Sand and gravel are the basic material for engineering construction, in a stone crusher plant, the common raw materials to produce sand and gravel includes cobblestone, granite, gabbro, basalt and limestone. For different raw materials, the choice of crushing equipment is also different. So how to choose the appropriate crushing equipment?
First of all, when we categorize the raw materials, we can roughly divide the raw materials into hard stones and soft stones.
Hard stone is mainly represented by cobblestone, granite and basalt, whose hardness is basically above 150Mpa. When processing such raw materials, jaw crusher and cone crusher combination is the top consideration. According to the requirements of the finished product, shaping machine like the impact crusher or VSI sand making machine will be added to produce cubic shape products, shaping machine reduces the needle flaky products. Finally, the vibrating screen is used for sorting to separate the crushed stones into different groups of sand and gravels.
Secondly, when processing soft stone, such as limestone, sandstone and other stones with hardness below 150Mpa, the choice of crushing equipment can consider jaw crusher, impact crusher, heavy hammer crusher, also according to the requirements of the finished product can be combined with the use of impact crusher or VSI sand making machine for shaping, which will eliminate the needle flaky materials, as well as improve the efficient of sand production. Usually, it can reach about 60% of the sand rate.
One thing to note here is that limestone varies greatly in its hardness depending on its silica content. We must pay great attention when judging the hardness of the stone. If it is a limestone with high silica content, a Symons cone crusher is required for secondary crushing.
There are many ways to choose sand and gravel processing equipment in a stone crusher plant design, and the specific needs of designing need to take the following into consideration, hardness of raw materials, looseness, mud content, finished product requirements and other factors.
Details to be considered in the design process
Production line design should not only consider ore raw materials, but also other factors such as finished product requirements, site environment, environmental requirements, construction costs and post-operation costs.
First, when designing the process flow, the actual situation of the site must be taken into account, such as the raw material situation, production capacity, finished product requirements, site size, electricity, inbound and outbound roads, drop of each platform of the site, drainage, wind direction, maintenance access, and other factors. These need to be considered comprehensively when make the layout of the entire plant.
The layout of equipment should be as compact as possible to facilitate the operation and management at a later stage. The design of crushing process should consider the principle of multi-stage crushing, generally there are secondary crushing, tertiary crushing, etc. The specific method to be used should be determined according to the raw material, output and finished product requirements.
Second, the choice of crushing equipment. Choose the appropriate crushing and processing equipment based on different raw materials. Here it is necessary to pay attention to the equipment selection, according to the design capacity requirements, equipment in front should match the following equipment in the whole plant, it should avoid the large capacity equipment in front small capacity in the end, or vice versa. At the same time, it should also consider the feeding requirements of the equipment, the material crushed by the previous equipment must meet the feeding requirements of the subsequent equipment to prevent jamming phenomenon.
Thirdly, the choice of screening equipment, if the site condition allows, try to choose larger capacity of the vibrating screen. It has adequate and effective screening, not only sorts the qualified productions, but also improves the production capacity.
Fourth, the choice of supporting environmental protection facilities, many countries pay more and more attention to environmental protection, the previous kind of crude, high-pollution production model has been unable to adapt to the needs of modern stone crusher plant. Environmental protection should focus on the three aspects: noise, dust, sewage. Its emission standards should be in line with the current national environmental protection standards.
Fifth, the finished material yard can be designed as manual loading or automatic weighing and loading system. Automatic weighing and loading system can not only greatly improve the loading efficiency, but also effectively reduce the labor cost.
Sixth, as the stone crusher plant capacity is getting bigger and bigger now, when making design of the control system and monitoring system in the quarry, centralized control, intelligent management and monitoring system should be designed in order to facilitate the later operation and management of the stone crusher plant.