Preparation process of environment-friendly construction waste recycled aggregate

Abstract

The invention discloses an environment-friendly construction waste recycled aggregate preparation technology. The technology comprises the following steps of S1, collection, classification, primary treatment and transfer of construction waste, S2, primary crushing, S3, fine sorting of the construction waste, S4, magnetic separation, S5, secondary crushing, S6, tertiary crushing and winnowing and S7, sand making treatment. S8, cleaning and dewatering; S9, strengthening and shaping treatment; S10, secondary cleaning and dewatering; and S11, finished product packaging. According to the method, multiple fine sorting procedures are adopted, and technologies such as magnetic separation and winnowing are combined, so that various impurities in the construction waste can be effectively removed, the purity and quality of the recycled aggregate can be remarkably improved, and the recycled aggregate can better meet the requirements of construction engineering on the performance of the aggregate; the construction waste can be efficiently converted into recycled aggregates of different specifications, and the utilization rate of the construction waste is increased.

Description

Technical Field

[0001] The invention relates to the field of building material recycling, and in particular to an environmentally friendly construction waste recycled aggregate preparation process. Background Art

[0002] As the construction industry develops rapidly, the disposal of construction waste has become an environmental and resource issue that needs to be solved urgently. Traditional methods of construction waste disposal are mostly landfill or stacking, which not only occupies a large amount of land, but may also cause soil and water pollution, as well as air pollution problems such as dust. Processing construction waste into recycled aggregates for use in construction projects can not only reduce environmental pressure, but also save natural aggregate resources. However, the existing preparation process still has shortcomings in improving the performance of recycled aggregates, reducing energy consumption, and ensuring a comprehensive balance of environmental benefits. Summary of the invention

[0003] The purpose of the present invention is to provide an environmentally friendly construction waste recycled aggregate preparation process to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: An environmentally friendly construction waste recycled aggregate preparation process comprises the following steps: Step S1: Collection, classification, preliminary treatment and transportation of construction waste: Collect construction waste, count and input the information of the collected construction waste simultaneously for later viewing, and then classify and screen the construction waste according to different categories such as concrete blocks, bricks, metals, wood, plastics, etc. through a combination of manual and mechanical methods, remove large impurities and obvious non-construction waste, and obtain relatively pure construction waste raw materials. Use waste treatment equipment to preliminarily process the classified construction waste, and then use transfer equipment to transfer the classified materials to waste storage points and crushers respectively; Step S2: Initial crushing: The classified construction waste raw materials are transported to the crusher for primary crushing, and the construction waste smaller than the sieve holes is screened out by a vibrating screen, and the construction waste that cannot pass through the sieve holes is collected, and the construction waste that cannot pass through the sieve holes is repeatedly dumped into the crusher through a transfer device for repeated crushing. The particle size of the crushed material is controlled to be 100-500 mm; Step S3: Fine sorting of construction waste: The pre-crushed construction waste is transported to the fine sorting platform via a conveyor belt, where manual and optical recognition equipment are used to further remove residual impurities such as small pieces of wood and plastic fragments.

[0005] Step S4: Magnetic separation: Use magnetic separation equipment to separate the metal components of the materials after the initial crushing, such as steel bars, nails and other metal materials. These metal materials can be recycled and reused, and the materials after magnetic separation will enter the next step; Step S5: Secondary crushing: The construction waste after magnetic separation is sent to the crusher for secondary grinding and crushing to reduce the particle size of the material to 20-60 mm, and then screened through a vibrating screen. The material with a particle size greater than 60 mm is returned to the impact crusher for crushing again, forming a closed loop for multiple cycles until the material with a particle size less than 20 mm is obtained. When all crushing is completed, it proceeds to the next step.

[0006] Step S6: Tertiary crushing and air separation: The crusher is used for three times of crushing and grinding to further refine the material particle size to 5-20 mm. The material after three crushing is screened by a vibrating screen, and the material with a particle size greater than 10 mm is transported to the cone crusher for further crushing, forming a closed-loop multiple circulation. The fine material with a particle size less than 10 mm is transported to the silo for collection and standby, and 10-20 mm coarse aggregate is obtained. After that, air separation equipment is used to use wind power to blow away light impurities in the material, such as dust, light plastic particles, etc., to obtain a relatively pure intermediate aggregate product.

[0007] Step S7: Sand making process: The fine material collected in step S5 is transported to a sand making machine for sand making. The material after sand making is screened again to obtain fine aggregate of 0-5 mm and medium aggregate of 5-10 mm.

[0008] Step S8: Cleaning and dehydration: The coarse aggregate, medium aggregate and fine aggregate are respectively sent to the cleaning equipment to be cleaned with circulating water to remove impurities such as dirt and dust attached to the surface of the aggregate. The cleaned aggregate enters the dehydration equipment for dehydration treatment to reduce the moisture content of the aggregate.

[0009] Step S9: Strengthening and shaping processing: The dehydrated recycled aggregate is sent to the strengthening treatment device, and the aggregate is soaked with specific chemical reagents to improve the strength and durability of the aggregate. The soaking time is 2-6 hours. The treated aggregate is dried and then sent to the shaping machine. Through the collision and friction between the aggregates and between the aggregates and the internal components of the equipment, the particle shape of the aggregate is improved, making it closer to the shape characteristics of natural aggregates, thereby improving its applicability in building materials such as concrete.

[0010] Step S10: Secondary cleaning and dehydration: The aggregates that have been strengthened and shaped are sent to the cleaning equipment again for secondary cleaning with circulating water to remove the strengthening solution and other impurities remaining on the surface. The washed aggregates are sent to the dewatering screen for dehydration to reduce the moisture content of the aggregates for subsequent storage and transportation; Step S11: Finished product packaging: According to different particle size requirements, the dehydrated recycled aggregate is graded using a multi-layer vibrating screen, which can be divided into products of different specifications such as 0-5 mm, 5-10 mm, 10-20 mm, etc. Finally, the graded recycled aggregate is packaged separately to obtain environmentally friendly construction waste recycled aggregate products; Preferably, the garbage disposal equipment in step S1 includes a cleaning machine and a waste liquid recovery tank; Preferably, the transfer equipment in step S1 and step S2 includes a transfer machine and an elevator; Preferably, the classification and screening method in step S1 includes manual selection or precipitation or color sorting equipment; Preferably, the crusher in step S2 is a heavy hammer crusher; Preferably, the mesh diameter of the vibrating screen in step S2 is 100-500 mm; Preferably, the crusher in steps S2, S5 and S6 is provided with a nozzle, and the nozzle sprays water mist toward the discharge port of the crusher; Preferably, the crusher in step S5 is an impact crusher; Preferably, the mesh diameter of the vibrating screen in step S5 is 20-60 mm; Preferably, the crusher in step S6 is a cone crusher; Preferably, the mesh diameter of the vibrating screen in step S6 is 5-10 mm; Preferably, the chemical reagent in step S8 is a strengthening solution containing an active aluminosilicate component.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts multiple fine sorting processes, combined with magnetic separation, wind separation and other technologies, which can effectively remove various impurities in construction waste, significantly improve the purity and quality of recycled aggregates, so that it can better meet the requirements of construction projects for aggregate performance. Through scientific and reasonable classification, crushing, screening, magnetic separation and other processes, construction waste can be efficiently converted into recycled aggregates of different specifications, thereby improving the utilization rate of construction waste; The present invention adopts graded crushing, grinding, strengthening and shaping treatment, which can accurately control the particle size and shape of the recycled aggregate. The produced recycled aggregate is closer to natural aggregate in terms of strength and particle shape, thereby improving its substitution rate in building materials such as concrete, which is beneficial to saving natural aggregate resources. The washing and dehydration steps ensure the cleanliness of the recycled aggregate, which is beneficial to its application in construction projects. The strengthening treatment step further improves the performance of the recycled aggregate, so that it can better replace natural aggregate, reduce the exploitation of natural resources, and has good environmental and economic benefits. The present invention can separate and recycle metals and other recyclable impurities, further improve the comprehensive utilization rate of resources, reduce the discharge of waste, and has good environmental and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The present invention is a schematic diagram of a process flow for preparing environmentally friendly recycled aggregate from construction waste. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0014] See also Figure 1 , the present invention provides a technical solution: An environmentally friendly construction waste recycled aggregate preparation process, characterized by comprising the following steps: Step S1: Collection, classification, preliminary treatment and transportation of construction waste: Collect construction waste, count and input the information of the collected construction waste simultaneously for later viewing, and then classify and screen the construction waste according to different categories such as concrete blocks, bricks, metals, wood, plastics, etc. through a combination of manual and mechanical methods, remove large impurities and obvious non-construction waste, and obtain relatively pure construction waste raw materials. Use waste treatment equipment to preliminarily process the classified construction waste, and then use transfer equipment to transfer the classified materials to waste storage points and crushers respectively; Step S2: Initial crushing: The classified construction waste raw materials are transported to the crusher for primary crushing, and the construction waste smaller than the sieve holes is screened out by a vibrating screen, and the construction waste that cannot pass through the sieve holes is collected, and the construction waste that cannot pass through the sieve holes is repeatedly dumped into the crusher through a transfer device for repeated crushing. The particle size of the crushed material is controlled to be 100-500 mm; Step S3: Fine sorting of construction waste: The pre-crushed construction waste is transported to the fine sorting platform via a conveyor belt, where manual and optical recognition equipment are used to further remove residual impurities such as small pieces of wood and plastic fragments.

[0015] Step S4: Magnetic separation: Use magnetic separation equipment to separate the metal components of the materials after the initial crushing, such as steel bars, nails and other metal materials. These metal materials can be recycled and reused, and the materials after magnetic separation will enter the next step; Step S5: Secondary crushing: The construction waste after magnetic separation is sent to the crusher for secondary grinding and crushing to reduce the particle size of the material to 20-60 mm, and then screened through a vibrating screen. The material with a particle size greater than 60 mm is returned to the impact crusher for crushing again, forming a closed loop for multiple cycles until the material with a particle size less than 20 mm is obtained. When all crushing is completed, it proceeds to the next step.

[0016] Step S6: Tertiary crushing and air separation: The crusher is used for three times of crushing and grinding to further refine the material particle size to 5-20 mm. The material after three crushing is screened by a vibrating screen, and the material with a particle size greater than 10 mm is transported to the cone crusher for further crushing, forming a closed-loop multiple circulation. The fine material with a particle size less than 10 mm is transported to the silo for collection and standby, and 10-20 mm coarse aggregate is obtained. After that, air separation equipment is used to use wind power to blow away light impurities in the material, such as dust, light plastic particles, etc., to obtain a relatively pure intermediate aggregate product.

[0017] Step S7: Sand making process: The fine material collected in step S5 is transported to a sand making machine for sand making. The material after sand making is screened again to obtain fine aggregate of 0-5 mm and medium aggregate of 5-10 mm.

[0018] Step S8: Cleaning and dehydration: The coarse aggregate, medium aggregate and fine aggregate are respectively sent to the cleaning equipment to be cleaned with circulating water to remove impurities such as dirt and dust attached to the surface of the aggregate. The cleaned aggregate enters the dehydration equipment for dehydration treatment to reduce the moisture content of the aggregate.

[0019] Step S9: Strengthening and shaping processing: The dehydrated recycled aggregate is sent to the strengthening treatment device, and the aggregate is soaked with specific chemical reagents to improve the strength and durability of the aggregate. The soaking time is 2-6 hours. The treated aggregate is dried and then sent to the shaping machine. Through the collision and friction between the aggregates and between the aggregates and the internal components of the equipment, the particle shape of the aggregate is improved, making it closer to the shape characteristics of natural aggregates, thereby improving its applicability in building materials such as concrete.

[0020] Step S10: Secondary cleaning and dehydration: The aggregates that have been strengthened and shaped are sent to the cleaning equipment again for secondary cleaning with circulating water to remove the strengthening solution and other impurities remaining on the surface. The washed aggregates are sent to the dewatering screen for dehydration to reduce the moisture content of the aggregates for subsequent storage and transportation; Step S11: Finished product packaging: According to different particle size requirements, the dehydrated recycled aggregate is graded using a multi-layer vibrating screen, which can be divided into products of different specifications such as 0-5 mm, 5-10 mm, 10-20 mm, etc. Finally, the graded recycled aggregate is packaged separately to obtain environmentally friendly construction waste recycled aggregate products; In this embodiment, preferably, the garbage disposal equipment in step S1 includes a cleaning machine and a waste liquid recovery tank; the construction raw materials are preliminarily and simply cleaned by the cleaning machine, thereby reducing the content of impurities such as soil and dust on the surface of the materials, and facilitating the subsequent processing of the materials; In this embodiment, preferably, the transfer equipment in step S1 and step S2 includes a transfer machine and an elevator; the materials are transferred and lifted by the transfer machine and the elevator, which facilitates the transportation of the materials between the subsequent steps; In this embodiment, preferably, the classification and screening method in step S1 includes manual selection or precipitation or color sorting equipment; In this embodiment, preferably, the crusher in step S2 is a heavy hammer crusher; the hammer crusher has the advantage of completing a large amount of crushing work in a short time, thereby being able to facilitate the rapid crushing of a large amount of materials and obtain materials with large particle diameters; In this embodiment, preferably, the mesh diameter of the vibrating screen in step S2 is 250 mm; the vibrating screen with a diameter of 250 mm can facilitate the producer to quickly obtain the crushed and up-to-specification materials, thereby facilitating the producer to control the specifications of the materials obtained in the initial crushing step; In this embodiment, preferably, a nozzle is provided on the crusher in steps S2, S5 and S6, and the nozzle sprays water mist toward the discharge port of the crusher; the water mist can absorb construction dust, which helps to prevent construction dust from polluting the air; In this embodiment, preferably, the crusher in step S5 is an impact crusher; the impact crusher has the advantage of a large crushing ratio, and can complete the centering, fine crushing and coarse, medium and fine crushing operations at one time, simplifying the crushing process. In this embodiment, preferably, the mesh diameter of the vibrating screen in step S5 is 20-60 mm; using a vibrating screen with mesh diameters of 20-60 mm of various specifications and multiple layers can effectively screen the material obtained in step S5, ensuring that the particle size of subsequent materials can be less than 20 mm; In this embodiment, preferably, the crusher in step S6 is a cone crusher; the cone crusher has a large crushing ratio and high efficiency, which can meet the demand for more refined crushing of materials and effectively improve production efficiency; In this embodiment, preferably, the mesh diameter of the vibrating screen in step S6 is 5-10 mm; The vibrating screen with a mesh diameter of 5-10 mm can limit the particle size of the material obtained in step S6, so that the material obtained in this step can be easily processed in the subsequent sand making step, and fine aggregates of 0-5 mm and medium aggregates of 5-10 mm can be obtained later; In this embodiment, preferably, the chemical reagent in step S8 is a fortified solution containing active aluminosilicate components; the fortified solution containing active aluminosilicate components has the advantages of good stability and improved material performance, and active aluminosilicate can be used as a main component to form a gelling material with a three-dimensional network structure through an alkali-excited reaction, and has the advantages of high strength, high durability, acid and alkali resistance, etc., and the active aluminosilicate components are usually widely available, some of which come from industrial waste or natural minerals. Their application can realize the resource utilization of waste, reduce pollution to the environment, and meet the requirements of sustainable development. Example 2

[0021] See also Figure 1 , the present invention provides a technical solution: An environmentally friendly construction waste recycled aggregate preparation process, characterized by comprising the following steps: Step S1: Collection, classification, preliminary treatment and transportation of construction waste: Collect construction waste, count and input the information of the collected construction waste simultaneously for later viewing, and then classify and screen the construction waste according to different categories such as concrete blocks, bricks, metals, wood, plastics, etc. through a combination of manual and mechanical methods, remove large impurities and obvious non-construction waste, and obtain relatively pure construction waste raw materials. Use waste treatment equipment to preliminarily process the classified construction waste, and then use transfer equipment to transfer the classified materials to waste storage points and crushers respectively; Step S2: Initial crushing: The classified construction waste raw materials are transported to the crusher for primary crushing, and the construction waste smaller than the sieve holes is screened out by a vibrating screen, and the construction waste that cannot pass through the sieve holes is collected, and the construction waste that cannot pass through the sieve holes is repeatedly dumped into the crusher through a transfer device for repeated crushing. The particle size of the crushed material is controlled to be 100-500 mm; Step S3: Fine sorting of construction waste: After pre-crushing, the construction waste is transported to the fine sorting platform through a conveyor belt, where manual and optical recognition equipment are combined to further remove residual impurities, such as small pieces of wood and plastic fragments; Step S4: Magnetic separation: Use magnetic separation equipment to separate the metal components in the materials after the initial crushing, such as steel bars, nails and other metal materials. These metal materials can be recycled and reused, and the materials after magnetic separation enter the next step; Step S5: Secondary crushing: The construction waste after magnetic separation is sent to the crusher for secondary grinding and crushing to reduce the particle size of the material to 20-60 mm. Then it is screened through a vibrating screen, and the material with a particle size greater than 60 mm is returned to the impact crusher for crushing again, and a closed circuit is formed for multiple cycles until the material with a particle size less than 20 mm is obtained. When all crushing is completed, it enters the next step; Step S6: Tertiary crushing and air separation: The crusher is used for three times of crushing and grinding to further refine the material particle size to 5-20 mm. The material after three crushing is screened by a vibrating screen, and the material with a particle size greater than 10 mm is transported to the cone crusher for further crushing, and a closed-loop multiple cycle is formed. The fine material with a particle size less than 10 mm is transported to the silo for collection and standby, and a coarse aggregate of 10-20 mm is obtained. After that, the wind separation equipment is used to use wind power to blow away the light impurities in the material, such as dust, light plastic particles, etc., to obtain a relatively pure intermediate aggregate product; Step S7: Sand making process: The fine material collected in step S5 is transported to a sand making machine for sand making, and the material after sand making is screened again to obtain fine aggregate of 0-5 mm and medium aggregate of 5-10 mm; Step S8: Cleaning and dehydration: The coarse aggregate, medium aggregate and fine aggregate are respectively sent to the cleaning equipment to be cleaned with circulating water to remove dirt, dust and other impurities attached to the surface of the aggregate. The washed aggregates are sent to the dehydration equipment for dehydration treatment to reduce the moisture content of the aggregates; Step S9: Strengthening and shaping processing: The dehydrated recycled aggregate is sent to the strengthening treatment device, and the aggregate is soaked with specific chemical reagents to improve the strength and durability of the aggregate. The soaking time is 2-6 hours. The treated aggregate is dried and then sent to the shaping machine. Through the collision and friction between the aggregates and between the aggregates and the internal components of the equipment, the particle shape of the aggregate is improved, making it closer to the shape characteristics of natural aggregates, and improving its applicability in building materials such as concrete; Step S10: Secondary cleaning and dehydration: The aggregates that have been strengthened and shaped are sent to the cleaning equipment again for secondary cleaning with circulating water to remove the strengthening solution and other impurities remaining on the surface. The washed aggregates are sent to the dewatering screen for dehydration to reduce the moisture content of the aggregates for subsequent storage and transportation; Step S11: Finished product packaging: According to different particle size requirements, the dehydrated recycled aggregate is graded using a multi-layer vibrating screen, which can be divided into products of different specifications such as 0-5 mm, 5-10 mm, 10-20 mm, etc. Finally, the graded recycled aggregate is packaged separately to obtain environmentally friendly construction waste recycled aggregate products; In this embodiment, preferably, the garbage disposal equipment in step S1 includes a cleaning machine and a waste liquid recovery tank; the construction raw materials are preliminarily and simply cleaned by the cleaning machine, thereby reducing the content of impurities such as soil and dust on the surface of the materials, and facilitating the subsequent processing of the materials; In this embodiment, preferably, the transfer equipment in step S1 and step S2 includes a transfer machine and an elevator; the materials are transferred and lifted by the transfer machine and the elevator, which facilitates the transportation of the materials between the subsequent steps; In this embodiment, preferably, the classification and screening method in step S1 includes manual selection or precipitation or color sorting equipment; In this embodiment, preferably, the crusher in step S2 is a heavy hammer crusher; the hammer crusher has the advantage of completing a large amount of crushing work in a short time, thereby being able to facilitate the rapid crushing of a large amount of materials and obtain materials with large particle diameters; In this embodiment, preferably, the mesh diameter of the vibrating screen in step S2 is 100 mm; the vibrating screen with a mesh diameter of 100 mm can limit the particle size of the material obtained in the initial crushing step, making it more convenient for the producer to obtain the material with a specified particle size, thereby facilitating the subsequent more detailed crushing work; In this embodiment, preferably, a nozzle is provided on the crusher in steps S2, S5 and S6, and the nozzle sprays water mist toward the discharge port of the crusher; the water mist can absorb construction dust, which helps to prevent construction dust from polluting the air; In this embodiment, preferably, the crusher in step S5 is an impact crusher; the impact crusher has the advantage of a large crushing ratio, and can complete the centering, fine crushing and coarse, medium and fine crushing operations at one time, simplifying the crushing process; In this embodiment, preferably, the mesh diameter of the vibrating screen in step S5 is 20-60 mm; using a vibrating screen with mesh diameters of 20-60 mm of various specifications and multiple layers can effectively screen the material obtained in step S5, ensuring that the particle size of subsequent materials can be less than 20 mm; In this embodiment, preferably, the crusher in step S6 is a cone crusher; the cone crusher has a large crushing ratio and high efficiency, which can meet the demand for more refined crushing of materials and effectively improve production efficiency; In this embodiment, preferably, the mesh diameter of the vibrating screen in step S6 is 5-10 mm; The vibrating screen with a mesh diameter of 5-10 mm can limit the particle size of the material obtained in step S6, so that the material obtained in this step can be easily processed in the subsequent sand making step, and fine aggregates of 0-5 mm and medium aggregates of 5-10 mm can be obtained later; In this embodiment, preferably, the chemical reagent in step S8 is a fortified solution containing active aluminosilicate components; the fortified solution containing active aluminosilicate components has the advantages of good stability and improved material performance, and active aluminosilicate can be used as a main component to form a gelling material with a three-dimensional network structure through an alkali-excited reaction, and has the advantages of high strength, high durability, acid and alkali resistance, etc., and the active aluminosilicate components are usually widely available, some of which come from industrial waste or natural minerals. Their application can realize the resource utilization of waste, reduce pollution to the environment, and meet the requirements of sustainable development.

[0022] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0023] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly construction waste recycled aggregate preparation process, characterized by: The following steps are involved: Step S1: Collection, classification, preliminary treatment and transportation of construction waste: Collect construction waste, count and input the information of the collected construction waste simultaneously for later viewing, and then classify and screen the construction waste according to different categories such as concrete blocks, bricks, metals, wood, plastics, etc. through a combination of manual and mechanical methods, remove large impurities and obvious non-construction waste, and obtain relatively pure construction waste raw materials. Use waste treatment equipment to preliminarily process the classified construction waste, and then use transfer equipment to transfer the classified materials to waste storage points and crushers respectively; Step S2: Initial crushing: The classified construction waste raw materials are transported to the crusher for primary crushing, and the construction waste smaller than the sieve holes is screened out by a vibrating screen, and the construction waste that cannot pass through the sieve holes is collected, and the construction waste that cannot pass through the sieve holes is repeatedly dumped into the crusher through a transfer device for repeated crushing. The particle size of the crushed material is controlled to be 100-500 mm; Step S3: Fine sorting of construction waste: After pre-crushing, the construction waste is transported to the fine sorting platform through a conveyor belt, where manual and optical recognition equipment are combined to further remove residual impurities, such as small pieces of wood and plastic fragments; Step S4: Magnetic separation: Use magnetic separation equipment to separate the metal components in the materials after the initial crushing, such as steel bars, nails and other metal materials. These metal materials can be recycled and reused, and the materials after magnetic separation enter the next step; Step S5: Secondary crushing: The construction waste after magnetic separation is sent to the crusher for secondary grinding and crushing to reduce the particle size of the material to 20-60 mm. Then it is screened through a vibrating screen, and the material with a particle size greater than 60 mm is returned to the impact crusher for crushing again, and a closed circuit is formed for multiple cycles until the material with a particle size less than 20 mm is obtained. When all crushing is completed, it enters the next step; Step S6: Tertiary crushing and air separation: The crusher is used for three times of crushing and grinding to further refine the material particle size to 5-20 mm. The material after three crushing is screened by a vibrating screen, and the material with a particle size greater than 10 mm is transported to the cone crusher for further crushing, and a closed-loop multiple cycle is formed. The fine material with a particle size less than 10 mm is transported to the silo for collection and standby, and a coarse aggregate of 10-20 mm is obtained. After that, the wind separation equipment is used to use wind power to blow away the light impurities in the material, such as dust, light plastic particles, etc., to obtain a relatively pure intermediate aggregate product; Step S7: Sand making process: The fine material collected in step S5 is transported to a sand making machine for sand making, and the material after sand making is screened again to obtain fine aggregate of 0-5 mm and medium aggregate of 5-10 mm; Step S8: Cleaning and dehydration: The coarse aggregate, medium aggregate and fine aggregate are respectively sent to the cleaning equipment to be cleaned with circulating water to remove dirt, dust and other impurities attached to the surface of the aggregate. The washed aggregates are sent to the dehydration equipment for dehydration treatment to reduce the moisture content of the aggregates; Step S9: Strengthening and shaping processing: The dehydrated recycled aggregate is sent to the strengthening treatment device, and the aggregate is soaked with specific chemical reagents to improve the strength and durability of the aggregate. The soaking time is 2-6 hours. The treated aggregate is dried and then sent to the shaping machine. Through the collision and friction between the aggregates and between the aggregates and the internal components of the equipment, the particle shape of the aggregate is improved, making it closer to the shape characteristics of natural aggregates, and improving its applicability in building materials such as concrete; Step S10: Secondary cleaning and dehydration: The aggregates that have been strengthened and shaped are sent to the cleaning equipment again for secondary cleaning with circulating water to remove the strengthening solution and other impurities remaining on the surface. The washed aggregates are sent to the dewatering screen for dehydration to reduce the moisture content of the aggregates for subsequent storage and transportation; Step S11: finished product packaging; According to different particle size requirements, multi-layer vibrating screens are used to grade the dehydrated recycled aggregates, which can be divided into products of different specifications such as 0-5 mm, 5-10 mm, 10-20 mm, etc. Finally, the graded recycled aggregates are packaged separately to obtain environmentally friendly construction waste recycled aggregate products.

2. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The garbage disposal equipment in step S1 includes a cleaning machine and a waste liquid recovery tank.

3. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The transfer equipment in step S1 and step S2 includes a transfer machine and an elevator.

4. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The classification and screening methods in step S1 include manual selection or sedimentation or color sorting equipment.

5. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The crusher in step S2 is a heavy hammer crusher.

6. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The mesh diameter of the vibrating screen in step S2 is 100-500 mm.

7. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The crusher in steps S2, S5 and S6 is provided with a nozzle, and the nozzle sprays water mist toward the discharge port of the crusher.

8. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The crusher in step S5 is an impact crusher.

9. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The mesh diameter of the vibrating screen in step S5 is 20-60 mm.

10. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The crusher in step S6 is a cone crusher.

11. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The mesh diameter of the vibrating screen in step S6 is 5-10 mm.

12. The process for preparing environmentally friendly recycled aggregate from construction waste according to claim 1, characterized in that: The chemical reagent in step S8 is a strengthening solution containing active aluminosilicate components.

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