Coal gangue sand and gravel aggregate production system and production method

Abstract

The present invention belongs to the technical field of solid waste treatment, and discloses a production system and a production method of gangue sand and gravel aggregates. The production system of gangue sand and gravel aggregates includes a crushing and processing device and a multi-stage sorting device. The material outlet of the multi-stage sorting device includes a low calorific value coal product output end, a coal product output end and a plurality of gangue aggregate output ends. The low calorific value coal product output end is connected to a coal washing system, one of the gangue aggregate output ends is connected to a sand making device, the machine-made sand product output end of the material outlet of the sand making device is connected to a sand washing system, and the wastewater output ends of the coal washing system and the sand washing system are connected to a wastewater treatment system. The production method of gangue sand and gravel aggregates performs preliminary treatment on the gangue raw materials through multiple crushing and screening links to separate coal products and a plurality of coarse aggregate products; obtains the required machine-made sand products through sand making crushing and sand making screening links; and then produces coal slime byproducts through wastewater treatment, so as to realize efficient treatment and full utilization of the gangue raw materials.

Description

Technical Field

[0001] The invention belongs to the technical field of coal gangue solid waste treatment, and relates to a coal gangue sand and gravel aggregate production system and a production method. Background Art

[0002] Gangue is a solid waste discharged during the production process of coal mines, accounting for 10%-20% of the raw coal output, and is one of the largest solid wastes discharged in my country. Gangue mainly contains inorganic matter and a small amount of organic matter, among which the main components of inorganic matter are SiO2, Al2O3 and CaO, etc. Large amounts of accumulated gangue are very harmful. While occupying a large amount of land, it will also cause environmental problems such as soil pollution, water pollution, and air pollution. However, from the perspective of resource attributes, gangue is a valuable secondary resource, so its resource utilization is a necessary measure to reduce environmental pollution, which is of great significance to the realization of green development of my country's coal industry, recycling of solid waste and sustainable development.

[0003] At present, in the fields of civil engineering construction such as buildings, roads, and railways, most of the machine-made sand and gravel aggregates used for concrete construction are machine-made sand and coarse aggregates that meet national construction standards after screening and crushing from sand and gravel mined from mines and rivers. However, the cost of ordinary mine sand and gravel and river sand and gravel mining is high, and large-scale mining will also have a serious impact on the natural environment.

[0004] Therefore, considering the above two reasons, coal enterprises are currently in urgent need of a production process that can not only absorb large-scale stockpiled coal gangue, but also utilize the sand and gravel aggregates required for the construction of coal gangue production projects. Summary of the invention

[0005] The purpose of the present invention is to provide a coal gangue sand and gravel aggregate production system and production method, which solves the problem of coal gangue solid waste accumulation and storage occupying a large amount of land and causing environmental pollution in the prior art, and realizes efficient and full utilization of the existing large amount of coal gangue resources.

[0006] A technical solution adopted by the present invention is that a coal gangue sand and gravel aggregate production system includes a crushing and processing device, the material outlet of the crushing and processing device is connected to a multi-stage sorting device, the material outlet of the multi-stage sorting device includes a low calorific value coal product output end, a coal product output end and several gangue aggregate output ends, one of the gangue aggregate output ends is also connected to a sand making device, and the material outlet of the sand making device includes a machine-made sand product output end.

[0007] The output end of the low calorific value coal product is connected to the coal washing system, and the output end of the machine-made sand product is connected to the sand washing system. The material outlets of the coal washing system and the sand washing system both include a solid material output end and a wastewater output end, and the wastewater output ends of the coal washing system and the sand washing system are commonly connected to the wastewater treatment system.

[0008] The present invention is also characterized in that the crushing processing device includes a coarse crushing discharge bin, a coarse crushing crusher and a medium and fine crushing crusher connected in sequence, the discharge outlet of the coarse crushing discharge bin is connected to the feed port of the coarse crushing crusher, and the discharge port of the coarse crushing crusher is connected to the feed port of the medium and fine crushing crusher through a conveying mechanism.

[0009] The multi-stage sorting device includes a first screening device, a sorting device, and a second screening device. The discharge port of the medium and fine crusher is connected to the feed port of the first screening device through a conveying mechanism, and the discharge port of the first screening device includes a first large particle outlet, a first medium particle outlet, and a first small particle outlet, wherein the first large particle outlet is connected to the feed port of the medium and fine crusher through a conveying mechanism, the first medium particle outlet is connected to the feed port of the sorting device through a conveying mechanism, and the output end of the low calorific value coal product is set at the first small particle outlet.

[0010] The sorting equipment is provided with two material outlets, and the coal product output end is arranged at one of the material outlets, and the coal product output end is connected to the coal product pile shed through a conveying mechanism, and the other material outlet is connected to the feed port of the second screening equipment through a conveying mechanism.

[0011] The gangue aggregate output end is arranged at the discharge port of the second screening equipment, and the discharge port of the second screening equipment includes a second large particle outlet, a second medium particle outlet and a second small particle outlet, wherein the second large particle outlet is connected to the finished aggregate bin one through a conveying mechanism, the second medium particle outlet is connected to the finished aggregate bin two through a conveying mechanism, and the second small particle outlet includes two connecting ends, one of which is connected to the finished aggregate bin three through a conveying mechanism.

[0012] The sand making device includes a sand making crusher and a sand making screening device. The feed port of the sand making crusher is connected to the other connecting end of the second small particle outlet through a conveying mechanism, and the discharge port of the sand making crusher is connected to the feed port of the sand making screening device through a conveying mechanism.

[0013] The discharge port of the sand making and screening equipment includes a third large aggregate outlet, a third medium aggregate outlet and a third small aggregate outlet, wherein the third large aggregate outlet is connected to the feed port of the sand making crusher through a conveying mechanism, the third medium aggregate outlet includes two connecting ends, one of which is connected to the feed port of the sand making crusher through a conveying mechanism, and the machine-made sand product output end is arranged at the other connecting end of the third medium aggregate outlet and the third small aggregate outlet.

[0014] The present invention is also characterized in that a water spraying device is arranged above the first screening device and the sand making screening device.

[0015] The coal washing system is located below the first screening device, and includes a first spiral sand washing machine and a first fine sand recovery machine which are connected in sequence. The feed port of the first spiral sand washing machine is connected below the first small particle outlet of the first screening device, and the solid material output end of the coal washing system is arranged at the discharge port of the first fine sand recovery machine, and the discharge port of the first fine sand recovery machine is connected to a low calorific value coal pile shed through a conveying mechanism;

[0016] The sand washing system is located below the sand making and screening equipment. The sand washing system includes a second spiral sand washing machine and a second fine sand recovery machine which are connected in sequence. The feed port of the second spiral sand washing machine is connected to the bottom of the third small particle outlet of the sand making and screening equipment, and is connected to the other connection end of the third medium particle outlet. The solid material output end of the sand washing system is arranged at the discharge port of the second fine sand recovery machine, and the discharge port of the second fine sand recovery machine is connected to the machine-made sand pile shed through a conveying mechanism.

[0017] The wastewater output end of the coal washing system is arranged at the wastewater outlet of the first spiral sand washing machine and the first fine sand recovery machine, and the wastewater output end of the sand washing system is arranged at the wastewater outlet of the second spiral sand washing machine and the second fine sand recovery machine.

[0018] The present invention is also characterized in that the wastewater treatment system comprises a wastewater tank, the water inlet of the wastewater tank is connected to the wastewater outlets of the first spiral sand washer, the first fine sand recovery machine, the second spiral sand washer and the second fine sand recovery machine, the water outlet of the wastewater tank is connected to the water inlet of the thickener, the upper water outlet of the thickener is connected to the water inlet of the clean water tank, the bottom slurry outlet of the thickener is connected to a slurry pump, and is connected to the feed inlet of the filter press through the slurry pump, and the drain outlet of the filter press is also connected to the water inlet of the clean water tank;

[0019] The water inlet of the water spraying device is connected with the clean water tank.

[0020] The present invention is also characterized in that the first screening device is provided with two sieves for controlling the screening size, which are a 5 mm sieve and a 31.5 mm sieve; the second screening device is provided with two sieves for controlling the screening size, which are a 10 mm sieve and a 20 mm sieve; the sand making screening device is provided with two sieves for controlling the screening size, which are a 3 mm sieve and a 5 mm sieve.

[0021] The present invention is also characterized in that the coarse crusher is a jaw crusher; the medium and fine crusher is an impact crusher; the sand-making crusher is a vertical shaft crusher; the first screening device, the second screening device and the sand-making screening device are all circular vibrating screens; the sorting equipment is an intelligent photoelectric sorter; and the conveying mechanism is a belt conveyor.

[0022] Another technical solution adopted by the present invention is a method for producing gangue sand and gravel aggregates, using the above-mentioned gangue sand and gravel aggregate production system, comprising the following production steps:

[0023] Step 1: Crushing

[0024] The gangue raw materials are continuously transported to the crushing and processing device for crushing, and then output to the multi-stage sorting link;

[0025] Step 2: Multi-stage screening

[0026] The materials after medium and fine crushing are screened. On the one hand, relatively large particles are screened out and transported back to the crushing process for cyclic crushing; on the other hand, relatively medium particles are screened out for further sorting, and coal products and gangue aggregates are sorted out. Gangue aggregates are further screened into multiple categories of coarse aggregate products, and part of the coarse aggregate products are transported to the sand making process as sand making raw materials; on the other hand, relatively small particles are screened out and processed as low calorific value coal products;

[0027] Step 3: Sand Making

[0028] First, the coarse aggregate product is crushed into sand and then screened. On the one hand, relatively large particles of material are screened out and transported back to the sand making and crushing link for circulating crushing; on the other hand, relatively small particles of material are screened out and processed as machine-made sand products; on the other hand, relatively moderate particles of material are screened out and divided into two parts for output, one part of which is transported back to the sand making and crushing link for circulating crushing together with the larger particles of material, and the other part is processed together with the smaller particles of material as machine-made sand products.

[0029] The present invention is also characterized in that:

[0030] Step 1 includes the following sub-steps:

[0031] Step 1.1: The gangue raw materials piled up in the unloading yard are transported to the coarse crushing unloading bin, and the gangue raw materials are continuously fed to the coarse crushing crusher through the coarse crushing unloading bin for coarse crushing;

[0032] Step 1.2: The coarsely crushed material is transported to the medium and fine crushing crusher through the conveying mechanism for medium and fine crushing, and the medium and fine crushed material is output through the conveying mechanism.

[0033] Step 2 includes the following sub-steps:

[0034] Step 2.1: The medium and fine crushed materials are first transported to the first screening device for screening, and then the screened materials are respectively output from the first large pellet outlet, the first medium pellet outlet and the first small pellet outlet according to the screening conditions of the first screening device;

[0035] Step 2.2: The materials output from the first large pellet outlet, the first medium pellet outlet and the first small pellet outlet are processed by the following methods respectively:

[0036] A. The material output from the first large particle outlet is returned to the medium and fine crusher through the conveying mechanism for re-medium and fine crushing. A closed circuit is formed between the first large particle outlet and the medium and fine crusher to cyclically crush larger pieces of coal gangue;

[0037] B. The material output from the first intermediate pellet outlet is transported to the sorting equipment through the conveying mechanism for sorting; the products after sorting include coal products and gangue aggregates. The coal products are transported to the coal product storage shed for storage and shipment through the conveying mechanism, and the gangue aggregates are processed through step 2.3;

[0038] C. The materials output from the first small pellet outlet enter the coal washing system for processing;

[0039] Step 2.3: The sorted gangue aggregate is transported to the second screening device through the conveying mechanism for screening. According to the screening conditions of the second screening device, the screened materials are respectively output from the second large particle outlet, the second medium particle outlet and the second small particle outlet;

[0040] Step 2.4: The materials output from the second largest pellet outlet, the second medium pellet outlet and the second smallest pellet outlet are processed by the following methods respectively:

[0041] A. The material output from the second largest aggregate outlet is used as a coarse aggregate product and is transported to the finished aggregate silo for storage and shipment through the conveying mechanism;

[0042] B. The material output from the second intermediate aggregate outlet is used as a coarse aggregate product and is transported to the finished aggregate silo 2 for storage and shipment through the conveying mechanism;

[0043] C. The material output from the second small aggregate outlet is divided into two parts. One part is used as a coarse aggregate product and is transported to the finished aggregate silo three for storage and shipment through the conveying mechanism. The other part is output as a sand making raw material through the conveying mechanism.

[0044] Step 3 includes the following sub-steps:

[0045] Step 3.1: The coarse aggregate product as the raw material for sand making is first transported to the sand making crusher for sand making crushing;

[0046] Step 3.2: The crushed materials are transported to the sand making screening equipment through the conveying mechanism for screening. According to the screening conditions of the sand making screening equipment, the screened materials are respectively output from the third largest particle outlet, the third medium particle outlet and the third small particle outlet;

[0047] Step 3.3: The materials output from the third largest pellet outlet, the third medium pellet outlet and the third smallest pellet outlet are processed by the following methods respectively:

[0048] A. The material output from the third largest particle outlet is returned to the sand making crusher through the conveying mechanism for re-sand making and crushing;

[0049] B. The material output from the third medium-sized granular material outlet is divided into two parts. One part is returned to the sand making crusher through the conveying mechanism for re-sand making and crushing, and the other part enters the sand washing system for processing;

[0050] C. The material output from the third small pellet outlet enters the sand washing system for processing.

[0051] The present invention is also characterized in that:

[0052] During the screening process of step 2.1 and step 3.2, a water spraying device is used to spray water;

[0053] In step 2.1, the screening conditions of the first screening device are that the material with a particle size ≥ 31.5 mm is output from the first large particle outlet, the material with a particle size of 5 mm ≤ < 31.5 mm is output from the first medium particle outlet, and the material with a particle size < 5 mm is output from the first small particle outlet;

[0054] In step 2.3, the screening conditions of the second screening equipment are that the material with a particle size of 20 mm ≤ < 31.5 mm is output from the second largest particle outlet, the material with a particle size of 10 mm ≤ < 20 mm is output from the second medium particle outlet, and the material with a particle size of 5 mm ≤ < 10 mm is output from the second small particle outlet;

[0055] In step 3.2, the screening conditions of the sand making screening equipment are that the material with a particle size ≥5mm is output from the third largest particle outlet, the material with a particle size of 3mm≤<5mm is output from the third medium particle outlet, and the material with a particle size of <3mm is output from the third small particle outlet;

[0056] The present invention is also characterized in that the steps of the coal washing system are as follows:

[0057] Step a1: the material output from the first small pellet outlet is processed by the first spiral sand washing machine and the first fine sand recovery machine in turn to produce low calorific value coal with a particle size of 0-5 mm; the wastewater discharged from the first spiral sand washing machine and the first fine sand recovery machine is discharged into the wastewater treatment system for treatment;

[0058] Step a2: The low calorific value coal is transported to the low calorific value coal storage shed for storage and shipment through the conveying mechanism.

[0059] The steps of sand washing system are as follows:

[0060] Step b1: Part of the material output from the third medium-granular material outlet and the material output from the third small-granular material outlet are processed by the second spiral sand washing machine and the second fine sand recovery machine in turn to produce machine-made sand products with a particle size of 0-5 mm; the wastewater discharged from the second spiral sand washing machine and the second fine sand recovery machine is discharged into the wastewater treatment system for treatment;

[0061] Step b2: The machine-made sand products are transported to the machine-made sand storage shed through the conveying mechanism for storage and shipment.

[0062] The steps of wastewater treatment system are as follows:

[0063] Step c1: The wastewater generated by the coal washing system and the sand washing system flows into the wastewater pool by gravity and is then transported to the thickener for sedimentation and separation treatment;

[0064] Step c2: The clean water on the upper layer of the thickener is transported to the clean water tank; the thick slurry at the bottom of the thickener is pumped to the filter press workshop through a slurry pump to further remove moisture; the mud cake produced by the filter press is transported to the coal mud pile shed for storage or shipment, and the clean water discharged from the filter press is transported to the clean water tank;

[0065] Step c3: The clean water pool supplies water to the sprinkler device to achieve recycling of water resources.

[0066] The present invention is also characterized in that the coarse crusher 2 adopts an open circuit crushing method for crushing.

[0067] The beneficial effects of the present invention are as follows: the coal gangue sand and gravel aggregate production system and coal gangue sand and gravel aggregate production method of the present invention are a full-process production system that combines and cooperates with coal gangue crushing, coal gangue sorting, coal gangue screening, coal washing, sand washing, wastewater treatment and other devices, and a full-process production process that processes coal gangue raw materials into a variety of high-quality sand and gravel aggregates and coal products, which can provide a large-scale disposal means for stockpiled coal gangue, and at the same time can realize high-quality and high-efficiency production of products such as coal gangue sand and gravel aggregates.

[0068] The gangue sand and gravel aggregate production system and production method provided by the present invention can produce 5mm-10mm, 10mm-20mm, 20mm-31.5mm gangue coarse aggregates, 0-5mm gangue machine-made sand and low calorific value coal, as well as coal and coal slime and other products. The product variety is wide and the application range is wide. The efficient and full utilization of gangue resources can be achieved, and the dust pollution in the production process is reduced, which is beneficial to the protection of the natural environment and the sustainable development of the coal industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 It is a structural schematic diagram of the coal gangue sand and gravel aggregate production system of the present invention;

[0070] Figure 2It is a process flow chart of the method for producing coal gangue sand and gravel aggregate in the present invention.

[0071] In the figure: 1. coarse crushing unloading bin; 2. coarse crusher; 3. medium and fine crusher; 4. first screening equipment; 5. sorting equipment; 6. second screening equipment; 7. sand making crusher; 8. sand making screening equipment; 9. water spraying device; 10. first spiral sand washing machine; 11. first fine sand recovery machine; 12. second spiral sand washing machine; 13. second fine sand recovery machine; 14. coal product storage shed; 15. low calorific value coal storage shed; 16. finished product aggregate bin one; 17. finished product aggregate bin two; 18. finished product aggregate bin three; 19. machine-made sand storage shed; 20. coal slime storage shed; 21. wastewater tank; 22. thickener; 23. filter press; 24. clear water tank. DETAILED DESCRIPTION

[0072] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0073] Embodiment 1:

[0074] like Figure 1 As shown, the coal gangue sand and gravel aggregate production system includes a coarse crushing unloading bin 1, a coarse crusher 2, a medium and fine crusher 3, a first screening device 4, a sorting device 5, a second screening device 6, a sand making crusher 7 and a sand making screening device 8 which are sequentially connected, and also includes a coal product stack 14, a low calorific value coal stack 15, a finished aggregate bin 1 16, a finished aggregate bin 2 17, a finished aggregate bin 3 18 and a machine-made sand stack 19;

[0075] The gangue raw materials to be crushed are input from the feed port of the coarse crushing unloading bin 1, the discharge outlet of the coarse crushing unloading bin 1 is connected to the feed port of the coarse crusher 2, the discharge port of the coarse crusher 2 is connected to the feed port of the medium and fine crusher 3 through a conveying mechanism, and the discharge port of the medium and fine crusher 3 is connected to the feed port of the first screening device 4 through a conveying mechanism.

[0076] The first screening device 4 is provided with three material outlets, namely a first large particle outlet, a first medium particle outlet and a first small particle outlet, wherein the first large particle outlet is connected to the feed port of the medium and fine crusher 3 through a conveying mechanism, the first medium particle outlet is connected to the feed port of the sorting device 5 through a conveying mechanism, and the first small particle outlet is connected to a coal washing system, and is connected to the low calorific value coal pile shed 15 through the coal washing system.

[0077] The sorting device 5 is provided with two material outlets, one of which is connected to the coal product stockpile 14 through a conveying mechanism, and the other is connected to the second screening device 6 through a conveying mechanism.

[0078] The second screening equipment 6 is also provided with three material outlets, namely a second large aggregate outlet, a second medium aggregate outlet and a second small aggregate outlet, wherein the second large aggregate outlet is connected to the finished aggregate bin 16 through a conveying mechanism, the second medium aggregate outlet is connected to the finished aggregate bin 17 through a conveying mechanism, and the second small aggregate outlet is respectively connected to the finished aggregate bin 3 18 and the feed port of the sand-making crusher 7 through a conveying mechanism, and the discharge port of the sand-making crusher 7 is connected to the feed port of the sand-making screening equipment 8 through a conveying mechanism.

[0079] The sand making and screening equipment 8 is also provided with three material outlets, namely the third largest particle outlet, the third medium particle outlet and the third small particle outlet, wherein the third largest particle outlet is connected to the feed port of the sand making crusher 7 through a conveying mechanism, the third small particle outlet is connected to the sand washing system, and is connected to the machine-made sand pile 19 through the sand washing system, and the third medium particle outlet is respectively connected to the feed port of the sand making crusher 7 and the feed port of the sand washing system through a conveying mechanism.

[0080] By adopting the above technical scheme, gangue crushing, gangue sorting, gangue screening, coal washing, sand washing, wastewater treatment and other devices are combined together and cooperated with each other to obtain a full-process gangue sand and gravel aggregate production system, which provides a large-scale disposal means for stockpiled gangue and can directly produce high-quality gangue sand and gravel aggregates and other products from gangue raw materials, thereby realizing high-quality and high-efficiency production of gangue sand and gravel aggregates and other products.

[0081] In this embodiment, the coal washing system is located below the first screening device 4, and the coal washing system includes a first spiral sand washing machine 10 and a first fine sand recovery machine 11 connected in sequence. The feed port of the first spiral sand washing machine 10 is connected to the bottom of the first small particle outlet of the first screening device 4, and the discharge port of the first fine sand recovery machine 11 is connected to the low calorific value coal pile 15 through a conveying mechanism.

[0082] The sand washing system is located below the sand making and screening equipment 8, and includes a second spiral sand washing machine 12 and a second fine sand recovery machine 13 connected in sequence. The feed port of the second spiral sand washing machine 12 is connected to the bottom of the third small particle outlet of the sand making and screening equipment 8, and is also connected to an output port of the third medium particle outlet. The discharge port of the second fine sand recovery machine 13 is connected to the machine-made sand pile 19 through a conveying mechanism.

[0083] A water spray device 9 is provided above the first screening device 4 and the sand making screening device 8. The wastewater outlets of the first spiral sand washing machine 10 and the first fine sand recovery machine 11, as well as the second spiral sand washing machine 12 and the second fine sand recovery machine 13 are all connected to the wastewater treatment system.

[0084] By adopting the above technical scheme, water is sprayed during the first screening and sand making screening process, and the spiral sand washing machine and fine sand recovery machine are used to process the underscreen material, which can effectively separate the coal slime, improve the quality of coal products and sand and gravel aggregate products, and also produce coal slime by-products.

[0085] In this embodiment, the wastewater treatment system includes a wastewater tank 21, the water inlet of the wastewater tank 21 is connected to the wastewater outlets of the first spiral sand washing machine 10, the first fine sand recovery machine 11, the second spiral sand washing machine 12 and the second fine sand recovery machine 13, the water outlet of the wastewater tank 21 is connected to the water inlet of the thickener 22, the upper water outlet of the thickener 22 is connected to the water inlet of the clear water tank 24, the bottom slurry outlet of the thickener 22 is connected to a slurry pump, and is connected to the feed inlet of the filter press 23 through the slurry pump, and the drain outlet of the filter press 23 is also connected to the water inlet of the clear water tank 24.

[0086] The water inlet of the water spray device 9 is connected to the clean water tank 24.

[0087] By adopting the above technical solution, the production water of coal gangue sand and gravel aggregate can be recycled through the wastewater treatment system, reducing the discharge of production wastewater and even achieving zero wastewater discharge.

[0088] Embodiment 2:

[0089] Based on Example 1, in this embodiment, the first screening device 4 is provided with two sieves for controlling the screening size, which are a 5 mm sieve and a 31.5 mm sieve; the second screening device 6 is provided with two sieves for controlling the screening size, which are a 10 mm sieve and a 20 mm sieve; the sand making screening device 8 is provided with two sieves for controlling the screening size, which are a 3 mm sieve and a 5 mm sieve.

[0090] In this embodiment, the coarse crusher 2 is a jaw crusher; the medium and fine crusher 3 is an impact crusher; and the sand making crusher 7 is a vertical shaft crusher. The first screening device 4, the second screening device 6 and the sand making screening device 8 are all circular vibrating screens. The sorting device 5 is an intelligent photoelectric sorter. Specifically, the intelligent photoelectric sorter can be a T108 flat-throwing intelligent sorter or a CN3000 intelligent sorter. The conveying mechanism is a belt conveyor.

[0091] Embodiment 3:

[0092] Gangue raw materials are usually piled up in large quantities at unloading sites. The gangue sand and gravel aggregate production method proposed in the present invention is used to process the gangue raw materials at the unloading site.

[0093] like Figure 2 As shown, the method for producing gangue sand and gravel aggregates, using the gangue sand and gravel aggregate production system proposed in Example 1 or 2, comprises the following production steps:

[0094] Step 1: Crushing process, including the following subdivision steps:

[0095] Step 1.1: The gangue raw materials accumulated at the unloading site are transported to the coarse crushing unloading bin 1 by a self-unloading vehicle. The gangue raw materials enter the coarse crushing crusher 2 through the coarse crushing unloading bin 1. This is the coarse crushing link. The coarse crushing crusher 2 uses a jaw crusher to crush in an open circuit crushing manner. In this step, the coarse crushing unloading bin 1 directly receives the gangue raw materials at the unloading site to achieve the purpose of continuously feeding the coarse crusher 2.

[0096] Step 1.2: The coarsely crushed material is conveyed to the medium and fine crusher 3 through a belt conveyor to enter the medium and fine crushing stage. The medium and fine crusher 3 uses an impact crusher, and the medium and fine crushed material is output through a conveying mechanism;

[0097] Step 2: Multi-stage screening, including the following subdivision steps:

[0098] Step 2.1: The medium and fine crushed materials are conveyed to the first screening device 4 by a belt conveyor to enter the first screening stage. The first screening device 4 uses a circular vibrating screen, and the screen mesh control size is 5mm and 31.5mm. The screened materials are respectively output from the first large particle outlet, the first medium particle outlet and the first small particle outlet. During the screening process, a water spraying device 9 is used to spray water, which can reduce dust pollution on the one hand and collect coal powder on the other hand;

[0099] Step 2.2: The materials output from the first large pellet outlet, the first medium pellet outlet and the first small pellet outlet are processed by the following methods respectively:

[0100] A. Materials with a particle size of ≥31.5 mm are discharged from the first large particle outlet, returned to the medium and fine crusher 3 through the belt conveyor, and re-entered the medium and fine crushing link, forming a closed circuit with the medium and fine crushing link to cyclically crush larger pieces of coal gangue;

[0101] B. Materials with a particle size of 5 mm ≤ and less than 31.5 mm are output from the first medium particle outlet and transported to the sorting device 5 by a belt conveyor to enter the sorting stage; the sorting device 5 uses an intelligent photoelectric sorter, and the products after sorting include coal products and gangue aggregates. The coal products are transported to the coal product storage shed 14 by a belt conveyor for storage and shipment, and the gangue aggregates are processed by step 2.3;

[0102] C. Materials with a particle size of less than 5 mm are discharged from the first small particle outlet and enter the coal washing system below the circular vibrating screen for processing;

[0103] In this step, an intelligent photoelectric sorter is used to sort the gangue. The intelligent photoelectric sorter is based on X-ray fluoroscopy, integrating other visible spectra, and detecting mineral structure and material composition in multiple dimensions. It uses advanced AI algorithms for real-time identification and precise classification, and cooperates with customized blowing modes to achieve precise separation of coal products and gangue aggregates. After sorting, the coal rate in the gangue aggregates is less than 2%, and the sorting accuracy and efficiency are high.

[0104] Step 2.3: The sorted gangue aggregate is conveyed to the second screening device 6 by a belt conveyor and enters the second screening stage. The second screening stage mainly screens the finished aggregate products. The second screening device 6 uses a circular vibrating screen with a screen size of 10 mm and 20 mm. The screened materials are respectively output from the second largest particle outlet, the second medium particle outlet and the second small particle outlet;

[0105] Step 2.4: The materials output from the second largest pellet outlet, the second medium pellet outlet and the second smallest pellet outlet are processed by the following methods respectively:

[0106] A. Materials with a particle size of 20 mm or less and less than 31.5 mm are regarded as coarse aggregate products and are output from the second largest aggregate outlet and transported to the finished aggregate bin 16 for storage and shipment by a belt conveyor;

[0107] B. Materials with a particle size of 10 mm or less and less than 20 mm are taken as coarse aggregate products and are output from the second intermediate aggregate outlet and transported to the finished aggregate silo 17 for storage and shipment via a belt conveyor;

[0108] C. The materials with a particle size of 5mm≤<10mm are divided into two parts after being discharged from the second small particle outlet. One part is used as a coarse aggregate product and is transported to the finished aggregate bin No. 318 for storage and shipment through a belt conveyor, and the other part is used as a sand making raw material and is discharged through a belt conveyor;

[0109] In this step, the proportion of the two parts of materials after the 5mm≤particle size<10mm materials are discharged from the second small particle outlet is determined according to the actual production plan or product target of the coarse aggregate products and machine-made sand products to be produced. If necessary, the production of the 5mm≤particle size<10mm grade coarse aggregate products or the production of machine-made sand products can also be stopped.

[0110] Step 3: Sand making, including the following subdivision steps:

[0111] Step 3.1: The coarse aggregate product as the raw material for sand making is first transported to the sand making crusher 7 to enter the sand making crushing stage. The sand making crusher 7 is a vertical shaft crusher;

[0112] Step 3.2: The crushed material is conveyed to the sand making and screening device 8 by a belt conveyor and enters the third screening link, which can also be called the sand making and screening link. The sand making and screening device 8 uses a circular vibrating screen, and the screen mesh control size is 3mm and 5mm. The screened material is output from the third largest particle outlet, the third medium particle outlet and the third small particle outlet respectively. The water spraying device 9 is also used to spray water during the screening process, which can reduce dust pollution on the one hand and collect coal powder on the other hand;

[0113] Step 3.3: The materials output from the third largest pellet outlet, the third medium pellet outlet and the third smallest pellet outlet are processed by the following methods respectively:

[0114] A. Materials with a particle size of ≥5 mm are output from the third largest particle outlet and returned to the sand making crusher 7 through the belt conveyor to re-enter the sand making and crushing link;

[0115] B. The materials with a particle size of 3mm≤<5mm are divided into two parts after being discharged from the third medium particle outlet. One part is returned to the sand making crusher 7 through the belt conveyor to re-enter the sand making and crushing link, and the other part enters the sand washing system under the circular vibrating screen for processing;

[0116] C. Materials with particle size less than 3mm are output from the third small particle outlet and enter the sand washing system below the circular vibrating screen for processing.

[0117] In this step, the third largest particle outlet and the third medium particle outlet form a closed circuit with the sand making and crushing link to cyclically crush relatively large particles of material.

[0118] In this step, a process combining sand crushing and sand screening is set up, and the third medium-grained material outlet and the third small-grained material outlet jointly output the machine-made sand product, realizing the adjustment function of the machine-made sand particle grading, and effectively ensuring the product quality of the coal gangue machine-made sand. Specifically, the division ratio of the two parts of materials after the 3mm≤particle size<5mm material is output from the third medium-grained material outlet is also determined according to the product requirements of the machine-made sand product to be produced.

[0119] In this embodiment, the steps of the coal washing system are as follows:

[0120] Step a1: the material with a particle size of less than 5 mm output from the first small particle outlet is processed by the first spiral sand washing machine 10 and the first fine sand recovery machine 11 in sequence to produce low calorific value coal with a particle size of 0-5 mm; the wastewater discharged from the first spiral sand washing machine 10 and the first fine sand recovery machine 11 is discharged into the wastewater treatment system for treatment;

[0121] Step a2: The low calorific value coal is transported to the low calorific value coal storage shed 15 by a belt conveyor for storage and shipment.

[0122] In this embodiment, the steps of the sand washing system are as follows:

[0123] Step b1: Part of the material with a particle size of 3 mm ≤ < 5 mm output from the third medium-granular material outlet and the material with a particle size of < 3 mm output from the third small-granular material outlet are processed by the second spiral sand washing machine 12 and the second fine sand recovery machine 13 in sequence to produce machine-made sand products with a particle size of 0-5 mm; the wastewater discharged from the second spiral sand washing machine 12 and the second fine sand recovery machine 13 is discharged into the wastewater treatment system for treatment;

[0124] Step b2: The machine-made sand products are transported to the machine-made sand storage shed 19 by a belt conveyor for storage and shipment.

[0125] In this embodiment, the steps of the wastewater treatment system are as follows:

[0126] Step c1: The wastewater generated by the coal washing system and the sand washing system flows into the wastewater pool 21 by gravity, and then is transported to the thickener 22 for sedimentation and separation treatment;

[0127] Step c2: The clean water on the upper layer of the thickener 22 is transported to the clean water tank 24; the thick slurry at the bottom of the thickener 22 is pumped to the filter press workshop by a slurry pump to further remove moisture; the mud cake produced by the filter press 23 is transported to the coal mud pile shed 20 for storage or shipment; the clean water discharged from the filter press 23 is transported to the clean water tank 24;

[0128] Step c3: The clean water tank 24 supplies water to the water spraying device 9 to realize the recycling of water resources.

[0129] In the above technical scheme, in the first screening link and the sand making screening link, the first screening equipment 4 and the sand making screening equipment 8 may also generate a small amount of wastewater in the process of screening materials, and the wastewater can also flow into the wastewater pool 21 by gravity for treatment.

[0130] The working principle of this embodiment is that the coal gangue sand and gravel aggregate production method performs preliminary processing on the coal gangue raw materials through the coarse crushing stage, the medium and fine crushing stage, the first screening stage, and the sorting stage, and then separates the coal products and the gangue aggregate products, and performs cyclic crushing simultaneously in the sorting stage to improve the production efficiency and product quality of the coal products and the gangue aggregate products; the gangue aggregate is classified through the second screening stage to obtain a variety of high-quality coarse aggregate products; part of the coarse aggregate is processed through the sand making crushing stage and the sand making screening stage to obtain the required machine-made sand products, and at the same time, a process flow combining sand making crushing and sand making screening is adopted to improve the production efficiency and product quality of the machine-made sand products, and at the same time, the function of adjusting the particle grading of the machine-made sand products is also realized.

[0131] In addition, the present invention reduces dust pollution in the production process by spraying water during the first screening and sand making screening process, collects coal powder at the same time, and uses a coal washing system and a sand washing system to process the material under the screen. While further improving the quality of coal and sand and gravel aggregate products, it can also produce coal slime by-products, thereby achieving efficient and full utilization of coal gangue resources.

Claims

1. Coal gangue sand and gravel aggregate production system, characterized in that: It comprises a crushing and processing device, the material outlet of the crushing and processing device is connected to a multi-stage sorting device, the material outlet of the multi-stage sorting device comprises a low calorific value coal product output end, a coal product output end and a plurality of gangue aggregate output ends, one of the gangue aggregate output ends is also connected to a sand making device, and the material outlet of the sand making device comprises a machine-made sand product output end; The output end of the low calorific value coal product is connected to a coal washing system, the output end of the machine-made sand product is connected to a sand washing system, the material outlets of the coal washing system and the sand washing system both include a solid material output end and a wastewater output end, and the wastewater output ends of the coal washing system and the sand washing system are commonly connected to a wastewater treatment system; The crushing processing device comprises a coarse crushing discharge bin (1), a coarse crushing machine (2) and a medium and fine crushing machine (3) which are connected in sequence; the discharge outlet of the coarse crushing discharge bin (1) is connected to the feed inlet of the coarse crushing machine (2), and the discharge outlet of the coarse crushing machine (2) is connected to the feed inlet of the medium and fine crushing machine (3) through a conveying mechanism; The multi-stage sorting device comprises a first screening device (4), a sorting device (5) and a second screening device (6); the discharge port of the medium and fine crusher (3) is connected to the feed port of the first screening device (4) through a conveying mechanism, the discharge port of the first screening device (4) comprises a first large particle outlet, a first medium particle outlet and a first small particle outlet, wherein the first large particle outlet is connected to the feed port of the medium and fine crusher (3) through a conveying mechanism, the first medium particle outlet is connected to the feed port of the sorting device (5) through a conveying mechanism, and the low calorific value coal product output end is arranged at the first small particle outlet; The sorting device (5) is provided with two material outlets, the coal product output end is provided at one of the material outlets, the coal product output end is connected to a coal product stacking shed (14) via a conveying mechanism, and the other material outlet is connected to a feed port of a second screening device (6) via a conveying mechanism; The gangue aggregate output end is arranged at the discharge port of the second screening device (6), the discharge port of the second screening device (6) comprises a second large aggregate outlet, a second medium aggregate outlet and a second small aggregate outlet, wherein the second large aggregate outlet is connected to a finished aggregate bin 1 (16) via a conveying mechanism, the second medium aggregate outlet is connected to a finished aggregate bin 2 (17) via a conveying mechanism, and the second small aggregate outlet comprises two connection ends, one of which is connected to a finished aggregate bin 3 (18) via a conveying mechanism; The sand making device comprises a sand making crusher (7) and a sand making screening device (8), wherein the feed port of the sand making crusher (7) is connected to the other connection end of the second small particle outlet via a conveying mechanism, and the discharge port of the sand making crusher (7) is connected to the feed port of the sand making screening device (8) via a conveying mechanism; The discharge port of the sand making and screening equipment (8) comprises a third large aggregate outlet, a third medium aggregate outlet and a third small aggregate outlet, wherein the third large aggregate outlet is connected to the feed port of the sand making crusher (7) via a conveying mechanism, the third medium aggregate outlet comprises two connection ends, one of which is connected to the feed port of the sand making crusher (7) via a conveying mechanism, and the machine-made sand product output end is arranged at the other connection end of the third medium aggregate outlet and the third small aggregate outlet.

2. The coal gangue sand and gravel aggregate production system according to claim 1, characterized in that: A water spray device (9) is provided above the first screening device (4) and the sand making screening device (8); The coal washing system is located below the first screening device (4), and comprises a first spiral sand washer (10) and a first fine sand recovery machine (11) which are connected in sequence, the feed inlet of the first spiral sand washer (10) being connected to the first small particle outlet of the first screening device (4), the solid material output end of the coal washing system being arranged at the discharge port of the first fine sand recovery machine (11), and the discharge port of the first fine sand recovery machine (11) being connected to a low calorific value coal pile shed (15) via a conveying mechanism; The sand washing system is located below the sand making and screening equipment (8), and comprises a second spiral sand washing machine (12) and a second fine sand recovery machine (13) which are connected in sequence, the feed port of the second spiral sand washing machine (12) being connected to the third small particle outlet and the other connection end of the third medium particle outlet of the sand making and screening equipment (8), the solid material output end of the sand washing system being arranged at the discharge port of the second fine sand recovery machine (13), and the discharge port of the second fine sand recovery machine (13) being connected to an organic sand storage shed (19) via a conveying mechanism; The wastewater output end of the coal washing system is arranged at the wastewater outlets of the first spiral sand washing machine (10) and the first fine sand recovery machine (11), and the wastewater output end of the sand washing system is arranged at the wastewater outlets of the second spiral sand washing machine (12) and the second fine sand recovery machine (13).

3. The coal gangue sand and gravel aggregate production system according to claim 2, characterized in that: The wastewater treatment system comprises a wastewater pool (21), the water inlet of the wastewater pool (21) is connected to the wastewater outlets of the first spiral sand washer (10), the first fine sand recovery machine (11), the second spiral sand washer (12) and the second fine sand recovery machine (13), the water outlet of the wastewater pool (21) is connected to the water inlet of the thickener (22), the upper water outlet of the thickener (22) is connected to the water inlet of the clean water pool (24), the bottom slurry outlet of the thickener (22) is connected to a slurry pump and is connected to the feed inlet of the filter press (23) through the slurry pump, and the drain outlet of the filter press (23) is also connected to the water inlet of the clean water pool (24); The water inlet of the water spray device (9) is connected to the clean water tank (24).

4. The coal gangue sand and gravel aggregate production system according to any one of claims 1 to 3, characterized in that: The first screening device (4) is provided with two screens for controlling the screening size, namely a 5 mm screen and a 31.5 mm screen; The second screening device (6) is provided with two screens for controlling the screening size, namely a 10 mm screen and a 20 mm screen; The sand making and screening equipment (8) is provided with two screens for controlling the screening size, namely a 3 mm screen and a 5 mm screen.

5. The coal gangue sand and gravel aggregate production system according to claim 4, characterized in that: The coarse crusher (2) is a jaw crusher; the medium and fine crusher (3) is an impact crusher; and the sand making crusher (7) is a vertical shaft crusher; The first screening device (4), the second screening device (6) and the sand making screening device (8) are all circular vibrating screens; The sorting equipment (5) is an intelligent photoelectric sorting machine; The conveying mechanisms all adopt belt conveyors.

6. A method for producing coal gangue sand and gravel aggregate, characterized in that: The production system of coal gangue sand and gravel aggregate as claimed in any one of claims 3 to 5 comprises the following production steps: Step 1: Crushing The gangue raw materials are continuously transported to the crushing and processing device for crushing, and then output to the multi-stage sorting link; Step 2: Multi-stage screening The materials after medium and fine crushing are screened. On the one hand, relatively large particles are screened out and transported back to the crushing process for cyclic crushing; on the other hand, relatively medium particles are screened out for further sorting, and coal products and gangue aggregates are sorted out. Gangue aggregates are further screened into multiple categories of coarse aggregate products, and part of the coarse aggregate products are transported to the sand making process as sand making raw materials; on the other hand, relatively small particles are screened out and processed as low calorific value coal products; Step 3: Sand Making First, the coarse aggregate product is crushed into sand and then screened. On the one hand, relatively large particles of material are screened out and transported back to the sand making and crushing link for circulating crushing; on the other hand, relatively small particles of material are screened out and processed as machine-made sand products; on the other hand, relatively moderate particles of material are screened out and divided into two parts for output, one part of which is transported back to the sand making and crushing link for circulating crushing together with the larger particles of material, and the other part is processed together with the smaller particles of material as machine-made sand products.

7. The method for producing coal gangue sandstone aggregate according to claim 6, characterized in that: Step 1 includes the following sub-steps: Step 1.1: The gangue raw materials accumulated at the unloading site are transported to the coarse crushing unloading bin (1), and the gangue raw materials are continuously fed to the coarse crushing crusher (2) through the coarse crushing unloading bin (1) for coarse crushing; Step 1.2: The coarsely crushed material is transported to the medium and fine crushing machine (3) through a conveying mechanism for medium and fine crushing, and the medium and fine crushed material is output through the conveying mechanism; Step 2 includes the following sub-steps: Step 2.1: The medium and fine crushed material is first transported to the first screening device (4) for screening, and then the screened material is output from the first large pellet outlet, the first medium pellet outlet and the first small pellet outlet according to the screening conditions of the first screening device (4); Step 2.2: The materials output from the first large pellet outlet, the first medium pellet outlet and the first small pellet outlet are processed by the following methods respectively: A. The material output from the first large particle outlet is returned to the medium and fine crusher (3) through the conveying mechanism for re-medium and fine crushing. A closed circuit is formed between the first large particle outlet and the medium and fine crusher (3), and relatively large pieces of coal gangue are cyclically crushed; B. The material output from the first intermediate pellet outlet is transported to the sorting device (5) through a conveying mechanism for sorting; the products after sorting include coal products and gangue aggregates. The coal products are transported to the coal product storage shed (14) through the conveying mechanism for storage and shipment, and the gangue aggregates are processed according to step 2.3; C. The materials output from the first small pellet outlet enter the coal washing system for processing; Step 2.3: The sorted gangue aggregate is transported to the second screening device (6) through the conveying mechanism for screening, and the screened materials are respectively output from the second large aggregate outlet, the second medium aggregate outlet and the second small aggregate outlet according to the screening conditions of the second screening device (6); Step 2.4: The materials output from the second largest pellet outlet, the second medium pellet outlet and the second smallest pellet outlet are processed by the following methods respectively: A. The material output from the second largest aggregate outlet is used as a coarse aggregate product and is transported to the finished aggregate silo 1 (16) through a conveying mechanism for storage and shipment; B. The material output from the second intermediate aggregate outlet is used as a coarse aggregate product and is transported to the finished aggregate silo 2 (17) via a conveying mechanism for storage and shipment; C. The material output from the second small aggregate outlet is divided into two parts. One part is used as a coarse aggregate product and is transported to the finished aggregate bin three (18) through the conveying mechanism for storage and shipment. The other part is used as a sand making raw material and is output through the conveying mechanism. Step 3 includes the following sub-steps: Step 3.1: The coarse aggregate product as the raw material for sand making is first transported to a sand making crusher (7) for sand making crushing; Step 3.2: The crushed material is transported to the sand making screening device (8) through the conveying mechanism for screening. According to the screening conditions of the sand making screening device (8), the screened material is output from the third largest particle outlet, the third medium particle outlet and the third smallest particle outlet respectively; Step 3.3: The materials output from the third largest pellet outlet, the third medium pellet outlet and the third smallest pellet outlet are processed by the following methods respectively: A. The material output from the third largest particle outlet is returned to the sand making crusher (7) through the conveying mechanism for further sand making and crushing; B. The material output from the third intermediate material outlet is divided into two parts, one part is returned to the sand making crusher (7) through the conveying mechanism for re-sand making and crushing, and the other part enters the sand washing system for processing; C. The material output from the third small pellet outlet enters the sand washing system for processing.

8. The method for producing coal gangue sandstone aggregate according to claim 7, characterized in that: The water spraying device (9) is used to spray water during the screening process of step 2.1 and step 3.2; In step 2.1, the screening conditions of the first screening device (4) are as follows: materials with a particle size ≥ 31.5 mm are output from the first large particle outlet, materials with a particle size 5 mm ≤ < 31.5 mm are output from the first medium particle outlet, and materials with a particle size < 5 mm are output from the first small particle outlet; In step 2.3, the screening conditions of the second screening device (6) are as follows: materials with a particle size of 20 mm ≤ and less than 31.5 mm are output from the second largest particle outlet, materials with a particle size of 10 mm ≤ and less than 20 mm are output from the second medium particle outlet, and materials with a particle size of 5 mm ≤ and less than 10 mm are output from the second smallest particle outlet; In step 3.2, the screening conditions of the sand making and screening equipment (8) are as follows: materials with a particle size ≥ 5 mm are output from the third largest particle outlet, materials with a particle size 3 mm ≤ < 5 mm are output from the third medium particle outlet, and materials with a particle size < 3 mm are output from the third small particle outlet.

9. The method for producing coal gangue sandstone aggregate according to claim 8, characterized in that: The steps of the coal washing system are as follows: Step a1: the material output from the first small-grain material outlet is processed in turn by the first spiral sand washer (10) and the first fine sand recovery machine (11) to produce low calorific value coal with a particle size of 0-5 mm; the wastewater discharged from the first spiral sand washer (10) and the first fine sand recovery machine (11) is discharged into the wastewater treatment system for treatment; Step a2: The low calorific value coal is transported to the low calorific value coal storage shed (15) by the transport mechanism for storage and shipment; The steps of the sand washing system are as follows: Step b1: Part of the material output from the third medium-granular material outlet and the material output from the third small-granular material outlet are processed in turn by the second spiral sand washer (12) and the second fine sand recovery machine (13) to produce a machine-made sand product with a particle size of 0-5 mm; wastewater discharged from the second spiral sand washer (12) and the second fine sand recovery machine (13) is discharged into a wastewater treatment system for treatment; Step b2: The machine-made sand product is transported to the machine-made sand storage shed (19) through the transport mechanism for storage and shipment; The steps of the wastewater treatment system are as follows: Step c1: the wastewater generated by the coal washing system and the sand washing system flows into the wastewater pool (21) by gravity, and is then transported to the thickener (22) for sedimentation and separation treatment; Step c2: the clean water on the upper layer of the thickener (22) is transported to the clean water tank (24); the thick slurry at the bottom of the thickener (22) is pumped to the filter press workshop by a slurry pump to further remove water; the mud cake produced by the filter press (23) is transported to the coal mud pile shed (20) or shipped out of the factory; and the clean water discharged from the filter press (23) is transported to the clean water tank (24); Step c3: The clean water pool (24) supplies water to the water spraying device (9), thereby realizing the recycling of water resources.

Images