushing sections select inseparable crushing screening equipment.
One-section crushing circuit. A section of crushing is always used to supply autogenous grinding mill with appropriate feedstock, and usually constitutes a system with autogenous tumbling mill. The technological process is uncomplicated, has few facilities, and the plant covers small area. It adopts autogenous mill and semi-autogenous mill, and is only used for convenience of transportation in the open air or undergrounds mine.
Two-section crushing circuit. The circuit is usually used in little plant. It divides into two groups: two-section open circuit, closed circuit. Rude ore particle size is 200mm-400mm, product particle size is 12mm-30mm. If the product of first section crusher has much surplus, and the first section doesn’t put advance screening, namely adopt two-section closed circuit of it. Two-section open crushing circuit is only used in some re-election factories, or is used when small concentrator sends crushing plant contents into vertical mill directly.
Three-section crushing circuit. There are two basic form of the circuit: three-section open circuit and three-section closed circuit. three-section closed circuit, as the preparing work of grinding, is widely used in dressing plant which has all kinds of different scale, as long as the soil containing rate of raw ore isn’t high and can adapt. The crushed product of three-section open circuit crushing is coarse, but it can simplify the configuration of crushing plant in order to save the capital expenditure.
Four-section crushing circuit. It is set to get the crushing product which is below 8mm, and then achieves the technology for energy saving of “more crush and less grind”.
The crushing circuit of mineral washing process with sand cleaning machine. When the mud content of feedstock is over 5%~10% and the water content is over 5%~8%, it should increase ore washing process in crushing circuit.
So, we can adopt this circuit when the feedstock of mineral grinding doesn’t request strictly, when the coarse grinding of grinding section adopts grinding rod equipment, and when solve the shale ore of which the water content is not high and solve the terrain limit.