A dynamic control method for ecological sediment solidification based on clay mineral composition

Abstract

The sediments from rivers and lakes are soft soils with high water content and organic matter, which have poor engineering properties such as high compressibility, large porosity and low strength. Usually, they are pretreated by the sun drying method, and then cement, lime and other curing materials are added as road fillers, which is time-consuming, labor-intensive, costly and polluting to the environment. The present invention relates to a method for preparing a sediment solidification composite substrate by using high-water content sediment as road filler after pretreatment and rationally utilizing the concept of stimulating the potential curing activity in industrial solid waste. From the perspective of "treating waste with waste", this method establishes a framework for designing sediment curing agent components from the aspects of gelation and compaction strength. Taking into account the activity of clay minerals in sediment, large industrial solid wastes such as yellow phosphorus slag, blast furnace slag and calcium carbide slag are introduced into the preparation of ecological curing agents. It is proposed to dynamically control the dosage of curing materials according to the clay minerals and active components in solid wastes, so as to maximize the activity of clay minerals and solid wastes, and can be applied to the design and evaluation of solid waste-cured sediments.

Description

Technical Field

[0001] The present invention belongs to the technical field of foundation treatment in transportation engineering and civil engineering, and particularly relates to a dynamic control method for ecological sediment solidification based on clay mineral composition. Background Art

[0002] Using a cement-lime mixture to solidify sediment is a common reinforcement technology used both domestically and internationally. Cement is the primary solidifying material in this method. During the solidification process, cement undergoes a chemical reaction to form a solid, granular substance, effectively solidifying the sediment and addressing the problem of sediment disposal. Cement-solidified sediment reduces its volume, allowing it to be used as a construction material, such as roadbed filler, thereby reducing disposal costs. Solidified sediment also reduces harmful emissions from the sediment, thus minimizing environmental damage. However, the solidification process requires the addition of appropriate amounts of cement and lime, which can be costly for large amounts of sediment. Cement also produces large amounts of greenhouse gases, such as carbon dioxide, during the solidification process, significantly impacting the environment. Furthermore, cement-solidified sediment requires time to cure, increasing time and cost. While cement-solidified sediment is a simple technique, it releases significant amounts of greenhouse gases during the solidification process, and the curing time is long for large amounts of sediment. Therefore, there is an urgent need to develop a substance that can partially replace cement to create a solidifying agent specifically for solidifying sediment.

[0003] There is an urgent need to find a material that can replace cement to effectively solidify sediments while ensuring environmental protection. In recent years, a large number of researchers have conducted research on the use of solid waste for sediment solidification, such as using industrial waste residue in conjunction with cement to solidify sediments. This not only partially replaces cement as a raw material for solidifying sediments, but also solves the problems of high energy consumption and pollution caused by cement and the resource utilization of industrial waste residue. At the same time, it also promotes the effective utilization of river and lake sediments and industrial solid waste, which is of great significance to environmental protection and resource utilization.

[0004] The rapid growth of the world's population, urbanization, and industrialization have inevitably led to a continuous increase in the amount of solid waste generated worldwide. Global solid waste production is estimated to be between 7 and 9 billion tons annually, and continues to increase dramatically. In 2016, global municipal solid waste production reached nearly 2.01 billion tons annually and is projected to reach 3.4 billion tons by 2050. However, only approximately 30% of this solid waste is effectively treated, leaving large amounts of industrial solid waste to accumulate in material yards, occupying significant land resources and posing significant ecological and environmental risks. To improve the resource utilization of industrial solid waste and reduce its adverse environmental impacts, research on its reuse is urgently needed. Researchers have investigated the use of industrial solid waste in cement-based solidification sludge, which is then used as a solidifying agent for road fill and other construction materials. This approach consumes significant amounts of industrial solid waste, effectively treating vast quantities of river and lake sediments in an economically and ecologically sound manner while also meeting national requirements for the resource utilization of large quantities of industrial solid waste.

[0005] Current research has primarily investigated the optimal dosage of industrial solid waste for sediment solidification based on the physical properties of sediments. However, the interaction between soil minerals and the solidifying agent has been neglected. Consequently, the solidifying agent does not effectively solidify the sediment, and other soils with the same properties exhibit varying degrees of solidification efficacy with the same solidifying agent. Industrial solid waste contains potentially active components (SiO2, CaO, Al2O3, and Fe2O3), which vary in content with different amounts of industrial solid waste and within different types of industrial solid waste. The content of these active components directly impacts the effectiveness of the prepared solidifying agent in solidifying sediments.

[0006] This phenomenon hinders the widespread use of solid waste in sediment reinforcement. Furthermore, in actual reinforcement, simply adding a curing agent based solely on the physical properties of the sediment (such as moisture content and liquid limit) can hardly achieve the desired curing effect. Therefore, further research is needed to determine how to rationally formulate industrial solid waste into a curing agent that effectively solidifies sediment.

[0007] Active clay minerals in sediment interact with hydration products generated during the hydration of industrial solid waste, thereby affecting the mechanical properties of the solidified sediment. Sediments from different regions contain varying amounts of active clay minerals, and different clay minerals exhibit distinct dissolution reaction characteristics. However, previous solid waste material component design frameworks have not considered the role of active clay minerals in sediment during the solidification process, resulting in certain limitations in solid waste material design. This present invention incorporates active clay mineral components in sediment into effective solidification components, further improving the solid waste-based component design framework.

[0008] Due to its high water content, low strength, and high compressibility, using sediment as roadbed filler is challenging and poses potential risks to the project. To address this challenge, various sediment reinforcement methods are available. Currently, the most common methods include preloading, organic solidification, and thermal solidification. While these three methods can significantly improve soil strength and stability, they require significant energy consumption and have environmental impacts. Therefore, there is an urgent need to find a method that can significantly solidify sediment, simplify construction, and reduce energy consumption. Summary of the Invention

[0009] The present invention aims to solve the problem of solidifying active components in sediment with a sediment curing agent. Based on a control model of the curing activity excitation index and aluminum, calcium, and silicon ratios for potential active components in industrial solid waste, and taking into account the activity of clay minerals in the clay component of the sediment, the present invention formulates a curing agent that significantly solidifies the sediment. The resulting solidified sediment has a simple construction process, is environmentally friendly, and exhibits higher unconfined compressive strength.

[0010] In order to solve the above problems, this application is implemented through the following technical solutions:

[0011] A dynamic control method for ecological sediment solidification based on clay mineral composition comprises the following steps:

[0012] S1. Drying and grinding the industrial solid waste for preparing the bottom mud solidifying agent to obtain respective industrial solid waste powders;

[0013] S2. Measure the content of active components of the industrial solid waste powder in step S1 by XRF i,j The curing activity excitation index η of industrial solid waste powder was measured by the activity index test i ;

[0014] S3. Test the content of active components in clay minerals of sediment by oriented XRD * i，j , through w t-i,j , w 0-i,j Obtain the η of clay minerals in the sediment * i ;

[0015] S4, step S2 n i , ε i,j and n in step S3 * i , ε * i，j Substitute into the cement three-rate value control model to obtain the mass ratio of industrial solid waste in the bottom mud solidifier M i ;

[0016] S5. Adding an expansion agent component to the sediment curing agent configured in step S4 and preparing a sediment sample for curing. After curing for 28 days, a sediment foundation sample with a certain dry density is obtained, and the amount of the expansion agent component is determined according to the dry density;

[0017] S6, according to the industrial solid waste mass ratio M in step S4 i The bottom mud curing agent is prepared according to the dosage of the expansion agent component in step S5, and the bottom mud is added to obtain the solidified soil samples for curing for 7 days, 28 days, and 60 days, to obtain the solidified bottom mud of ordinary Portland cement with a certain dry density and unconfined compressive strength greater than that of ordinary Portland cement after curing for 7 days, 28 days, and 60 days.

[0018] The specific surface area of ​​the powder in step S1 is 300m 2 / kg~400m 2 / kg.

[0019] In step S1, the industrial solid waste is selected from one or more of fly ash, yellow phosphorus slag, blast furnace slag and carbide slag;

[0020] Among them, the active excitation components and the contents of each component of fly ash are 53.2% CaO, 8.2% Fe2O3, 22.4% SiO2, and 1.3% Al2O3 respectively; the active excitation components and the contents of each component of yellow phosphorus slag are 36.82% CaO, 4.3% Fe2O3, 37.24% SiO2, and 4.83% Al2O3 respectively; the active excitation components and the contents of each component of blast furnace slag are 37.2% CaO, 2.0% Fe2O3, 38.3% SiO2, and 16.4% Al2O3 respectively; the active excitation components and the contents of each component of calcium carbide slag are 92.4% CaO, 0.4% Fe2O3, and 3.8% SiO2 respectively.

[0021] The industrial solid waste powder in step S2 is one or more of fly ash powder, yellow phosphorus slag powder, blast furnace slag powder and carbide slag powder.

[0022] The activity index test formula in step S2 is: i =δ i / B;

[0023] Among them, δ i is the i-th type of industrial solid waste A i The 28-day compressive strength of the test mortar is in MPa. B is the 28-day compressive strength of the cement-based reference mortar, in MPa.

[0024] When i=1, it indicates that the industrial solid waste is fly ash; when i=2, it indicates that the industrial solid waste is blast furnace slag; when i=3, it indicates that the industrial solid waste is carbide slag; when i=4, it indicates that the industrial solid waste is yellow phosphorus slag;

[0025] When j is 1, it indicates that the potential curing active component is SiO2, when j is 2, it indicates that the potential curing active component is Fe2O3, when j is 3, it indicates that the potential curing active component is Al2O3, and when j is 4, it indicates that the potential curing active component is CaO;

[0026] η i It represents the solidification activity excitation index of solid waste i in industrial solid waste;

[0027] ε i，j represents the chemical content of the potential solidification active component j in the i-th solid waste;

[0028] Among them, ε 1，1 =22.4%, ε 1，2 =8.2%, ε 1，3 =1.3%,ε 1，4 =53.2%;

[0029] ε 2，1 =38.3%, ε 2，2 =2%,ε 2，3 =16.4%, ε 2，4 =37.2%;

[0030] ε 3，1 =3.8%, ε 3，2 =0.4%, ε 3，3 =0,ε 3，4 =92.4%;

[0031] ε 4，1 =37.24%, ε 4，2 =4.3%, ε 4，3 =4.83%, ε 4，4 =36.82%;

[0032] Among them, δ1=42.34MPa, δ2=45.08MPa, δ3=48.08MPa, δ4=46.17MPa, B=51.7MPa;

[0033] eta1=0.819, eta2=0.872, eta3=0.93, eta4=0.893.

[0034] In the step S3,

[0035] ε * i，j is the mass content of chemical components of potential solidification active component j in clay mineral i in the sediment;

[0036] η * iis the reaction dissolution rate of the potential solidification active components in the clay minerals in the sediment;

[0037] η * i =w t-i,j / w 0-i,j ;

[0038] When i is 1, it indicates that the clay mineral is kaolinite; when i=2, it indicates that the clay mineral is montmorillonite; when i is 3, it indicates that the clay mineral is illite;

[0039] j is a natural number greater than zero: when j is 1, it indicates that the latent curing active component is SiO2, when j is 2, it indicates that the latent curing active component is Fe2O3, when j is 3, it indicates that the latent curing active component is Al2O3, and when j is 4, it indicates that the latent curing active component is CaO;

[0040] Preferably, in step S3, 0-i,j is the original content of j potential solidification active components in i clay minerals in the sediment;

[0041] Where: w 0-1,1 =46.1%, w 0-1,3 =39.5%, w 0-1,2 =0.3%, w 0-1,4 =0.01%,

[0042] w 0-2,1 =63.3%, w 0-2,3 =18.1%, w 0-2,2 =3.1%, w 0-2,4 =0.03%,

[0043] w 0-3,1 =53.2%, w 0-3,3 =26.9%, w 0-3,2 =8.2%, w 0-3,4 =0.05%,

[0044] w t-i,j is the reaction dissolution amount of j potential solidification active components in i clay mineral in the sediment;

[0045] w t-1,1 =2.72%, w t-1,3 =2.33%, w t-1,2 =0.02%, w t-1,4 =0,

[0046] w t-2,1 =7.60%, w t-2,3 =2.17%, w t-2,2 =0.37%, w t-2,4=0,

[0047] w t-3,1 =4.31%, w t-3,3 =2.18%, w t-3,2 =0.66%, w t-3,4 =0,

[0048] Preferably, the clay minerals in the bottom mud in step S3 are kaolinite, montmorillonite and illite; wherein the kaolinite content is 16.4%, the montmorillonite content is 8.55%, and the illite content is 19.77%;

[0049] SiO2 content in the active components of kaolinite ε * 1，1 =46.1%, Al2O3 content ε * 1，3 =39.5%, Fe2O3 content ε * 1，2 =0.3%, CaO content ε * 1，4 =0.01%;

[0050] SiO2 content in the active component of montmorillonite ε * 2，1 =63.3%, Al2O3 content ε * 2，3 =18.1%, Fe2O3 content ε * 2，2 =3.1%, CaO content ε * 2，4 =0.03%;

[0051] SiO2 content in active activation components of illite ε * 3，1 =53.2%, Al2O3 content ε * 3，3 =26.9%, Fe2O3 content ε * 3，2 =8.2%, CaO content ε * 3，4 =0.05%;

[0052] Preferably, in step S3, n * 1=5.9%,η * 2=12.0%,η * 3=8.1%.

[0053] The cement three-rate value control model in step S4 is:

[0054]

[0055]

[0056]

[0057] Among them, C i，j= η i ×ε i，j , C * i，j= η * i ×ε * i，j ; The total number of types n of industrial solid wastes is 4, namely fly ash, yellow phosphorus slag, blast furnace slag, and carbide slag. Among the three modulus values of cement: SM is the silica modulus, 1.7 < SM < 2.7; IM is the alumina modulus, 0.9 < IM < 1.7; KH is the calcium modulus, 0.9 < KH < 1.0; w IBP is the admixture amount of the curing agent;

[0058] C i，j represents the activated content of the jth potential curing activity excitation component in the ith industrial solid waste;

[0059] C * i，j represents the activated content of the jth potential curing activity excitation component in the ith clay mineral.

[0060] In the step S4, M i is the mass ratio of the ith solid waste in the industrial solid waste to the bottom sludge curing agent; In terms of mass ratio, the ratio M i in the bottom sludge curing agent is M fly ash: M yellow phosphorus slag: M blast furnace slag: M carbide slag = 21.4% - 30%: 10% - 16.7%: 19% - 20%: 40% - 42.9%.

[0061] In the step S5, the expansion agent component is one of phosphogypsum, desulfurized gypsum, citric acid gypsum, titanium gypsum or fluorogypsum.

[0062] Among them, the components and contents contained in phosphogypsum are: CaO is 36.24%, Fe2O3 is 0.97%, SiO2 is 11.42%, MgO is 0.09%, Na2O is 1.03%, P2O5 is 0.02%, TiO2 is 0.17%, and SO3 is 43.22%.

[0063] Preferably, in the step S5, in terms of mass ratio, bottom sludge curing agent: expansion agent component: bottom sludge = 0.1 - 0.2: 0.015 - 0.04: 1.

[0064] The dry density of the bottom sludge foundation preparation sample in the step S5 is 900 kg / m 3 -1600 kg / m3 .

[0065] Preferably, in step S5, the mass ratio M of the bottom mud curing agent in step S4 is adjusted according to the mass fraction I of the determined expansion agent component. i They are M fly ash: M yellow phosphorus slag: M blast furnace slag: M carbide slag = 18.19~24: 8~14.2: 16~16.14: 32~36.47;

[0066] Preferably, in step S5, the SiO2 content in the sludge is 73.23%, the Al2O3 content is 14.66%, the Fe2O3 content is 6.09%, the CaO content is 0.70%, the P2O5 content is 0.48%, the K2O content is 2.33%, the MnO content is 0.08%, the TiO2 content is 1.05%, and the SO3 content is 1.15%.

[0067] Preferably, in step S6, the unconfined compressive strength of ordinary Portland cement after curing for 7 days is 0.65 MPa, the unconfined compressive strength after curing for 28 days is 1.13 MPa, and the unconfined compressive strength after curing for 60 days is 1.25 MPa;

[0068] Preferably, in step S6, the dry density of the solidified soil sample with a certain dry density is 900 kg / m 3 ~1200kg / m 3 .

[0069] Preferably, in step S6, the mass ratio of the bottom mud curing agent: the expansion agent component: the bottom mud is 0.1-0.2: 0.015-0.04: 1.

[0070] Preferably, in step S6, the expansion agent component is the same as that in step S5.

[0071] Preferably, the bottom mud in step S6 is the same as the bottom mud in step S5.

[0072] More preferably, the dosage of the expansion agent component corresponding to the first inflection point of the dry density variation curve in step S6 is a more economical dosage.

[0073] The steps and principles of the above-mentioned dynamic control method for ecological sediment solidification based on clay mineral composition are as follows:

[0074] Step 1: Select raw materials

[0075] The raw materials are industrial solid waste with a large number of potential curing active components. The prepared curing agent can ensure that the bottom mud meets the corresponding engineering performance after curing;

[0076] Step 2: Obtain the curing activity excitation content of potential curing activity excitation components in various types of industrial solid waste

[0077] The curing active components in various industrial solid wastes and clay minerals were analyzed. The potential curing active components in industrial solid wastes and clay minerals are mainly four chemical substances, namely SiO2, CaO, Al2O3 and Fe2O3. Based on the established curing active content determination model, the active content C of the potential curing active components in various industrial solid wastes and clay minerals can be obtained. i，j and C * i，j , the above-mentioned curing activation content determination model is:

[0078] C i，j= η i *ε i，j

[0079] C i，j represents the active excitation content of the jth potential solidification active excitation component in the i-th industrial solid waste; η i represents the solidification activity excitation index of solid waste i in industrial solid waste; ε i，j represents the chemical composition content of the potential solidification activity stimulating component j in the i-th type of solid waste; j is a natural number greater than zero: when j is 1, it means that the potential solidification activity stimulating component is SiO2, when j is 2, it means that the potential solidification activity stimulating component is Fe2O3, when j is 3, it means that the potential solidification activity stimulating component is Al2O3, and when j is 4, it means that the potential solidification activity stimulating component is CaO;

[0080] C * i，j= η * i *ε * i，j

[0081] C * i，j represents the active excitation content of the jth potential curing active excitation component in the i-th clay mineral; η * i is the reaction dissolution rate of the potential solidification active components in the clay minerals in the sediment; ε * i，j is the mass content of the chemical component j of the potential solidification activity stimulating component in the i clay mineral in the sediment; j is a natural number greater than zero: when j is 1, it indicates that the potential solidification activity stimulating component is SiO2; when j is 2, it indicates that the potential solidification activity stimulating component is Fe2O3; when j is 3, it indicates that the potential solidification activity stimulating component is Al2O3; when j is 4, it indicates that the potential solidification activity stimulating component is CaO;

[0082] Step 3: Obtain various types of industrial solid waste A i Mass ratio Mi ;

[0083] Taking into account the composition of clay minerals, the configuration ratio M of each industrial solid waste in the sediment reinforcement base material is determined according to the constructed solidification activity excitation intensity control model. i , through the cement TCM control model (Three Chemical Moduli, i.e. three rate values), which specifically includes silicon rate (SM), aluminum rate (IM), and calcium rate (KH) control models.

[0084]

[0085]

[0086]

[0087] Among them, M i is the mass ratio of solid waste i in industrial solid waste to the bottom mud solidifying agent, w IBP is the curing agent dosage;

[0088] Step 4: Prepare the bottom mud curing agent

[0089] According to the various types of industrial solid waste A obtained in step 3 i Mass ratio M i Prepare the bottom mud curing agent at room temperature.

[0090] Step 5. Obtain the mass fraction of the expansion agent component I

[0091] Add different mass ratios of expansive agent components to the sediment curing agent prepared in step 4, select specific sediment foundation to prepare samples for curing experiments, measure the dry density of the samples after curing, draw a dry density change curve, and determine the mass fraction I of the expansive agent component according to the change trend of the dry density curve.

[0092] Step 6: Prepare the bottom mud curing agent

[0093] According to the various types of industrial solid waste A obtained in step three i Mass ratio M i The mass fraction I of the expansion agent component determined in step five can be reconfigured into the bottom mud solidifying agent at room temperature.

[0094] Preferably, the curing agent prepared in step 6 needs to be further verified for its curing performance (unconfined compressive strength). Specifically, the prepared curing agent is mixed with the bottom mud to prepare a sample. After the sample is cured for 28 days, its unconfined compressive strength is measured. If the strength does not meet the engineering requirements, the curing agent dosage needs to be increased. IBP Repeat steps three to six until the unconfined compressive strength of the bottom mud after solidification by the configured curing agent meets the engineering performance requirements.

[0095] Preferably, the solidification activity excitation index η of the i-th industrial solid waste described in step 2 is obtained by an activity excitation index test. i :

[0096] η i =δ i / B

[0097] Where δ i Refers to the i-th type of industrial solid waste A i B is the 28d compressive strength of the test mortar, and B is the 28d compressive strength of the cement-based reference mortar.

[0098] Preferably, the contents of active components of kaolinite, montmorillonite and illite in the clay minerals of the sediment are tested by oriented XRD. * i，j , and then calculate the reaction dissolution rate η of the solidification active components of clay minerals in the sediment * i .

[0099] Preferably, the industrial by-product gypsum selected as the expansion agent component includes but is not limited to phosphogypsum, desulfurized gypsum, citric acid gypsum, titanium gypsum or fluorinated gypsum.

[0100] Preferably, there are four types of industrial solid waste in step one, specifically including fly ash, carbide slag, yellow phosphorus slag, and blast furnace slag, but not limited to these four types of industrial solid waste.

[0101] Preferably, the industrial solid waste in step 1 is dried and ground into a specific surface area of ​​300m 2 / kg 400m 2 / kg of powder.

[0102] Preferably, in step 5, the dry density of the prepared solidified soil sample is measured after curing for 28 days.

[0103] Preferably, in step five, the mass fraction I of the expansion agent component is the expansion agent component content corresponding to the first inflection point in the dry density variation curve.

[0104] The present invention is a method for preparing a sediment reinforcement and curing agent for roadbed filling. The ecological sediment curing dynamic control method based on clay mineral composition is configured according to the following proportions for various industrial solid wastes used for sediment curing, wherein the amount of the curing agent in Example 1 is 10% of the wet mass of the sediment (the wet mass of the sediment is the mass of the original sediment obtained by on-site sampling, the same below), and the content of the curing agent is: 18.19 wt% fly ash, 15 wt% phosphogypsum, 14.2 wt% yellow phosphorus slag, 16.14 wt% blast furnace slag and 36.47 wt% calcium carbide slag; the amount of the curing agent in Example 2 is 20% of the wet mass of the sediment, and the content of the curing agent is: 24 wt% fly ash, 20 wt% phosphogypsum, 8 wt% yellow phosphorus slag, 16 wt% blast furnace slag and 32 wt% calcium carbide slag.

[0105] The chemical composition contents of the corresponding potential solidification active components in the above-mentioned fly ash, phosphogypsum, yellow phosphorus slag, and blast furnace slag are shown in Table 1 below:

[0106] Table 1 Potential solidification active components and their contents (%) in various industrial solid wastes

[0107]

[0108] The chemical composition content of each potential curing active excitation component in Table 1 above was obtained through XRF measurement test.

[0109] Beneficial effects: Compared with the existing technology, the present invention has the following advantages:

[0110] 1. This invention considers the interaction between clay minerals and hydration products, combines the solubility characteristics of different clay minerals, and improves the existing solid waste component design framework to design a sediment solidifier with better solidification effect, providing a more efficient way to utilize industrial solid waste. The solidified sediment can be used as roadbed filler and meets the requirements of highway roadbed and basement standards.

[0111] 2. The method of preparing a sludge solidifying agent from industrial solid waste proposed in the present invention can achieve efficient utilization of industrial solid waste and significantly improve the strength of solidified sludge;

[0112] 3. This invention can dispose of a large amount of industrial solid waste, reduce cement consumption, is environmentally friendly, has a simple process flow, is low in cost, and can significantly improve the strength of solidified sediment, complying with the strategic goal of green and low-carbon development;

[0113] 4. The present invention optimizes the proportion of solid waste in the sediment solidifier, taking into account the interaction between clay minerals and hydration products in the sediment, and comprehensively considers the composition, activity, fineness of the solid waste, and the reaction dissolution rate of the potential solidification active components in the clay minerals. This promotes the hydration, volcanic ash, and alkali-induced reaction performance of the solidified soil, which is not only conducive to the formation of cementitious products but also allows for more accurate control of the type and state of the reaction products, providing a new approach to the utilization of solid waste-based solidified soil. The present invention can provide a way to recycle and increase the value of industrial solid waste.

[0114] 5. This invention addresses the shortcomings of existing curing technologies and curing agent preparation. By optimizing the ratios of potentially curing-active components, such as SiO2, CaO, Al2O3, and Fe2O3, found in industrial solid waste (fly ash, carbide slag, yellow phosphorus slag, and blast furnace slag), this invention develops a sediment curing agent. These potentially curing-active components activate the industrial solid waste, and when properly formulated into a curing agent, the solid waste exhibits a significant curing effect on the sediment. Based on the concept of activating the potentially curing-active components in industrial solid waste, composite substrates for sediment reinforcement are prepared using various solid waste compositions. The proposed method is economical, rational, and controllable in curing effect. It significantly reduces the consumption of natural energy sources, such as cement, by using industrial solid waste to partially replace cement in the preparation of a curing agent for sediment curing, resulting in an economical and environmentally friendly approach. This method establishes a design framework for sediment curing material components based on both gel and strength. A large amount of industrial solid waste, such as yellow phosphorus slag, blast furnace slag, and carbide slag, is introduced into the preparation of sediment solidifiers. It is proposed to add corresponding industrial solid waste according to the composition of clay minerals to stimulate the activity of sediment to the greatest extent. This method provides a more reasonable industrial solid waste design and selection and the amount of similar solid waste for the solidification of sediment, which not only improves the efficiency of sediment solidification, but also can recycle and utilize a large amount of industrial solid waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0115] Figure 1 This is the flow chart for preparing the bottom mud solidifying agent;

[0116] Figure 2 It is the design framework diagram of industrial solid waste components;

[0117] Figure 3 This is a diagram showing the method for determining the optimal dosage of gypsum-based solid waste in sediment; DETAILED DESCRIPTION

[0118] Clay minerals are the clay components of sediments. To further clarify the objectives, technical solutions and advantages of the present invention, the present invention is described in detail below with reference to the following examples.

[0119] Step 1: Select raw materials

[0120] The raw materials are industrial solid wastes with a large amount of potential curing active components, and the prepared curing agent can ensure that the bottom mud meets the corresponding engineering properties after curing;

[0121] Step 2: Obtain the curing activity excitation content of potential curing activity excitation components in various types of industrial solid waste

[0122] The potential solidification active components in various industrial solid wastes and clay minerals were analyzed. The potential solidification active components in industrial solid wastes and clay minerals are mainly four chemical substances, namely SiO2, CaO, Al2O3 and Fe2O3. Based on the established solidification active content determination model, the active excitation content C of the potential solidification active components in various industrial solid wastes and clay minerals can be obtained. i，j and C * i，j ; The above-mentioned curing activity excitation content determination model is:

[0123] C i，j= η i *ε i，j

[0124] C i，j represents the active excitation content of the jth potential solidification active excitation component in the i-th industrial solid waste; η i represents the solidification activity excitation index of solid waste i in industrial solid waste; ε i，j represents the chemical composition content of the potential solidification activity stimulating component j in the i-th type of solid waste; j is a natural number greater than zero: when j is 1, it means that the potential solidification activity stimulating component is SiO2, when j is 2, it means that the potential solidification activity stimulating component is Fe2O3, when j is 3, it means that the potential solidification activity stimulating component is Al2O3, and when j is 4, it means that the potential solidification activity stimulating component is CaO;

[0125] C * i，j= η * i *ε * i，j

[0126] C * i，j represents the active excitation content of the jth potential curing active excitation component in the i-th clay mineral; η * i is the reaction dissolution rate of the potential solidification active components in the clay minerals in the sediment; ε * i，jis the mass content of the chemical component j of the potential solidification activity stimulating component in the i clay mineral in the sediment; j is a natural number greater than zero: when j is 1, it indicates that the potential solidification activity stimulating component is SiO2; when j is 2, it indicates that the potential solidification activity stimulating component is Fe2O3; when j is 3, it indicates that the potential solidification activity stimulating component is Al2O3; when j is 4, it indicates that the potential solidification activity stimulating component is CaO;

[0127] Step 3: Obtain the A of various industrial solid wastes i Mass ratio M i

[0128] Taking into account the composition of clay minerals, the configuration ratio M of each industrial solid waste in the sediment reinforcement base material is determined according to the constructed solidification activity excitation intensity control model. i , through the cement TCM control model (Three Chemical Moduli, i.e. three rate values), specifically including the silicon rate (SM), aluminum rate (IM), and calcium rate (KH) control models;

[0129]

[0130]

[0131]

[0132] Among them, M i is the mass ratio of solid waste i in industrial solid waste to the bottom mud solidifying agent, w IBP is the curing agent dosage.

[0133] Step 4: Prepare the bottom mud curing agent

[0134] According to the various types of industrial solid waste A obtained in step 3 i Mass ratio M i Prepare the bottom mud curing agent at room temperature.

[0135] Step 5. Obtain the mass fraction of the expansion agent component I

[0136] Add expansion agent components of different mass ratios to the curing agent prepared in step 4, select specific bottom mud foundation to prepare samples for curing experiments, measure the dry density of the samples after curing, draw a dry density change curve, and determine the mass fraction I of each expansion agent component according to the change trend of the dry density curve.

[0137] The by-product gypsum containing an expansive component, including but not limited to phosphogypsum, desulfurized gypsum, citric acid gypsum, titanium gypsum, or fluorinated gypsum, is added in step 5. This by-product gypsum reacts with the silica-alumina phase in an alkaline environment to produce hydration products. These hydration products adhere to the surface of the sediment soil particles, causing them to agglomerate and increase in size. The soil particles are then encapsulated by the calcium silicate hydrate (CSH) gel, filling the pores between the soil particles and tightly linking the soil together. This demonstrates that the rational allocation of industrial solid waste can maximize the potential of the active components in solidification, improving the solidification effect.

[0138] Step 6: Prepare the bottom mud solidifying agent.

[0139] According to the various types of industrial solid waste A obtained in step three i Mass ratio M i and the mass fraction I of the expansion agent component determined in step 5, the bottom mud solidifying agent can be reconfigured at room temperature;

[0140] Preferably, the curing agent prepared in step 6 needs to be further verified for its curing performance (unconfined compressive strength). Specifically, the prepared curing agent is mixed with the bottom mud to prepare a sample. After the sample is cured for 28 days, its unconfined compressive strength is measured. If the strength does not meet the engineering requirements, the curing agent dosage needs to be increased. IBP Make corrections and repeat steps 3 to 6 to prepare the curing agent until the unconfined compressive strength of the bottom mud after curing with the corrected curing agent meets the engineering performance requirements.

[0141] Preferably, the solidification activity excitation index η of the i-th industrial solid waste described in step 2 is obtained by an activity excitation index test. i :η i =δ i / B;

[0142] Where δ i Refers to the i-th type of industrial solid waste A i B is the 28d compressive strength of the test mortar, and B is the 28d compressive strength of the cement-based reference mortar.

[0143] Preferably, the reaction dissolution rate η of the latent curing active excitation component in the clay mineral is * i Obtained by directional XRD.

[0144] In the following examples, if not otherwise specified, when performing the XRD test on the oriented film, the preparation of the oriented film specifically includes three steps. Step 1: Weigh 40 mg of the dried sample and place it in a 10-ml test tube. Add 0.7 ml of distilled water and stir well. Use ultrasonic waves to disperse the clay particles, let it stand for 30 min, pour the supernatant onto a glass slide, and air-dry it to prepare a natural oriented film (N film); Step 2: Place the N film prepared in Step 1 in an ethylene glycol vapor atmosphere for saturation treatment. The ethylene glycol vapor atmosphere is kept constant at 60 °C, and the constant temperature time is not less than 8 h; Step 3: Bake the ethylene glycol-saturated film at 550 °C for not less than 2.5 h, and naturally cool it to room temperature to obtain the oriented film.

[0145] If not otherwise specified, the curing condition is that the sample is cured in a curing box at a temperature of 20 °C and a humidity greater than 90% ± 3%. The content is the mass fraction.

[0146] Example 1

[0147] Select industrial solid wastes with large stockpiles and low utilization rates in Yichang City, specifically including fly ash, phosphogypsum, yellow phosphorus slag, blast furnace slag, and carbide slag. Pre-dry and grind fly ash, blast furnace slag, carbide slag, phosphogypsum, and yellow phosphorus slag to a powder with a specific surface area between 300 m 2 / kg and 400 m 2 / kg for later use. The main chemical components of the solid waste measured by combining XRF are shown in Table 2: Table 2 lists the main components and loss on ignition of the solid waste (the remainder is other impurities, not detailed here).

[0148] Through the activity excitation index test, the results are shown in Table 3. The measured activity excitation indexes η i of fly ash, blast furnace slag, carbide slag, and yellow phosphorus slag are 0.819, 0.872, 0.93, and 0.893 respectively. According to the oriented XRD, the reaction dissolution rates η i * of the potential curing activity excitation components of clay minerals (kaolinite, montmorillonite, and illite) are 5.9%, 12.0%, and 8.1% respectively.

[0149] According to the cement TCM control model, 1.7 < SM < 2.7, 0.9 < IM < 1.7, 0.9 < KH < 1.0, the contents of industrial solid wastes added to the sediment curing agent are determined as follows: 21.4 wt% fly ash, 16.7 wt% yellow phosphorus slag, 19 wt% blast furnace slag, and 42.9 wt% carbide slag.

[0150] Table 2 Chemical composition and content (%) of solid waste for preparing sediment curing agent

[0151]

[0152] Table 3 Test results of industrial solid waste activity index

[0153]

[0154] The bottom mud in Fuzhou was selected. The mineral composition of the bottom mud is shown in Table 4. A curing experiment was carried out. The above-mentioned curing agent was added to the bottom mud according to 10% of the wet mass of the bottom mud. 5 wt%, 10 wt%, 15 wt%, and 20 wt% of phosphogypsum were added as the expansion agent component respectively. After the obtained solidified soil samples were subjected to standard curing for 28 days, a dry density change curve was drawn to determine the optimal dosage of the expansive component phosphogypsum I. The curing agent dosage obtained by the cement TCM control model was adjusted. The corrected curing agent dosage was 18.19 wt% fly ash, 14.2 wt% yellow phosphorus slag, 16.14 wt% blast furnace slag, 36.47 wt% carbide slag, and 15 wt% phosphogypsum. The dissolution reaction amount of the curing active excitation component of the three clay minerals w t and reaction dissolution rate η i * See Table 5.

[0155] Table 4 Fuzhou sediment minerals and mass fraction of each component (%)

[0156]

[0157] Table 5 Reaction dissolution amount of solidification active components of three clay minerals

[0158]

[0159] The curing agent configured by the invention and the same amount of industrial solid waste (the amount added is 10% of the wet mass of the sediment) were added to the sediment to solidify the sediment. Curing samples with different curing agents were prepared. The samples were cured in a standard curing room for 7d, 28d and 60d, and then their unconfined compressive strength was measured, which is listed in Table 6-1.

[0160] Table 6-1 Unconfined compressive strength of solidified sediment (MPa)

[0161]

[0162] Example 2

[0163] Other method steps are with embodiment 1, and difference is that the incorporation amount of bottom mud curing agent is 20%, and solid waste component proportioning is: 30 wt% fly ash, 10 wt% yellow phosphorus slag, 20 wt% blast furnace slag, 40 wt% carbide slag.Choose the bottom mud of Fuzhou to carry out solidification experiment, in bottom mud, add the curing agent of above-mentioned configuration.Add 5 wt%, 10 wt%, 15 wt%, 20 wt% phosphogypsum as expansion agent component respectively, after obtained solidified soil sample is carried out standard curing 28d, draw dry density variation curve diagram, determine the dosage of expansive component phosphogypsum I, the curing agent dosage that cement TCM control model is drawn is adjusted, and the curing agent dosage after revision is 24 wt% fly ash, 8 wt% yellow phosphorus slag, 16 wt% blast furnace slag, 32 wt% carbide slag and 20 wt% phosphogypsum. The curing agent configured by the invention and the same amount of industrial solid waste (the amount added is 20% of the wet mass of the sediment) were added to the sediment to solidify the sediment. Curing samples with different curing agents were prepared. The samples were cured in a standard curing room for 7d, 28d and 60d, and then their unconfined compressive strength was measured, which is listed in Table 6-2.

[0164] In addition, when the content of the expansion agent component is selected in the embodiment of this patent, the dry density of the solidified soil is 900kg / m 3 -1600kg / m 3 The corresponding dosage of the expansion agent component has a beneficial effect on the strength of the solidified soil. Considering the economic benefits, the solidified soil density is selected as 900kg / m 3 -1200kg / m 3 It also has higher strength.

[0165] The industrial solid waste added to the curing agent needs to be dried and ground to a specific surface area of ​​300m 2 / kg~400m 2 When configuring a solidifying agent for powders between 100 and 200 kg, grinding costs must also be considered. Based on market prices, fly ash costs 200 yuan / ton, blast furnace slag costs 160 yuan / ton, carbide slag costs 200 yuan / ton, phosphogypsum costs 120 yuan / ton, yellow phosphorus slag costs 140 yuan / ton, and ordinary Portland cement costs 450 yuan / ton. The calculated costs for configuring the solidifying agent in Examples 1 and 2 are 173 yuan / ton and 172.8 yuan / ton, respectively. The strength of the sediment solidified with the solidifying agent after 28 days of solidification was 1.17 times and 1.14 times that of ordinary Portland cement, respectively. This demonstrates that the sediment solidifying agent offers excellent economic benefits and curing effectiveness.

[0166] Table 6-2 Unconfined compressive strength of solidified sediment (MPa)

[0167]

[0168] Furthermore, the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or change some of the technical features, such as the types of industrial solid waste and sediment. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A dynamic control method for ecological sediment solidification based on clay mineral composition, characterized in that: The following steps are involved: S1. Drying and grinding the industrial solid waste for preparing the bottom mud solidifying agent to obtain respective industrial solid waste powders; S2. Measure the content of active components of the industrial solid waste powder in step S1 by XRF i,j The curing activity excitation index η of industrial solid waste powder was measured by the activity index test i ; S3. Test the content of active components in clay minerals of sediment by oriented XRD * i，j , through w t-i,j , w 0-i,j Obtain the η of clay minerals in the sediment * i ; S4, step S2 n i , ε i,j and n in step S3 * i , ε * i，j Substitute into the cement three-rate value control model to obtain the mass ratio of industrial solid waste in the bottom mud solidifier M i ; S5. Adding an expansion agent component to the sediment curing agent configured in step S4 and preparing a sediment sample for curing. After curing for 28 days, a sediment foundation sample with a certain dry density is obtained, and the amount of the expansion agent component is determined according to the dry density; S6, according to the industrial solid waste mass ratio M in step S4 i and preparing a sediment curing agent by adding the expansion agent component in step S5, adding the sediment to prepare a solidified soil sample and curing for 7 days, 28 days, and 60 days, to obtain a solidified sediment of ordinary Portland cement having a certain dry density and an unconfined compressive strength greater than that of the samples cured for 7 days, 28 days, and 60 days; The industrial solid waste powder in step S2 is one or more of fly ash powder, yellow phosphorus slag powder, blast furnace slag powder and carbide slag powder; In step S4, M i is the mass ratio of solid waste i in the industrial solid waste to the bottom mud solidifying agent; In terms of mass ratio, the proportion of M in the bottom mud solidifier is i M fly ash: M yellow phosphorus slag: M blast furnace slag: M carbide slag = 21.4%~30%: 10%~16.7%: 19%~20%: 40%~42.9%; In step S5, the expansion agent component is phosphogypsum; The revised curing agent dosage is 24 wt% fly ash, 8 wt% yellow phosphorus slag, 16 wt% blast furnace slag, 32 wt% carbide slag and 20 wt% phosphogypsum; the curing agent addition amount is 20% of the wet mass of the sludge.

2. The method for dynamic control of ecological sediment solidification based on clay mineral composition according to claim 1, characterized in that: The specific surface area of ​​the powder in step S1 is 300m 2 / kg~400m 2 / kg.

3. The method for dynamic control of ecological sediment solidification based on clay mineral composition according to claim 1, characterized in that: In step S1, the industrial solid waste is selected from one or more of fly ash, yellow phosphorus slag, blast furnace slag and carbide slag; in, The active components and contents of each component of fly ash are 53.2% CaO, 8.2% Fe2O3, 22.4% SiO2, and 1.3% Al2O3; The active components and contents of each component of yellow phosphorus slag are 36.82% CaO, 4.3% Fe2O3, 37.24% SiO2, and 4.83% Al2O3; The active components and contents of each component in blast furnace slag are 37.2% CaO, 2.0% Fe2O3, 38.3% SiO2, and 16.4% Al2O3; The active components and contents of each component of carbide slag are 92.4% CaO, 0.4% Fe2O3, and 3.8% SiO2, respectively.

4. The method for dynamic control of ecological sediment solidification based on clay mineral composition according to claim 1, characterized in that: The activity index test formula in step S2 is: i =δ i / B; Among them, δ i is the i-th type of industrial solid waste A i The 28-day compressive strength of the test mortar is in MPa. B is the 28-day compressive strength of the cement-based reference mortar, in MPa. When i=1, it indicates that the industrial solid waste is fly ash; when i=2, it indicates that the industrial solid waste is blast furnace slag; when i=3, it indicates that the industrial solid waste is carbide slag; when i=4, it indicates that the industrial solid waste is yellow phosphorus slag; When j is 1, it indicates that the potential curing active component is SiO2, when j is 2, it indicates that the potential curing active component is Fe2O3, when j is 3, it indicates that the potential curing active component is Al2O3, and when j is 4, it indicates that the potential curing active component is CaO; η i It represents the solidification activity excitation index of solid waste i in industrial solid waste; ε i，j It represents the chemical content of the potential solidification active component j in the i-th type of solid waste.

5. The method for dynamic control of ecological sediment solidification based on clay mineral composition according to claim 1, characterized in that: In the step S3, ε * i，j is the mass content of chemical components of potential solidification active component j in clay mineral i in the sediment; η * i is the reaction dissolution rate of the potential solidification active components in the clay minerals in the sediment; or * i =w t-i,j / w 0-i,j ; When i is 1, it indicates that the clay mineral is kaolinite; when i=2, it indicates that the clay mineral is montmorillonite; when i is 3, it indicates that the clay mineral is illite; j is a natural number greater than zero: when j is 1, it indicates that the potential curing active excitation component is SiO2; when j is 2, it indicates that the potential curing active excitation component is Fe2O3; when j is 3, it indicates that the potential curing active excitation component is Al2O3; when j is 4, it indicates that the potential curing active excitation component is CaO.

6. The method for dynamic control of ecological sediment solidification based on clay mineral composition according to claim 1, characterized in that: The cement three-rate value control model in step S4 is: Among them, C i，j= η i × ε i，j , C * i，j= η * i × ε * i，j ; The total number of types n of industrial solid wastes is 4, namely fly ash, yellow phosphorus slag, blast furnace slag, and carbide slag. In the three modulus values of cement: SM is the silica modulus, 1.7 < SM < 2.7; IM is the alumina modulus, 0.9 < IM < 1.7; KH is the lime modulus, 0.9 < KH < 1.0; w IBP is the dosage of the curing agent; C i，j It represents the active excitation content of the jth potential solidification active excitation component in the i-th industrial solid waste; C * i，j It represents the active excitation content of the jth potential solidification active excitation component in the i-th clay mineral.

7. The method for dynamic control of ecological sediment solidification based on clay mineral composition according to claim 1, characterized in that: The dry density of the mud foundation sample prepared in step S5 is 900 kg / m 3 -1600 kg / m 3 .

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