The crushing process of the mineral processing plant we are now designing generally has two stages of crushing and three stages of three stages, and these two forms of crushing are divided into open and closed circuits.The following will introduce the characteristics of these crushing processes in detail.
1. Two-stage crushing process
The two-stage crushing process is divided into two forms: two-stage open circuit and two-stage one-closed circuit.The resulting broken product has a coarse particle size and is only used in some simple small mineral processing plants or industrial pilot plants. The first stage can not be pre-sieved.In order to make the particle size of the crushed product smaller, some small mineral processing plants use a two-stage and one-closed-circuit crushing process. The difference between it and the two-stage open circuit is actually that there is an additional screening link, which makes the grinding efficiency of the grinder can be improved. Of course, there are gains and losses. The disadvantage of this is that the crusher wears out quickly and the amount of maintenance increases.In actual production, most of the two-stage crushing processes are used in combination with jaw crushers and cone crushers.The two-stage one-closed-circuit crushing process is suitable for use in small mineral processing plants when processing raw ore with small particle size underground mining.
2. Three-stage crushing process
The three-stage crushing process can also be divided into two types: three-stage open circuit and three-stage one closed circuit.The three-stage one-closed-circuit crushing process is currently widely used.It has low requirements for ore, as long as the ore contains less mud and does not block the crusher and sieve, it can be effectively adapted.The three-stage one-closed-circuit crushing process can control the particle size of the product to 12-0mm, which can provide an ideal feed for grinding operations.Therefore, there are more selected factories that use this process.
Compared with the three-stage open-circuit crushing process and the three-stage one-closed circuit, the particle size of the crushed minerals obtained is generally thicker, but its greater advantage is to simplify the equipment configuration of the crushing workshop and save infrastructure investment.Therefore, when the particle size requirements of the ore feed for grinding are not strict and the rough grinding of the grinding section adopts rod grinding, or when dealing with muddy ores with high water content and terrain restrictions, etc., a three-stage open circuit can be used.
Compared with the three-stage and one-closed circuit, the three-stage open circuit has three main advantages: 1. When dealing with ore with high mud content and water content, it is not easy to block the screen and crushing chamber.2. If the crushing process of three-stage open circuit plus rod grinding is used, there is no need for complex closed-circuit screening and transportation of returned products.3. The three-stage open circuit produces less dust in the production process, so labor hygiene conditions can be improved.
The three-stage one closed circuit is mainly suitable for grinding minerals with coarse particle size (re-selection plant) or processing brittle (tungsten, tin ore) and high-density (lead ore) minerals.
