System for sand and gravel processing and concrete production

Abstract

The application relates to a sandstone processing and concrete production system. The application is suitable for the technical field of sandstone processing and concrete production. The technical scheme of the application comprises a transportation and unloading mechanism, a material screening mechanism, a material crushing mechanism, a sand making mechanism, a concrete production mechanism, a water supply mechanism and a wastewater treatment mechanism. The material screening mechanism comprises a first screening device for primary screening treatment, a second screening device for secondary screening treatment and a third screening device for multi-stage screening treatment. The material crushing mechanism comprises a first crushing device, a second crushing device and a third crushing device. The second crushing device and the second screening device form a first closed loop, and the third crushing device and the third screening device form a second closed loop. The sand making mechanism can obtain materials and perform sand making treatment. The concrete production mechanism can obtain production raw materials and materials and perform stirring treatment to obtain concrete. The water supply mechanism can provide clean water. The wastewater treatment mechanism can collect generated wastewater.

Description

Technical Field

[0001] This utility model relates to the field of sand and gravel processing and concrete production technology, and in particular to a system for sand and gravel processing and concrete production. Background Technology

[0002] In the construction of large-scale infrastructure projects such as water conservancy, transportation, and energy, sand and gravel aggregates are a core component of concrete. Their quality stability, gradation rationality, particle shape, and supply continuity directly affect the mechanical properties, durability, construction efficiency, and overall structural safety and construction costs of the concrete. With the continuous expansion of project scale and the increasingly rapid pace of construction, higher requirements are being placed on the high-quality, large-volume, and stable supply of aggregates.

[0003] However, traditional sand and gravel processing systems generally suffer from the following prominent problems: The process flow design is crude: the crushing stage is not configured properly, or over-crushing leads to a surge in energy consumption and an increase in needle-shaped and flaky particles, or under-crushing results in a low yield and frequent rework; there is a lack of effective closed-loop control between screening and crushing, making it difficult to accurately control particle size distribution and stone powder content, which affects aggregate quality. Low system integration: The sand and gravel processing system and the concrete mixing plant often operate independently, with information and material flow disconnected. It is impossible to dynamically adjust the aggregate output and gradation according to the concrete pouring strength, resulting in inventory backlog or supply shortage, which affects the continuity of construction. Environmental governance lags behind: Wastewater generated during crushing, screening, and transfer processes has not been systematically collected and treated for resource recovery, resulting in environmental pollution.

[0004] Therefore, developing a system for sand and gravel processing and concrete production that features a reasonable process flow, integrated production mode, strong system linkage, good adaptability, and is economical and environmentally friendly has significant practical importance and application value. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a system for sand and gravel processing and concrete production, in view of the above-mentioned problems.

[0006] The technical solution adopted by this utility model is: a system for sand and gravel processing and concrete production, comprising: The transport and unloading mechanism can transfer materials from the material source to the unloading platform; The material screening mechanism includes a first screening device, a second screening device and a third screening device. The first screening device is used to receive the material output from the unloading platform and perform primary screening. The second screening device is used to perform secondary screening on the material after primary screening to obtain a first stockpile. The third screening device is used to perform multi-stage screening on the material after secondary screening to obtain a second stockpile, a third stockpile and a fourth stockpile. The material crushing mechanism includes a first crushing device, a second crushing device, and a third crushing device. The second crushing device and the second screening device form a first closed loop, and the third crushing device and the third screening device form a second closed loop, so that the first crushing device, the second crushing device, and the third crushing device can respectively perform coarse crushing on materials with a particle size higher than the preset particle size threshold of the primary screening process, perform medium and fine crushing on materials with a particle size higher than the preset particle size threshold of the secondary screening process, and perform ultrafine crushing on materials with a particle size higher than the preset particle size threshold of the multi-stage screening process. The sand making unit is capable of obtaining the material that has undergone multi-stage screening to obtain the third stockpile and then performing sand making to obtain the fourth stockpile. A concrete production facility is capable of acquiring raw materials and materials from a second, third, and fourth stockpile, and mixing them to obtain concrete. The water supply system is capable of providing clean water for the spraying treatment in the material screening system, the sand washing treatment in the sand making system, and the mixing treatment in the concrete production system. Wastewater treatment facilities are capable of collecting wastewater generated from spraying, sand washing, and mixing processes.

[0007] Through the aforementioned technical means, multiple screening devices in the material screening mechanism constitute multi-stage screening. The crushing equipment in the material crushing mechanism works in conjunction with the screening equipment to form a closed-loop crushing cycle, achieving precise grading and closed-loop control of materials of different particle sizes to obtain stockpiles of different particle sizes. The closed-loop cycle structure can reduce ineffective crushing and rework, and improve the yield. The sand making mechanism uses materials that meet the particle size requirements for directional sand making. The concrete production mechanism uses stockpiles of different particle sizes to further produce concrete. The integrated design of sand and gravel processing and concrete production realizes the tiered utilization of materials. The wastewater treatment mechanism can also centrally collect and treat wastewater, realizing the resource utilization or harmless disposal of production wastewater, and reducing dust and sewage emissions.

[0008] In some embodiments, the first screening device includes a bar feeder. The material output from the unloading platform is fed into the bar feeder. If the material output from the unloading platform does not meet the preset particle size threshold of the bar feeder, the material is fed into the first crushing device for crushing. The material obtained from the crushing process of the first crushing device and the material that meets the preset particle size threshold of the bar feeder are piled up to form a semi-finished product pile. The material in the semi-finished product pile can be fed into the second screening device for secondary screening.

[0009] In some embodiments, the second screening device includes a first circular vibrating screen. The material that has undergone primary screening is fed into the first circular vibrating screen. If the material that has undergone primary screening does not meet the preset particle size threshold of the first circular vibrating screen, the material is fed into the second crushing device for crushing. The material obtained by the crushing process of the second crushing device and the material that meets the preset particle size threshold of the first circular vibrating screen form the first stockpile.

[0010] In some embodiments, the third screening device includes a second circular vibrating screen with three layers of screens inside. The material after secondary screening is fed into the second circular vibrating screen. If the material after secondary screening does not meet the preset first-level particle size threshold of the second circular vibrating screen, the material is fed into the second crushing device for crushing. The material output from the second crushing device is fed into the second screening device to form the first closed-loop cycle. If the material meets the preset primary particle size threshold of the second circular vibrating screen but does not meet the preset secondary particle size threshold of the second circular vibrating screen, the corresponding material portion will be retained to form the second stockpile and sent to the third crushing equipment for crushing. The material output from the third crushing equipment will be sent to the second circular vibrating screen to form the second closed-loop circulation. If the material meets the preset secondary particle size threshold of the second circular vibrating screen but does not meet the preset tertiary particle size threshold of the second circular vibrating screen, the corresponding material portion will be retained to form the third stockpile and sent to the sand making mechanism. If the material meets the preset three-stage particle size threshold of the second circular vibrating screen, the resulting material and the output material of the sand making mechanism will accumulate to form the fourth material pile.

[0011] In some embodiments, the preset particle size threshold for the primary screening process is 150 mm, the preset particle size threshold for the secondary screening process is 80 mm, the preset first-stage particle size threshold for the second circular vibrating screen is 40 mm, the preset second-stage particle size threshold for the second circular vibrating screen is 20 mm, and the preset third-stage particle size threshold for the second circular vibrating screen is 5 mm.

[0012] In some embodiments, the water supply mechanism includes a clear water tank and a spraying device, which are connected by a pipeline. The output end of the second circular vibrating screen is equipped with a first spiral sand washer and a first dewatering screen. The first spiral sand washer can wash the material that meets the preset three-stage particle size threshold of the second circular vibrating screen. The first dewatering screen can dewater the washed material to obtain the fourth material pile. The spraying device can draw water from the clear water tank and transport it for spraying the material being screened in the second circular vibrating screen.

[0013] In some embodiments, the sand making mechanism includes a rod mill, a second spiral sand washer, and a second dewatering screen. The water supply mechanism includes a clear water tank and a rod mill water supply device. The material that meets the preset secondary particle size threshold of the second circular vibrating screen but does not meet the preset tertiary particle size threshold of the second circular vibrating screen is fed into the rod mill for sand making. The rod mill water supply device can extract water from the clear water tank and transport it for sand making in the rod mill. The second spiral sand washer can wash the material obtained from the rod mill. The second dewatering screen can dewater the washed material to obtain the fourth stockpile.

[0014] In some embodiments, the first crushing device includes a jaw crusher, the second crushing device includes a cone crusher, and the third crushing device includes a vertical shaft impact crusher.

[0015] In some embodiments, the concrete production facility includes a conveyor belt, bulk cement trucks, bulk admixture trucks, an air compressor station, cement silos, fly ash silos, a gasification jet pump, an admixture room, and a mixing station. The water supply facility includes a clear water tank. Gasification jet pumps are installed between the cement silos, fly ash silos, and the mixing station. The raw materials include cement and fly ash. The bulk cement trucks can transport cement to the site, the bulk admixture trucks can transport fly ash to the site, and the conveyor belt can transport the second material pile... The materials from the third and fourth stockpiles are transported to the site. The air compressor station generates compressed air to send cement and fly ash into the cement silo and fly ash silo respectively. The gasification jet pump sends the cement from the cement silo and the fly ash from the fly ash silo into the mixing plant. The admixture room sends admixtures into the mixing plant. The clear water tank sends water into the mixing plant through the water supply pipeline. The mixing plant mixes the cement, fly ash, water, admixtures, and materials from the second, third, and fourth stockpiles to obtain concrete.

[0016] Another technical solution adopted by this utility model is: a processing method for a system of sand and gravel processing and concrete production, comprising the following steps: S1. Raw material transportation and unloading: Loaders are used to load materials from the source or transfer yard into dump trucks, and the dump trucks transport the materials to the unloading platform. S2. Primary screening and coarse crushing: The material from the unloading platform is fed into the first screening equipment for primary screening. If the particle size of the material is greater than the preset particle size threshold of the primary screening, it is fed into the first crushing equipment for coarse crushing. Otherwise, the material that passes through directly and the material after coarse crushing together form a semi-finished product stockpile. S3. Secondary screening and medium-fine crushing closed loop: The material in the semi-finished material pile is sent to the second screening equipment for secondary screening. If the particle size of the material is larger than the preset particle size threshold of the secondary screening, it is sent to the second crushing equipment for medium-fine crushing. The crushed material is sent back to the second screening equipment to form the first closed loop. Otherwise, the material that passes through directly is partially piled up to form the first stockpile, and the remaining part is sent to the third screening equipment. S4. Multi-stage screening and ultra-fine crushing circulation: The third screening equipment performs multi-stage screening on the fed material. If the particle size of the material does not meet the preset first-stage particle size threshold of the third screening equipment, it is returned to the second crushing equipment for medium and fine crushing. If the particle size of the material is between the preset primary particle size threshold and the preset secondary particle size threshold of the third screening equipment, the material is partially piled up to form a second stockpile, and the remaining part is sent to the third crushing equipment for ultra-fine crushing. The crushed material is then sent back to the third screening equipment to form a second closed-loop cycle. If the particle size of the material is between the preset primary particle size threshold and the preset secondary particle size threshold of the third screening equipment, then part of the material is piled up to form the third stockpile, and the remaining part is sent to the sand making mechanism for wet sand making. If the material meets the preset three-stage particle size threshold of the third screening equipment, it will enter the sand washing and dewatering process and together with the material obtained by the wet sand making mechanism to form the fourth stockpile. S5. Concrete raw material preparation and mixing: Obtain raw materials including aggregates, cement, fly ash, admixtures provided by the admixture room and clean water provided by the water supply unit from the second, third and fourth stockpiles. Mix the raw materials in the mixing plant according to the design mix ratio to produce concrete. S6. Finished product transportation and wastewater recycling: The mixed concrete is transported to the construction site by concrete mixer trucks, and various types of wastewater generated during the production process are collected through pipelines to the wastewater treatment facility.

[0017] The beneficial effects of this utility model are: 1. This solution achieves precise grading and closed-loop control of materials with different particle sizes by setting up three-stage screening and three-stage crushing equipment, and constructing a first closed-loop cycle of "second crushing equipment – ​​second screening equipment" and a second closed-loop cycle of "third crushing equipment – ​​third screening equipment". This closed-loop structure can dynamically adjust crushing parameters based on screening results, avoiding over-crushing or under-crushing, thereby optimizing particle shape, controlling stone powder content, improving yield, significantly enhancing the rationality and quality stability of aggregate gradation, and thus solving the problem of extensive process flow design.

[0018] 2. This system organically integrates the aggregate processing system with the concrete production facility, allowing aggregates of different particle sizes from the second, third, and fourth stockpiles to be directly used as raw materials for concrete mixing. This integrated design streamlines the material and information flow between aggregate production and concrete preparation, possessing the potential to dynamically adjust aggregate output and gradation according to concrete pouring requirements, thereby improving supply continuity and reducing the risk of inventory backlog or shortages.

[0019] 3. This system is equipped with a water supply mechanism and a wastewater treatment mechanism to systematically collect and treat the wastewater generated in the screening, spraying, sand washing and mixing processes, so as to realize the recycling of water resources or discharge in compliance with standards, effectively reduce environmental pollution and meet the requirements of green construction and sustainable development. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the system structure in this application.

[0021] Explanation of reference numerals in the attached figures: 1. Material source; 2. Loader; 3. Dump truck; 4. Unloading platform; 5. Bar feeder; 6. Jaw crusher; 7. Semi-finished material stockpile; 8. First circular vibrating screen; 9. Cone crusher; 10. First stockpile; 11. Second circular vibrating screen; 12. Clear water tank; 13. Spraying device; 14. Vertical shaft impact crusher; 15. Rod mill; 16. Rod mill water supply device; 17. Second spiral sand washer; 18. Second dewatering screen; 19. First spiral sand washer; 20. First dewatering screen; 21. Second stockpile; 22. Third stockpile; 23. Fourth stockpile; 24. Air compressor station; 25. Bulk cement transport truck; 26. Cement silo; 27. Bulk admixture transport truck; 28. Fly ash silo; 29. ​​Gasification jet pump; 30. Admixture room; 31. Mixing station; 32. Wastewater treatment facility.

[0022] This specification includes references to "one embodiment" or "implementation". The use of the phrase "in one embodiment" or "in an embodiment" does not necessarily refer to the same embodiment. Specific features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure.

[0023] The term "comprising" is open-ended. As used in the appended claims, it does not exclude additional structures or steps.

[0024] "First," "second," etc. As used in this article, these terms serve as labels for the nouns preceding them and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0026] Example 1: Combination Figure 1 As shown, this embodiment is a system for sand and gravel processing and concrete production, including a transportation and unloading mechanism, a material screening mechanism, a material crushing mechanism, a sand making mechanism, a concrete production mechanism, a water supply mechanism, and a wastewater treatment mechanism 32. The material screening mechanism includes a first screening device, a second screening device, and a third screening device, and the material crushing mechanism includes a first crushing device, a second crushing device, and a third crushing device.

[0027] The transport and unloading mechanism can transfer materials from material source 1 to unloading platform 4. The first screening device is used to receive the materials output from unloading platform 4 and perform primary screening. The first crushing device can coarsely crush materials that are larger than the preset particle size threshold of the primary screening. The second screening device is used to perform secondary screening on the materials that have undergone primary screening to obtain the first stockpile 10. The second crushing device can perform medium and fine crushing on materials that are larger than the preset particle size threshold of the secondary screening. A first closed-loop cycle is formed between the second crushing device and the second screening device. The third screening device is used to perform multi-stage screening on the materials that have undergone secondary screening to obtain the second stockpile 21, the third stockpile 22, and the fourth stockpile 23. The third crushing device can perform ultra-fine crushing on materials that are larger than the preset particle size threshold of the multi-stage screening. A second closed-loop cycle is formed between the third crushing device and the third screening device.

[0028] The sand-making unit is able to obtain the material from the third stockpile 22 after multi-stage screening and perform sand-making processing to obtain the fourth stockpile 23. The concrete production unit is able to obtain the raw materials and the materials from the second stockpile 21, the third stockpile 22, and the fourth stockpile 23 and perform mixing processing to obtain concrete. The water supply unit is able to provide clean water required for the spraying treatment in the material screening unit, the sand washing treatment in the sand-making unit, and the mixing treatment in the concrete production unit. The wastewater treatment unit 32 is able to collect the wastewater generated from the spraying treatment, sand washing treatment, and mixing treatment.

[0029] In some implementations, the first crushing device includes a jaw crusher 6, the second crushing device includes a cone crusher 9, and the third crushing device includes a vertical shaft impact crusher 14.

[0030] Jaw crusher 6 is selected for coarse crushing due to its advantages such as simple structure, light weight, convenient installation and maintenance, stable and reliable operation, convenient discharge port adjustment, and low risk of material jamming. Cone crusher 9 is selected for medium and fine crushing due to its high crushing ratio and strong adaptability. Vertical shaft impact crusher 14 is selected for ultrafine crushing due to its ability to adjust particle size ratio and shape materials.

[0031] In some implementations, the first screening device includes a bar feeder 5. The material output from the unloading platform 4 is fed into the bar feeder 5. If the material output from the unloading platform 4 does not meet the preset particle size threshold of the bar feeder 5, the material is fed into the first crushing device for crushing. The material obtained from the crushing process of the first crushing device and the material obtained from the material that meets the preset particle size threshold of the bar feeder 5 are piled up to form a semi-finished product pile 7. The material in the semi-finished product pile 7 can be fed into the second screening device for secondary screening.

[0032] When the material from the unloading platform 4 falls onto the bar feeder 5, the material below the bar feeder 5 directly enters the semi-finished product stockpile 7 for storage, while the material above the bar feeder 5 enters the jaw crusher 6 for crushing and then enters the semi-finished product stockpile 7 for storage.

[0033] In some implementations, the second screening device includes a first circular vibrating screen 8. The material that has undergone primary screening is fed into the first circular vibrating screen 8. The first circular vibrating screen 8 has a screen inside. If the material that has undergone primary screening does not meet the preset particle size threshold of the first circular vibrating screen 8, the material is fed into a cone crusher 9 for crushing. The material obtained by the cone crusher 9 and the material that meets the preset particle size threshold of the first circular vibrating screen 8 form a first stockpile 10.

[0034] In some implementations, the third screening device includes a second circular vibrating screen 11, which has three layers of screens inside. The material after secondary screening is fed into the second circular vibrating screen 11. If the material after secondary screening does not meet the preset primary particle size threshold of the second circular vibrating screen 11, the material is fed into a cone crusher 9 for crushing. The material output from the cone crusher 9 is fed into the first circular vibrating screen 8 to form a first closed loop. If the material meets the preset primary particle size threshold of the second circular vibrating screen 11 but does not meet the preset secondary particle size threshold of the second circular vibrating screen 11, the corresponding material portion will be retained to form a second stockpile 21 and fed into the vertical shaft crusher 14 for crushing. The material output from the vertical shaft crusher 14 will be fed into the second circular vibrating screen 11 to form a second closed-loop circulation. If the material meets the preset secondary particle size threshold of the second circular vibrating screen 11 but does not meet the preset tertiary particle size threshold of the second circular vibrating screen 11, the corresponding material portion will be retained to form the third stockpile 22 and sent to the sand making mechanism. If the material meets the preset three-stage particle size threshold of the second circular vibrating screen 11, the resulting material and the output material of the sand making mechanism will accumulate to form the fourth stockpile 23.

[0035] Furthermore, the preset particle size threshold for the primary screening process is 150mm, the preset particle size threshold for the secondary screening process is 80mm, the preset first-stage particle size threshold for the second circular vibrating screen 11 is 40mm, the preset second-stage particle size threshold for the second circular vibrating screen 11 is 20mm, and the preset third-stage particle size threshold for the second circular vibrating screen 11 is 5mm. Specifically, the screen mesh size can be flexibly adjusted according to actual production needs.

[0036] The first stockpile 10 generated by the first closed-loop cycle includes bedding material, drainage material, etc. In the first closed-loop cycle, the first circular vibrating screen 8 is linked with the cone crusher 9 to ensure that materials smaller than 80mm meet the standards. In the second closed-loop cycle, the second circular vibrating screen 11 is linked with the vertical shaft impact crusher 14 to ensure that materials smaller than 40mm are finely separated as needed. Materials that do not meet the standards are automatically returned to the crusher, forming a dynamic balance of "screening, crushing, and re-screening".

[0037] In some implementations, the water supply mechanism includes a clear water tank 12 and a spray device 13, which are connected by a pipeline. The spray device 13 corresponds to a screen. The output end of the second circular vibrating screen 11 is equipped with a first spiral sand washer 19 and a first dewatering screen 20. The first spiral sand washer 19 can wash the sand that meets the preset three-stage particle size threshold of the second circular vibrating screen 11. The first dewatering screen 20 can dewater the washed sand to obtain a fourth stockpile 23. The spray device 13 can draw water from the clear water tank 12 and transport it for spraying the material being screened in the second circular vibrating screen 11.

[0038] In some implementations, the sand making mechanism includes a rod mill 15, a second spiral sand washer 17, and a second dewatering screen 18. The water supply mechanism includes a clear water tank 12 and a rod mill water supply device 16. Materials that meet the preset secondary particle size threshold of the second circular vibrating screen 11 but do not meet the preset tertiary particle size threshold of the second circular vibrating screen 11 are fed into the rod mill 15 for sand making. The rod mill water supply device 16 can extract water from the clear water tank 12 and transport it for sand making in the rod mill 15. The second spiral sand washer 17 can wash the material obtained from the rod mill 15. The second dewatering screen 18 can dewater the washed material to obtain a fourth stockpile 23.

[0039] Spiral sand washing machines effectively remove mud and impurities from manufactured sand, controlling mud and stone powder content. Traditional production methods are simplistic: wet production consumes a lot of water and is difficult to treat, while dry production causes severe dust pollution. To optimize the process, dry production aggregates are prone to high powder content and are susceptible to powder coating due to weather conditions, while wet production involves high water consumption, large-scale wastewater, and high investment. This embodiment adopts a semi-dry production process, where aggregates are processed wet only from the third screening equipment onwards. This allows for controllable powder content in the aggregates, a relatively small wastewater scale, and saves water resources and investment.

[0040] In some implementations, the concrete production facility includes a conveyor belt, bulk cement trucks 25, bulk admixture trucks 27, an air compressor station 24, cement silos 26, fly ash silos 28, an aeration jet pump 29, an admixture room 30, and a mixing plant 31. The water supply system includes a clear water tank 12. An aeration jet pump 29 is installed between the cement silos 26, fly ash silos 28, and the mixing plant 31. The raw materials include cement and fly ash. The bulk cement trucks 25 transport cement to the site, the bulk admixture trucks 27 transport fly ash to the site, and the conveyor belts transport the second stockpile 21, the third stockpile 27, and the fourth stockpile 38. The materials from stockpiles 22 and 23 are transported to the site. The air compressor station 24 generates compressed air to send cement and fly ash into cement silos 26 and fly ash silos 28, respectively. The gasification jet pump 29 sends cement from cement silos 26 and fly ash from fly ash silos 28 into mixing plant 31. The admixture room 30 sends admixtures into mixing plant 31. The clear water tank 12 sends water into mixing plant 31 via a water supply pipe. Mixing plant 31 mixes cement, fly ash, water, admixtures, and materials from stockpiles 21, 22, and 23 to obtain concrete.

[0041] Furthermore, this embodiment employs an automated batching system, which includes high-precision sensors and an intelligent control module. This system accurately weighs raw materials such as cement, sand, gravel, admixtures, and water according to a preset mix ratio, ensuring batching accuracy. Automated batching systems are a common engineering technique and are effectively compatible with the system in this embodiment. Simultaneously, the mixing plant 31 in this embodiment utilizes high-efficiency mixing equipment, enabling uniform and rapid mixing of concrete and ensuring stable concrete quality.

[0042] The implementation principle of the sand and gravel processing and concrete production system of this utility model embodiment is as follows: This system employs a combination of multi-stage screening, multi-stage crushing, and closed-loop circulation to achieve precise particle size control. Different particle size thresholds (such as 150mm, 80mm, 40mm, 20mm, and 5mm) are set, and materials are screened step by step according to particle size. Each stage corresponds to a specific crushing device to avoid over- or under-crushing and optimize energy consumption and yield.

[0043] The bar feeder 5, in conjunction with the jaw crusher 6, pre-screens oversized materials with a particle size >150mm, crushing only the oversized material. The cone crusher 9, in conjunction with the first circular vibrating screen 8, stably produces aggregate with a particle size of 40mm~80mm, which is the bedding stockpile. The vertical shaft impact crusher 14, in conjunction with the second circular vibrating screen 11, precisely controls the production of the second stockpile 21 with a particle size of 20mm~40mm, which is the coarse aggregate; the third stockpile 22 with a particle size of 5mm~20mm, which is the medium aggregate; and the fourth stockpile 23 with a particle size <5mm, which is the manufactured sand.

[0044] The first spiral sand washing machine 19 and the first dewatering screen 20 can wash and dewater the manufactured sand obtained from the second circular vibrating screen 11. The second spiral sand washing machine 17 and the second dewatering screen 18 can wash and dewater the material obtained from the sand making mechanism. Thus, the two mechanisms work together to form a dual sand washing and dewatering system.

[0045] In common practice, aggregate processing and concrete production are separate operations. Concrete raw materials are often purchased externally, and their quality is easily affected by market conditions and weather, making quality control difficult. This system integrates the aggregate processing system with the concrete production facility. These two systems are independent and do not interfere with each other. Aggregates produced by the aggregate processing system are stored in stockpiles, and the subsequent concrete production system can retrieve the required amount of aggregate in real time via conveyor belts based on the pouring intensity, achieving on-demand aggregate supply. The control systems for aggregate processing and concrete production can be centrally located, linked in real time, and uniformly managed. This system offers advantages such as stable and controllable raw materials, integrated production modes, strong system linkage, good adaptability, and economic and environmental benefits. Material and information flows are initially integrated, improving responsiveness. Aggregate production and concrete mixing are completed within the same system, achieving "on-demand production" through conveyor belts and other equipment, responding to pouring plans and avoiding supply interruptions or stockpiling.

[0046] By setting up a wastewater treatment facility 32, wastewater from screening, spraying, sand washing, and mixing processes is collected in a unified manner; at the same time, water is circulated through the clear water tank 12 to achieve cascade utilization and partial reuse of water resources, reducing external discharge.

[0047] Example 2: This embodiment describes a processing method for a sand and gravel processing and concrete production system, applied to the sand and gravel processing and concrete production system described in Embodiment 1, and includes the following steps: S1. Raw material transportation and unloading: Loader 2 loads material from material source 1 or transfer yard into dump truck 3, and dump truck 3 transports the material to unloading platform 4.

[0048] S2. Primary screening and coarse crushing: The material from the unloading platform 4 is fed into the first screening equipment for primary screening. If the particle size of the material is greater than the preset particle size threshold of the primary screening, it is fed into the first crushing equipment for coarse crushing. Otherwise, the material that passes through directly and the material after coarse crushing together form a semi-finished product stockpile 7.

[0049] S2.1 The material in the unloading platform 4 falls onto the bar feeder 5. The material above the bar feeder 5 enters the jaw crusher 6 for crushing and then enters the semi-finished product stockpile 7 for storage. The material below the bar feeder 5 directly enters the semi-finished product stockpile 7 for storage.

[0050] S3, Secondary screening and medium-fine crushing closed loop: The material in the semi-finished material pile 7 is sent to the second screening equipment for secondary screening. If the particle size of the material is larger than the preset particle size threshold of the secondary screening, it is sent to the second crushing equipment for medium-fine crushing. The crushed material is sent back to the second screening equipment to form the first closed loop. Otherwise, the material that passes through directly is partially piled up to form the first material pile 10, and the remaining part is sent to the third screening equipment.

[0051] S3.1 The inner layer of screen of the first circular vibrating screen 8 is used to screen the material into two types: >80mm and <80mm. Among them, the material >80mm is transported to the cone crusher 9 for crushing, and the crushed material is returned to the first circular vibrating screen 8 for screening to form the first closed-loop cycle. A portion of the material <80mm is retained and transported to the stockpile to form the first stockpile 10, and the remaining material is transported to the second circular vibrating screen 11 for screening.

[0052] S4. Multi-stage screening and ultra-fine crushing circulation: The third screening equipment performs multi-stage screening on the fed material. If the particle size of the material does not meet the preset first-stage particle size threshold of the third screening equipment, it is returned to the second crushing equipment for medium and fine crushing. If the particle size of the material is between the preset primary particle size threshold and the preset secondary particle size threshold of the third screening equipment, the material is partially piled up to form the second stockpile 21, and the remaining part is sent to the third crushing equipment for ultra-fine crushing. The crushed material is then sent back to the third screening equipment to form the second closed-loop cycle. If the particle size of the material is between the preset primary particle size threshold and the preset secondary particle size threshold of the third screening equipment, the material is partially stockpiled to form the third stockpile 22, and the remaining part is sent to the sand making mechanism for wet sand making. If the material meets the preset three-stage particle size threshold of the third screening equipment, it enters the sand washing and dewatering process and together with the material obtained by the wet sand making mechanism to form the fourth stockpile 23.

[0053] S4.1 The second circular vibrating screen 11 is equipped with three layers of screens to separate the material into four types: >40mm, 40mm~20mm, 20mm~5mm, and <5mm. Among them, the material >40mm is returned to the cone crusher 9 for crushing; a portion of the material from 40mm to 20mm is retained to form the second stockpile 21, and the remaining portion is transported to the vertical shaft crusher 14 for crushing. After crushing, the material is returned to the second circular vibrating screen 11 for screening; a portion of the material from 20mm to 5mm is retained to form the third stockpile 22, and the remaining portion is transported to the rod mill 15 for sand making; the material <5mm is dewatered by the first spiral sand washer 19 and the first dewatering screen 20 and then stockpiled to form the fourth stockpile 23.

[0054] S4.2 The sand making process adopts a wet process. After the sand making is completed, the material is washed by the second spiral sand washing machine 17 and dewatered by the second dewatering screen 18 before entering the fourth stockpile 23 for storage.

[0055] S5. Concrete raw material preparation and mixing: raw materials include aggregates from the second stockpile 21, the third stockpile 22 and the fourth stockpile 23, cement, fly ash, admixtures provided by the admixture room 30 and clean water provided by the water supply system. All raw materials are mixed in the mixing plant 31 according to the design mix ratio to produce concrete.

[0056] S5.1 The material in the first stockpile 10 is loaded onto the dump truck 3 by the loader 2 and transported to the target site. The materials in the second stockpile 21, the third stockpile 22 and the fourth stockpile 23 are transported to the mixing plant 31 of the concrete production facility by conveyor belt.

[0057] S5.2 Cement and fly ash are transported to the site by bulk cement trucks and bulk admixture transport vehicles 27. The compressed air generated by the air compressor station 24 is used to pneumatically transport the cement and fly ash into the cement tank 26 and fly ash tank 28. When the mixing plant 31 is running, the cement and fly ash in the tanks are transported into the mixing plant 31 by the gasification jet pump 29.

[0058] S5.3 After the admixtures in admixture room 30 are prepared, add them into mixing station 31.

[0059] S5.4 The production water in the mixing plant 31 is water from the clear water tank 12. Materials, cement, fly ash, admixtures and water are mixed in a certain proportion to obtain concrete.

[0060] S6. Finished product transportation and wastewater recycling: The mixed concrete is transported to the construction site by concrete mixer trucks, and various types of wastewater generated during the production process are collected through pipelines to the wastewater treatment facility 32.

[0061] S6.1 Various types of wastewater include wastewater generated during concrete mixing, wastewater generated during sand screening and washing, and wastewater generated from the storage of wet materials in the stockpile.

[0062] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A system for sand and gravel processing and concrete production, characterized in that, include: The transport and unloading mechanism can transfer the material from the material source (1) to the unloading platform (4). The material screening mechanism includes a first screening device, a second screening device and a third screening device. The first screening device is used to receive the material output from the unloading platform (4) and perform primary screening. The second screening device is used to perform secondary screening on the material after primary screening to obtain a first stockpile (10). The third screening device is used to perform multi-stage screening on the material after secondary screening to obtain a second stockpile (21), a third stockpile (22) and a fourth stockpile (23). The material crushing mechanism includes a first crushing device, a second crushing device, and a third crushing device. The second crushing device and the second screening device form a first closed loop, and the third crushing device and the third screening device form a second closed loop, so that the first crushing device, the second crushing device, and the third crushing device can respectively perform coarse crushing on materials with a particle size higher than the preset particle size threshold of the primary screening process, perform medium and fine crushing on materials with a particle size higher than the preset particle size threshold of the secondary screening process, and perform ultrafine crushing on materials with a particle size higher than the preset particle size threshold of the multi-stage screening process. The sand making unit is able to obtain the material that has been screened through multiple stages to obtain the third stockpile (22) and perform sand making to obtain the fourth stockpile (23). The concrete production facility is able to obtain raw materials and materials from the second stockpile (21), the third stockpile (22), and the fourth stockpile (23) and perform mixing treatment to obtain concrete; The water supply system is capable of providing clean water for the spraying treatment in the material screening system, the sand washing treatment in the sand making system, and the mixing treatment in the concrete production system. Wastewater treatment facility (32) is capable of collecting wastewater generated from spray treatment, sand washing treatment and mixing treatment.

2. The system for sand and gravel processing and concrete production according to claim 1, characterized in that: The first screening equipment includes a bar feeder (5). The material output from the unloading platform (4) is fed into the bar feeder (5). If the material output from the unloading platform (4) does not meet the preset particle size threshold of the bar feeder (5), the material is sent to the first crushing equipment for crushing. The material obtained by the crushing of the first crushing equipment and the material obtained by the bar feeder (5) are piled up to form a semi-finished product pile (7). The material in the semi-finished product pile (7) can be sent to the second screening equipment for secondary screening.

3. A system for aggregate processing and concrete production according to claim 1, characterized in that: The second screening device includes a first circular vibrating screen (8). The material after primary screening is fed into the first circular vibrating screen (8). If the material after primary screening does not meet the preset particle size threshold of the first circular vibrating screen (8), the material is sent to the second crushing device for crushing. The material obtained by the crushing of the second crushing device and the material obtained by the first circular vibrating screen (8) form the first stockpile (10).

4. A system for aggregate processing and concrete production according to claim 1, characterized in that: The third screening device includes a second circular vibrating screen (11). The second circular vibrating screen (11) has three layers of screens inside. The material after secondary screening is fed into the second circular vibrating screen (11). If the material after secondary screening does not meet the preset first-level particle size threshold of the second circular vibrating screen (11), the material is sent to the second crushing device for crushing. The material output from the second crushing device is sent to the second screening device to form the first closed loop. If the material meets the preset first-level particle size threshold of the second circular vibrating screen (11) but does not meet the preset second-level particle size threshold of the second circular vibrating screen (11), the corresponding material portion is retained to form the second material pile (21) and sent to the third crushing equipment for crushing. The material output from the third crushing equipment is sent to the second circular vibrating screen (11) to form the second closed-loop circulation. If the material meets the preset secondary particle size threshold of the second circular vibrating screen (11) but does not meet the preset tertiary particle size threshold of the second circular vibrating screen (11), the corresponding material portion will be retained to form the third stockpile (22) and sent to the sand making mechanism. If the material meets the preset three-stage particle size threshold of the second circular vibrating screen (11), the material obtained and the output material of the sand making mechanism will accumulate to form the fourth stockpile (23).

5. A system for aggregate processing and concrete production according to claim 4, characterized in that: The preset particle size threshold for the primary screening process is 150 mm, the preset particle size threshold for the secondary screening process is 80 mm, the preset first-level particle size threshold for the second circular vibrating screen (11) is 40 mm, the preset second-level particle size threshold for the second circular vibrating screen (11) is 20 mm, and the preset third-level particle size threshold for the second circular vibrating screen (11) is 5 mm.

6. A system for aggregate processing and concrete production according to claim 4, characterized in that: The water supply mechanism includes a clear water tank (12) and a spray device (13). The clear water tank (12) and the spray device (13) are connected by a pipeline. The output end of the second circular vibrating screen (11) is equipped with a first spiral sand washing machine (19) and a first dewatering screen (20). The first spiral sand washing machine (19) can wash the sand that meets the preset three-stage particle size threshold of the second circular vibrating screen (11). The first dewatering screen (20) can dewater the washed sand to obtain the fourth material pile (23). The spray device (13) can draw water from the clear water tank (12) and transport it for spraying the material in the second circular vibrating screen (11) that is being screened.

7. The system for sand and gravel processing and concrete production according to claim 4, characterized in that: The sand making mechanism includes a rod mill (15), a second spiral sand washer (17) and a second dewatering screen (18). The water supply mechanism includes a clear water tank (12) and a rod mill water supply device (16). The material that meets the preset secondary particle size threshold of the second circular vibrating screen (11) but does not meet the preset tertiary particle size threshold of the second circular vibrating screen (11) is fed into the rod mill (15) for sand making. The rod mill water supply device (16) can extract water from the clear water tank (12) and transport it for the sand making process of the rod mill (15). The second spiral sand washer (17) can wash the material obtained by the rod mill (15). The second dewatering screen (18) can dewater the washed material to obtain the fourth stockpile (23).

8. The system for sand and gravel processing and concrete production according to claim 1, characterized in that: The first crushing equipment includes a jaw crusher (6), the second crushing equipment includes a cone crusher (9), and the third crushing equipment includes a vertical shaft crusher (14).

9. A system for aggregate processing and concrete production according to claim 1, characterized in that: The concrete production facility includes a conveyor belt, a bulk cement transport vehicle (25), a bulk admixture transport vehicle (27), an air compressor station (24), a cement silo (26), a fly ash silo (28), an aeration jet pump (29), an admixture room (30), and a mixing station (31). The water supply facility includes a clear water tank (12). An aeration jet pump (29) is installed between the cement silo (26), the fly ash silo (28), and the mixing station (31). The raw materials include cement and fly ash. The bulk cement transport vehicle (25) can transport cement to the site, the bulk admixture transport vehicle (27) can transport fly ash to the site, and the conveyor belt can transport the second material pile (21) and the third material pile (27) to the site. The materials from the pile (22) and the fourth pile (23) are transported to the site. The air compressor station (24) can generate compressed air to send cement and fly ash into the cement tank (26) and fly ash tank (28) respectively. The gasification jet pump (29) can send the cement in the cement tank (26) and the fly ash in the fly ash tank (28) into the mixing station (31). The admixture room (30) can send the admixture into the mixing station (31). The clear water tank (12) sends water into the mixing station (31) through the water supply pipe. The mixing station (31) can mix cement, fly ash, water, admixture and the materials from the second pile (21), the third pile (22) and the fourth pile (23) to obtain concrete.

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