Aggregate Crushing Plant & Processing Equipment
Sand and gravel aggregate production mainly include dry and semi-dry processes. Dry production means that the process of the entire production line is basically free of water. This dry type aggregate production process is mainly adopted in northern China. Semi-dry production means that there is no water in the section before crushing and before crushing, have high cleanliness. Semi-dry production processes are used more in southern China. In this process, sewage containing soil and stone powder is treated by a thickener and a filter press, the water circulation utilization rate would be improved greatly. The description of effect aggregate crushing plant and processing equipment as following:
1 Basic information about the aggregate production line
1) Capacity: 1 000 t/h gravel aggregate.
2) Product variety: 0.075~4.75 mm, 4.75~15 mm, 15~31.5 mm gravel aggregate.
3) Characteristics of raw materials: The limestone and clay content are large.
4) The quality of gravel aggregate meets the requirements of GB/T 14685-2011 “Construction pebble and gravel”.
5) Environmental protection emission standards: Dust emission concentration ≤20 mg/Nm 3 , wastewater reaches zero emission, and noise emission meets national standards.
2 Main aggregate processing equipment
The semi-dry sand aggregate production line can be simply summarized as crushing, sifting, sludge-containing wastewater treatment and gravel aggregate storage. In order to obtain aggregate products in line with national standards, the selection of aggregate production equipment plays a decisive role in the design of the production line, which mainly depends on the physical properties of the raw materials (such as the hardness of the raw materials, the abrasiveness index, the soil content, etc.) and the local Market demand.
The aggregate production process is determined as a three-stage crushing system consisting of a rotary crusher and a two-stage cone crusher, a three-stage screening system for circular vibrating screens, a silt handling system after screening, and a finished material storage system. The main equipment includes 1 rotary crusher, 2 pre-screening vibrating screens, 2 standard medium-cone crusher, 2 short-head crushing cone crushers, 4 first-stage screening vibrating screens, 8 finished products. Screening vibrating screen, 4 double spiral sand washing machines, 2 sets of cyclone sets, 4 sets of water filter shakers, 1 set of thickeners, 3 sets of filter presses.
1) Coarse crusher
The coarse crushing equipment used for the production of aggregates is generally a rotary crusher, jaw crusher and impact crusher. According to the production capacity requirements (rough crushing more than 1 200 t / h), the characteristics of raw materials containing more soil and the market demand for sand and gravel aggregate products, combined with the general map of the plant, the process layout, the coarse crushing equipment uses the rotary crusher. go to jaw rock crusher, impact crusher price.
2) Medium and fine crusher
Fine crushing equipment in aggregates is generally available with cone crushers and impact crushers. The cone crusher is mainly suitable for crushing rock with high hardness and high abrasive index, and the product has less powdery material. The impact crusher is mainly suitable for crushing rock with medium or low hardness and abrasive index. The product has more powdery materials. The medium-crushing adopts the standard cone crusher, and the short-cut cone crusher is a good choice. cone crusher price.
3) Screening and washing equipment
Stone screening equipment generally uses a linear vibrating screen or a circular vibrating screen. The linear vibrating screen has a small processing capacity and is suitable for small particle size screening and small-yield production, and can be used for water filtration of aqueous materials. The circular vibrating screen has high screening efficiency and large processing capacity, and is suitable for large-size screening and large-scale production. When the pressure spraying system is arranged on the circular screening device, it can be used as a stone washing device. With the hydraulic flushing, the stone rolls and vibrates on the screen surface, and it is easier to wash away the fine mud adhering to the surface. For the mud powder and stone powder in the 0~4.75 mm product, you can choose the spiral sand washing machine or the bucket wheel sand washing machine to obtain the machine sand after washing.
4) Wastewater and mud treatment equipment
The sludge-containing wastewater after washing the aggregate of sand and gravel needs to be treated to achieve zero discharge of wastewater from the production line. After investigation of the wastewater treatment equipment and its use, the production line selected a system consisting of ahydro cyclones, a thickener concentrator and a filter press to treat the wastewater and mud, avoiding the direct discharge of muddy wastewater into the sedimentation tank. The disadvantage is that the floor space is large and the sedimentation tank is difficult to clean.
3 Aggregate process technology and flowsheet
The raw materials of the mine are coarsely broken by the rotary crusher and then stored in the intermediate material storage shed, and then transported to the limestone pre-screening workshop. After the pre-screening, the material larger than 31.5 mm is fed into the standard cone crusher for medium crushing; 4.75~31.5 mm The material is sent to the aggregate screening workshop together with the crushed material for a first-stage screening. When the soil content of the raw material is small, the material less than 4.75 mm after the pre-screening is also sent to the screening workshop for screening. When the soil content of the raw materials is large, the materials less than 4.75 mm are transported to the soil-containing waste storage shed for storage, and then used for the retaining cushion after the mining.
The rotary crusher, the pre-screening vibrating screen, the cone crusher and the material transfer point are all equipped with high-efficiency bag dust collectors for dust removal.
1) Sand and gravel aggregate washing.
The aggregate screening is composed of a three-stage wet screening. The wet screening of each stage is accomplished by vibrating the high pressure spray equipment installed on each screen surface and the material on the screen. After the materials from the pre-screening and medium-breaking workshops are screened by the first-stage sieve vibrating sieve, the materials larger than 31.5 mm are returned to the medium-sized crushing workshop and then broken. The material less than 4.75 mm is sent to the double-screw sand washing machine of the water washing sand workshop together with the washing stone wastewater for sand washing. 4.75~31.5 mm of aggregate is transported to the second and third grade finished vibrating screen for further screening. The 15~31.5 mm and 4.75~15 mm aggregates after the second and third stage screening are sent to the respective finished product yards. The fine mud powder of less than 4.75 mm under the sieve is also sent to the double-screw sand washing machine of the water washing sand workshop together with the washing stone wastewater for sand washing.
2) Waste processing system.
The material less than 4.75 mm is separated with the washing stone wastewater by the double-screw sand washing machine, and the separated sewage enters the cyclone group for separation again, and the separated mechanical sand product is transported to the 0.075-4.75 mm stack. The separated sewage is then concentrated into a concentration tank and concentrated by a thickener, and the dosing process is carried out during the concentration process. The concentrated upper liquid of the liquid flows into the clear water tank and is recycled to the production line by the clean water pump. The lower mud passes through the intermediate buffer pool and is pumped through the slurry to the filter press workshop for pressure filtration. The crushed mud cake scrap is stored separately in the mud cake dump for reclamation after mining.
3) Product storage and shipping.
The washed products are stored in the open air. Motor vibrating feeders and belt scales are set under each product pile and then transported to the dock for shipment. At least two belt scales are placed under each pile to control the reasonable gradation of the aggregate of sand and gravel.
JXSC mining machinery manufacturer provides a full set of aggregate processing plant equipment, gravel processing plant design is available. Contact us to know the sand washing machine, sand making machine price.