Shield muck resource utilization method based on two-stage treatment

Abstract

The invention relates to the technical field of shield muck recycling, in particular to a shield muck resource utilization method based on two-stage treatment.The shield muck resource utilization method based on two-stage treatment.The shield muck resource utilization method based on two-stage treatment.The shield muck resource utilization method comprises the following steps that S1, mixtures in each shield muck pile are removed, and clean muck is obtained; s2, measuring the primary moisture content of the clean muck; s3, calculating the addition amount of an additive; s4, adding an additive into the clean muck, and mixing to obtain primarily treated muck; standing to obtain secondary treatment muck; s5, obtaining the components of the modifier, and the target liquid limit and the target plasticity index of the target product; s6, obtaining the adding proportion of each component of the modifier required by the pile of secondary treatment residue soil; and S7, mixing the secondary treatment residue soil with a modifier to obtain a target product. The problems of high water content, difficulty in precipitation, high viscosity and difficulty in solidification of the muck are effectively solved, the ratio of the modifier is optimized, the liquid-plastic limit and the soil property of the modifier are improved, and the stability and applicability of a final product are improved.

Description

Technical Field

[0001] The invention relates to the technical field of shield slag recycling, and in particular to a shield slag resource utilization method based on two-stage processing. Background Art

[0002] With the rapid development of urban underground space development, shield tunneling, as an efficient, safe and highly mechanized construction method, has been widely used in the construction of rail transit, municipal roads, urban integrated pipelines and other projects.

[0003] However, during the construction of shield tunnels, a large amount of shield waste will be generated as the tunnel is excavated. At present, the treatment of shield waste mainly faces the following difficulties: (1) external transportation, direct discharge or disposal by imitating the cement-stabilized soil mixing method. The utilization rate of solid waste materials is low, the amount of abandoned soil is large and a large number of abandoned soil dumping sites are required. The low performance of the improved soil limits the scope of the waste resource utilization scenario and is difficult to meet the needs of large-scale resource utilization; (2) the water content of shield waste is high. The measured data of multiple shield waste samples show that the moisture content of the waste is about 32-36%, which is much higher than the optimal water content of roadbed soil. The water content of the slag is usually around 14%, and this part of the water is non-free water. The traditional drying method is time-consuming and labor-intensive, and the economic cost of mechanical methods such as drying is far higher than the acceptable level of the project; (3) The shield tunnel passes through the stratum section containing various soil phases such as silt, silty clay, and silty silty clay. The slag composition is complex and has great variability. Due to the presence of impurities in the slag, the slag has high compressibility and low shear strength. The slag needs to be improved for resource utilization; (4) Traditional methods usually lack refined management and scientific treatment methods, resulting in unstable slag quality, which is difficult to meet the requirements of high-quality engineering materials. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a shield slag resource utilization method based on two-stage treatment, which effectively solves the problems of high moisture content, difficulty in precipitation, high viscosity and difficulty in solidification of slag by accurately calculating the amount of admixture added and combining the standing time and environmental parameters. Furthermore, by accurately measuring the secondary moisture content and component analysis, the ratio of the improver is customized to promote chemical reactions in the slag, improve its liquid limit and plastic limit and soil properties, and enhance the stability and applicability of the final product.

[0005] A shield slag resource utilization method based on two-stage processing of the present invention comprises the following steps:

[0006] S1. Classify and pile up the shield slag according to the soil source type to obtain multiple shield slag piles, remove the impurities in each shield slag pile to obtain clean slag, and the clean slag is also stored in separate piles to obtain clean slag piles;

[0007] By stacking in categories, it is possible to ensure that the source of each batch of slag is consistent, reduce product quality fluctuations caused by large component variability, and ensure stable performance of the final product;

[0008] By removing impurities, we can not only protect the processing equipment and simplify the process, but also optimize the physical and chemical properties of the slag, reduce the variability of the components, and ensure the performance consistency and reliability of the final product. In addition, removing impurities helps reduce the risk of environmental pollution, comply with environmental regulations, reduce processing costs, and improve economic benefits. This process not only improves the purity and applicability of the slag, but also lays a solid foundation for resource utilization.

[0009] S2. Measure the primary moisture content of clean soil;

[0010] When measuring the primary moisture content, at least three sampling points should be selected at different heights of each net slag pile to ensure that the entire slag pile is covered. After obtaining the moisture content of the sampling points, the above moisture content is averaged to obtain the primary moisture content of each shield slag pile. The method of multi-point sampling and averaging is used to measure the primary moisture content of shield slag, which improves the representativeness and accuracy of the data.

[0011] S3. According to the production task, the required standing time of the clean slag and the environmental parameters during the standing time are obtained, and the amount of admixture added is calculated according to the primary moisture content, the preset moisture content target value, the standing time and the environmental parameters during the standing time;

[0012] The standing time here refers to the time it takes for the primary treated slag stored in piles to become the secondary treated slag. The standing time can be obtained in advance according to the production task to calculate the amount of admixture to be added;

[0013] The primary moisture content refers to the initial moisture content of the clean soil before treatment. If the primary moisture content is high, more admixtures are needed to solidify the moisture; conversely, if the primary moisture content is low, the amount of admixtures required is relatively small.

[0014] The preset moisture content target value is for the secondary treated slag. In the process of calculating the amount of admixture added, the primary moisture content and the preset moisture content target value are used as two endpoint values, which play a decisive role in the amount of admixture added;

[0015] The longer the standing time, the more water evaporates, causing the moisture content to naturally decrease. Therefore, when determining the amount of admixture to be added, the change in moisture during the standing time must be considered;

[0016] Environmental parameters include temperature, humidity, and wind speed;

[0017] Among them, high temperature will accelerate the evaporation of water, which may cause part of the water in the shield slag to volatilize, thereby reducing the amount of admixtures used;

[0018] In a high humidity environment, water evaporates slowly, and water absorption may even occur, which will increase the demand for admixtures; in a low humidity environment, water evaporates quickly, and the amount of admixture added will decrease;

[0019] When the wind speed is high, the evaporation rate of water is accelerated, especially in the surface layer. Therefore, in an environment with high wind speed, it may be necessary to give extra consideration to the rapid loss of surface water and appropriately reduce the amount of admixture;

[0020] S4. According to the calculated amount of admixture added, the admixture is added to the clean slag, and then mixed to obtain primary treated slag, and the primary treated slag is stored in piles; the primary treated slag stored in piles is left to stand to obtain secondary treated slag; the main body of the preset moisture content target value is the secondary treated slag;

[0021] This step is the primary treatment process of the present invention. In this process, the admixture reacts with the free water in the soil particles, converting the free water into crystal water and gel-bound water, reducing the natural moisture content of the slag, improving the static adhesion of the slag, and at the same time, ion exchange occurs to reduce the thickness of the double electric layer of the soil colloid particles, so that the soil particles are close to each other to produce agglomeration, and improving the surface properties of the slag;

[0022] The primary treated soil is stored in piles, so that the temperature and humidity distribution inside the small piles are more uniform. At the same time, the smaller piles are more convenient for the natural evaporation of water, which helps to reach the preset moisture content target value faster, shorten the standing time, improve the processing efficiency, and reduce the amount of admixtures;

[0023] During the static process, the admixture reacts fully with the moisture in the slag to reduce the moisture content. At the same time, during the static process, with the change of moisture and the occurrence of chemical reactions, the slag may experience volume contraction or expansion; appropriate static time can help these physical changes stabilize and avoid unexpected deformation in subsequent use;

[0024] S5. Obtain target liquid limits and target plasticity indexes of each component of the improver and the target product;

[0025] This step is a key step in realizing the resource utilization of shield slag, which helps to optimize the physical and chemical properties of slag, ensure the quality and stability of the final product, and improve the efficiency of resource utilization to meet diverse engineering needs. By scientifically and rationally selecting the modifier and setting the appropriate target liquid limit and target plasticity index, it can provide a solid guarantee for the effective treatment and wide application of shield slag.

[0026] S6, measuring the secondary moisture content of each pile of secondary treated slag and analyzing the composition of the secondary treated slag, inputting the measurement results of the secondary moisture content and the composition of the secondary treated slag, each component of the improver, the target liquid limit and the target plasticity index into a pre-constructed improver optimization model, and obtaining the required addition ratio of each component of the improver for the pile of secondary treated slag;

[0027] The moisture content of each pile of secondary treated slag is different for the following reasons: Wind speed and direction may vary significantly at different locations within the shield slag storage site; for example, slag piles located on the windward side will be exposed to stronger winds, and the rate of water evaporation will be faster; while slag piles located on the leeward side or blocked by other obstacles (such as buildings, trees or other slag piles) will be subject to weaker winds and the water will evaporate relatively slowly; smaller piles have a larger surface area to volume ratio, which means that their surface area in contact with the external environment is relatively large, and water can evaporate more easily through the surface. In contrast, the molecules in larger piles are farther away from the surface, and the process of water evaporating to the external environment is slower, and the internal water is retained longer, resulting in a higher moisture content;

[0028] By accurately measuring the secondary moisture content of each pile of secondary treated soil and combining it with detailed component analysis, the most appropriate ratio of improver can be tailored for each pile of soil, which avoids the "one-size-fits-all" approach in traditional methods and ensures that each pile of soil can get the best treatment plan according to its specific characteristics; by obtaining the secondary moisture content, composition, target liquid limit and target plasticity index of each pile of soil and inputting them into the optimization model, the changes in the treatment process can be monitored in real time, the treatment plan can be adjusted in time, and the controllability and predictability of the entire treatment process can be enhanced;

[0029] S7, weighing the improver according to the addition ratio of each component of the improver, mixing the secondary treated slag with the improver to obtain the target product;

[0030] Precisely controlling the amount of modifier added avoids over or under addition, reduces waste and lowers costs. This method enables each pile of slag to be optimally treated according to its specific characteristics, maximizes resource utilization efficiency, and achieves a win-win situation in economic and environmental benefits.

[0031] As a preferred embodiment of the present invention, the admixture is powdered calcium quicklime;

[0032] Quicklime reacts with the water in the slag in a 1:1 ratio to form calcium hydroxide, which further reacts with carbon dioxide to form calcium carbonate. These compounds can fill the gaps between slag particles and increase the bonding force between particles, thereby improving the static bonding of the slag, which helps to improve the structural strength and stability of the slag, making it more suitable for use as an engineering material;

[0033] During the hydration process, quicklime undergoes ion exchange, which reduces the thickness of the double electric layer of soil particles, bringing soil particles closer together and causing agglomeration. This agglomeration effect improves the surface properties of the slag, reduces the sliding and separation tendency between soil particles, and enhances the overall mechanical properties. In addition, it also promotes the densification of the internal structure of the slag, reduces porosity, and improves shear strength.

[0034] As a preferred embodiment of the present invention, the improver is silicate cement, quicklime and fly ash;

[0035] When silicate cement meets water, it reacts with water to form hydration products such as calcium silicate gel (CSH). These hydration products have high cohesiveness and strength, and can firmly bond the soil particles together to form a solid structure.

[0036] Quicklime reacts with water to form calcium hydroxide, which further reacts with carbon dioxide to form calcium carbonate (CaCO3), which fills the gaps between the slag particles, increases the bonding force between the particles, and improves the static bonding of the slag;

[0037] Adding quicklime again can further optimize the liquid and plastic limits of the slag, making it closer to the requirements of ideal engineering materials, reducing difficulties in the construction process, and improving the stability and applicability of the final product;

[0038] Fly ash contains a large amount of active silica and alumina, which can react with calcium hydroxide in a humid environment to produce more calcium silicate gel (CSH), further enhancing the cohesiveness and strength of the slag;

[0039] Portland cement, quicklime and fly ash work together to form a complex chemical reaction network. Portland cement provides the main hydration product, quicklime reduces the water content and enhances the bonding, and fly ash further enhances the structural strength through the volcanic ash effect. This synergistic effect makes the improved slag have higher compressive strength, better compaction and stability.

[0040] As a preferred embodiment of the present invention, the method for determining the amount of the additive in step S3 comprises the following steps:

[0041] S31, obtaining the weight W1 of the shield slag pile, the weight W2 of the mixed material, and the primary moisture content; the weight W1 of the shield slag pile can be obtained by measuring the weight difference before and after the slag truck is unloaded, the weight of the mixed material can be directly weighed, and the primary moisture content is the primary moisture content of the clean slag obtained in step S2;

[0042] S32, obtaining a preset target moisture content value of the secondary treated slag, the preset target moisture content value is an empirical value, and the preset target moisture content value suitable for the current project can be summarized by analyzing the impact of different moisture contents on the quality of the final product by drawing on the treatment experience and historical data of previous similar projects;

[0043] S33. Use the following formula to calculate the amount of admixture added:

[0044] W3 = (W1-W2)*(C1-C2)*k;

[0045] Wherein, W3 is the amount of admixture required; C1 is the primary moisture content; C2 is the preset moisture content target value of the secondary treated slag; k is the compensation value;

[0046] The admixture used is quicklime, which reacts with water in a 1:1 ratio to produce slaked lime;

[0047] C1-C2 in the formula reflects the difference between the primary moisture content and the preset moisture content target value, ensuring the accuracy of moisture adjustment. Through W1-W2, the interference of impurities is eliminated, ensuring that the calculation is based on the weight of the net slag, and improving the accuracy of the calculation. Considering that quicklime and water react in a 1:1 ratio to produce slaked lime, the calculation in the formula can accurately reflect the required amount of quicklime to ensure that sufficient chemical reaction occurs and achieves the expected improvement effect. The compensation value k is also introduced to take into account the influence of standing time and environmental factors (such as temperature, humidity, wind speed, etc.) on the amount of admixture added, ensuring the quality stability and reliability of the final product.

[0048] As a preferred solution of the present invention, the method for calculating k comprises the following steps:

[0049] S331, obtaining the static time S of the primary processed slag, and then obtaining the average temperature T, average humidity R and average wind speed G during the static time S, to obtain a static parameter set; in order to obtain the average temperature, average humidity and average wind speed during the future static time, various methods such as meteorological forecast data, intelligent prediction model, environmental simulation and on-site real-time monitoring can be used;

[0050] S332, setting the static time influence factor and the basic compensation coefficient k b ;

[0051] Based on experience or industry standards, a basic compensation coefficient is initially set, which reflects the optimal addition ratio of admixtures without the influence of additional environmental factors;

[0052] The setting of the standing time influencing factor is also based on empirical values ​​and literature research, reflecting the effect of different standing times on water volatilization;

[0053] S333. Determine an average temperature influence factor, an average humidity influence factor, and an average wind speed influence factor according to the acquired static parameter set;

[0054] The average temperature influencing factor, average humidity influencing factor and average wind speed influencing factor are also based on empirical values ​​and literature research, reflecting the influence of different environmental parameters on water volatilization;

[0055] S334. Calculate k using the following formula:

[0056] k=k b *F S *F T *F R *F G ;

[0057] Where k is the compensation value, F S is the influence factor of the static time, F T is the average temperature influence factor, F R is the average humidity impact factor, F G is the average wind speed influencing factor;

[0058] The above method for calculating the compensation value k systematically considers environmental parameters such as standing time, average temperature, humidity and wind speed, and sets the basic value of each influencing factor in combination with empirical values ​​and literature research. It uses meteorological forecast data, intelligent prediction models and real-time on-site monitoring to ensure accurate prediction of future conditions, achieves precise control of the amount of admixture, reduces waste and cost, improves the reliability of treatment effects and the physical and chemical properties of the improved slag, and provides a scientific basis and technical support for the high-quality resource utilization of shield slag.

[0059] As a preferred embodiment of the present invention, the method for obtaining the target liquid limit and the target plasticity index in S5 comprises the following steps:

[0060] S61. Clarify the expected use of the improved slag according to the project requirements;

[0061] S62. Consult industry specifications and standard documents to understand the recommended target liquid limit and target plasticity index range for specific project types;

[0062] The above method for obtaining the target liquid limit and target plasticity index ensures that the physical properties of the improved slag meet the requirements of specific engineering types by clarifying the intended use of the improved slag and consulting industry specifications and standard documents. This method not only improves the targeted and scientific nature of slag treatment, but also ensures the quality and applicability of the final product, reduces testing costs and time, and provides reliable technical support and guarantee for engineering projects.

[0063] As a preferred embodiment of the present invention, the method for constructing the modifier optimization model comprises the following steps:

[0064] S6a, collecting historical target products that meet the target liquid limit and target plasticity index, and recording the measurement results of the secondary moisture content and secondary treated slag composition of the historical target products, and the addition ratio of each component of the modifier, to obtain an original data set;

[0065] S6b, preprocessing the original data set, and selecting model input data from the original data set;

[0066] As a preferred embodiment of this invention, in order to ensure the quality of basic data, the data can be preprocessed, including cleaning the collected data, removing outliers, filling missing values, normalizing and standardizing the data, converting the eigenvalues ​​to a uniform range, etc. Subsequent steps can expand the data set by generating new samples based on the preprocessed clean data.

[0067] S6c, setting a disturbance amplitude range, adding random disturbance to the model input data according to the disturbance amplitude range, generating new model input data, and calculating model output data based on the new model input data to obtain an enhanced data set;

[0068] Specifically, random disturbances must be kept within the range allowed by physics or experiments. The disturbance amplitude range can be set and the disturbance amplitude should be controlled within a reasonable range. By introducing slight disturbances on the existing feature data, including Gaussian noise, uniform noise, etc., more samples can be generated to simulate data fluctuations in real scenarios. After generating new input samples, known formulas, empirical laws or simple models need to be used to recalculate the output to ensure the physical meaning and logical consistency of the enhanced data.

[0069] S6d. Verify the data distribution in the enhanced data set and perform a data balance check;

[0070] After the enhanced data is generated, the enhanced data can be manually or rule-verified to ensure that the enhanced data conforms to the actual physical or experimental rules and avoid generating unreasonable samples; the data distribution can be checked to compare whether the distribution of the enhanced data is consistent with that of the original data to ensure that the enhanced data does not deviate from the actual physical or experimental meaning. At the same time, the rationality of the enhanced data can be checked to confirm whether the enhanced samples are within the expected range; finally, a data balance check can be performed to ensure that the enhanced data set covers all areas of the input space and avoid too sparse distribution of some eigenvalues.

[0071] S6e. Select a machine learning model as the infrastructure of the improver optimization model, use the verified enhanced data set to train and optimize the improver optimization model, and deploy the optimized improver optimization model to practical applications to predict and analyze new data.

[0072] Specifically, the improver optimization model can select a neural network model, a random forest model, a support vector regression model, etc., and for training and optimizing the improver optimization model, the enhanced data set can be divided into a training set and a test set. The model is trained with the training set, and the hyperparameters of the model are adjusted according to the change in loss during the training process; the performance of the trained model on unseen data is evaluated with the test set to obtain the model evaluation results, and the model is tuned according to the model evaluation results. The tuning methods include adjusting the model architecture, modifying the loss function, and adjusting the hyperparameters; it should be noted that the enhanced data can only be used for the training set, and the test set must contain only real data.

[0073] The above-mentioned method for constructing the modifier optimization model systematically collects and processes data of historical target products, uses machine learning models for training and tuning, and finally deploys them in practical applications, ensuring that the model can accurately predict and analyze new data. This method not only improves the scientificity and accuracy of the slag improvement process, but also ensures the stability and reliability of the model through steps such as data preprocessing, data enhancement, model training, and performance evaluation, reduces the cost and time of trial and error, improves the efficiency and quality of engineering projects, and provides strong technical support for the efficient and stable utilization of slag resources.

[0074] As a preferred embodiment of the present invention, the method for measuring the secondary moisture content of each pile of secondary treated slag in S6 includes:

[0075] Randomly select multiple points at different heights and depths from the secondary treatment slag pile for sampling, and calculate the average moisture content of multiple sampling points;

[0076] The above method was used to measure the secondary moisture content of the secondary treated slag. By randomly selecting multiple points from different heights and depths of the slag pile for sampling, and calculating the average moisture content of multiple sampling points, the representativeness and accuracy of the measurement results were ensured. This method can not only comprehensively reflect the distribution of moisture content inside the slag pile, avoiding the deviation of single-point sampling, but also improve the reliability and stability of the data, providing a scientific basis for subsequent analysis and processing, and ensuring the precise control and optimization of the slag improvement process.

[0077] As a preferred embodiment of the present invention, the mixed material includes large stones, metal fragments, wood chips and plastic products. In addition to the above mixed materials, other types may also be included, such as glass fragments, etc.;

[0078] The presence of impurities significantly affects the target product quality of shield waste, including its physical and chemical properties, engineering application performance and resource utilization efficiency. Therefore, when processing shield waste, these impurities should be removed as much as possible to ensure the high quality and wide applicability of the final product and promote green construction and sustainable development.

[0079] As a preferred embodiment of the present invention, the fly ash is of grade II;

[0080] The particle fineness of grade II fly ash is between grade I and grade III, which not only ensures good fluidity and easy mixing, but also improves the density and compaction effect of slag to a certain extent.

[0081] Finally, quality inspection is carried out. Specifically, compaction test: use the sand filling method to test, the compaction should meet the design requirements; deflection test: use the Beckman beam to test, the deflection value should meet the design requirements; other inspection items: longitudinal elevation, centerline deviation, width, flatness, cross slope, side slope, etc. must meet the design requirements.

[0082] Compared with the prior art, the present invention has the following beneficial effects:

[0083] (1) The present invention ensures that the source of each batch of slag is consistent by stacking it in categories and accurately measuring the primary moisture content, thereby reducing the fluctuation in product quality caused by component variability. The method of multi-point sampling and averaging improves the representativeness and accuracy of the data, providing a solid foundation for subsequent processing. In addition, by removing impurities, the physical and chemical properties of the slag are optimized, the amount of abandoned soil is reduced, and the demand for stacking sites is reduced;

[0084] (2) The present invention combines the standing time and environmental parameters to accurately calculate the amount of admixture added, effectively solving the problem of moisture regulation. By storing in piles, uniform reaction and moisture evaporation are promoted, the standing time is shortened and the processing efficiency is improved. This method not only avoids the time-consuming and labor-intensive problems of traditional airing, but also avoids the high economic costs brought by mechanical methods such as drying. At the same time, the admixture reacts fully with moisture during the standing process, further improving the physical properties of the slag, making it more in line with the requirements of engineering materials.

[0085] (3) The present invention customizes the ratio of improvers by accurately measuring the secondary moisture content and component analysis, thereby promoting chemical reactions in the slag and improving its liquid limit, plastic limit and soil properties. This method avoids a "one-size-fits-all" approach and ensures that each pile of slag can receive the optimal treatment plan based on its specific properties. By obtaining the secondary moisture content, composition, target liquid limit and plasticity index of each pile of slag and inputting them into the optimization model, the changes in the treatment process can be monitored in real time, and the treatment plan can be adjusted in a timely manner, thereby enhancing the controllability and predictability of the entire treatment process. Finally, the amount of improver added is accurately controlled to achieve efficient, environmentally friendly and high-performance resource utilization of shield slag, thereby maximizing resource utilization efficiency and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0087] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0088] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0089] Secondly, the term "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0090] Embodiment 1:

[0091] S1. Classify and stack shield slag according to soil source type to obtain multiple shield slag piles, remove impurities in the shield slag piles, such as large stones, metal fragments, wood chips and plastic products, to obtain clean slag, and stack the clean slag separately to form clean slag piles;

[0092] S2. The primary moisture content of one of the net slag piles was measured to be 38%;

[0093] S3. For the above-mentioned clean slag pile, according to the production task, the standing time and the environmental parameters during the standing time are obtained, and the addition amount of the admixture (powdered calcium quicklime) is calculated according to the primary moisture content, the preset moisture content target value, the standing time and the environmental parameters during the standing time;

[0094] The data are as follows:

[0095] Standing time: 16 days;

[0096] Preset moisture content target value B: 14%;

[0097] Shield mound weight W1: 30 tons;

[0098] Mixed matter weight W2: 0.2 tons;

[0099] First-level moisture content C1: 38%;

[0100] Within 16 days of standing: average temperature T: 21.3℃; average humidity R: 60.4%; average wind speed G: 3.2m / s;

[0101] Basic compensation coefficient k b =1.0. Based on the empirical value, when the standing time is 16 days, due to the long standing time, more water evaporates, and the standing time influence factor F S is 0.19; considering the environmental factors within 16 days of standing, the average temperature is moderate, and the average temperature influence factor F T 1, the humidity is higher than usual, and the average humidity influence factor F R is 1.06, the average wind speed is moderate, and the average wind speed influence factor F G is 1.0;

[0102] Use the following formula to calculate the amount of admixture to be added:

[0103] W3=(W1-W2)*(C1-C2)*k b *F S *F T *F R *F G ;

[0104] W3 = (30-0.2)*(0.38-0.14)*1*0.19*1*1.06*1 = 1.44 tons;

[0105] S4, according to the calculated admixture amount of 1.44 tons, the admixture (powdered calcium quicklime) is added to the clean slag, and then fully mixed to obtain primary treated slag, and the primary treated slag is stored in piles, and the primary treated slag stored in piles is left to stand for 16 days to obtain secondary treated slag;

[0106] S5, modifiers include Portland cement, quicklime and Class II fly ash;

[0107] According to the project requirements and industry specifications, the target liquid limit is 24% and the target plasticity index is 16;

[0108] S6. Measure the secondary moisture content of one of the secondary treated slag piles and analyze its composition. The secondary moisture content is 15%. The composition analysis results are: quartz accounts for 30%, feldspar accounts for 15%, clay minerals account for 20%, and other substances such as slaked lime account for 35%;

[0109] The above data were input into the pre-built modifier optimization model to obtain the addition ratio of each modifier component required for the secondary treatment of the slag pile; the addition ratio output by the model was: Portland cement: 2%, quicklime: 1%, and Class II fly ash: 5%;

[0110] S7, weighing the improver according to the addition ratio of each component of the improver, and fully mixing the secondary treated slag with the improver to finally obtain the target product;

[0111] Embodiment 2:

[0112] On the basis of S1-S5 in Example 1, in step S6, the secondary moisture content of another pile of secondary treated slag different from Example 1 is measured and its components are analyzed, wherein the secondary moisture content is 14.1%, and the component analysis results are: quartz accounts for 31%, feldspar accounts for 16%, clay minerals account for 20%, and other substances such as slaked lime account for 33%;

[0113] The above data were input into the pre-built modifier optimization model to obtain the addition ratio of each modifier component required for the secondary treatment of the slag pile; the addition ratio output by the model was: Portland cement: 2.05%, quicklime: 1.02%, and Class II fly ash: 4.96%;

[0114] Weigh the improver according to the adding ratio of each component of the improver, fully mix the secondary treated slag and the improver, and finally obtain the target product;

[0115] Comparative Example:

[0116] On the basis of S1-S5 in Example 1, in step S6, the secondary moisture content of another pile of secondary treated slag different from that in Example 1 and Example 2 is measured, and the secondary moisture content is 16.2%;

[0117] According to manual experience, the proportion of each component of the modifier is: Portland cement: 3%, quicklime: 2%, Class II fly ash: 5%;

[0118] Weigh the improver according to the adding ratio of each component of the improver, fully mix the secondary treated slag and the improver, and finally obtain the target product;

[0119] The target products prepared in Example 1, Example 2 and the comparative example were tested, and the test results are shown in Table 1:

[0120]

[0121] The above-mentioned embodiment is a method for resource utilization of shield slag based on two-stage treatment. Through systematic data collection, calculation of admixture addition amount, removal of impurities, and application of improver optimization model, the accuracy and reliability of slag treatment are ensured. In Example 1 and Example 2, by measuring the specific moisture content and composition of the secondary treated slag, and inputting these data into the pre-constructed improver optimization model, the accurate addition ratio of each component of the improver is obtained. This model-based method not only improves the scientificity and consistency of slag improvement, but also significantly reduces the trial and error cost and time.

[0122] In contrast, the proportion of modifier addition was determined solely by manual experience. Although the target product was finally obtained by mixing, its accuracy and reliability were low, and the consistency of different batches of slag treatment could not be guaranteed. This highlights the important benefits of the modifier optimization model: it can dynamically adjust the proportion of modifiers according to specific conditions to ensure that each pile of slag can achieve the expected physical and chemical properties, thereby improving the overall quality and efficiency of the project. By using the optimization model, the maximum utilization of slag resources is achieved, promoting green construction and sustainable development.

[0123] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for resource utilization of shield slag based on two-stage processing, characterized in that: The following steps are involved: S1. Classify and pile up shield slag according to soil source type to obtain multiple shield slag piles, remove impurities in each shield slag pile, and obtain clean slag; S2. Measure the primary moisture content of clean soil; S3. According to the production task, the required standing time of the clean slag and the environmental parameters during the standing time are obtained, and the amount of admixture added is calculated according to the primary moisture content, the preset moisture content target value, the standing time and the environmental parameters during the standing time; S4, adding the admixture to the clean slag according to the calculated amount of admixture added, and then mixing to obtain primary treated slag, and storing the primary treated slag in piles; after the primary treated slag stored in piles is left to stand, secondary treated slag is obtained; the main body of the preset moisture content target value is the secondary treated slag; S5. Obtain target liquid limits and target plasticity indexes of each component of the improver and the target product; S6, measuring the secondary moisture content of each pile of secondary treated slag and analyzing the composition of the secondary treated slag, inputting the measurement results of the secondary moisture content and the composition of the secondary treated slag, each component of the improver, the target liquid limit and the target plasticity index into a pre-constructed improver optimization model, and obtaining the required addition ratio of each component of the improver for the pile of secondary treated slag; S7. Weigh the improver according to the addition ratio of each component of the improver, mix the secondary treated slag with the improver to obtain the target product.

2. The shield slag resource utilization method based on two-stage processing according to claim 1 is characterized in that: The admixture is powdered calcium quicklime.

3. The shield slag resource utilization method based on two-stage processing according to claim 1 is characterized in that: The improvers are silicate cement, quicklime and fly ash.

4. The shield slag resource utilization method based on two-stage processing as claimed in claim 2 is characterized in that: The method for determining the amount of the admixture added in step S3 comprises the following steps: S31, obtaining the weight W1 of the shield slag pile, the weight W2 of the mixed material, and the primary moisture content; S32, obtaining a preset target moisture content value of the secondary treated slag; S33. Use the following formula to calculate the amount of admixture added: W3=(W1-W2)*(C1-C2)*k; Among them, W3 is the amount of admixture required; C1 is the primary moisture content; C2 is the preset moisture content target value of the secondary treated slag; k is the compensation value.

5. The shield slag resource utilization method based on two-stage processing according to claim 4 is characterized in that: The method for calculating k comprises the following steps: S331, obtaining the static time S of the primary processed slag, and then obtaining the average temperature T, average humidity R and average wind speed G during the static time S to obtain a static parameter set; S332, setting the static time influence factor and the basic compensation coefficient k b ; S333. Determine an average temperature influence factor, an average humidity influence factor, and an average wind speed influence factor according to the acquired static parameter set; S334. Calculate k using the following formula: k=k b *F S *F T *F R *F G ; Where k is the compensation value, F S is the influence factor of the static time, F T is the average temperature influence factor, F R is the average humidity impact factor, F G is the average wind speed influencing factor.

6. The shield slag resource utilization method based on two-stage processing according to claim 1 is characterized in that: The method for obtaining the target liquid limit and the target plasticity index in S5 comprises the following steps: S61. Clarify the expected use of the improved slag according to the project requirements; S62. Consult industry specifications and standards documents to understand the recommended target liquid limit and target plasticity index range for specific project types.

7. The shield slag resource utilization method based on two-stage processing according to claim 1 is characterized in that: The method for constructing the improver optimization model comprises the following steps: S6a, collecting historical target products that meet the target liquid limit and target plasticity index, and recording the measurement results of the secondary moisture content and secondary treated slag composition of the historical target products, and the addition ratio of each component of the modifier, to obtain an original data set; S6b, preprocessing the original data set, and selecting model input data from the original data set; S6c, setting a disturbance amplitude range, adding random disturbance to the model input data according to the disturbance amplitude range, generating new model input data, and calculating model output data based on the new model input data to obtain an enhanced data set; S6d. Verify the data distribution in the enhanced data set and perform a data balance check; S6e. Select a machine learning model as the infrastructure of the improver optimization model, use the verified enhanced data set to train and optimize the improver optimization model, and deploy the optimized improver optimization model to practical applications to predict and analyze new data.

8. The shield slag resource utilization method based on two-stage processing according to claim 1 is characterized in that: The method for measuring the secondary moisture content of each pile of secondary treated slag in S6 comprises: Multiple points were randomly selected from different heights and depths of the secondary treatment slag pile for sampling, and the average moisture content of the multiple sampling points was calculated.

9. The shield slag resource utilization method based on two-stage processing according to claim 1 is characterized in that: The mix included large rocks, metal fragments, wood scraps and plastic items.

10. The shield slag resource utilization method based on two-stage processing according to claim 3 is characterized in that: The fly ash is used class.

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