A method for grading recycling cement product electric pole, precast waste slurry and waste material

Abstract

The application belongs to the technical field of concrete recycling, and discloses a cement product electric pole, prefabricated part waste slurry and waste crushing graded recycling and reusing method. The process stores the liquid waste slurry in a sealed manner and stabilizes the cementitious activity, realizes supernatant circulation reuse through standing separation, and forms high-activity regenerated slurry through composite activation and carbonization auxiliary treatment of the bottom slurry and graded slurry, and realizes multi-path reuse. There is no waste water discharge and solid waste residue in the whole process. The potential cementitious substances in the waste slurry are fully activated. The process gradually crushes and shapes the pure concrete block material, effectively improves the aggregate particle morphology defects, and improves the rationality and physical stability of the aggregate grade. The coupling process combining dry screening and wet cyclone grading is adopted, AI intelligent control module is used to realize accurate sorting of materials according to particle size and hydration activity, and ultra-fine powder generated in the crushing process is completely recovered and classified and utilized.

Description

Technical Field

[0001] This invention belongs to the field of concrete recycling technology, specifically relating to a graded recycling and reuse method for crushing and recycling cement product poles, precast component waste slurry, and waste materials. This method is applicable to the recycling and reuse of liquid waste slurry and solid waste generated during the production of cement poles, municipal concrete precast components, pipe segments, and square piles. The liquid waste slurry includes centrifugal residue, mixing residue, mold cleaning slurry, and equipment cleaning slurry. The solid waste includes scrapped cement poles, defective precast components, scrap materials, and demolding waste residue. Background Technology

[0002] Cement poles and precast concrete components for municipal / transportation infrastructure are core building blocks. Their production inevitably generates two types of waste: First, liquid waste slurry, including residual slurry from centrifugal molding, leftover slurry from mixing plants, and waste slurry from equipment and mold cleaning, rich in unhydrated cement particles, hydrated calcium silicate, calcium hydroxide, and other cementitious active components; second, solid waste, including scrapped poles, defective precast components, scrap materials, and demolding waste, primarily a composite of hardened cement paste and natural aggregates, while also containing metallic impurities such as reinforcing steel bars and wire. Existing recycling technologies for this type of waste face the following technical challenges: Liquid waste slurry is often simply dewatered and then landfilled or used as filler in low amounts. The active cementitious components are not effectively activated, and a large amount of alkaline wastewater is discharged, causing soil and water pollution. Furthermore, the active components are not fully recovered and closed-loop synergistic, and low-carbon activation technology is not combined to improve resource utilization.

[0003] The crushing and grading process is crude, and only conventional screening is used to achieve simple separation of coarse and fine aggregates. The ultrafine powder generated during the crushing process is not accurately graded by particle size or differentiated by activity. The disordered addition of ultrafine powder can easily lead to deterioration of the workability of fresh concrete, a significant increase in the shrinkage rate of hardened body, and a decrease in durability. Moreover, grading and modification are carried out in separate steps.

[0004] The recycled components have not undergone directional modification, and there are a large number of microcracks in the interface transition zone between waste cement stone and natural aggregate. Direct use will result in low interfacial bond strength and high water absorption of recycled concrete, which cannot meet the mechanical properties and impermeability, freeze-thaw resistance and durability requirements of high-strength prestressed components such as utility poles. Moreover, most of the modification is done on a single component, without achieving differentiated adaptation modification of all components, resulting in poor performance stability when used at high dosages. Summary of the Invention

[0005] The purpose of this invention is to provide a graded recycling and reuse method for crushing cement product poles, precast component waste slurry, and waste materials, in order to solve one or more of the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for graded recycling and reuse of cement product poles, precast component waste slurry, and waste materials, comprising the following specific steps: Furthermore, in the classification and impurity removal stage, the waste generated during the production of cement poles and precast components is divided into two main categories according to its physical state: liquid waste slurry and solid waste. The solid content of the liquid waste slurry is within the range of 15% to 35%, and the storage temperature is 15 to 30°C. All the liquid waste slurry is sent to a sealed storage tank and temporarily stored with continuous stirring at a speed of 50 to 80 r / min. At the same time, 0.1 to 0.3% of polycarboxylate dispersant (for storage) is added to retain the gelling active components in the waste slurry. The closed stirring and dispersion stabilization treatment of liquid waste slurry stabilizes the state of gelled particles and retains potential active sites, preventing self-coagulation or activity decay of the waste slurry during the temporary storage stage, and ensuring that the bottom slurry maintains the best reaction state when it enters the activation process.

[0007] The solid waste is first subjected to high-frequency pulse electromagnetic debonding treatment. The electromagnetic debonding treatment time is 35 seconds per piece. The interface vibration of the steel bars and the concrete matrix is ​​caused by a pulse magnetic field of 10~15kHz. The vibration frequency can be dynamically adjusted according to the thickness of the waste. After being pre-crushed by jaw crusher to a particle size of ≤100mm, the concrete blocks are separated from the metal impurities and light impurities through a dual separation process of strong magnetic separation and negative pressure air separation, resulting in pure concrete blocks. At the same time, the separated metal impurities are classified and recycled, and the light impurities are treated to render them harmless.

[0008] Furthermore, in the crushing and shaping stage, the pure concrete blocks obtained from the classification and impurity removal stage are fed into a three-stage gradient crushing and shaping system, which sequentially completes three-stage processing: jaw crushing, cone crushing, and vertical shaft impact crushing. The jaw crushing controls the output particle size to ≤50mm; the cone crushing controls the output particle size to ≤20mm; and the vertical shaft impact crushing controls the output particle size to ≤5mm. The stone-on-stone shaping process reduces the content of needle-like and flaky aggregates to ≤8%, optimizing the aggregate particle shape. The three-stage crushing and shaping process, along with the supernatant spraying of waste slurry, forms a coordinated operation. The feeding speed of the three-stage crushing is 810t / h for jaw crushers, 57t / h for cone crushers, and 3~5t / h for vertical shaft crushers. The stone-on-stone shaping process optimizes the aggregate particle shape and reduces needle-like and flaky particles from a physical perspective. The negative pressure spraying process suppresses dust while flushing all the ultrafine powder generated by crushing into the slurry system, preventing ultrafine powder residue in the crushing equipment from affecting the aggregate shaping effect.

[0009] The entire crushing process uses the supernatant of the liquid waste slurry after standing for 2 hours in the classification and impurity removal stage as the spray liquid to spray the crushing chamber under negative pressure to suppress dust. During the spraying process, the ultrafine powder generated by crushing is simultaneously introduced into the waste slurry system. All the wastewater after spraying is returned to the slurry storage tank in the classification and impurity removal stage. At the same time, a filter membrane is installed in the return pipeline to remove tiny impurities.

[0010] Furthermore, in the precise grading stage, the material after crushing and shaping in the crushing and shaping stage is first subjected to dry multi-layer vibrating screening, and divided into recycled coarse aggregate, recycled fine aggregate, and dry ultrafine powder according to particle size. At the same time, a coupled process of dry screening and wet cyclone grading is adopted, with the number of dry screening layers (46 layers) and vibration frequency (20~30Hz). Combined with the AI ​​intelligent control module, the material of all particle sizes is graded according to activity and application. The AI ​​intelligent control module includes an online data acquisition unit, a multi-dimensional feature fusion unit, a hierarchical parameter prediction unit, a closed-loop control execution unit, and a historical data storage unit.

[0011] The online data acquisition unit is used to collect the particle size distribution, hydration activity index, feed flow rate, material moisture content, and ambient temperature and humidity of the graded materials; the multi-dimensional feature fusion unit is used to form the grading state characteristics from the above data; the grading parameter prediction unit is used to output the screening frequency, cyclone speed, material residence time, and feed valve opening based on the grading state characteristics; the closed-loop control execution unit is used to send the output parameters to the dry screening machine and the wet cyclone grading system; and the historical data storage unit is used to store grading data, control parameters, and operating status.

[0012] The dry ultrafine powder, the wastewater from the spray return during the crushing and shaping stage, and the waste slurry bottom slurry from the storage tank during the classification and impurity removal stage are mixed evenly and sent to a two-stage wet cyclone classification system. The particles are separated by cyclone centrifugal force according to particle size and hydration activity to obtain two types of ultrafine components: regenerated active micro powder and regenerated inert micro mud. The particle size of the regenerated active micro powder is 5~15μm, and the particle size of the regenerated inert micro mud is <5μm. The classification of this invention uses the hydration activity index as the core criterion and combines it with particle size distribution to complete a two-dimensional precise sorting. Components containing unhydrated cement particles and highly active hydration products are classified as regenerated active micro powders, while components mainly composed of inert minerals and low-activity microcrystals are classified as regenerated inert micro mud.

[0013] The supernatant after grading is all returned to the crushing and shaping stage and recycled as a spray liquid; the AI ​​intelligent control module detects the particle size distribution and activity index of the graded materials in real time and dynamically adjusts the screening frequency and cyclone speed.

[0014] Furthermore, the modification and activation stage performs differentiated and directional modification on the recycled coarse aggregate, recycled fine aggregate, recycled active micro powder, and recycled inert micro mud obtained in the precise grading stage. The recycled coarse aggregate is treated with a vacuum negative pressure immersion treatment using a composite modification liquid of nano silica and silane coupling agent. It is immersed for 15 minutes under a negative pressure environment of ~0.08MPa. During the immersion process, 0.2~0.4% graphene oxide is added. The modification liquid penetrates into the microcracks on the surface of the aggregate through capillary action. The recycled fine aggregate is treated with a surface coating of waste slurry activated in the subsequent waste slurry activation stage. Under high-speed stirring conditions, 0.3-0.5% nano-calcium carbonate is added to form a uniform hydrated gel shell layer on the surface of the fine aggregate. The recycled active micro powder is activated by a mechanical and chemical composite activation process. Under low-temperature ball milling conditions of 60-80℃, 0.5-1.0% triethanolamine and 2-3% calcium hydroxide composite activator are added, along with 0.1-0.2% sodium sulfate, and the mixture is ball milled for 15-20 minutes. The recycled inert micro-mud is modified with a composite of calcium stearate and fly ash for surface hydrophobicity, and is used as a waterproof filler and rheology modifier.

[0015] Furthermore, in the waste slurry activation stage, the liquid waste slurry in the slurry storage tank of the classification and impurity removal stage is allowed to settle and the supernatant is circulated to the crushing and shaping stage as a spraying liquid. The bottom slurry is mixed evenly with the intermediate slurry of the wet classification stage in the precision classification stage, and a composite alkali activator is added. The amount of the composite alkali activator added is 3-5% of the solid content of the waste slurry. At the same time, CO2 carbonization is introduced to assist activation. The activator is stirred at high speed at 1200 r / min for 20-30 min at room temperature to obtain a stable activated waste slurry. Formula for the dosage of composite alkali activator: The unit is g / kg; This indicates the mass of the water glass-sodium hydroxide composite alkali activator, which is used to break the hydration passivation layer of waste slurry cementitious particles and activate the active components of silicon and aluminum. It represents the total mass of solid components in liquid waste slurry, which is the total mass of unhydrated cement, hydration products and other solid substances in the waste slurry, and the unit is g / kg; The percentage of the composite alkali activator by mass is the ratio of the activator mass to the solid content of the waste slurry, and the value ranges from 3% to 5%.

[0016] The liquid waste slurry settling process is completed in a closed stainless steel conical settling tank. The tank interior is treated with anti-corrosion and wear-resistant materials, and the bottom of the tank adopts a 60° conical mud collection structure to facilitate the centralized collection and transportation of bottom slurry. The settling tank is placed in a constant temperature and sealed workshop, with the ambient temperature stably controlled at 15~30℃. There is no mechanical vibration, no external stirring, and no fluid disturbance throughout the process, providing stable conditions for solid-liquid gravity separation. After settling for 2 hours, a clear interface between the supernatant and the bottom slurry is formed inside the tank, without turbidity or suspended flocculent matter. The supernatant is extracted using a low-level slow suction method to avoid disturbing the bottom slurry layer.

[0017] Alkali activation and carbonation-assisted activation work synergistically. The alkali activator first breaks down the hydration passivation layer of the cementitious particles in the waste slurry, releasing the internal active silica-alumina components. Meanwhile, CO2 carbonation simultaneously regulates the alkalinity of the slurry and generates stable calcium carbonate gel, thereby improving the storage stability of the activated waste slurry.

[0018] The activated waste slurry is divided into three streams to achieve 100% full-component recycling. Each recycling stream is equipped with an adaptive adjustment module. The first stream is used for the coating modification of recycled fine aggregate in the modification and activation stage, and the amount of activated waste slurry delivered is dynamically adjusted according to the amount of fine aggregate used. The second stream is used as mixing water, and part of it is used for the preparation of recycled cement products. The dosage ratio is adjusted according to the strength grade of the product. The third stream is used for the preparation of composite modifying liquid in the modification and activation stage, matching the concentration requirements of the modifying liquid.

[0019] Furthermore, in the product preparation stage, the proportions of each recycled component modified in the modification and activation stage are determined according to the strength grade, workability, and durability requirements of the target cement product. The amount of each component is determined according to the aforementioned substitution ratio of recycled coarse aggregate, recycled fine aggregate, recycled active micro-powder, recycled inert micro-mud, and activated waste slurry. Specifically, during batching, the recycled coarse aggregate, recycled fine aggregate, recycled active micro-powder, and recycled inert micro-mud are first added to a forced mixer for dry mixing to initially disperse the solid components. Then, activated waste slurry and remaining mixing water are added for wet mixing. Finally, a polycarboxylate-based high-efficiency water-reducing agent is added and mixing continues to ensure the water-reducing agent is evenly dispersed in the cementitious system. After prestressing, centrifugal molding or casting, and standard steam curing, recycled cement poles or recycled concrete precast components are obtained.

[0020] Formula for the amount of recycled components to be replaced: This represents the actual mass of the i-th type of recycled raw material, which is the amount of recycled components used in the production of recycled cement products, in kg. This represents the baseline feed mass of the i-th type of raw material, which is the standard amount of raw material required to produce ordinary cement products of the same specification, in kg. The coefficient representing the substitution rate of the i-th type of recycled component for the virgin raw material represents the proportion of virgin material that can be replaced by the recycled component. This indicates that the coefficient of recycled coarse aggregate replacing natural crushed stone is 60%~80%; This indicates that the coefficient of recycled fine aggregate replacing natural river sand is 50%~60%; This indicates that the coefficient of recycled active micro powder replacing P·O42.5 cement is 20%~30%; This indicates the coefficient of replacement of mineral fillers with recycled inert micro-mud, which is 10%~15%. This indicates the coefficient of activated waste slurry replacing mixing water, which is 30%~50%.

[0021] The high proportion of replacement of each recycled component is based on the synergistic adaptation and regulation of the modified performance. The modified gradation of coarse and fine aggregates complements each other. The hydration process of the active micro powder matches that of cement. The hydrophobic properties of the inert micro mud meet the density requirements of the system. The active components of the activated waste slurry participate in the hydration reaction simultaneously. The performance defects of a single recycled material are offset by the synergistic effect of multiple components.

[0022] Furthermore, the quality control and regulation stage conducts real-time online monitoring of the raw material composition and hydration degree of each batch of waste, the particle size distribution and activity index of the graded materials, the water absorption rate and micro powder activity index of the modified aggregate, and the durability indicators including the mechanical properties, impermeability, freeze resistance, and shrinkage rate of the final recycled products. At the same time, a full-process traceability database of raw material characteristics, grading parameters, performance indicators of modified components, and product performance is established, and the AI ​​intelligent control module is combined to realize intelligent control of the entire process. The test data is fed back to the aforementioned stages in real time. The crushing and screening parameters, modifier dosage, activation process parameters and mixing ratio are dynamically adjusted through the AI ​​intelligent control module. At the same time, an abnormality warning module is set up, with abnormality warning levels (general / serious). When the test index exceeds the standard range, the machine will automatically stop for adjustment.

[0023] The beneficial effects of this invention are as follows: 1. The process of this invention stores liquid waste slurry in a sealed manner and stabilizes its gelling activity. The supernatant is recycled and reused through static separation. The bottom slurry and graded slurry are treated with composite activation and carbonization to form a highly active regenerated slurry that can be reused through multiple pathways. There is no wastewater discharge or solid waste residue throughout the process. The potential gelling substances in the waste slurry are fully activated, making it able to replace conventional mixing water and some gelling materials, reducing cement and water consumption, reducing carbon emissions from production, and realizing the transformation of waste slurry from waste into high-value raw materials.

[0024] 2. The process of this invention performs step-by-step crushing and shaping optimization on pure concrete blocks, effectively improving aggregate particle morphology defects and enhancing aggregate gradation rationality and physical stability. It adopts a coupled process combining dry screening and wet cyclone classification, and uses an AI intelligent control module to achieve precise sorting of materials according to particle size and hydration activity, completely recovering and classifying the ultrafine powder generated during the crushing process for utilization. It avoids problems such as deterioration of workability of the mixture, excessive shrinkage rate of hardened body, and decreased durability caused by disordered mixing of ultrafine powder, making the quality of recycled aggregate and micro powder uniform and controllable, and meeting the performance standards, which can stably meet the raw material requirements of high-strength prestressed components such as cement poles.

[0025] 3. This invention employs specialized modification processes to precisely repair micro-cracks on the aggregate surface, strengthen the interfacial adhesion between aggregate and cementitious materials, stimulate the potential hydration activity of micro-powder, and optimize the hydrophobic and rheological properties of materials, targeting the different material characteristics of recycled coarse aggregate, fine aggregate, active micro powder, and inert micro mud. The modified recycled components can achieve a high proportion of replacement of natural aggregate and cement, improving problems such as weak interfacial transition zone and loose internal structure in recycled concrete, and enhancing the mechanical strength, impermeability, and freeze-thaw durability of the product.

[0026] 4. This invention recycles the supernatant after the liquid waste slurry has settled, using it as the spraying liquid in the crushing and shaping stage. The spraying wastewater is filtered and returned to a closed storage tank, creating a closed-loop circulation of spraying water, graded supernatant, and waste slurry activation water within the process, reducing the discharge of production wastewater. By classifying and recycling metallic impurities and treating lightweight impurities harmlessly, and by reusing recycled coarse aggregate, recycled fine aggregate, recycled activated micro-powder, recycled inert micro-mud, and activated waste slurry in product preparation and modification processes, cement-based waste enters the corresponding resource utilization pathway, reducing the pressure of waste slurry and waste material storage and transportation. Simultaneously, dust and noise emissions are controlled through negative pressure spraying for dust suppression, closed conveying, filtration and return, and equipment sound insulation and noise reduction, making the production process more in line with green and low-carbon production requirements. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the entire process of this invention. Figure 2 This is a closed-loop process diagram for the activation and recycling of liquid waste slurry according to the present invention; Figure 3 This is a flowchart of the solid waste crushing, grading, and modification process of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figures 1 to 3 As shown, this embodiment of the invention provides a method for graded recycling and reuse of cement product poles, precast component waste slurry, and waste materials, including the following specific steps: In this embodiment of the invention, the waste generated during the cement product manufacturing process is classified into two main categories according to its physical state: liquid waste slurry and solid waste. The liquid waste slurry is a cement-based slurry-like waste that still contains moisture and can flow through pipelines, storage tanks, or pumping systems, including centrifugal residue, stirring residue, mold cleaning slurry, or equipment cleaning slurry. The solid waste is cement-based waste that has hardened into blocks or solid granules, including scrapped cement poles, defective precast parts, scrap materials, or demolding waste. It is continuously stirred and temporarily stored at a speed of 50-80 r / min, while 0.1-0.3% of a polycarboxylate dispersant (for slurry storage) is added to retain the gelling active components in the waste slurry. The liquid waste slurry includes centrifugal residue, stirring residue, and equipment cleaning waste slurry. The polycarboxylate dispersant (for slurry storage) is polycarboxylate-based. The polycarboxylate dispersant (for slurry storage) is a low-viscosity liquid formulation, quantitatively delivered to the sealed slurry storage tank via a variable frequency metering pump. The addition point is located in the center of the circulating flow field of the stirring paddle inside the tank, ensuring rapid diffusion of the agent throughout the tank. Continuous stirring at 50-80 r / min is maintained throughout the addition process. After the agent is added, the stirring time is extended to 15 minutes to ensure the polycarboxylate dispersant (for slurry storage) fully coats the unhydrated cement particles and hydration products in the waste slurry, preventing particle agglomeration and bridging effects. The sealed slurry storage tank is maintained under a slight positive pressure seal throughout the process, isolating external air and impurities from entering. Simultaneously, the tank temperature is maintained at 15-30℃ to prevent temperature fluctuations from affecting the dispersion effect. For long-term temporary storage, stirring is initiated for 3 minutes every 2 hours to continuously stabilize the uniformity and gelling activity of the waste slurry.

[0030] The solid waste is first treated with high-frequency pulsed electromagnetic stripping, where a 10-15kHz pulsed magnetic field causes interfacial vibration and separation between the reinforcing bars and the concrete matrix. The vibration frequency can be dynamically adjusted according to the thickness of the waste to improve stripping efficiency and the integrity of the concrete matrix. When the thickness is >50mm, the frequency is adjusted to 13-15kHz, and when the thickness is ≤50mm, the frequency is adjusted to 10-12kHz. The solid waste includes scrapped utility poles, defective precast components, scrap materials, and demolding waste. The high-frequency pulse electromagnetic debonding operation uses a fully automatic horizontal electromagnetic debonding integrated machine. The equipment has a rated working power of 15~20kW and a stable operating voltage of 380V. The waste material is evenly spread into the debonding station via a belt conveyor. The thickness of the spread material is strictly controlled at 50~100mm and the surface is flat without stacking. The conveyor belt runs at a constant speed of 0.5m / min to ensure that the waste material stays in the electromagnetic action area for a sufficient time, and the pulse magnetic field fully acts on the interface between the steel bar and the concrete. After the debonding is completed, an automatic sorting station is set up. The separated steel bars are collected by magnetic rollers into a special material box, and the concrete blocks fall into the subsequent conveying channel.

[0031] After being pre-crushed by jaw crusher to a particle size ≤100mm, the material is then separated by a dual separation process of strong magnetic separation and negative pressure air separation. The magnetic field strength of the strong magnetic separation is 1000~1500Gs, and the negative pressure value of the negative pressure air separation is ~0.05~~0.07MPa. This process separates metallic impurities such as steel bars and iron wires from lightweight impurities such as plastics, wood chips, and curing felt, resulting in pure concrete blocks. At the same time, the separated metallic impurities are classified and recycled, and the lightweight impurities are treated to render them harmless.

[0032] The strong magnetic separation and negative pressure air separation adopt a series continuous collaborative operation mode. The pre-crushed concrete blocks first enter the drum-type strong magnetic separator. The magnetic field area fully covers the material flow path, and metal impurities are efficiently adsorbed and separated from the material flow as the drum rotates. After iron removal, the material enters the negative pressure air separation chamber. The airflow in the chamber is uniformly laminar. Light impurities are separated to the dust collection device under the action of directional negative pressure airflow. The concrete blocks fall steadily to the discharge end by their own gravity.

[0033] In this embodiment of the invention, the crushing and shaping stage feeds the pure concrete blocks obtained from the classification and impurity removal stage into a three-stage gradient crushing and shaping system, sequentially completing three stages of processing: jaw crushing, cone crushing, and vertical shaft impact crushing. The jaw crushing controls the output particle size to ≤50mm; the cone crushing controls the output particle size to ≤20mm; and the vertical shaft impact crushing controls the output particle size to ≤5mm. The stone-on-stone shaping process reduces the content of needle-like and flaky aggregates to ≤8%, optimizing the aggregate particle shape. The three-stage gradient crushing and shaping system adopts a linked feeding control. Each stage of equipment is connected by a belt conveyor, and the feeding speed is matched step by step. The feeding rate of the jaw crusher is controlled at 8~10t / h, the feeding rate of the cone crusher is controlled at 5~7t / h, and the feeding rate of the vertical shaft impact crusher is controlled at 3~5t / h. The gap of the crushing chamber is precisely adjusted according to the discharge particle size requirements. The entire process adopts a stone-on-stone shaping mode to reduce the generation of micro-cracks in the aggregate crushing process and stably control the content of needle-like and flaky aggregates to no more than 8%.

[0034] The entire crushing process uses the supernatant from the liquid waste slurry after standing for 2 hours in the classification and impurity removal stage as the spray liquid to perform negative pressure spraying and dust suppression on the crushing chamber. The spraying pressure is 0.3~0.5MPa and the atomized particle size is (50~100μm). During the spraying process, the ultrafine powder generated by crushing is simultaneously carried into the waste slurry system. All the wastewater after spraying is returned to the slurry storage tank in the classification and impurity removal stage. At the same time, a filter membrane with a pore size of 0.1μm is installed in the return pipeline to remove tiny impurities and avoid pipeline blockage and impurity accumulation.

[0035] The negative pressure spray dust suppression uses high-pressure atomizing nozzles with a spray pressure stable at 0.3~0.5MPa. The nozzles are evenly distributed at the feed inlet and discharge outlet of the crushing chamber. The spray wastewater is filtered using a cross-flow membrane filter with a filtration pressure controlled at 0.2MPa. Automatic backwashing is performed every 8 hours of operation, using supernatant as the backwashing medium and lasting for 5 minutes to maintain stable membrane permeability.

[0036] The ultrafine powder generated from crushing is recovered in a closed system with the negative pressure spray liquid. Dust suppression and powder recovery are completed simultaneously, and no ultrafine powder is lost to the external environment. The recovered ultrafine powder is filtered through a filter membrane with the spray wastewater and then returned to the slurry storage tank to fully mix with the liquid slurry, achieving 100% resource utilization of solid waste.

[0037] In this embodiment of the invention, the precise grading stage first performs dry multi-layer vibrating screening on the material after crushing and shaping in the crushing and shaping stage. The number of screening layers is 4 to 6, the vibration frequency is 20 to 30 Hz, and the material is divided into recycled coarse aggregate, recycled fine aggregate, and dry ultrafine powder according to particle size. The particle size of recycled coarse aggregate is 5 to 20 mm, the particle size of recycled fine aggregate is 0.15 to 5 mm, and the particle size of dry ultrafine powder is <0.15 mm. At the same time, a coupled process of dry screening and wet cyclone grading is adopted, combined with an AI intelligent control module to achieve grading of materials of all particle sizes according to activity and application. The dry ultrafine powder, wastewater from the crushing and shaping stage spray return, and waste slurry from the storage tank in the classification and impurity removal stage are mixed evenly and sent to a two-stage wet cyclone classification system. The mixture is then separated by particle size and hydration activity using centrifugal force. The first-stage cyclone speed is 1200-1500 r / min, and the second-stage cyclone speed is 1800-2200 r / min, yielding two types of ultrafine components: regenerated active micro-powder and regenerated inert micro-mud. The regenerated active micro-powder has a particle size of 5-15 μm and is mainly composed of unhydrated cement particles and highly active hydrated calcium silicate. The regenerated inert micro-mud has a particle size <5 μm and is mainly composed of inert calcium silicate, calcium hydroxide microcrystals, and clay components. The dry screening and wet cyclone classification adopt a closed-loop conveying structure. The ultrafine powder produced by dry screening is directly sent into the wet mixing tank through a negative pressure suction device, where it is quickly mixed with the sprayed return wastewater and waste slurry bottom slurry. An online concentration detection probe is set at the connection point to adjust the solid-liquid ratio of the mixing system in real time, ensuring that the concentration of the material entering the wet cyclone system is within the optimal classification range, avoiding cyclone blockage due to excessively high concentration and reduced classification efficiency due to excessively low concentration.

[0038] The supernatant after grading is all returned to the crushing and shaping stage and recycled as a spray liquid; the AI ​​intelligent control module detects the particle size distribution and activity index of the graded materials in real time and dynamically adjusts the screening frequency and cyclone speed.

[0039] The AI ​​intelligent control module is a dedicated intelligent control model customized for the scenario of graded recycling of concrete waste. It consists of five modules connected in sequence: an online data acquisition unit, a multi-dimensional feature fusion unit, a graded parameter intelligent prediction unit, a closed-loop control execution unit, and a historical data storage unit. The online data acquisition unit connects to an online laser particle size analyzer, a rapid hydration activity detector, a material flow sensor, and an ambient temperature and humidity sensor to collect raw data such as the full particle size distribution curve, hydration activity index, real-time feed flow rate, material moisture content, and ambient temperature and humidity of the graded materials in real time. The multi-dimensional feature fusion unit uses a lightweight convolutional neural network to extract and fuse features from multi-source data, focusing on mining the intrinsic correlation between particle size distribution and hydration activity, and the matching features between material flow rate and classification efficiency. The intelligent prediction unit for grading parameters adopts a multi-layer neural network structure, with layers consisting of an input layer, a two-dimensional convolutional layer, a max pooling layer, a fully connected layer, and an output layer. It fits the mapping relationship between material characteristics and grading process parameters through deep learning. The closed-loop control execution unit directly connects to the electrical control system of the dry screening machine and the wet hydrocyclone, receiving and executing the control commands output by the model. The data storage unit stores classification data, control parameters, and operating status in real time. The input data of this module includes real-time particle size distribution data of the classified materials, hydration activity index, material feed flow rate, material moisture content, and ambient temperature and humidity. The output data includes the optimal vibration frequency of the dry multi-layer vibrating screen, the classification speed of the secondary wet hydrocyclone, the material classification residence time, and the matching parameters of the feed valve opening.

[0040] In this embodiment of the invention, the modified activation stage performs differentiated directional modification on the recycled coarse aggregate, recycled fine aggregate, recycled active micro powder, and recycled inert micro mud obtained in the precise grading stage, based on their material characteristics and the high strength, impermeability, and freeze-thaw resistance requirements of cement poles and precast components. The recycled coarse aggregate is treated with a vacuum negative pressure immersion solution of nano-silica and silane coupling agent composite modification liquid. The nano-silica content in the nano-silica and silane coupling agent composite modification liquid is 1~2%, and the silane coupling agent content is 0.5~1.0%. It is immersed for 15 minutes under a negative pressure environment of ~0.08MPa. During the immersion process, 0.2~0.4% graphene oxide is added. The modification liquid penetrates into the microcracks on the surface of the aggregate through capillary action, improves the aggregate strength, repairs the surface microcracks, and achieves hydrophobic modification of the interface, thereby improving the interfacial bonding strength between the aggregate and cement stone. The nano-silica and silane coupling agent composite modified liquid uses deionized water as the dispersion solvent. First, the silane coupling agent is added to the deionized water and stirred at 800 r / min for 10 minutes for hydrolysis treatment. Then, the nano-silica powder is added and stirred at high speed for 20 minutes until uniformly dispersed. During the preparation process, a small amount of polycarboxylic acid dispersant (for slurry storage) is added to prevent the agglomeration of nanoparticles. The composite modified liquid is prepared and used immediately. After preparation, it is immediately transferred to a vacuum soaking tank to avoid prolonged storage that may cause the modified liquid to become ineffective.

[0041] The vacuum negative pressure soaking of recycled coarse aggregate is carried out in a sealed pressure-resistant vacuum soaking tank. The vacuum soaking pressure holding time for coarse aggregate is 5 minutes for vacuuming and holding, followed by 15 minutes for soaking. The tank body is made of carbon steel with an anti-corrosion lining, and the sealing door is equipped with double silicone sealing rings. After the aggregate is loaded into the tank, the tank door is sealed first, and a vacuum is drawn at a constant rate to ~0.08MPa and held for 5 minutes to fully remove air from the microcracks and pores inside the aggregate. Then, the composite modification liquid is slowly injected, and the vacuum state is maintained to continue soaking for 15 minutes, so that the modification liquid can fully penetrate into the pores and microcracks inside the aggregate. After soaking, the air pressure inside and outside the tank is slowly balanced first, and then the tank door is opened to remove the aggregate. The aggregate is placed on a draining rack to drain naturally for 5 minutes to remove the free modification liquid on the surface, and then it can proceed to the next process.

[0042] The recycled fine aggregate is treated with a surface coating of waste slurry activated in the subsequent waste slurry activation stage. 0.3-0.5% nano-calcium carbonate is added while stirring at a speed of 1000-1200 r / min to form a uniform hydrated cementitious shell layer on the surface of the fine aggregate, optimizing particle size distribution, improving the workability and water retention of the fresh slurry, and enhancing the filling performance of the fine aggregate. The coating treatment of recycled fine aggregate is carried out in a closed modified mixer. First, the recycled fine aggregate is put into the mixer and pre-mixed for 5 minutes. Then, the activated waste slurry is sprayed at a uniform speed while nano-calcium carbonate is continuously added. The mixing speed is maintained at 1000~1200r / min throughout the process, and the total coating treatment time is controlled within 20 minutes. After the treatment, the fine aggregate is left to stand and age for 10 minutes to allow the surface hydration gelatinous shell layer to initially take shape.

[0043] The regenerated active micro powder is activated by a mechanical and chemical composite activation process. Under low-temperature ball milling conditions of 60-80℃, 0.5-1.0% of triethanolamine and 2-3% of calcium hydroxide composite activator are added, along with 0.1-0.2% of sodium sulfate. After ball milling for 15-20 minutes, the passivation layer of hydration products on the surface of the micro powder is destroyed, and the hydration activity of unhydrated cement particles is activated. It can be used as an auxiliary cementitious material to directly replace cement. The recycled inert micro mud is modified by combining calcium stearate and fly ash for surface hydrophobicity modification. It is used as a waterproof filler and rheology modifier to improve the impermeability of the hardened body, while improving the utilization rate of waste materials and avoiding waste of inert micro mud. The amount of calcium stearate is 1~2% and the amount of fly ash is 5~8%.

[0044] Formula for total dosage of recycled inert micro-mud modifier: The total mass of the regenerated inert micro-mud hydrophobic modifier is the sum of the masses of calcium stearate and fly ash modifiers, expressed in g / kg. The total mass of the regenerated inert micro-mud to be modified is expressed as the mass of the inert micro-mud component obtained by wet cyclone classification, in kg. This indicates the percentage of calcium stearate by mass, which is the ratio of the mass of calcium stearate to the mass of micro-mud. It is used to achieve hydrophobic modification of the micro-mud surface and is 1% to 2%. This represents the percentage of fly ash by mass, which is the ratio of fly ash mass to micro-mud mass. It is used to synergistically optimize the rheological and filling properties of micro-mud, and its value ranges from 5% to 8%.

[0045] The hydrophobic modification of recycled inert micro-mud was completed in a biaxial zero-gravity mixing device (biaxial zero-gravity mixer). First, the recycled inert micro-mud was put into the mixer and dispersed for 3 minutes. Then, calcium stearate and fly ash were added in sequence and mixed at 60 r / min for 15 minutes. The mixing process was kept at room temperature and pressure to ensure that the modifier was uniformly coated on the surface of the micro-mud particles. After the modification was completed, it was transported to the storage silo and sealed for storage through a negative pressure suction device.

[0046] The differentiated modification process of the four types of recycled components follows the principle of synergistic adaptation. The modification parameters are matched in a targeted manner according to the core performance requirements of cement poles and precast components, such as high strength, impermeability, and frost resistance. The modification of coarse aggregate focuses on repairing microcracks and strengthening interfacial bonding, the modification of fine aggregate focuses on optimizing gradation and improving encapsulation, the modification of active micro powder focuses on stimulating hydration activity and replacing cement, and the modification of inert micro mud focuses on hydrophobic control and filling density. After the modification of each component is completed, pre-adaptation testing is carried out.

[0047] In this embodiment of the invention, during the waste slurry activation stage, the liquid waste slurry in the slurry storage tank of the classification and impurity removal stage is allowed to settle for 2 hours. The supernatant is then circulated to the crushing and shaping stage as a spraying liquid. The bottom slurry is mixed evenly with the intermediate slurry from the wet classification stage of the precision classification stage. A composite alkali activator is added. The composite alkali activator is a mixture of water glass and sodium hydroxide, with a modulus controlled at 1.2~1.4. The amount of the composite alkali activator added is 3~5% of the solid content of the waste slurry. At the same time, CO2 carbonization is introduced to assist activation. The gauge pressure is 0.05~0.1MPa, the carbonization time is 30~40min, and the activator is stirred at high speed at 1200r / min for 10~20min at room temperature to obtain a stable activated waste slurry. The water glass-sodium hydroxide composite alkali activator is prepared on-site. First, solid sodium hydroxide is slowly added to deionized water and stirred until completely dissolved. Then, liquid water glass is slowly poured into the sodium hydroxide solution and stirred at low speed for 30 minutes until uniformly mixed. The modulus is controlled to be stable between 1.2 and 1.4 by adjusting the mass ratio of water glass to sodium hydroxide. After compounding, the activator is added dropwise at a uniform rate to the mixture of bottom slurry and graded slurry using a metering pump. The dropwise addition time is controlled to be 10-15 minutes to ensure that the activator and waste slurry system are fully mixed and contacted, and to avoid excessive local alkalinity that could lead to slurry flocculation and agglomeration.

[0048] CO2 carbonization-assisted activation employs a closed carbonization reactor. CO2 gas is uniformly introduced into the waste slurry system through a bottom microporous aeration disc, with the gas flow rate controlled at 0.5~1.0 m³ / h. 3 / h, ensuring that the bubbles are small and uniform and in full contact with the slurry; monitor the pH value of the system in real time during the carbonization process, and determine the carbonization endpoint when the pH value drops to 10~11, stop the aeration, and avoid excessive carbonization that could lead to instability of the active components.

[0049] The activated waste slurry is recycled in three streams, each equipped with an adaptive adjustment module. The first stream is used for the coating modification of recycled fine aggregates in the modification and activation stage, and the amount of activated waste slurry delivered is dynamically adjusted according to the amount of fine aggregates used. The second stream serves as mixing water, partially replacing tap water in the preparation of recycled cement products, and the dosage ratio is adjusted according to the strength grade of the products, with an adjustment range of 30-50%. The third stream is used for the preparation of composite modifying liquid in the modification and activation stage, matching the concentration requirements of the modifying liquid to maximize the utilization of the active components of the waste slurry.

[0050] The three-way reuse flow adaptation and adjustment module adopts a real-time linkage control mode. Based on real-time data of the amount of recycled fine aggregate processed, the amount of mixing water required for the product, and the concentration of the composite modified liquid, it automatically adjusts the conveying flow rate and conveying speed of each activated waste slurry. Each pipeline is equipped with online concentration monitoring and flow control valves to ensure that the concentration and amount of active components in the activated waste slurry match the requirements of each process. The conveying pipeline adopts a heat tracing and insulation design to maintain a stable temperature of the waste slurry in the pipeline and avoid the release of active components or abnormal slurry consistency due to temperature changes. At the same time, low-speed guide vanes are installed in the pipeline to prevent sedimentation and stratification of the activated waste slurry during the conveying process.

[0051] In this embodiment of the invention, during the product preparation stage, the proportions of each recycled component modified in the modification and activation stage are determined according to the strength grade, workability, and durability requirements of the target cement product. The strength grade of the target cement product is determined based on the intended use of the product. Specifically, the concrete strength grade corresponding to recycled cement poles is C60 to C100, the concrete strength grade corresponding to municipal precast concrete components is C30 to C50, and the concrete strength grade corresponding to segmented concrete or square piles is C50 to C60. When determining the mix proportion, first determine the replacement ratios of recycled coarse aggregate, recycled fine aggregate, recycled activated micro powder, recycled inert micro mud, and activated waste slurry based on the target strength grade. Then, combine the water absorption rate, activity index, particle size distribution, and moisture content of the modified recycled components to adjust the water consumption, admixture dosage, and curing parameters accordingly. The proportion of recycled coarse aggregate replacing natural crushed stone is 60% to 80%, the proportion of recycled fine aggregate replacing natural river sand is 50% to 60%, the proportion of recycled activated micro powder replacing P·O42.5 grade silicate cement is 20% to 30%, and the proportion of recycled inert micro mud replacing 10% to 15% of mineral fillers. The activated waste slurry replaces 30% to 50% of the mixing water, and 0.05% to 0.1% of polycarboxylate-based high-efficiency water-reducing agent (for mixing) is added simultaneously. The polycarboxylate-based high-efficiency water-reducing agent (for mixing) is added post-admixed to maximize its water-reducing and dispersing effects and avoid premature contact with aggregates that could lead to performance loss. During mixing, recycled coarse aggregate, recycled fine aggregate, recycled active micro powder, and recycled inert micro mud are first added to a forced mixer and dry-mixed for 1 minute to ensure that the solid components are initially and evenly mixed. Then, activated waste slurry and conventional mixing water are added and wet-mixed for 2 minutes to form a uniform slurry system. Finally, the polycarboxylate-based high-efficiency water-reducing agent (for mixing) is added and mixing is continued for 1 minute to ensure that the polycarboxylate-based high-efficiency water-reducing agent (for mixing) is evenly dispersed in the gelling system.

[0052] Weigh each component according to the mixing ratio, and after forced mixing for 3-5 minutes, prestressing tensioning, centrifugation / casting molding, and standard steam curing, prepare recycled cement poles or precast components that meet the relevant performance requirements. The prestressing tensioning is for poles only, and the tensioning control stress is 1.2-1.3 times the design strength. The steam curing temperature is 80-90℃, and the curing time is 12-18 hours.

[0053] Standard steam curing is performed in four stages: static stop stage, standing at room temperature for 2 hours; heating stage, heating at a rate of 15°C per hour to 80~90°C; constant temperature stage, maintaining temperature fluctuations of ±2°C and curing humidity greater than or equal to 95%RH; and cooling stage, slowly cooling down to room temperature at a rate not exceeding 10°C per hour.

[0054] The cement poles are manufactured using a segmented centrifugal molding process, controlled in three stages: low-speed material distribution, medium-speed compaction, and high-speed dehydration. The low-speed (300 rpm) operation for 2 minutes completes the uniform distribution of the mixture; the medium-speed (600 rpm) operation for 3 minutes removes excess water and air bubbles; and the high-speed (1200 rpm) operation for 5 minutes achieves compacted molding. Municipal concrete precast components are manufactured using a casting and vibration molding process. The mixture is poured into the mold in layers, and each layer is uniformly compacted using an immersion vibrator with a vibration point spacing of no more than 200 mm. Vibration continues until the surface of the mixture shows signs of slurry and no continuous air bubbles overflow.

[0055] The prestressing tensioning employs a dual-control intelligent tensioning device that controls both stress and elongation. The device is pre-calibrated and qualified. The tensioning process is centered on stress control, supplemented by elongation verification. Tension is applied slowly and uniformly throughout, without impact or sudden increases or decreases. Once the set control stress is reached, the load is held for 3 minutes to ensure the prestressing tendons are subjected to sufficient and uniform stress distribution, effectively reducing subsequent stress loss. Anchoring is performed promptly after the load is held, ensuring a secure anchorage. The entire tensioning process automatically records data such as stress, elongation, and holding time, creating a dedicated tensioning file to ensure the prestressing effect of the recycled cement poles meets standards.

[0056] In this embodiment of the invention, the quality control and regulation stage performs real-time online detection on the raw material composition, hydration degree, particle size distribution and activity index of graded materials, water absorption rate and micro powder activity index of modified aggregates, and durability indicators including mechanical properties, impermeability, freeze resistance and shrinkage rate of the final recycled products for each batch of waste. The detection frequency is once every 30 minutes. At the same time, a full-process traceability database of raw material characteristics, grading parameters, performance indicators of modified components and product performance is established, and the AI ​​intelligent control module is combined to realize full-process intelligent control. The AI ​​intelligent control module is constructed by fusing deep learning algorithms and process fitting algorithms. It is adapted to the entire process quality control scenario of recycling and reusing cement product waste slurry and waste materials. The model training steps, core parameters, and application logic are as follows: 1. Collect no less than 1200 sets of historical continuous production data, including waste raw material composition, hydration degree, crushing and screening operation parameters, modifier dosage, waste slurry activation process parameters, material mixing ratio, mechanical properties of recycled products, impermeability, antifreeze properties, shrinkage rate, water absorption rate and other full-dimensional indicators, and construct a full-process traceability training dataset; 2. Standardize and normalize the dataset, remove outliers, and fill in missing values. Then, randomly divide the processed dataset into training and validation sets in a 7:3 ratio. 3. A hybrid model was built using a backpropagation neural network combined with a random forest regression algorithm. The input layer had 22 neurons, the hidden layer had 64, 48, 24, 12, 6, and 3 neurons respectively, and the output layer had 14 neurons. A stochastic gradient descent optimizer was selected, with a learning rate of 0.001, a batch size of 32, and 200 training iterations. During training, the model convergence criteria were set as follows: the performance prediction error of the recycled products ≤2% and the process parameter matching error ≤1%. 4. Use an independent validation set to verify the accuracy of the trained model. Once the verification is successful, deploy it to the end-to-end online quality control system. 5. The model receives input data in real time, such as raw material composition, graded material properties, modified component parameters, and waste slurry activation status. It quickly outputs the optimal parameters for crushing and screening, precise dosage of modifier, waste slurry activation adaptation parameters, material mix optimization scheme, and curing process adjustment suggestions. At the same time, all control data is synchronously written into the full-process traceability database. When the detection index exceeds the standard range, the abnormal early warning module will quickly trigger a shutdown adjustment command.

[0057] The full-process traceability database operates in a dual-mode system, combining cloud-based encrypted storage and local hardware backup. Data is collected every 30 minutes, and all production data is archived according to production batch, raw material number, equipment number, and production time, stored in a standardized and universal format. The database features hierarchical access control, with different personnel having different query and modification permissions. The system supports rapid data retrieval, filtering, and export based on multiple dimensions, including raw material source, process parameters, product model, and production period, and can automatically generate quality traceability reports and production analysis reports.

[0058] The detection data is fed back to the aforementioned stages in real time. The crushing and screening parameters, modifier dosage, activation process parameters and mixing ratio are dynamically adjusted through the AI ​​intelligent control module. The crushing and screening parameters include vibration frequency and cyclone speed, and the activation process parameters include stirring speed and carbonization time. At the same time, an abnormality warning module is set up to automatically stop the machine for adjustment when the detection index exceeds the standard range.

[0059] The anomaly warning module adopts a graded sound and light synchronous alarm mechanism, which is divided into general warning and severe warning according to the degree of exceeding the standard. The alarm signal is transmitted to the central control room and the field operation terminal simultaneously. After the warning is triggered, the system automatically cuts off the power supply to the core equipment such as crushing, mixing, molding and curing, locks the equipment operation program, and automatically records information such as abnormal indicators, occurrence time and related process parameters, and generates an anomaly handling work order. On-site personnel need to check the root cause of the problem according to the work order, correct the process parameters and complete the re-inspection. After the indicators are qualified, an unlocking application is submitted. The equipment can only be restarted after the system verifies and approves it. Semi-finished products produced during the abnormal period are automatically isolated and marked, and are prohibited from flowing into the next process.

[0060] During continuous production, the crushing and shaping stage employs a negative pressure spray dust suppression and closed-loop recovery structure. Spray wastewater is filtered through a membrane and then returned to a closed slurry storage tank, ensuring no external discharge of production wastewater. With closed hoods, negative pressure dust collection devices, and spray dust suppression devices installed at the crushing, screening, and conveying stations, the dust emission concentration in the work area can be controlled to no more than 10 mg / m³. 3 After soundproof covers, vibration damping foundations, or flexible connectors are installed on the outside of the crusher, screening machine, cyclone grading system, and mixing equipment, the operating noise of the equipment can be controlled to no more than 85dB. Metal impurities are classified and recycled after magnetic separation, light impurities are treated to render them harmless, and cement-based solid waste is crushed, graded, and modified to form recycled coarse aggregate, recycled fine aggregate, recycled active micro powder, and recycled inert micro mud, which then enter the subsequent product preparation process.

[0061] When preparing recycled cement poles using the method described in this embodiment, the mix design is based on a C60 strength grade, and the dosage of each component is determined within the substitution ratio range of the above-mentioned recycled coarse aggregate, recycled fine aggregate, recycled active micro powder, recycled inert micro mud, and activated waste slurry. After forced mixing, prestressing tensioning, centrifugal molding, and standard steam curing, the resulting recycled cement poles have a compressive strength of not less than 60 MPa, a permeability grade of not less than P12, a freeze-thaw resistance grade of not less than F200, and a shrinkage rate of not more than 0.03%. The above performance results show that this method can achieve resource recovery of waste slurry and waste materials while enabling recycled cement poles to meet the mechanical properties, permeability, freeze-thaw resistance, and volume stability requirements under the corresponding strength grade.

[0062] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0063] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components, characterized in that, The specific steps include the following: In the classification and impurity removal stage, the waste generated during the cement product production process is classified into liquid slurry and solid waste according to its physical state. The liquid slurry includes centrifugal residue, stirring residue, mold cleaning slurry or equipment cleaning slurry, and the solid waste includes scrapped cement poles, defective precast parts, scrap materials or demolding waste. The liquid slurry is temporarily stored in a closed container with stirring, and the solid waste is sequentially debonded, pre-crushed and sorted to remove impurities, resulting in pure concrete blocks. At the same time, the separated metal impurities are recovered and the lightweight impurities are treated to render them harmless. In the crushing and shaping stage, the pure concrete blocks are sent into the three-stage gradient crushing and shaping system to complete the crushing and particle shape optimization of aggregates. Throughout the crushing process, the supernatant after the liquid waste slurry has been settled and settled is used as the spraying liquid for negative pressure spraying to suppress dust. At the same time, the ultrafine powder generated by crushing is recovered. The spraying wastewater carrying the ultrafine powder is treated and then recycled. In the precise grading stage, a coupled dry screening and wet cyclone grading process is adopted, combined with an AI intelligent control module to classify the crushed and shaped materials according to particle size and hydration activity, to obtain recycled coarse aggregate, recycled fine aggregate, recycled active micro powder and recycled inert micro mud. The supernatant after grading is recycled and reused. The AI ​​intelligent control module detects and dynamically adjusts grading parameters, including screening frequency and cyclone speed, in real time. In the modification and activation stage, differentiated and targeted modification is carried out on various recycled components obtained from the grading process, in combination with the performance requirements of the target cement products, to optimize the strength, interfacial adhesion, hydration activity and impermeability of each recycled component. In the waste slurry activation stage, the liquid waste slurry is allowed to settle and the supernatant is recycled as a spraying liquid for reuse. The bottom slurry and the graded slurry are combined and then activated to obtain activated waste slurry. The activated waste slurry is then recycled to the modification and activation stage and the product preparation stage in multiple ways. In the product preparation stage, based on the performance requirements of the target cement product, the appropriate ratio of each recycled component after modification is determined. Each recycled component is mixed with activated waste slurry and appropriate admixtures, and recycled cement products are prepared through prestressing tensioning, molding and standard steam curing processes. During the quality control and regulation stage, the performance indicators of raw materials, intermediate products and final products throughout the entire process are monitored online in real time. A traceability database for the entire process is established, process parameters are dynamically adjusted in combination with intelligent algorithms, and an anomaly early warning module is set up.

2. The method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components according to claim 1, characterized in that, In the classification and impurity removal stage, the liquid waste slurry is sent into a sealed storage tank and temporarily stored by continuous stirring at a speed of 50~80 r / min. At the same time, 0.1~0.3% of the mass of the liquid waste slurry is added as a storage polycarboxylate dispersant. The solid waste is first subjected to electromagnetic debonding treatment with a high-frequency pulse magnetic field of 10~15kHz to vibrate and separate the steel bars from the concrete matrix interface. After being pre-crushed by jaw crusher to a particle size ≤100mm, the metal and light impurities are separated by a dual separation process of strong magnetic separation with a magnetic field strength of 1000~1500Gs and negative pressure air separation with a negative pressure value of -0.07MPa~-0.05MPa to obtain pure concrete blocks.

3. The method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components, as described in claim 2, is characterized in that... The three-stage gradient crushing and shaping system of the crushing and shaping stage consists of jaw crushing, cone crushing, and vertical shaft impact crushing. The jaw crushing controls the output particle size to ≤50mm, the cone crushing controls the output particle size to ≤20mm, and the vertical shaft impact crushing controls the output particle size to ≤5mm. The content of needle-shaped and flaky aggregates is controlled to no more than 8% through the stone-on-stone shaping process.

4. The method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components, as described in claim 3, is characterized in that... The spray liquid in the crushing and shaping stage is the supernatant of liquid waste slurry after standing for 2 hours. The wastewater after spraying is filtered through a filter membrane with a pore size of 5-20 μm to remove tiny impurities. All the filtrate is returned to the slurry storage tank in the classification and impurity removal stage for reuse. The filter membrane is backwashed and regenerated periodically.

5. The method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components, as described in claim 4, is characterized in that... In the precise grading stage, the crushed and shaped materials are first subjected to dry multi-layer vibrating screening, and divided into recycled coarse aggregate, recycled fine aggregate and dry ultrafine powder according to particle size. Then, the dry ultrafine powder, sprayed return wastewater and bottom slurry after pre-settling of liquid waste slurry are mixed evenly and sent to a two-stage wet cyclone grading system. The recycled active micro powder and recycled inert micro mud are separated according to particle size and hydration activity by cyclone centrifugal force. The AI ​​intelligent control module detects the particle size distribution and activity index of the graded materials in real time and dynamically adjusts the screening frequency and cyclone speed.

6. The method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components according to claim 5, characterized in that, In the modification and activation stage, the recycled coarse aggregate is treated with vacuum negative pressure immersion in a composite modification liquid of nano-silica and silane coupling agent; the recycled fine aggregate is treated with surface coating by activated waste slurry; and the recycled active micro powder is treated with a composite activation process of low temperature ball milling and chemical activation. The surface of the regenerated inert micro-mud is modified by combining 1-2% calcium stearate and 5-8% fly ash.

7. A method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components, as described in claim 6, is characterized in that... In the waste slurry activation stage, a water glass-sodium hydroxide composite alkali activator with a solid content of 3-5% and a modulus of 1.2-1.4 is added to the uniformly mixed bottom slurry and graded slurry. At the same time, CO2 carbonization is introduced to assist activation. The slurry is activated by high-speed stirring at a speed of 400-600 r / min at room temperature for 20-30 min to obtain activated waste slurry.

8. A method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components, as described in claim 7, characterized in that... The activated waste slurry is recycled in three separate streams. The first stream is used for coating and modification of recycled fine aggregates, the second stream is used as mixing water for the preparation of recycled cement products, and the third stream is used for the preparation of composite modified liquid. Each stream is equipped with a flow rate adaptation and adjustment module to dynamically adjust the delivery volume.

9. A method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components, as described in claim 8, characterized in that... In the product preparation stage, recycled coarse aggregate replaces 60-80% of natural crushed stone, recycled fine aggregate replaces 50-60% of natural river sand, recycled active micro powder replaces 20-30% of P·O42.5 grade silicate cement, recycled inert micro mud replaces 10-15% of mineral fillers, activated waste slurry replaces 30-50% of mixing water, and 0.05-0.1% of polycarboxylate-based high-efficiency water-reducing agent for mixing is added. After weighing each component according to the proportion, the recycled cement product is prepared by forced mixing, prestressing tensioning, molding, and standard steam curing.

10. A method for graded recycling and reuse of waste slurry and waste materials from cement product poles and precast components, as described in claim 9, characterized in that... The target cement products include recycled cement poles, municipal concrete precast components, pipe segments, or square piles; wherein the concrete strength grade corresponding to the recycled cement poles is C60 to C100, the concrete strength grade corresponding to the municipal concrete precast components is C30 to C50, and the concrete strength grade corresponding to the pipe segments or square piles is C50 to C60; and the amount of recycled coarse aggregate, recycled fine aggregate, recycled active micro powder, recycled inert micro mud, and activated waste slurry is adjusted within the substitution ratio range defined in claim 9 according to the corresponding concrete strength grade.

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