Method and system for resource treatment of construction waste

Abstract

The present invention discloses a method and system for resource treatment of construction waste, the method comprising crushing construction waste to obtain construction waste aggregate, mixing a first agent active substance with the aggregate to obtain a mixture, mixing a second agent active substance stimulator with the mixture to accelerate the hydration heat reaction to obtain a newly mixed recycled mixed slurry for subsequent resource treatment. The system comprises a crusher, a mixer, a slurry tank, a first agent barrel and a second agent barrel, the slurry tank is arranged on the ground, the mixer extends into the slurry tank, and the first and second agent delivery pipes respectively connected to the first and second agent barrels extend into the slurry tank. The method has high raw material utilization rate, low cost, and is green and environmentally friendly. It can extend the molding time and construction time, reduce the molding difficulty, the system can be processed on site, the design is flexible, and the agent ratio can be adjusted in real time, and it has good application value and application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of solid waste recycling, and relates to a method and system for resource processing of construction waste, and in particular to a method and system for on-site resource processing of construction waste. Background Art

[0002] In recent years, in order to promote the modernization of cities in my country, the number of old urban area renovation projects has continued to increase, emerging cities have continued to expand, and surrounding supporting facilities have been increasingly improved. This has led to the generation of demolition materials of old buildings and new construction waste. At present, construction is mainly based on cement materials. Therefore, a large amount of construction waste such as cement slag, bricks, and gravel is generated in the blasting of buildings and road renovation operations; and tunnel construction in urban rail transit construction will also generate a large amount of waste slag. Even if the existing technology can make most of the above-mentioned construction waste resources, the transportation and resource utilization of these construction wastes is still the most difficult problem for urban managers and construction units. If the construction waste is directly loaded and transported, the irregularity of the cement blocks will greatly reduce the transportation effect. The cement dust and slag that are accidentally scattered along the road during transportation will also have a very bad impact on the image of the city.

[0003] In addition, the treatment method of construction waste in my country is usually landfill or reuse, which has the disadvantages of single method, low utilization efficiency, and poor performance of recycled materials compared to raw materials. In recent years, many scholars have used the alkali excitation principle to recycle construction waste to produce a new type of gel material, so that the performance of the solidified material is better than that of the raw material, which is very popular in the market. However, the applicant has found through research that this kind of gel material has the disadvantages of too fast and uncontrollable solidification rate, that this method can only be used for construction waste with alkali excitation activity, and that when the activity of the waste building material is low or the moisture content exceeds 30%, it is easy to cause the material to be unable to form. Due to these defects, there are too many uncontrollable factors in actual construction applications, resulting in too high construction difficulty and risk, and it is rarely used in existing actual construction. Therefore, it is very necessary to study an effective method and system for the treatment and resource utilization of construction waste based on the alkali excitation principle. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art, especially the problem of insufficient operation and construction time caused by too fast molding time when recycling construction waste using the alkali excitation principle, as discovered by the applicant, and the problem of the inability to mold materials due to lack of active substances in the construction waste and too high moisture content of the construction waste. A method for resource treatment of construction waste that can delay molding time, reduce construction difficulty, is green and environmentally friendly, and has high early strength is provided. A matching system for resource treatment of construction waste that is highly operational and can change the material mix ratio at any time is also provided.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0006] A method for recycling construction waste, comprising the following steps:

[0007] S1. crushing the construction waste to obtain construction waste crushed aggregate;

[0008] S2. Mixing the first agent with the above-obtained construction waste aggregates and stirring, controlling the moisture content to be ≤20%, to obtain a fresh mixture, wherein the first agent is an active substance, and the active substance includes one or more of metakaolin, alumina powder, volcanic ash, fly ash, light-burned magnesium powder, blast furnace slag and steel slag;

[0009] S3. Mix and stir the second agent with the newly mixed mixture obtained above to carry out hydration heat reaction, wherein the second agent is an active substance stimulator, and the active substance stimulator is sodium silicate and phosphoric acid solution or the active substance stimulator is magnesium chloride, and the sodium silicate and phosphoric acid solution are used separately to generate a newly mixed recycled mixed slurry for subsequent resource recovery treatment.

[0010] In the above-mentioned method for resource treatment of construction waste, preferably, in step S1, the construction waste contains 5% to 60% by mass of active ingredients; in step S2, the mass of the active substance is 5% to 65% of the mass of the construction waste aggregate; in step S3, the mass of the active substance stimulator is 70% to 120% of the sum of the mass of the active substance and the mass of the active ingredients contained in the construction waste; when the active substance stimulator is sodium silicate and phosphoric acid solution, the mass of the phosphoric acid solution is 5% to 10% of the mass of the sodium silicate, and the mass concentration of the phosphoric acid solution is ≥85%.

[0011] In the above-mentioned method for resource recovery of construction waste, preferably, in step S3, when the active substance activator is sodium silicate and phosphoric acid solution, the modulus of sodium silicate is controlled to be 1.2 to 1.6; when the active substance activator is magnesium chloride, magnesium chloride and water are first prepared into a magnesium chloride solution and allowed to stand, and then mixed with the newly mixed material, the mass concentration of the magnesium chloride solution is ≥75%, and the standing time is 20h to 25h.

[0012] In the above-mentioned method for resource recovery of construction waste, preferably, in step S2, when the moisture content of the newly mixed material exceeds 20%, the moisture content is lowered by adding calcium oxide.

[0013] In the above-mentioned method for resource processing of construction waste, preferably, in step S2, the moisture content is controlled to be 5% to 10%.

[0014] In the above-mentioned method for resource processing of construction waste, preferably, in step S1, the construction waste includes one or more of cement blocks, broken bricks, gravel and slag, the crushing efficiency is 30t / h to 200t / h, and the particle size of the construction waste aggregate is 0.15mm to 30mm.

[0015] As a general technical concept, the present invention also provides a system for resource processing of construction waste, which is an on-site processing system. The system includes a crusher, a mixer, a slurry tank, a first agent barrel and a second agent barrel. The crusher is used to crush the construction waste and then send it into the slurry tank. The slurry tank is set on the ground. The mixer extends into the slurry tank. The outlet of the first agent barrel is connected to a first agent delivery pipe, which extends into the slurry tank. The outlet of the second agent barrel is connected to a second agent delivery pipe, which extends into the slurry tank.

[0016] The above-mentioned system for resource processing of construction waste preferably further comprises a water inlet pipe, which extends into the slurry tank.

[0017] In the above-mentioned system for resource processing of construction waste, preferably, the first agent delivery pipe is provided with a first agent delivery pump, the second agent delivery pipe is provided with a second agent delivery pump, and the water inlet pipe is provided with a water inlet delivery pump.

[0018] The above-mentioned system for resource processing of construction waste preferably also includes a bucket conveyor and a transport vehicle, wherein the bucket conveyor is used to transport the newly mixed recycled mixed slurry prepared in the slurry tank out of the slurry tank, and the transport vehicle is used to transport the newly mixed recycled mixed slurry in the bucket conveyor to the construction site.

[0019] In the above-mentioned system for resource processing of construction waste, preferably, the crusher is a crawler-type mobile crushing station or a tire-type mobile crushing station, the mixer is a vertical mixer, and the belt bucket conveyor is a chain bucket conveyor.

[0020] In the present invention, the components of the active material selected include one or more of alkaline metal oxides, SiO2, Al2O3, etc. The alkaline metal oxide is an alkaline metal oxide that reacts with silicon dioxide to form a silicate network structure or reacts with aluminum oxide to form an aluminate network structure. The alkaline metal oxide includes one or more of CaO, Na2O, K2O and MgO.

[0021] In the present invention, when the active material activators selected are sodium silicate and phosphoric acid, the sodium silicate and phosphoric acid are used separately, and can be mixed with the freshly mixed material successively, or can be added to the freshly mixed material simultaneously. The use of sodium silicate will accelerate the reaction process, and the use of phosphoric acid can delay the reaction time. The combination of the two can make the reaction proceed gently.

[0022] In the present invention, the active components in the construction waste include one or more of alkaline metal oxides, SiO2, Al2O3 and the like.

[0023] In the present invention, the modulus of sodium silicate can be controlled between 1.2 and 1.6 by adding sodium hydroxide.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] (1) The present invention provides a method for resource treatment of construction waste that can control the alkali-induced reaction time, reduce the difficulty of construction, and is also applicable to aggregates with high moisture content. Usually, the main chemical bond that ultimately maintains the crystal network structure in the alkali-induced reaction is the Si-O bond, which reacts with the hydrated silica gel generated by the hydrolysis of water glass (sodium silicate) in an alkaline solution to generate a CSH gel-like substance. The present invention provides an active substance + an active substance activator, uses sodium silicate (preferably sodium silicate within a certain modulus range) and a phosphoric acid solution or magnesium chloride as an alkaline activator, and uses a substance containing a bond weaker than the Si-O bond as an active substance, such as a Ca-O bond, a Mg-O bond, an Al-O-Al bond, etc. These substances are relatively easy to dissolve in the alkaline activator and are soluble in OH in the alkaline solution. - Under the strong action of ions, the stability of these bonds is overcome and activation energy sufficient to break the existing bonds is generated, producing AlO4 5- , Ca 2+ Mg 2+These ions are recombined in the mixture to form new CSH gel material. This reaction is milder than the ordinary alkali excitation reaction. In addition, when magnesium chloride solution is used as an excitation agent, the magnesium chloride solution will hydrolyze to generate OH after standing for a period of time. - , OH - With AlO4 5- , Ca 2+ Mg 2+ Combined with CSH, the pH value decreases, which further promotes the hydrolysis of magnesium chloride solution. When sodium silicate with a certain modulus range is used as an activator, phosphoric acid solution needs to be added. The active substance breaks the bond at the initial stage of hydration under alkaline conditions, and then phosphoric acid can inhibit the hydrolysis of sodium silicate. + With AlO4 5- , Ca 2+ Mg 2+ The cation exchange reaction can also balance the negative charge in the structure. These two processes are more controllable than the simple Si-O excitation reaction, which makes it more convenient for construction workers to operate the construction. This method can be used to recycle construction waste, avoid the use of cement, reduce the carbon dioxide emissions caused by cement manufacturing, and is green and environmentally friendly. For aggregates with high moisture content, calcium oxide can be used as a high-efficiency water reducer to reduce its moisture content in the preparation of the new mixture before the pulping reaction, which solves the problem of the inability to generate gel materials due to the high moisture content of the material in the alkali excitation reaction. In the actual construction application of auxiliary roads or water-stabilized materials, the compressive strength of the pavement can reach more than 25MPa within 28 days of construction, and the compressive strength of the water-stabilized material can reach more than 10MPa within 7 days of construction, and even more than 10MPa within 1-4 days. It can maximize the stabilization, reduction, harmlessness and resource utilization of construction waste, and has a good application prospect.

[0026] (2) The present invention provides a system for resource processing of construction waste, which can process construction waste on site and flexibly adjust the amount of active substances and stimulants required according to the effective components in the construction waste, solving the problems of unclear proportion of ordinary alkali stimulant reaction, low content of active substances in construction waste, and failure of stimulant reaction due to high moisture content of construction waste. The system is also equipped with a bucket conveyor and a transport vehicle, which can directly transport the prepared slurry to the construction site, avoiding the problem of too fast solidification time and insufficient operation time due to long-term exposure of materials to the environment, and has high application value and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the system structure for resource processing of construction waste in Example 1 of the present invention.

[0028] Legend:

[0029] 1. Crusher; 2. Mixer; 3. Conveyor with bucket; 4. Slurry tank; 5. First agent delivery pipe; 6. Second agent delivery pipe; 7. Water inlet pipe; 8. First agent push pump; 9. Second agent push pump; 10. Water inlet push pump; 11. Transport vehicle; 12. First agent barrel; 13. Second agent barrel. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0031] Unless otherwise specified, the materials and instruments used in the following examples are commercially available.

[0032] Embodiment 1:

[0033] A method for resource processing of construction waste of the present invention comprises the following steps:

[0034] S1. Crushing: Crush the construction waste, and control the crushing efficiency at 30t / h to obtain construction waste aggregate. Construction waste is a mixture of cement blocks, broken bricks and shield slag on the construction site. The mass of each cubic meter of construction waste is 1300kg, and the mass of active components in construction waste accounts for 56% of the mass of construction waste. The moisture content of construction waste aggregate is about 34%, and the particle size is 0.15mm~30mm. Construction waste aggregate contains coarse aggregate and fine aggregate. The particle size of coarse aggregate is 20mm<≤30mm, and the particle size of fine aggregate is 0.15mm~20mm.

[0035] S2. Adjust the proportion and moisture content of the active substance in the aggregate: Mix and stir the first agent with the above-mentioned crushed aggregate from construction waste. The first agent is the active substance Al2O3 powder. The mass of the active substance is 6.2% of the mass of the crushed aggregate from construction waste, that is, 80 kg of Al2O3 powder is used for each cubic meter of crushed aggregate from construction waste. Then, calcium oxide is added as a water reducing agent to adjust the moisture content of the material to 10%. Continue stirring to evenly mix the crushed aggregate from construction waste, Al2O3 powder and calcium oxide to obtain a freshly mixed material.

[0036] S3, slurry preparation: magnesium chloride is used as an active substance activator (second agent), and a MgCl2 solution with a mass concentration of 75% is prepared in advance and allowed to stand for 24 hours. The MgCl2 solution after standing is mixed and stirred with the newly mixed mixture obtained above, and the mass of magnesium chloride is 97% of the total mass of the active substance and the active components in the construction waste. After hydration and thermal reaction, a newly mixed recycled mixed slurry is obtained. The newly mixed recycled mixed slurry is conveyed to the transport vehicle 11 through the bucket conveyor 3 and transported to the off-site for resource utilization.

[0037] A system for resource processing of construction waste according to the present invention. The method for resource processing of construction waste according to the above embodiment can be implemented by using this system, but is not limited thereto.

[0038] Figure 1 The system for recycling construction waste is shown, which is an on-site processing system, including a crusher 1, a mixer 2, a slurry tank 4, a first agent barrel 12 and a second agent barrel 13. The crusher 1 is used to crush the construction waste and then feed it into the slurry tank 4. The slurry tank 4 is set on the ground, the mixer 2 extends into the slurry tank 4, the outlet of the first agent barrel 12 is connected to a first agent delivery pipe 5, and the first agent delivery pipe 5 extends into the slurry tank 4. The outlet of the second agent barrel 13 is connected to a second agent delivery pipe 6, and the second agent delivery pipe 6 extends into the slurry tank 4. In this embodiment, the slurry tank 4 can be directly excavated into a groove on the ground.

[0039] In this embodiment, a water inlet pipe 7 is also included, and the water inlet pipe 7 extends into the slurry tank 4. The water content of the material in the slurry tank 4 is regulated by transporting industrial water through the water inlet pipe 7.

[0040] In this embodiment, a first agent push pump 8 is provided on the first agent delivery pipe 5, which is used to deliver the first agent in the first agent barrel 12 to the slurry tank 4; a second agent push pump 9 is provided on the second agent delivery pipe 6, which is used to deliver the second agent in the second agent barrel 13 to the slurry tank 4; and a water inlet push pump 10 is provided on the water inlet pipe 7, which is used to deliver ordinary industrial water to the slurry tank 4.

[0041] In this embodiment, it also includes a bucket conveyor 3 and a transport vehicle 11. The bucket conveyor 3 is used to send the newly mixed recycled mixed slurry prepared in the slurry tank 4 out of the slurry tank 4 (it can be transported by the conveying device on the bucket conveyor 3), and the transport vehicle 11 is used to send the newly mixed recycled mixed slurry in the bucket conveyor 3 to the construction site. The newly mixed recycled mixed slurry is transported to the off-site for resource utilization by the transport vehicle 11, and the newly mixed recycled mixed slurry generated after the resource utilization treatment of the system can be used for construction or road cushion construction.

[0042] In this embodiment, the crusher 1 is a crawler-type mobile crushing station or a tire-type mobile crushing station, the mixer 2 is a vertical mixer, and the bucket conveyor 3 is a chain bucket conveyor.

[0043] In this embodiment, the first medicine barrel 12 and the second medicine barrel 13 are located above the slurry tank 4 , and the stirring paddle of the stirrer 2 is located inside the slurry tank 4 .

[0044] In this embodiment, the crusher 1 is a crawler-type cone mobile crusher with a specification (model) of HP300, a total machine weight of 48t, and an engine power of 400 kW; the first agent barrel 12 and the second agent barrel 13 are cylindrical PVC plastic barrels with an outer dimension of 2000 mm in diameter and 3000 mm in height; the mixer 2 is a vertical mixer with a model of JBQ, a mixing method of submersible mixing, an outer dimension (length × width × height) of 2050 mm × 2050 mm × 3750 mm, and a power of 2.2-22kW.

[0045] In this embodiment, the first medicine delivery pipe 5, the second medicine delivery pipe 6, and the water inlet pipe 7 are all rubber pipes that meet the HG2184-91 standard. In this embodiment, the preferred inner diameter of the rubber pipe is 203 mm.

[0046] In this embodiment, the first agent push pump 8, the second agent push pump 9, and the water inlet push pump 10 are all single-stage single-suction vertical centrifugal pumps, model NL100-16.

[0047] The workflow of the construction waste resource processing system of the above embodiment for processing construction waste is as follows:

[0048] The construction waste is crushed by a crusher 1 to obtain construction waste aggregates, and then the active material in the first agent barrel 12 is pushed into the slurry tank 4 through the first agent delivery pipe 5 by the first agent delivery pump 8. After being stirred by the mixer 2, the active material and the construction waste aggregates are evenly mixed to obtain a freshly mixed material. If the moisture content of the freshly mixed material is too high (more than 20%), calcium oxide can be added manually to lower the moisture content. If the moisture content needs to be increased, ordinary industrial water can be pushed into the slurry tank 4 through the water inlet pipe 7 by the water inlet delivery pump 10 for adjustment. Then, the active material activator in the second agent barrel 13 is delivered to the slurry tank 4 through the second agent delivery pipe 6 by the second agent delivery pump 9, and the freshly mixed recycled mixed slurry is obtained after rapid stirring by the mixer 2. Finally, it is transferred to the transport vehicle 11 by the bucket conveyor 3 and transported to the off-site for resource utilization.

[0049] In this embodiment, when the above-mentioned construction waste resource processing system is used to process construction waste on-site, the following steps are included:

[0050] (1) Crushing: The cement blocks, broken bricks and shield slag mixture on the construction site are transported to the crusher 1 through the conveyor belt of the crusher 1. Driven by the gears, they roll and squeeze each other to complete the crushing. The processing efficiency is controlled at 30t / h, and the crushed aggregate of construction waste is obtained, with a moisture content of about 34% and a particle size of 0.15mm to 30mm. The crushed aggregate of construction waste is sent to the slurry tank 4. The mass of each cubic meter of construction waste is 1300kg, and the mass of active components in construction waste accounts for 56% of the mass of construction waste.

[0051] (2) Adjusting the ratio and moisture content of the active material in the aggregate: The active material in the first agent barrel 12 is pushed into the slurry tank 4 through the first agent delivery pipe 5 by the first agent push pump 8. The active material is Al2O3 powder, and the mass of the active material is 6.2% of the mass of the crushed aggregate of construction waste. Then, calcium oxide is manually added as a water reducer to adjust the moisture content of the material to 10%, and the mixer 2 is started to stir, so that the crushed aggregate of construction waste, Al2O3 powder and calcium oxide are evenly mixed to obtain a freshly mixed material.

[0052] (3) Slurry preparation: magnesium chloride is used as the active material activator (second agent), and a MgCl2 solution with a mass concentration of 75% is prepared in advance, left to stand for 24 hours, and placed in the second agent barrel 13. The MgCl2 solution in the second agent barrel 13 is transported to the slurry tank 4 through the second agent delivery pipe 6 by the second agent push pump 9. The mass of magnesium chloride is 97% of the total mass of the active material and the active components in the construction waste. After hydration heat reaction, a freshly mixed recycled slurry is obtained. The freshly mixed recycled slurry is conveyed to the transport vehicle 11 through the bucket conveyor 3, and transported to the off-site resource utilization by the transport vehicle 11. The freshly mixed recycled slurry can replace or reduce the use of cement materials.

[0053] The present invention provides a method for resource treatment of construction waste which can delay molding time, reduce construction difficulty, be green and environmentally friendly, and have high early strength. It also provides a matching, highly operable, on-site resource treatment system for construction waste which can flexibly adjust the required active substance and stimulant ratio according to the effective ingredients in the construction waste. The system has high application value and good application prospects.

[0054] The method and system for resource treatment of construction waste of the present invention adjusts the proportion of active substances and water content of aggregates of construction waste crushed aggregates, and reasonably controls the reaction and molding time of materials, so that the original alkali-excited reaction solidification time under normal conditions is extended from about 10 minutes to more than 4 hours, solving the problem that the materials cannot be molded due to the lack of active substances in the recycled materials and the excessively high water content when the construction waste is recycled and reused by the alkali-excited principle, and makes up for the defects of too fast solidification time and insufficient operation and construction time caused by the long-term exposure of materials to the environment. The newly mixed recycled mixed slurry finally produced does not need to add cement, has low equipment operating costs, small losses, and high raw material utilization. The test results show that the system processes 240 tons of construction waste per day and produces 370 tons of newly mixed recycled mixed slurry, which can reach a compressive strength of 12.3MPa within 7 days and a compressive strength of 26.7MPa within 28 days for the production of paving materials.

[0055] Embodiment 2:

[0056] A method for resource treatment of construction waste of the present invention uses the system for resource treatment of construction waste in Example 1 to treat construction waste, comprising the following steps:

[0057] (1) Crushing: The broken bricks, stones and cement blocks on the construction site are conveyed to the crusher 1 through the conveyor belt of the crusher 1. Driven by the gears, the broken bricks, stones and cement blocks are rolled and squeezed against each other to complete the crushing. The processing efficiency is controlled at 80t / h to obtain construction waste aggregates. The water content of the aggregates is about 6% and the particle size is 0.15mm to 30mm. The construction waste aggregates are sent to the slurry tank 4. In this embodiment, the mass of each cubic meter of construction waste is 1450kg, and the mass of active components in the construction waste accounts for 59% of the mass of the construction waste.

[0058] (2) Adjust the ratio and moisture content of the active material in the aggregate: Use the first agent push pump 8 to push the active material in the first agent barrel 12 into the slurry tank 4 through the first agent delivery pipe 5. The active material is light-burned magnesium powder and metakaolin. The mass of the active material is 5.5% of the mass of the crushed aggregate of construction waste. The mass ratio of light-burned magnesium powder to metakaolin is 1:1, that is, 40 kg of light-burned magnesium powder and metakaolin are used for each cubic meter of crushed aggregate of construction waste. Then start the mixer 2 to stir so that the crushed aggregate of construction waste and the active material powder are evenly mixed. Then, 37 kg of industrial water is pumped into the slurry tank 4 through the water inlet pipe 7. After continuing to stir evenly, a new mixed material with a moisture content of 10% is obtained.

[0059] (3) Pulping: Sodium silicate and phosphoric acid solution are used as active material activators, but the two are used separately. The phosphoric acid solution is industrial grade with a mass concentration of 85%. The second agent push pump 9 is used to first transport the sodium silicate Na2O·1.4SiO2 in the second agent barrel 13 to the slurry tank 4 through the second agent delivery pipe 6, and then add the phosphoric acid solution to the second agent barrel 13, and then transport the phosphoric acid solution to the slurry tank 4 through the second agent delivery pipe 6. The total mass of the active material activator is 83% of the total mass of the active material and the active components in the construction waste, and the mass of the phosphoric acid solution in the active material activator is 5% of the mass of the sodium silicate. Immediately and quickly stir to obtain a freshly mixed recycled slurry. The freshly mixed recycled slurry is transported to the transport vehicle 11 through the bucket conveyor 3, and then transported to the off-site for resource utilization by the transport vehicle 11.

[0060] The method and system for on-site resource treatment of construction waste of the present invention, by pre-treating the aggregate active material ratio and moisture content of construction waste crushed aggregate, solves the problem of lack of active material in recycled materials and excessive moisture content causing the material to be unable to be formed when recycling construction waste using the alkali excitation principle, and makes up for the defects of long-term exposure of materials to the environment, resulting in too fast solidification time and insufficient operation and construction time. Tests have shown that the daily processing of construction waste can reach 640 tons, and 980 tons of newly mixed recycled mixed slurry can be produced, which can reach a compressive strength of 27.4MPa within 28 days when used to make paving materials.

[0061] Embodiment 3:

[0062] A method for resource processing of construction waste of the present invention uses the system for resource processing of construction waste in Example 1 to process construction waste, comprising the following steps:

[0063] (1) Crushing: Bricks, gravel and cement slag on the construction site are transported to the crusher 1 through the conveyor belt of the crusher 1. Driven by the gears, they roll and squeeze each other to complete the crushing. The processing efficiency is controlled at 160 t / h to obtain construction waste aggregate with a moisture content of about 6% and a particle size of 0.15 mm to 30 mm. The construction waste aggregate is sent to the slurry tank 4. In this embodiment, the mass of each cubic meter of construction waste is 1450 kg, and the mass of active components in the construction waste accounts for 53% of the mass of the construction waste.

[0064] (2) Adjusting the ratio and moisture content of the active material in the aggregate: The active material in the first agent barrel 12 is pushed into the slurry tank 4 through the first agent delivery pipe 5 by the first agent push pump 8. The active material is light-burned magnesium powder and Al2O3 powder. The mass of the active material is 6.2% of the mass of the crushed aggregate of construction waste. The mass ratio of light-burned magnesium powder to Al2O3 powder is 1:1, that is, 45 kg of light-burned magnesium powder and Al2O3 powder are used for each cubic meter of crushed aggregate of construction waste. The crushed aggregate of construction waste, light-burned magnesium powder and Al2O3 powder are mixed evenly by the mixer 2 to obtain a freshly mixed material. The moisture content of the freshly mixed material is 5.6%.

[0065] (3) Pulping: Using magnesium chloride as the active material activator (second agent), prepare a MgCl2 solution with a mass concentration of 75% in advance, let it stand for 24 hours, and place it in the second agent barrel 13. Use the second agent push pump 9 to transport the MgCl2 solution in the second agent barrel 13 to the slurry tank 4 through the second agent delivery pipe 6. The mass of magnesium chloride is 102% of the total mass of the active material and the active components in the construction waste. After hydration and thermal reaction, a freshly mixed recycled slurry is obtained. The freshly mixed recycled slurry is conveyed to the transport vehicle 11 through the bucket conveyor 3, and transported to the off-site for resource utilization by the transport vehicle 11.

[0066] The method and system for on-site resource treatment of construction waste of the present invention, by pre-treating the crushed aggregate of construction waste, changes the content and moisture content of active substances in the crushed aggregate of construction waste, and solves the problem that the content of active substances in construction waste is not high and the moisture content of construction waste is too high, resulting in failure of the excitation reaction. The newly mixed recycled mixed slurry finally produced does not require the addition of cement, has low equipment operating costs, low losses, and high raw material utilization. Tests have shown that 1,280 tons of construction waste are processed daily, and 1,830 tons of newly mixed recycled mixed slurry are produced for the production of water-stabilized materials. The compressive strength can reach 10.8 MPa within 7 days, meeting the 7d strength and compression resistance standard of water-stabilized materials.

[0067] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for resource treatment of construction waste, characterized in that: The following steps are involved: S1. crushing the construction waste to obtain construction waste crushed aggregate; S2. Mixing the first agent with the above-obtained construction waste aggregates, controlling the moisture content to be ≤20%, to obtain a fresh mixture, wherein the first agent is an active substance, and the active substance is one or more of metakaolin, alumina powder, volcanic ash, fly ash, blast furnace slag and steel slag; S3, mixing and stirring a second agent with the newly mixed material obtained above to carry out a hydration heat reaction, wherein the second agent is an active substance activator, and the active substance activator is sodium silicate and a phosphoric acid solution, and the sodium silicate and the phosphoric acid solution are used separately to generate a newly mixed recycled mixed slurry for subsequent resource recovery treatment; In step S2, the mass of the active substance is 5% to 65% of the mass of the crushed aggregate of the construction waste; in step S3, the mass of the active substance activator is 70% to 120% of the sum of the mass of the active substance and the mass of the active components contained in the construction waste; the mass of the phosphoric acid solution is 5% to 10% of the mass of the sodium silicate; and the mass concentration of the phosphoric acid solution is ≥ 85%; In step S3, the modulus of sodium silicate is controlled to be 1.2 to 1.

6.

2. A method for resource treatment of construction waste, characterized in that: The following steps are involved: S1. crushing the construction waste to obtain construction waste crushed aggregate; S2, mixing the first agent with the above-obtained construction waste aggregate, controlling the moisture content to be ≤20%, to obtain a freshly mixed material, wherein the first agent is an active substance, and the active substance is light-burned magnesium powder; S3, mixing and stirring a second agent with the newly mixed material obtained above to carry out a hydration heat reaction, wherein the second agent is an active substance stimulator, and the active substance stimulator is magnesium chloride, to generate a newly mixed regenerated mixed slurry for subsequent resource recovery treatment; In step S2, the mass of the active substance is 5% to 65% of the mass of the crushed aggregate of the construction waste; in step S3, the mass of the active substance stimulator is 70% to 120% of the sum of the mass of the active substance and the mass of the active components contained in the construction waste; In step S3, magnesium chloride and water are first prepared into a magnesium chloride solution and allowed to stand, and then mixed with the freshly mixed material, wherein the mass concentration of the magnesium chloride solution is ≥75%.

3. The method for recycling construction waste according to claim 2, characterized in that: In step S3, the standing time is 20 hours to 25 hours.

4. The method for resource treatment of construction waste according to any one of claims 1 to 3, characterized in that: In step S1, the construction waste contains 5% to 60% by mass of active ingredients.

5. The method for resource treatment of construction waste according to any one of claims 1 to 3, characterized in that: In step S2, when the moisture content of the fresh mixture exceeds 20%, the moisture content is lowered by adding calcium oxide.

6. The method for resource treatment of construction waste according to any one of claims 1 to 3, characterized in that: In step S2, the moisture content is controlled to be 5% to 10%.

7. The method for resource treatment of construction waste according to any one of claims 1 to 3, characterized in that: In step S1, the construction waste includes one or more of cement blocks, broken bricks, gravel and slag, the crushing efficiency is 30t / h to 200t / h, and the particle size of the construction waste aggregate is 0.15mm to 30mm.

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