Sand, gravel and aggregate are used as the basic materials of engineering buildings, and its commonly used raw materials are river stone, granite, diabase, basalt, limestone and so on. For different raw materials, the choice of crushing equipment is also different.

How to choose suitable crushing equipment according to the ore and raw materials?

In the process of processing, the appropriate processing equipment should be selected according to the different raw materials.

First of all, in the classification of raw materials, we can roughly divide raw materials into hard stone and soft stone.

Hard stone is mainly represented by river stone, granite and basalt, and their hardness is basically above 150Mpa. When processing such raw materials, the choice of crushing equipment usually considers the use of the jaw crusher, cone crusher, and then according to the requirements of the final product with the impact crusher (shaping machine) for shaping, to eliminate the stone in the crushing project produced by the needle and internal crack. Finally, the vibrating screen is used for sorting, and the crushed stone is sorted into final product sand, gravel and aggregate of various specifications.

Secondly, when processing soft stones, such as limestone, sandstone and other stones with a hardness below 150Mpa, the selection of crushing equipment can consider jaw crushers, impact crushers, and heavy hammer crushers. Also according to the requirements of the final product, the impact crusher (shaping machine) can be used for shaping, which can effectively increase the output of machine-made sand while eliminating the needle flakes and internal cracks generated during the crushing process of the stone. Usually, a machine-made sand rate of about 60% can be achieved.

One thing to note here is that the hardness of limestone varies greatly according to its silicon content. We must be very careful when judging the hardness of stone. If it is limestone with a high content of silicon, cone crusher is required when crushing.

There are many ways to choose sand and gravel aggregate processing equipment and process design. How to choose and match specific needs to be comprehensively considered based on various factors such as hardness, looseness, mud content, and final product requirements of unused raw materials.

Details to be paid attention to in the design

Production line design should not only consider the ore and raw materials but also take into account other factors such as the final product, site environment, environmental protection requirements, construction costs and post-operation costs.

1. When designing the process flow, it is necessary to consider the layout of the entire stockyard in combination with the actual situation of the site, such as raw material conditions, production, requirements for the final product, site size, power, access/exit roads, platform drop, drainage, wind direction, post-maintenance access and other factors. The equipment layout shall be as compact as possible to facilitate operation and management in the future. The design of the crushing process shall consider the principle of multi-stage crushing, generally including secondary crushing, tertiary crushing and four-stage crushing. Which method should be used should be determined according to the requirements of raw materials, production and the final product.

2. The crushing equipment choice, should be for different raw materials to choose suitable crushing processing equipment. What needs to be paid attention to here is that when selecting the equipment, it is necessary to select the equipment with matching capacity before and after according to the design output requirements, so as to avoid a large head and small tail or a large head and a small tail. At the same time, it is also necessary to consider the feeding requirements of the equipment, and the materials crushed by the previous equipment must meet the feeding requirements of the subsequent equipment to prevent the occurrence of material jams.

3. The selection of screening equipment should be considered as large as possible before conditions permit, adequate and effective screening can not only sort out qualified final product but also improve production.

4. The choice of supporting environmental protection facilities, as the country pays more and more attention to environmental protection, the previous extensive, high-pollution production mode has been unable to adapt to the needs of modern sand the quarry. Environmental protection should be focused on three aspects: noise, dust and sewage. The emission standards shall comply with the current national environmental protection standards.

5. The design of the final product stockyard, which can be designed as a manual loading or automatic weighing loading system. The automatic weighing and loading system can not only greatly improve the loading efficiency, but also effectively reduce the labor cost.

6. With the increasing scale of the quarry in sand, the centralized control, intelligent management and monitoring system should be designed when the quarry control system and monitoring system are designed, so as to facilitate the sand of the later operation management of the quarry.