Sand and gravel production line equipment types – how to choose

Selection and analysis of primary crushing equipment

The primary crushing equipment of the sand and gravel production line is the main link to mark and control the production capacity of the sand and gravel processing system. When selecting primary crushing equipment, it is necessary not only to meet the requirements of crushing output, but also to meet the requirements of the quarry to supply large pieces of wool (particle size). Generally speaking, jaw crusher and gyratory crusher are used more as primary crushing equipment.

The structure of jaw crushing equipment is relatively simple, the maintenance is relatively easy, the price is relatively cheap, the height of the machine is low, the size of the feeding port is large, and the width of the discharging port can be adjusted, so it is widely used in small and medium-scale sand and gravel processing systems. Applications. The gyratory crushing equipment can be filled with materials, the output of a single machine is relatively high, the particle size of the product is relatively uniform, the production cost is relatively low, the work operation is stable, and the operation is relatively reliable, so the gyratory crusher is generally used in large-scale sand and gravel processing systems. As a primary crushing equipment.

Selection of medium and fine crushing equipment

The purpose of medium and fine crushing in the sand and gravel processing system is to crush the oversized boulders and adjust the production gradation of the sand and gravel materials. The fine crushing equipment is mainly used to prepare small aggregates for the rod mill machine-made sand. Generally speaking, the cone crusher is used as the medium and fine crushing equipment. For small sand and gravel systems, a flutter crusher can be chosen. Because the impact force of the impact crusher is relatively large and the particle size of the product is relatively fine. When it is used to crush medium-hard ores, it is better to use a counterattack or a hammer crusher as the fine crushing equipment. This is because the hammer crusher has large feeding particle size, high yield and good particle shape. Super crushing, coarse, medium and fine crushing in one step. The output is increased by 30% year-on-year, and the needle flake (powder) is less than 20%, which is more energy-saving.

Sand and gravel production line – selection analysis of sand making equipment

In China, the most widely used sand-making equipment is the middle-peripheral discharge rod mill with shaft hole feeding at both ends and middle side hole discharging. Other equipments include hammer-type and impact-type crushers. For example, the Dvorak Dam in the United States uses a gyratory disc crusher. Japan is developing a cone crushing machine-made sand composed of upper and lower crushing chambers. According to the production practice, the artificial sand produced by the rod mill has better performance. That is, a fineness modulus has only one particle size gradation.

Therefore, as long as the fineness modulus of the artificial sand is determined, its particle size gradation is also determined. Which has nothing to do with the lithology of the raw material and the operating parameters of the rod mill. At the same time, the fineness of the product can be considered to be controlled, that is, as long as the operating parameters are adjusted. The fineness modulus of the artificial sand required for the design can be obtained. In terms of the performance of the equipment, the rod mill has the following characteristics, simple structure, convenient operation, stable production, reliable operation, good product particle shape, and uniform particle size composition, so it is a relatively superior sand making equipment. .

Fourth, the selection analysis of mud washing equipment

For artificial sand and gravel materials with rocks as raw materials, due to the development of karst in the material yard, a large amount of clay is filled. But the cleaning method of filling high-pressure water on the screening machine cannot make the mud content meet the requirements. It is said that it is necessary to increase the equipment for washing mud. For example, in the above-mentioned Wujiangdu project, two 8300×2400mm mud washing machines were made to scrub the aggregate below 60mm. According to actual measurements, the average value of the mud amount can be reduced from 12.7% before flushing to 0.43% after flushing. Production practice shows that for the sand and gravel processing system with limestone as raw material. The mud washing machine is a must-have equipment.

Analysis of selection and dehydration equipment

According to the production characteristics of artificial sand and gravel. A heavy-duty vibrating screen can be used as the pre-screening equipment. The self-centering vibrating screen is used as the screening corridor screen. And the resonance screen is used as the second screen. This arrangement is more reasonable. Production practice shows that the resonance screen has the following advantages. Such as high equipment output, good screen washing quality, low power consumption and small dynamic load on the equipment foundation. In conjunction with the dehydration equipment of the grit chamber and the rod mill in the screening floor. The high weir type spiral classifier is often used.

Selection and analysis of feeding equipment

Now there are quantitative feeding equipment, such as electromagnetic vibrating feeder. According to the above-mentioned practical experience of the Wujiangdu project, the trough feeder is a relatively good feeding equipment. It has the following advantages: simple structure of the equipment, self-manufacturing, uniform feeding. Not easy to block, suitable for materials with high moisture content and high viscosity. And can be used for materials that do not bear the pressure of the ore column and the feeding particle size is less than 450 mm feeding site.