Method, system and control device for regulating the properties of carbonation filling paste

Abstract

The present disclosure relates to a method, system and control device for regulating the performance of carbon sequestration filling slurry, using industrial solid waste as raw material, combining with glauber's salt and alkali residue composite activator, establishing a mapping relationship model of performance index and process parameters, through pre-carbonization and intensified carbonization grading process, considering the pumpability of slurry and the strength of filling body; The system integrates raw material storage metering, mixing and slurry preparation, grading carbonization, conveying and filling, CO2 gas supply and regulation and control modules, realizes full-process closed-loop control relying on online monitoring and model dynamic correction, self-adapts to raw material and working condition fluctuations, can efficiently consume large quantities of industrial solid waste, improve CO2 mineralization and carbon sequestration efficiency, and is suitable for mine goaf cementation filling, and has multiple benefits of resource recycling, carbon emission reduction and engineering stability.

Description

Technical Field

[0001] This disclosure relates to the field of solid waste resource utilization and material treatment technology, specifically to a method, system and control equipment for regulating the properties of carbon sequestration filling slurry. Background Technology

[0002] In practical engineering applications, solving solid waste disposal and carbon sequestration faces significant bottlenecks: First, due to the complex composition and varying activity of multi-source solid wastes such as coal gangue, fly ash, and steel slag, filling slurries made primarily from these materials suffer from large fluidity deviations, unstable setting times, and slow early strength development, making it difficult to meet the requirements of long-distance pumping and timely load-bearing. Second, and more fundamentally, the workability (pumpability) and mechanical strength (especially early strength) of the materials are difficult to coordinate. If the CO2 carbonization process is delayed or the strength is insufficient to ensure fluidity, then… Early-stage bearing capacity is poor, threatening mine safety. If rapid and high-concentration carbonization is implemented in pursuit of high strength, premature and excessive carbonate formation can easily lead to a sharp drop in slurry fluidity or even blockage of pipelines. Furthermore, existing processes mostly adopt single or fixed carbonization modes, and key parameters such as activator ratio, water-binder ratio, CO2 concentration, and ventilation regime lack dynamic optimization mechanisms based on performance feedback. This results in large batch-to-batch dispersion of material performance and unstable CO2 carbon fixation efficiency. A closed-loop performance control technology system that runs through the entire life cycle of material preparation, pumping, filling, and hardening has not yet been formed.

[0003] Therefore, developing an integrated method and system that can synergistically optimize the solid waste ratio and carbonization process, and achieve precise control of workability and intensity, has become an urgent need to promote the engineering application of this technology. Summary of the Invention

[0004] The purpose of this disclosure is to solve the problem of balancing workability and strength in carbon sequestration filling slurry, and to achieve synergistic optimization of solid waste disposal, CO2 mineralization and sequestration and mine filling.

[0005] To address the above problems, this application provides a method for regulating the properties of carbon-fixing backfill slurry, comprising the following steps:

[0006] S1. Obtain the preset performance parameters of the carbon-fixed filling slurry, input them into the performance parameter and process parameter mapping relationship model, and obtain the corresponding process parameters of the carbon-fixed filling slurry. S2. Based on the process parameters, measure the content of each component of the carbon-fixed filling slurry and mix them to obtain the carbon-fixed filling slurry. S3. Based on the process parameters, the solid carbon filling slurry obtained in step S2 is subjected to graded carbonization treatment. S4. Obtain the actual performance parameters of the current batch of carbon-fixing filling slurry, compare the actual performance parameters with the preset performance parameters in step S1, calculate the process parameters of the next batch of carbon-fixing filling slurry based on the deviation obtained from the comparison using the mapping relationship model, and update the mapping relationship model based on the actual performance parameters and the actual process parameters.

[0007] As a further improvement of this application, in step S1, the performance parameters include the slump of the carbon-fixed filling slurry, the pumping pressure, and at least one compressive strength selected from the range of 1 day to 28 days; the process parameters include the content of each component of the carbon-fixed filling slurry, the CO2 concentration and aeration rate introduced at each stage of the graded carbonization treatment, and the carbonization time.

[0008] As a further improvement to this application, in step S2, the carbon-fixing filling slurry includes industrial solid waste, an activator, water, and additives, wherein the activator includes sodium sulfate and alkaline residue. Preferably, the mass ratio of sodium sulfate to alkaline residue is 1:5 to 3:5.

[0009] As a further improvement to this application, the industrial solid waste is selected from at least one of coal gangue, fly ash, steel slag, slag powder, and mineral processing tailings.

[0010] As a further improvement of this application, the industrial solid waste, by mass percentage, comprises: 40%–60% coal gangue, 15%–30% fly ash, and 5%–20% steel slag and / or slag powder; the industrial solid waste and the activator together constitute the cementitious material; the mass ratio of water to cementitious material is 0.55–0.75.

[0011] As a further improvement of this application, the admixture includes a polycarboxylate superplasticizer and a retarder. Preferably, the mass of the polycarboxylate superplasticizer is 0.1% to 1.5% of the mass of the cementitious material, and the mass of the retarder is 0.05% to 0.5% of the mass of the cementitious material.

[0012] As a further improvement of this application, in step S3, the graded carbonization treatment includes: during the slurry preparation and transportation stage of the solid carbon filling slurry, introducing CO2 of a first concentration for pre-carbonization treatment to keep the slurry in a flowing state; and after the solid carbon filling slurry is injected into the target filling area, introducing CO2 of a second concentration for enhanced carbonization treatment to promote the slurry to enter the in-situ hardening stage; wherein the second concentration is greater than the first concentration.

[0013] As a further improvement of this application, the ventilation rate of the second concentration of CO2 is 1.5 to 10 times that of the first concentration of CO2.

[0014] As a further improvement of this application, the first concentration is 5% to 30% by volume, the ventilation rate of the CO2 at the first concentration is 0.1 to 0.3 m³ / h, and the ventilation time is 0.1 to 0.4 h; the second concentration is 40% to 95% by volume, the ventilation rate of the CO2 at the second concentration is 0.3 to 1.0 m³ / h, and the ventilation time is 2 to 24 h.

[0015] As a further improvement of this application, in step S4, the actual performance parameters include at least the slump, pumping pressure and at least one compressive strength selected from the range of 1 day to 28 days, which can be obtained in real time.

[0016] To achieve the above objectives, this application also provides a system for regulating the properties of carbon fixation backfill slurry, comprising: The raw material storage and metering module is used to supply raw materials according to the content of each component; The mixing and pulping module is connected to the raw material storage and metering module and is used to make the mixed raw materials into a pulp. CO2 supply module, used to provide CO2 of different concentrations; A slurry delivery module is used to communicate with the target filling area to deliver slurry to the target filling area; The control module is connected to the raw material storage and metering module, the mixing and pulping module, the slurry conveying module and the CO2 gas supply module. It stores a mapping model between performance parameters and process parameters, and is used to receive the performance parameters of the carbon-fixed filling slurry and output the corrected process parameters of the carbon-fixed filling slurry. The performance testing module is used to detect the actual performance parameters of the carbon-fixed filling slurry and send them to the control module; the control module calculates and outputs the corrected process parameters to at least one of the raw material storage and metering module, the mixing and pulping module, the slurry conveying module, and the CO2 gas supply module based on the deviation between the actual performance parameters and the preset performance parameters through a built-in mapping relationship model. Wherein: the front section of the mixing and pulping module and the pulp conveying module are configured as a pre-carbonization zone, and the rear section of the pulp conveying module and its connection end with the target filling area are configured as an enhanced carbonization zone.

[0017] To achieve the above objectives, this application also provides a control device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described above.

[0018] The specific benefits of this application are as follows: This application establishes a mapping model between performance parameters and process parameters, and combines it with a graded carbonization and closed-loop control mechanism. This effectively solves the core problems of unstable slurry fluidity, insufficient early strength, and difficulty in balancing workability and mechanical strength caused by large fluctuations in the composition of multi-source industrial solid waste. While ensuring the long-distance pumpability of carbon-fixed filling slurry, it significantly improves the early and later compressive strength and avoids the risk of pipeline blockage caused by rapid high-concentration carbonization.

[0019] This application also employs a composite activator of calcium sulfate and alkali residue to precisely control the alkalinity and concentration of carbonizable calcium ions in the system. Combined with a staged carbonization process, it can gently generate carbonate crystal nuclei during the flow stage to stabilize the slurry, and rapidly promote the generation of a large amount of carbonate and densification of the structure during the in-situ hardening stage, thereby significantly improving the efficiency of CO2 mineralization and carbon fixation and the integrity of the filling body.

[0020] This application also relies on online performance monitoring and model-based dynamic correction to achieve closed-loop optimization of the entire process from batching, pulping, grading and carbonization to conveying and filling, effectively reducing batch performance dispersion. It can adapt to changes in raw materials, environment and working conditions without relying on fixed empirical ratios, significantly improving engineering stability and applicability.

[0021] Meanwhile, this application uses bulk industrial solid wastes such as coal gangue, fly ash, steel slag, and slag powder as the main raw materials, combined with activators, additives and graded carbonization to achieve large-scale solid waste disposal and permanent CO2 sequestration. It has the dual benefits of resource recycling and carbon emission reduction. The overall system has a simple structure, a high degree of process integration and clear control logic. It can be well adapted to mine filling scenarios such as coal mine goaf and abandoned roadways, and has outstanding engineering practicality, green and low-carbon value and prospects for large-scale promotion. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a system for regulating the properties of carbon-fixed filling slurry provided in Example 1.

[0023] In the diagram: 1. Raw material storage and metering module; 2. Mixing and pulping module; 3. Control module; 4. CO2 gas supply module; 5. Slurry conveying module; 6. Target filling area; 7. First concentration CO2 control valve; 8. Second concentration CO2 control valve; 9. Gas supply branch pipe. Detailed Implementation

[0024] As can be seen from the background technology, the technical problem to be solved by this application is to overcome the shortcomings of existing carbon sequestration filling slurry technology, such as the difficulty in balancing workability and strength, the extensive CO2 carbonization process, and the lack of closed-loop parameter optimization. Specifically, carbon sequestration filling slurries with industrial solid wastes such as coal gangue, fly ash, and steel slag as the main raw materials have performance bottlenecks such as large deviations in slurry fluidity, unstable setting time, and insufficient early strength under high solid waste content. Moreover, existing technologies lack performance control throughout the entire life cycle of material preparation, pumping, filling, and hardening, facing two core contradictions: the inherent contradiction between workability and strength (rapid CO2 carbonization easily leads to slurry pipe blockage, while delayed carbonization affects early load-bearing capacity) and extensive process control (traditional single carbonization mode lacks dynamic parameter adjustment, resulting in low carbon sequestration efficiency and discrete performance). Therefore, this application aims to provide an integrated dynamic control method and system for synergistically optimizing solid waste ratio and carbonization process. By establishing a mapping relationship model between performance parameters and process parameters, and performing closed-loop correction of process parameters based on the comparison results of real-time performance detection and target values, the flowability, pumpability and early and late strength of carbon sequestration filling materials are coordinated and unified, while significantly improving the efficiency of CO2 mineralization carbon sequestration.

[0025] This application provides a method for regulating the properties of carbon-fixed backfill slurry, comprising the following steps: S1. Obtain the preset performance parameters of the carbon-fixed filling slurry, input them into the performance parameter-process parameter mapping model, and obtain the corresponding process parameters of the carbon-fixed filling slurry; wherein: the performance parameters include the slump, pumping pressure, and at least one compressive strength selected from the age range of 1 day to 28 days of the carbon-fixed filling slurry; the process parameters include the content of each component of the carbon-fixed filling slurry, the CO2 concentration and aeration rate introduced at each stage of the graded carbonization treatment, and the carbonization time. The performance parameter-process parameter mapping model is established based on a sample set consisting of actual process parameters and corresponding actual performance parameters from multiple batches of carbon-fixed filling slurry, trained or fitted; the preset performance parameters are set according to engineering requirements.

[0026] The performance parameter and process parameter mapping model is a function model (such as f(X)) established based on historical data using multivariate multinomial regression or machine learning algorithms. Its working principle is as follows: Preset performance parameters (such as slump 180-220mm, 1-day strength ≥1.0MPa, etc.) are used as input. Through inverse model solving or optimization, a set of recommended process parameters (such as activator ratio, CO2 concentration, etc.) is obtained. This achieves intelligent decision-making from target-driven to parameter-preset, overcoming the blindness of traditional experience-based ratios.

[0027] S2. Based on the process parameters, measure the content of each component of the carbon-fixed filling slurry and mix them to obtain the carbon-fixed filling slurry; wherein: the carbon-fixed filling slurry includes industrial solid waste, activator, water, and additives, and the activator includes calcium sulfate and alkali residue. According to the process parameters output in S1, the system automatically controls the raw material storage and metering module, accurately weighs the solid waste, activator, water, and additives according to the set ratio (e.g., 50% coal gangue, 25% fly ash, water-binder ratio 0.65, etc.), and mixes them uniformly in the slurry mixing device.

[0028] S3. Based on the process parameters, the carbon-fixed filling slurry obtained in step S2 is subjected to graded carbonization treatment. The graded carbonization treatment includes: during the slurry preparation and transportation stage of the carbon-fixed filling slurry, a first concentration of CO2 is introduced for pre-carbonization treatment to keep the slurry in a flowing state; and after the carbon-fixed filling slurry is injected into the target filling area, a second concentration of CO2 is introduced for enhanced carbonization treatment to promote the slurry to enter the in-situ hardening stage; wherein the second concentration is greater than the first concentration.

[0029] Staged carbonation refers to employing differentiated CO2 conditions at different stages. Specifically, pre-carbonation is implemented during the slurry transport stage (from slurry preparation to filling the backfill area), introducing a low concentration of CO2 (e.g., 5%-30%) to gently generate carbonate crystal nuclei, initially stabilizing the slurry structure while avoiding significant loss of fluidity due to excessively rapid reactions, thus ensuring pumpability. Enhanced carbonation is implemented during the in-situ hardening stage after the slurry enters the goaf or roadway, introducing a high concentration of CO2 (e.g., 40%-95%) to promote rapid and abundant carbonate crystal formation, filling pores and densifying the structure, thereby rapidly improving early and later strength and maximizing CO2 carbon fixation efficiency. This concentration-staged approach is a key means of synergistically controlling workability and strength, and its working principle lies in matching the optimal reaction kinetics conditions of the material under different physical states (fluid / solid).

[0030] S4. Obtain the actual performance parameters of the current batch of carbon-fixing filling slurry, compare the actual performance parameters with the preset performance parameters in step S1, and calculate the process parameters of the next batch of carbon-fixing filling slurry based on the deviation obtained from the comparison using the mapping relationship model. Update the mapping relationship model based on the actual performance parameters and the actual process parameters. The actual performance parameters include at least the slump, pumping pressure, and at least one compressive strength selected from the range of 1 to 28 days, which can be obtained in real time. The actual performance parameters of the slurry and hardened body are collected in real time or periodically using an online detection system (such as a slump meter, pressure sensor, or strength testing machine) and compared with the preset performance parameters set in S1. If a deviation occurs (such as excessively high pumping pressure or excessively low strength), the deviation information is fed back to the control module. This module re-optimizes the calculated process parameters based on the mapping relationship model (such as adjusting the activator ratio or changing the CO2 aeration rate), and uses the corrected recommended process parameters for the production control of the next batch, forming a closed loop of monitoring-comparison-optimization-execution. This allows for dynamic adaptation to raw material fluctuations and continuous improvement in performance stability and carbon fixation efficiency.

[0031] In an optional embodiment, the mass ratio of sodium sulfate to alkali residue is 1:5 to 3:5. Sodium sulfate (Na₂Ca(SO₄)₂) provides Ca. 2+ The source and sulfate ions, along with the alkaline residue, provide a high-alkalinity environment. Maintaining a mass ratio of 1:5 to 3:5 synergistically regulates the initial alkalinity of the system and the amount of Ca available for carbonation. 2+ Concentration. Excessive alkalinity due to too much alkaline residue may affect the morphology of subsequent carbonization products; excessive calcium sulfate may prematurely generate large amounts of ettringite, affecting fluidity. This optimal range ensures a balance between activation effect and slurry workability.

[0032] In an optional implementation, the industrial solid waste is selected from at least one of coal gangue, fly ash, steel slag, slag powder, and mineral processing tailings. These wastes are rich in active components such as silicon, aluminum, calcium, and magnesium, and are the main source of cementitious matrix and carbonization reactants. This technical solution is inclusive of solid waste from different sources, and its compositional fluctuations can be adapted through a subsequent closed-loop control model, enhancing its engineering applicability.

[0033] In an optional implementation, the first concentration is 5% to 30% by volume, the aeration rate of the CO2 at the first concentration is 0.1 to 0.3 m³ / h, and the aeration time is 0.1 to 0.4 h. The process parameters for this carbon dioxide during the pre-carbonation stage ensure that the carbonation reaction proceeds slowly, generating sufficient amounts of carbonate to form crystal nuclei and improve slurry stability, but not enough to cause a sharp increase in viscosity leading to pipe blockage.

[0034] The second concentration is 40%–95% by volume, the aeration rate of CO2 at the second concentration is 0.3–1.0 m³ / h, and the aeration time is 2–24 h. The enhanced carbonation stage provides sufficient CO2 partial pressure and mass transfer motive force, driving the carbonation reaction to proceed fully and rapidly, generating a large amount of carbonate to fill the pores, significantly improving early strength (such as 1-day strength) and achieving efficient carbon fixation.

[0035] In an optional implementation, the ventilation rate of the second concentration of CO2 is 1.5 to 10 times that of the first concentration of CO2. This ensures distinctly different reaction intensities in the two stages from a mass transfer kinetics perspective. Too low a rate multiplier results in insufficient enhancement, while too high a rate may lead to waste or localized overheating. This range effectively guarantees a gradual, initial, and then dramatic fractional effect.

[0036] In an optional implementation, the industrial solid waste, by mass percentage, comprises: 40%–60% coal gangue, 15%–30% fly ash, and 5%–20% steel slag and / or slag powder; the industrial solid waste and the activator together constitute the cementitious material; the mass ratio of water to cementitious material is 0.55–0.75. Coal gangue serves as the main aggregate and source of silica and alumina, fly ash provides active silica and alumina and microbead lubrication effect, and steel slag / slag powder provides a highly active calcium and magnesium source. The above proportions ensure that the cementitious system has sufficient activity and a reasonable particle size distribution. The mass ratio of water to cementitious material is the water-cement ratio. If the water-cement ratio is too low (<0.55), the slurry is too viscous and has poor fluidity; if the water-cement ratio is too high (>0.75), the strength development is slow and the porosity is high. The above-set water-cement ratio range satisfies the fluidity required for pumping and ensures high density and strength after carbonization and hardening.

[0037] In an optional embodiment, the admixture includes a polycarboxylate superplasticizer and a retarder. The mass of the polycarboxylate superplasticizer is 0.1% to 1.5% of the mass of the cementitious material, and the mass of the retarder is 0.05% to 0.5% of the mass of the cementitious material. The polycarboxylate superplasticizer can adsorb onto the particle surface and generate a steric hindrance effect, significantly improving the fluidity of the slurry at low water-cement ratios and ensuring pumpability. The retarder can appropriately delay the slurry setting, providing a time window for pre-carbonization curing and long-distance pumping, and preventing premature hardening in the delivery pipe. The two work synergistically to further refine the workability and setting time of the slurry.

[0038] This application provides a system for regulating the properties of carbon-fixing backfill slurry, comprising: The raw material storage and metering module is used to supply raw materials according to the content of each component; The mixing and pulping module is connected to the raw material storage and metering module and is used to make the mixed raw materials into a pulp. CO2 supply module, used to provide CO2 of different concentrations; A slurry delivery module is used to communicate with the target filling area to deliver slurry to the target filling area; The control module is connected to the raw material storage and metering module, the mixing and pulping module, the slurry conveying module and the CO2 gas supply module. It stores a mapping model between performance parameters and process parameters, and is used to receive the performance parameters of the carbon-fixed filling slurry and output the corrected process parameters of the carbon-fixed filling slurry. The performance testing module is used to detect the actual performance parameters of the carbon-fixed filling slurry and send them to the control module; the control module calculates and outputs the corrected process parameters to at least one of the raw material storage and metering module, the mixing and pulping module, the slurry conveying module, and the CO2 gas supply module based on the deviation between the actual performance parameters and the preset performance parameters through a built-in mapping relationship model. Wherein: the front section of the mixing and pulping module and the pulp conveying module are configured as a pre-carbonization zone, and the rear section of the pulp conveying module and its connection end with the target filling area are configured as an enhanced carbonization zone.

[0039] Specifically, the system for implementing the above-mentioned method for regulating the performance of carbon-fixed backfill slurry mainly includes a raw material storage and metering module, a mixing and slurry preparation module, a slurry conveying module, a CO2 supply module, and a regulation module. The raw material storage and metering module provides industrial solid waste, activators, water, additives, etc., according to the content of each component. The activators preferably include sodium sulfate and alkali residue. The mixing and slurry preparation module is connected to the raw material storage and metering module and is used to mix and prepare the slurry according to the metered component content to obtain the carbon-fixed backfill slurry. The mixing and slurry preparation module, the slurry conveying module, and the target filling area are connected and divided into a pre-carbonization zone and an enhanced carbonization zone. The pre-carbonization zone includes the front section of the mixing and slurry preparation module and the slurry conveying module, used to gently carbonize and cure the flowing carbon-fixed backfill slurry by introducing a first concentration of CO2, maintaining the pumpability of the slurry. The enhanced carbonization zone includes the rear section of the slurry conveying module and the target filling area, used to introduce a second concentration of CO2, higher than the first concentration, into the in-situ hardening stage of the carbon-fixed backfill slurry. 2. Enhanced carbonation curing is carried out to promote rapid carbonate formation and densification of the filling structure; the slurry conveying module is used to transport the carbonized filling slurry after graded carbonization to the target filling area, such as the goaf or abandoned roadway, and can realize the filling operation through the connected pipeline network, multi-point branch nozzles and CO2 supply branch pipes set at the filling end or inside the goaf. At the same time, CO2 can continue to be supplied during the in-situ hardening process to achieve integrated in-situ carbonization; the CO2 gas supply module serves as the CO2 gas source for the entire system, preferably using industrial boiler or generator set exhaust gas and / or high-purity CO2, and is equipped with a gas pretreatment unit, a compression and storage unit and a concentration mixing and distribution unit in sequence, to provide CO2 of different concentrations and flow rates to the pre-carbonization zone, the enhanced carbonization zone and the CO2 supply branch pipes in the slurry conveying module respectively.

[0040] The control module is connected to the raw material storage and metering module, the mixing and pulping module, the slurry conveying module, and the CO2 gas supply module. Specifically, it includes an industrial control computer and a parameter optimization program stored therein. This control module receives carbon-fixed filling slurry performance parameters from each module, including slump or spread, pumping pressure in the conveying pipeline, slurry density and temperature, and at least one compressive strength selected from 1 day to 28 days of age. Simultaneously, based on a preset performance index-process parameter mapping relationship model, it compares the above performance parameters with the target performance index and calculates the deviation, using it as input to solve and update the activator ratio, water-binder ratio, and two-stage CO2 carbonization parameters. Finally, it outputs the corrected carbon-fixed filling slurry process parameters and sends them to the raw material storage and metering module, the mixing and pulping module, the slurry conveying module, and the CO2 gas supply module, realizing closed-loop control of the workability and strength of the carbon-fixed filling material.

[0041] In the above technical solution, the modules are connected in sequence according to the process flow, realizing the integration of the physical process from batching → pulping → graded carbonization → conveying and filling. The pre-carbonization zone and the enhanced carbonization zone correspond to the graded carbonization steps in the method, which are usually achieved by setting aeration devices in different pipe sections or areas. The control module, as the control core of the system, is connected to all execution and detection modules. It has a built-in performance-process parameter mapping model and optimization algorithm, which can automatically calculate and issue process parameter correction instructions based on the actual performance parameters monitored in real time or periodically, driving the entire system to achieve closed-loop operation. It is the hardware foundation for the control to be realized.

[0042] This application also provides a control device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described above. The control device may be an industrial computer, a PLC, or an embedded controller, etc. The computer program contains the logic for implementing all steps S1 to S4, particularly the algorithms for establishing and calling the mapping relationship model, performing data comparison, and optimizing parameters.

[0043] In an optional implementation, the mapping model between performance parameters and process parameters is established through the following steps: 1) Defining output / input variables and establishing a performance prediction model In actual production, corresponding performance parameters – process parameters – are collected for each batch of carbon-fixed filling slurry. And store them in the database to form a sample set:

[0044] Based on a database, a performance prediction model is established using multivariate multinomial regression or machine learning algorithms. ,in, , in: Slump refers to the degree of collapse. Pumping pressure This refers to the compressive strength after one day of enhanced carbonization curing. This refers to the compressive strength after 7 days of enhanced carbonization curing. This refers to the compressive strength after 28 days of enhanced carbonization curing; , This represents the mass ratio of sodium sulfate to alkali residue. Represents the water-to-glue ratio. Represents the first concentration. The ventilation rate represents the first concentration of CO2. Ventilation time representing the first CO2 concentration. Represents the second concentration. The ventilation rate represents the second concentration of CO2. Ventilation time representing the second concentration of CO2.

[0045] The prediction functions for each component are as follows: 。

[0046] Preferably, the prediction function for each component adopts a quadratic polynomial form:

[0047] coefficient , , Determined by the least squares method or other fitting algorithms, preferably fitted using the following function:

[0048] 2) Construct the target performance parameter vector as follows: , Among them, the slump target value is Pumping pressure target value The target compressive strength after one day of enhanced carbonization curing is [value missing]. The target compressive strength after 7 days of enhanced carbonization curing is [value missing]. The target compressive strength after 28 days of enhanced carbonization curing is [value missing]. , 3) Construct an objective function in the form of the sum of squared deviations between the predicted and target values:

[0049] in, These are the weighting coefficients for each performance indicator. For the performance vector The predicted value of each component, For the performance vector The target value of each component; 4) Constraints and Solving for the Optimal Solution Under the constraint of the range of process parameters defined in this application, the optimal parameter vector is solved: , The feasible region Ω is formed by process boundary constraints, and preferably includes: x1∈[1 / 5, 3 / 5] (mass ratio of sodium sulfate to alkali residue); x2∈[0.55, 0.75]; x3∈[0.05, 0.30], x4∈[0.1, 0.3], x5∈[0.1, 0.4]; x6∈[0.40, 0.95], x7∈[0.3, 1.0], x8∈[2, 24].

[0050] In the solution process, gradient descent, genetic algorithms, and / or other numerical optimization methods can be used to iteratively solve the above function to obtain the optimal parameter vector X. X The content of each component in the corresponding carbon-fixing filling slurry, the CO2 concentration and aeration rate at each stage of the graded carbonization process, and the carbonization time are used as recommended process parameters for the next batch of steps S2 and S3; and these parameters will be added in subsequent production. Data is continuously written to the database, and the update function is used. The model parameters and / or weighting coefficients are used to achieve functional closed-loop iterative optimization of the workability and strength of carbon-fixed filling slurry.

[0051] It should be clarified that the preset performance parameters mentioned in the above technical solution are obtained from the predicted values, while the target values ​​are the optimized recommended performance parameters.

[0052] The technical solutions of this disclosure will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0053] To make the above-mentioned objectives, features and advantages of this disclosure more apparent and understandable, the disclosure will be further described in detail below with reference to specific embodiments.

[0054] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0055] Example 1 This embodiment provides a system for regulating the properties of carbon-fixing backfill slurry, such as... Figure 1As shown, the entire system consists of a raw material storage and metering module 1, a mixing and slurry preparation module 2, a slurry conveying module 5, a CO2 gas supply module 4, a performance testing module, and a control module 3. The raw material storage and metering module 1 stores and measures the content of each component according to process parameters for industrial solid wastes such as coal gangue, fly ash, steel slag and / or slag powder, and optional tailings. The mixing and slurry preparation module 2, connected to the raw material storage and metering module 1, mixes the metered industrial solid wastes, an activator composed of calcium sulfate and alkali residue, water, and additives to form a uniform carbon-fixing filling slurry. The slurry conveying module 5 transports the slurry along pipelines to the target filling area 6, such as the goaf or abandoned roadway, and completes the distribution and filling operations. The mixing and slurry preparation module 2, the slurry conveying module 5, and the target filling area 6 are connected. The slurry transport module is divided into a pre-carbonation zone and an enhanced carbonation zone, corresponding to the initial low-concentration pre-carbonation stage and the later high-concentration enhanced carbonation stage in the slurry transport process, respectively. The CO2 supply module provides CO2 with different volume fractions and flow rates to the pre-carbonation zone and the enhanced carbonation zone through the first concentration CO2 control valve 7, the second concentration CO2 control valve 8, and the supplementary gas branch pipe 9, respectively. The control module 3 is connected to the raw material storage and metering module 1, the mixing and slurry preparation module 2, the slurry transport module 5, and the CO2 supply module 4. It stores a performance parameter and process parameter mapping relationship model, which is used to collect performance parameters such as slump, pumping pressure, and at least one compressive strength selected from 1 day to 28 days of age. Based on the performance parameter and process parameter mapping relationship model, it outputs the corrected process parameters for the next batch, realizing closed-loop control. The performance testing module is used to detect the actual performance parameters of the carbon-fixed filling slurry and send them to the control module; the control module calculates and outputs the corrected process parameters to at least one of the raw material storage and metering module, the mixing and pulping module, the slurry conveying module, and the CO2 gas supply module based on the deviation between the actual performance parameters and the preset performance parameters through the built-in mapping relationship model.

[0056] Taking cemented backfilling in goaf as an application scenario, the first step is to set preset performance parameters according to engineering requirements. These parameters are then input into a performance parameter-process parameter mapping model to obtain the corresponding process parameters. The target slump is 180–220 mm to meet long-distance pumping requirements, the pumping process requires stable pressure and no pipe blockage, and the target strength of the backfill body meets early bearing capacity requirements while maintaining continuous strength growth at 7 days and 28 days. Subsequently, the content of each component is measured according to the process parameters, selecting 50% coal gangue and 25% fly ash. The mixture consists of 10% slag powder, with the remainder being activators and admixtures. The water-cement ratio is 0.65. The mass ratio of calcium sulfate to alkali slag in the activator is 2:5. The dosage of polycarboxylate superplasticizer is 0.8% of the total mass of the cementitious materials, and the dosage of retarder is 0.15% of the total mass of the cementitious materials. The mixture is then mixed in a mixing and pulping module to form a homogeneous carbon-fixed filling slurry. After pulping, the slurry immediately enters the pre-carbonization zone for pre-carbonization treatment, where 15% CO2 (by volume) is introduced at a ventilation rate of 0.2 m³ / s. 3 The carbonation time is 0.2h. This stage generates a small amount of carbonate nuclei through mild carbonation and inhibits water separation from the slurry, maintaining the fluidity and pumpability of the carbon-fixed filling slurry. After being pumped to the downstream section of the delivery pipeline and into the target filling area such as the goaf, the slurry enters the enhanced carbonation zone for enhanced carbonation treatment. CO2 with a volume fraction of 80% is introduced at a ventilation rate of 0.5 m³ / h for 6h. This stage promotes rapid carbonate formation and densifies the filling structure, significantly improving the compressive strength from 1d to 28d. To improve the efficiency of CO2 mineralization and carbon fixation, the actual performance parameters of the carbon-fixed filling slurry were obtained through an online detection system and compared with the preset performance parameters. Based on the comparison results, the process parameters were dynamically corrected. The slump of the slurry met the target window and the pumping pressure was stable. No pipe blockage occurred during the entire transportation process. The 1-day strength of the filling material met the early bearing requirements, and the 7-day and 28-day strength continued to increase steadily. This fully verifies that the combination of graded carbonization and closed-loop control in this disclosure can achieve a synergistic improvement in the workability and strength of the carbon-fixed filling slurry.

[0057] Example 2 1) Database Construction In continuous production, the collected data will be... Performance parameters of the carbon-filled slurry were collected. -Process parameters Stored in the database to form a sample set:

[0058] 2) Establish a performance prediction function Based on the sample set in the database, a performance prediction model is established using multivariate multinomial regression or machine learning algorithms. ,in, , in: Slump refers to the degree of collapse. Pumping pressure This refers to the compressive strength after one day of enhanced carbonization curing. This refers to the compressive strength after 7 days of enhanced carbonization curing. This refers to the compressive strength after 28 days of enhanced carbonization curing; , This represents the mass ratio of sodium sulfate to alkali residue. Represents the water-to-glue ratio. Represents the first concentration. The ventilation rate represents the first concentration of CO2. Ventilation time representing the first CO2 concentration. Represents the second concentration. The ventilation rate represents the second concentration of CO2. Ventilation time representing the second concentration of CO2.

[0059] The prediction functions for each component are as follows: 。

[0060] Preferably, the prediction function for each component adopts a quadratic polynomial form:

[0061] coefficient , , Determined by the least squares method or other fitting algorithms, preferably fitted using the following function:

[0062] 3) Construct the objective function and constraints The target performance vector is set as follows: , Among them, the slump target value is Pumping pressure target value The target compressive strength after one day of enhanced carbonization curing is [value missing]. The target compressive strength after 7 days of enhanced carbonization curing is [value missing]. The target compressive strength after 28 days of enhanced carbonization curing is [value missing]. ; The objective function is constructed as follows: ; in, These are the weighting coefficients for each performance indicator. For the performance vector The predicted value of each component, For the performance vector The target value of each component; Under the constraint of the range of process parameters defined in this application, the optimal parameter vector is solved: , The feasible region Ω is formed by process boundary constraints, and preferably includes: x1∈[1 / 5, 3 / 5] (mass ratio of sodium sulfate to alkali residue); x2∈[0.55, 0.75]; x3∈[0.05, 0.30], x4∈[0.1, 0.3], x5∈[0.1, 0.4]; x6∈[0.40, 0.95], x7∈[0.3, 1.0], x8∈[2, 24].

[0063] 4) Optimize hyperparameters and limit updates (feasibility parameters) Preferred target window: =180±20mm, ≤8MPa ≥1.0MPa ≥3.0MPa ≥6.0MPa; the preferred weighting coefficient is... =0.25、 =0.25、 =0.20、 =0.15、 =0.15. When using gradient descent optimization, the learning rate α = 0.01–0.10, the maximum number of iterations is 50–300, and the convergence threshold ε = 10. (-4) ~10 (-3) When using a genetic algorithm, the population size is 20–80, the crossover probability is 0.6–0.9, the mutation probability is 0.01–0.10, and the number of iterations is 30–150. To avoid viscosity jumps and pipe blockage risks caused by parameter mutations, the following limits are preferably set: |Δx2|≤0.02, |Δx3|≤0.05, |Δx4|≤0.05, |Δx5|≤0.05h, |Δx6|≤0.05, |Δx7|≤0.10, |Δx8|≤1h.

[0064] 5) Example of iterative update strategy When the The batch had excessively high pumping pressure and low slump (P> And S < When the first concentration of CO2 is reduced, the aeration rate x4 and the aeration time x5 are preferably reduced first, and the water-cement ratio x2 and the water-reducing agent dosage are finely adjusted within the constraints to restore pumpability; when pumpability is stable but the strength is low (σ1, σ7 or σ 28 When the concentration is below the target, it is preferable to increase the second concentration x6, the aeration rate of the second concentration of CO2 x7, or extend the aeration time of the second concentration of CO2 x8 to promote carbonate formation and structural densification. The obtained X... As the recommended setting value for the k+1th batch, the newly added batch data is continuously written into the database to update the prediction model parameters, thereby achieving functional closed-loop iterative optimization.

[0065] The detailed descriptions listed above are merely specific descriptions of feasible implementations of this disclosure and are not intended to limit the scope of protection of this disclosure. All equivalent implementations or modifications made without departing from the spirit of the art of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for regulating the properties of carbon-fixing filling slurry, characterized in that, Includes the following steps: S1. Obtain the preset performance parameters of the carbon-fixed filling slurry, input them into the performance parameter and process parameter mapping relationship model, and obtain the corresponding process parameters of the carbon-fixed filling slurry. S2. Based on the process parameters, measure the content of each component of the carbon-fixed filling slurry and mix them to obtain the carbon-fixed filling slurry. S3. Based on the process parameters, the solid carbon filling slurry obtained in step S2 is subjected to graded carbonization treatment. S4. Obtain the actual performance parameters of the current batch of carbon-fixing filling slurry, compare the actual performance parameters with the preset performance parameters in step S1, calculate the process parameters of the next batch of carbon-fixing filling slurry based on the deviation obtained from the comparison using the mapping relationship model, and update the mapping relationship model based on the actual performance parameters and the actual process parameters.

2. The method according to claim 1, characterized in that, In step S2, the carbon-fixing filling slurry includes industrial solid waste, activator, water, and additives, wherein the activator includes calcium sulfate and alkaline residue.

3. The method according to claim 2, characterized in that, The industrial solid waste is selected from at least one of coal gangue, fly ash, steel slag, slag powder, and mineral processing tailings.

4. The method according to claim 3, characterized in that, The industrial solid waste, by mass percentage, comprises: 40%–60% coal gangue, 15%–30% fly ash, and 5%–20% steel slag and / or slag powder; the industrial solid waste and the activator together constitute the cementitious material; the mass ratio of water to cementitious material is 0.55–0.

75.

5. The method according to claim 4, characterized in that, The admixtures include polycarboxylate superplasticizers and retarders.

6. The method according to claim 5, characterized in that, The mass of the polycarboxylate superplasticizer is 0.1% to 1.5% of the mass of the cementitious material, and the mass of the retarder is 0.05% to 0.5% of the mass of the cementitious material.

7. The method according to claim 1, characterized in that, In step S3, the graded carbonization treatment includes: during the slurry preparation and transportation stage of the solid carbon filling slurry, introducing CO2 of a first concentration for pre-carbonization treatment to keep the slurry in a fluid state; and after the solid carbon filling slurry is injected into the target filling area, introducing CO2 of a second concentration for enhanced carbonization treatment to promote the slurry to enter the in-situ hardening stage; wherein the second concentration is greater than the first concentration.

8. The method according to claim 7, characterized in that, The ventilation rate of the second concentration of CO2 is 1.5 to 10 times that of the first concentration of CO2.

9. A system for regulating the properties of carbon-fixing filling slurry, characterized in that, include: The raw material storage and metering module is used to supply raw materials according to the content of each component; The mixing and pulping module is connected to the raw material storage and metering module and is used to make the mixed raw materials into a pulp. CO2 supply module, used to provide CO2 of different concentrations; A slurry delivery module is used to communicate with the target filling area to deliver slurry to the target filling area; The control module is connected to the raw material storage and metering module, the mixing and pulping module, the slurry conveying module and the CO2 gas supply module. It stores a mapping model between performance parameters and process parameters, and is used to receive the performance parameters of the carbon-fixed filling slurry and output the corrected process parameters of the carbon-fixed filling slurry. The performance testing module is used to detect the actual performance parameters of the carbon-fixed filling slurry and send them to the control module; Based on the deviation between the actual performance parameters and the preset performance parameters, the control module calculates and outputs the corrected process parameters to at least one of the raw material storage and metering module, the mixing and pulping module, the slurry conveying module, and the CO2 gas supply module through a built-in mapping relationship model. Wherein: the front section of the mixing and pulping module and the pulp conveying module are configured as a pre-carbonization zone, and the rear section of the pulp conveying module and its connection end with the target filling area are configured as an enhanced carbonization zone.

10. A control device, characterized in that, It includes a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program to implement the method as described in any one of claims 1 to 8.

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