Highly encapsulated solidified sludge and method for its production

Abstract

The application discloses a kind of high-wrapping solidified silt and preparation method thereof, it is related to soil solidification technical field.The application utilizes solidified agent to solidify silt, can realize the efficient solidification effect of silt, obtain the silt solidification product with excellent mechanical property.The solidified agent of the application includes solid waste cementitious component and organic reinforcing component, wherein, solid waste cementitious component includes carbide slag, gypsum and mineral powder with mass ratio of 13-17:13-17:66-74, organic reinforcing component includes xanthan gum and casein with mass ratio of 1:0.8-1.2, and the mass ratio of solid waste cementitious component and organic reinforcing component is 7:2.5-3.5.The application solves the problems of high water content, low strength and poor stability of dredged silt through the organic synergistic effect of the composite cementing system of carbide slag, gypsum and mineral powder and xanthan gum, casein, realizes the efficient solidification and resource utilization of dredged silt, and promotes the development of low-carbon engineering materials.

Description

Technical Field

[0001] This invention relates to the field of soil stabilization technology, and in particular to a highly encapsulating stabilized silt soil and its preparation method. Background Technology

[0002] With the acceleration of urbanization, large amounts of silt with high water content are generated during river dredging, lake dredging, and water environment management. This type of solid waste is characterized by high fluidity, high permeability, and complex organic matter content. Direct landfilling or disposal can easily lead to waste of land resources, secondary water pollution, and greenhouse gas emissions. Traditional treatment methods often rely on cement or lime solidification, but these methods have significant drawbacks: on the one hand, the large amount of cement used results in high costs and high carbon emissions; on the other hand, relying solely on inorganic cementing materials makes it difficult to form a dense structure, and the strength of the solidified material is generally low, making it difficult to meet the requirements of engineering filling. Summary of the Invention

[0003] The purpose of this invention is to provide a highly encapsulating solidified silt and its preparation method to solve the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] One of the technical solutions of this invention is to provide a silt solidification agent, comprising a solid waste cementing component and an organic reinforcing component;

[0006] The solid waste gelling component includes carbide slag, gypsum, and mineral powder; the organic reinforcing component includes xanthan gum and casein.

[0007] The mass ratio of carbide slag, gypsum, and mineral powder is 13-17:13-17:66-74; the mass ratio of xanthan gum and casein is 1:0.8-1.2.

[0008] The mass ratio of the solid waste gelling component to the organic reinforcing component is 7:2.5-3.5.

[0009] The second technical solution of the present invention provides a method for preparing the above-mentioned silt solidification agent, comprising the following steps:

[0010] The solid waste cementing component and the organic reinforcing component are mixed in water to obtain the silt solidification agent.

[0011] The third technical solution of the present invention is to provide the application of the above-mentioned silt solidifying agent in silt solidification.

[0012] Fourth technical solution of the present invention: A method for solidifying silt, comprising the following steps:

[0013] The silt solidifying agent is mixed with the silt to solidify the silt.

[0014] As a further preferred embodiment of the present invention, the dry mass ratio of the silt solidifying agent to the silt is 5-6:100.

[0015] Fifth technical solution of the present invention: Provides a solidified sludge, which is prepared by the above-mentioned solidification method.

[0016] The sixth technical solution of the present invention provides a method for calculating the dosage of the above-mentioned silt solidifying agent in silt based on the degree of encapsulation, wherein the dosage of the silt solidifying agent in silt is calculated according to the formula for calculating the degree of encapsulation.

[0017] The formula for calculating the coverage degree is:

[0018]

[0019] In the formula, m is the mass of the curing agent added, m0 is the mass of the silt, ρ is the density of the silt, ρ1 is the density of the solid waste gelling component, ρ2 is the density of xanthan gum, ρ3 is the density of casein, and α = 0.95.

[0020] Wherein, the wrapping degree P = 0-1.

[0021] This invention uses waste silt as a base material and achieves simultaneous improvement in the mechanical properties and seepage prevention performance of silt through the synergistic solidification effect of multi-source solid waste components and bio-based cementitious materials. The solidification system consists of the following components: (1) Solid waste cementitious components: a composite system of carbide slag-gypsum-mineral powder is adopted, in which carbide slag provides active Ca(OH)2 to activate the pozzolanic effect of mineral powder, gypsum regulates the setting time and participates in the formation of ettringite, and the three form a dense network structure through the dual reaction of "alkali activation-sulfate activation"; (2) Organic reinforcing components: a composite biopolymer of xanthan gum and casein is selected, in which xanthan gum forms a three-dimensional network skeleton through hydrogen bonding to improve the encapsulation, and the hydrophobic groups of casein reduce the porosity by bonding with the interface of solid waste components. The two work together to achieve micro-nano scale coating of silt particles.

[0022] This invention achieves efficient encapsulation and structural reinforcement of silt particles through the synergistic mechanism of a composite solid waste cementing system of carbide slag-gypsum-mineral powder and xanthan gum-casein organic reinforcing components. Based on the alkaline activation characteristics of carbide slag, it releases... Under the activation of gypsum sulfate, the active silica-alumina components in the mineral powder rapidly generate nanoscale CSH gel and ettringite network, forming a dense base cementing layer that effectively fills soil pores and enhances the rigidity of the framework. Xanthan gum constructs a three-dimensional network structure through β-1,4 glycosidic bonds, physically coating the dispersed gel and soil particles, enhancing the system's integrity and resistance to deformation. Simultaneously, the hydrophobic groups of casein optimize the pore structure through interfacial orientation, and its carboxylic acid groups chelate with metal ions on the mineral surface, further strengthening the interparticle bonding strength.

[0023] This invention fully leverages the synergistic advantages of the organic-inorganic composite system. Through the skeletal support of xanthan gum and the interfacial modification of casein, it promotes the directional and dense arrangement of soil particles. During this process, the formation of hydrophobic microdomains in casein significantly inhibits water infiltration pathways, while the continuous growth of solid waste gel products dynamically couples with the organic network, forming a multi-level structure of "rigid support - flexible encapsulation - hydrophobic sealing." This structure can resist stress concentration caused by external loads and dissipate energy through microdomain deformation, thereby simultaneously improving the material's mechanical strength and impermeability.

[0024] This invention can modify low-permeability silt into engineering filler with unconfined compressive strength >1.5MPa, while realizing the high-value utilization of industrial by-products such as carbide slag and desulfurization gypsum. Compared with cement-stabilized soil, it reduces carbon emissions by more than 30%, and has good ecological and environmental benefits and engineering economics.

[0025] Preferably, this invention introduces the concept of coating degree for the curing agent dosage. The coating degree P refers to the extent to which the curing agent covers and tightly coats the surface of silt particles and between particles, and its calculation formula is as follows:

[0026]

[0027] Where d is the average particle size of silt (mm); t is the thickness of the curing agent coating (mm); and the value of k depends on the particle shape. For particles that are close to spheres, k≈1; for particles that are flat or elongated, k>1. In this invention, k is approximately taken as 1.

[0028] The formula for calculating package thickness is:

[0029]

[0030] Where d is the average particle size of the silt (cm), m is the mass of the solidifying agent added (g), m0 is the mass of the soil (g), and ρ is the density of the silt (g / cm³). 3 ), ρ1 is the density of the solid waste component (g / cm³) 3 ), ρ2 is the density of xanthan gum (g / cm³) 3 ), ρ3 is the casein density (g / cm³) 3`), where α is the distribution coefficient, and in this invention, α is taken as 0.95.

[0031] Substituting the corrected t into the original wrapping formula, we obtain the corrected wrapping formula:

[0032]

[0033] Where m is the mass of the solidifying agent added (g), m0 is the mass of the soil (g), and ρ is the density of the silt soil (g / cm³). 3 ), ρ1 is the density of the solid waste component (g / cm³) 3 ), ρ2 is the density of xanthan gum (g / cm³) 3 ), ρ3 is the casein density (g / cm³) 3 ), α=0.95.

[0034] Complete encapsulation refers to the degree to which the curing agent completely covers and fills the entire surface of the soil particles and all the pores between the particles. In this ideal state, each soil particle is like being surrounded by a continuous, seamless curing agent "shell," with no unencapsulated soil surface. In this invention, the encapsulation thickness reaches 1×10⁻⁶. -5 mm is considered a complete wrap, and the wrapping degree p is approximately 1, which is considered a complete wrap.

[0035] In the process of designing the mixing ratio of the curing agent and silt, the present invention calculates the amount of curing agent by using the above formula to achieve complete coating of the silt.

[0036] Based on the different particle size and density of the silt, and under the premise of meeting the initial conditions, the dosage of the solidifying agent is adjusted to achieve complete encapsulation.

[0037] This invention achieves precise control from microscopic encapsulation to macroscopic properties by dynamically adjusting the ratio of solid waste to organic components, adapting to silt soils with different particle size distributions and moisture contents. The solidified soil exhibits low permeability, high stability, and environmental compatibility, and can replace traditional cement-based materials in engineering scenarios such as roadbed filling and slope protection, providing a systematic solution for the resource utilization of dredged silt and the low-carbon conversion of industrial solid waste.

[0038] Preferably, the organic reinforcing component is mixed with the soil sample in a wet-mixing manner. Wet mixing allows for better integration of the organic reinforcing component with the soil sample, resulting in better encapsulation of soil particles and improved impermeability and compressive strength of the resulting solidified soil.

[0039] Preferably, the method for solidifying silt includes the following steps:

[0040] (1) Dry the carbide slag, gypsum and mineral powder, then mix and grind them to obtain a mixture;

[0041] (2) Dissolve xanthan gum and casein in distilled water, stir and control the consistency to avoid it becoming too thick, to obtain a colloid;

[0042] (3) Add the mixture from step (1) to the colloidal system obtained in step (2) and stir continuously with a magnetic stirrer until all solid waste (powder) is completely dissolved and a uniform gel is formed, which is the curing agent.

[0043] (4) The curing agent and silt are mixed by an automatic rotary mixer, wherein the mass ratio of curing agent to silt is 5:100. After stirring for 5 minutes, the mixture is left to stand for 1 to 2 hours to obtain a premixed mixture.

[0044] (5) Pour the premixed mixture evenly into the feed hopper of the fully automatic press. The fully automatic press feeds the mixed premixed mixture and pours it evenly into a cylindrical mold with a diameter of 50mm and a height of 50mm. After the cube is pressed and demolded, it is cured for 28 days at an air temperature of 20℃±2℃. During the curing process, water should be sprayed on the specimen every 4 hours to ensure the humidity of the specimen. The curing time should not be less than 28 days to solidify the silt. Then the brick can be put into use.

[0045] Preferably, in step (3), the mixture should be spread evenly in layers until the predetermined mass ratio is reached before mixing.

[0046] Preferably, during the mixing process in step (4), attention should be paid to the actual thickness of the silt and the curing agent when the layers are separated. The thickness and uniformity of each layer of curing agent should be strictly controlled to ensure that the curing agent components can be evenly covered on the silt layer. The mixing time should not be less than 5 minutes.

[0047] Preferably, during the stirring process in step (4), the silt that has clumped together should be crushed to ensure that the solidifying agent components can effectively enter the interior of the silt.

[0048] Preferably, in step (5), polypropylene is used as the mold material to prevent the specimen from sticking to the mold wall during demolding. Additionally, a linear groove is cut into the mold to facilitate specimen extraction. During specimen fabrication, this groove is blocked by two pipe fasteners at the top and bottom of the mold, and the upper and lower surfaces are slightly trimmed to avoid uneven stress distribution. Two sheets of filter paper can also be placed on the top and bottom surfaces to prevent stress localization.

[0049] The mechanism of action of this invention is as follows:

[0050] The core mechanism of this invention stems from the synergistic effect of the solid waste cementing system and organic composite materials, achieving dense encapsulation and structural reinforcement of soil particles through multi-scale interactions. In an alkaline environment, carbide slag releases active calcium components, which react with the silica-alumina components in gypsum and mineral powder to form a cementing network. This network fills the pores between soil particles and neutralizes the surface charge of clay minerals, promoting enhanced interparticle attraction and directional aggregation. Xanthan gum, with its unique three-dimensional network molecular structure, physically coats the dispersed cementing products and soil particles, enhancing interfacial adhesion through hydrogen bonding and inhibiting particle slippage and pore regeneration. Simultaneously, casein hydrophobic groups are oriented at the cement-soil interface, forming a non-polar barrier to block water infiltration pathways, while its carboxylic acid groups further chelate free metal ions, optimizing interparticle bonding strength.

[0051] The dynamic coupling of solid waste components and organic materials forms a "rigid skeleton-flexible encapsulation" composite system. The carbide slag-gypsum-mineral powder system generates a stable calcium silicate network through continuous hydration, providing the soil with basic bearing capacity. Xanthan gum's spatial network structure dissipates stress through elastic deformation under load, preventing brittle cracking. Casein, through interfacial modification, strengthens the chemical bonding at the multiphase interface, making it difficult for water and corrosive media to penetrate the material's interior. Through the synergistic effect of these three components, soil particles are continuously encapsulated from microscopic to macroscopic levels, exhibiting a gradient compaction of the pore structure. The overall material demonstrates balanced mechanical properties and environmental stability.

[0052] This invention is based on the synergistic innovation of solid waste-based cementitious systems and bio-composite materials, achieving a dual improvement in engineering performance and environmental benefits through a multi-level mechanism. The carbide slag-gypsum-mineral powder composite system activates a synergistic cementitious effect under alkaline conditions. The carbide slag provides an active calcium source to drive the pozzolanic reaction of the silica-alumina components in the mineral powder, while the gypsum promotes the growth of ettringite whiskers through sulfate activation, forming a dense three-dimensional network framework that significantly improves the compressive strength and volume stability of the soil. Xanthan gum, with its high-molecular-weight chain structure, forms a spatial encapsulation layer, strengthening the interfacial bonding between the cement and soil particles through hydrogen bonding, while simultaneously inhibiting the generation and propagation of drying shrinkage cracks, ensuring the long-term durability of the material. Casein hydrophobic groups are directionally enriched at the microscopic interface, effectively blocking water penetration pathways. Its selective chelation with metal ions further optimizes the pore structure, giving the solidified soil both low permeability and corrosion resistance.

[0053] This invention innovatively integrates the advantages of industrial solid waste and bio-based materials to construct a dynamic interpenetrating structure of "cementing reinforcement - flexible toughening - hydrophobic sealing". The large-scale utilization of industrial byproducts such as carbide slag and gypsum not only reduces the cost of cementing materials but also decreases carbon emissions from traditional cement production processes. The synergistic effect of xanthan gum and casein overcomes the functional limitations of single biomaterials, forming a composite encapsulation system adaptable to complex engineering environments. This technology enables the green upgrade of dredged sludge from waste material to engineering filler, promoting the practical application of the "waste-to-waste" technology approach in geotechnical engineering and providing a systematic solution for the resource-based disposal of sludge and the construction of low-carbon infrastructure in coastal areas.

[0054] This invention can effectively solve the problems of poor permeability and low utilization rate of silt. Through the directional deconstruction and bridging catalysis of casein molecules under alkaline conditions, and after compression molding, the compressive strength of silt is significantly improved, and it can be directly used for roadbed filling, overcoming the problems of high water content and low strength of silt.

[0055] This invention introduces the concept of encapsulation degree to precisely optimize the pore structure of solidified soil. When the encapsulation degree is appropriate, the solidifying agent fills the pores between soil particles and encapsulates them, resulting in a more uniform pore distribution. A reasonable encapsulation degree helps improve the air permeability and water permeability of the solidified soil. Precise control of material usage reduces waste. The introduction of the encapsulation degree concept helps accurately determine the amount of solidifying agent needed in the solidified soil. By quantifying the encapsulation degree, it is clear how much solidifying agent is required to achieve the ideal encapsulation effect, avoiding waste of excess solidifying agent. Different types of soil have different soil particle characteristics, and therefore require different encapsulation degrees. By rationally configuring the solidifying agent according to their characteristics, material waste caused by blindly adding solidifying agent without understanding soil properties is avoided. This achieves efficient material utilization.

[0056] This invention, by adjusting the ratio of solid waste to organic components, adapts to silt soils with different engineering characteristics, enabling the solidified soil to possess low permeability, high bearing capacity, and long-term durability. It can be widely used in engineering scenarios such as soft soil treatment and ecological slope protection, providing an innovative path for the resource utilization of silt.

[0057] The present invention discloses the following technical effects:

[0058] This invention addresses the problems of high water content, low strength, and poor stability of dredged sludge through the synergistic effect of a composite cementing system of carbide slag, gypsum, and mineral powder, combined with xanthan gum and casein. In the solid waste component, carbide slag and mineral powder form a dense cementing network under gypsum activation, significantly improving the strength of the soil skeleton. In the organic reinforcing component, xanthan gum encapsulates sludge particles through a spatial network structure, while the hydrophobic properties of casein further optimize the pore structure. Together, these components synergistically enhance the material's impermeability and overall stability.

[0059] This invention replaces traditional cement with industrial solid waste and combines the green modification effect of bio-based materials to achieve efficient solidification and resource utilization of dredged sludge, thereby promoting the development of low-carbon engineering materials. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0061] Figure 1 This is a particle size distribution diagram of silt. Detailed Implementation

[0062] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0063] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0064] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0065] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0066] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0067] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0068] Example 1

[0069] Silt soil parameters: average particle size 0.0052 mm, density 1.4 g / cm³. 3 The soil permeability coefficient is 2.5 × 10⁻⁶. - 5 cm / s; According to the "Technical Standard for Application of Soil Stabilizer" (CJJ / T 286-2018), the optimal moisture content is determined by compaction test, and the soil is thoroughly mixed with the stabilizer at the optimal moisture content. Figure 1 This is a particle size distribution diagram of silt.

[0070] The curing agent composition is as follows: Component A (solid waste gelling component): carbide slag: gypsum: mineral powder = 15:15:70 (mass ratio); Component B (organic reinforcing component): xanthan gum: casein = 1:1 (mass ratio); Component A: Component B = 7:3 (mass ratio).

[0071] Envelope formula:

[0072]

[0073] Where m is the mass of the solidifying agent added (g), m0 is the mass of the soil (g), and ρ is the density of the silt soil (g / cm³). 3 ), ρ1 is the density of the solid waste component (g / cm³) 3 ), ρ2 is the density of xanthan gum (g / cm³) 3 ), ρ3 is the casein density (g / cm³) 3 ), α=0.95.

[0074] Complete wrap condition: Wrap degree P≈1.

[0075] Preparation of highly encapsulating solid waste sludge:

[0076] (1) Dry the carbide slag, gypsum and mineral powder and then grind them to obtain a mixture;

[0077] (2) Dissolve xanthan gum and casein in distilled water, with the total mass ratio of xanthan gum and casein to water being 1:10, and stir until a colloid with a viscosity of 500 mPa·s is formed.

[0078] (3) The mixture obtained in step (1) is added to the colloid in step (2) by spreading it evenly in layers. The mixture is stirred continuously with a magnetic stirrer until all solid waste (powder) is completely dissolved and a uniform colloid is formed, which is the curing agent.

[0079] (4) Mix 50g of curing agent with 1kg of silt using an automatic rotary mixer (P≈1) (wherein, the density of component A is 2.8g / cm³). 3 Xanthan gum has a density of 1.5 g / cm³. 3 The casein density is 1.2 g / cm³. 3 After stirring for 5 minutes, let the mixture stand for 2 hours to obtain a premixed mixture;

[0080] (5) Pour the mixed premixed mixture evenly into the feed hopper of the fully automatic press. The fully automatic press feeds the mixed premixed mixture and pours it evenly into a cylindrical mold (polypropylene material) with a diameter of 50mm and a height of 50mm. After the cube is demolded, it is cured for 28 days at an air temperature of 20℃±2℃. During the curing process, water should be sprayed on the curing specimen every 4 hours to ensure the humidity of the specimen. The curing time is 28 days before the brick is put into use.

[0081] The following multiple sets of curing agent-silt mixtures with different proportions were prepared according to the above method. Six parallel specimens were selected from each set, corresponding to numbers 1-6:

[0082] Group 1: The mass ratio of solidifying agent to silt is 0.02:1;

[0083] Group 2: The mass ratio of solidifying agent to silt is 0.03:1;

[0084] Group 3: The mass ratio of solidifying agent to silt is 0.04:1;

[0085] Group 4: The mass ratio of solidifying agent to silt is 0.05:1;

[0086] Group 5: The mass ratio of solidifying agent to silt is 0.06:1;

[0087] Group 6: The mass ratio of curing agent to silt is 0.07:1.

[0088] According to the test method for compressive strength of masonry blocks in the "Standard for Geotechnical Testing Methods" (GB / T 50123-2019), prepare the test block specimens, place the specimens flat in the center of the pressure plate, and apply the load perpendicular to the compression surface. The loading should be uniform and stable, without impact or vibration. The loading rate should be (2~6) kN / s until the specimen fails, and record the maximum unconfined compressive strength F. ucs According to the "Standard for Geotechnical Testing Methods" (GB / T 50123-2019), variable head permeability tests were conducted, and the compressive strength and permeability coefficient were calculated according to the standard formulas, as shown in Table 1.

[0089] Table 1 28d compressive strength and permeability coefficient

[0090]

[0091] According to the test results, when the mass ratio of curing agent to silt is between 0.04 and 0.07 (groups 3-6), the average 28-day compressive strength of the cured silt specimens is above 1.5 MPa; the average 28-day compressive strength of group 1 (casein to silt mass ratio of 0.02:1) and group 2 (curing agent to silt mass ratio of 0.03:1) is below 1.5 MPa.

[0092] Compressive strength of composite curing agents with different dosages in Comparative Examples 1-4

[0093] The silt used in Comparative Examples 1-4 had a particle size of 0.00045 cm and a density of 1.7 g / cm³. 3 The soil permeability coefficient is 1.8 × 10⁻⁶. -5 .

[0094] The steps for solidifying silt in Comparative Examples 1-4 are the same as in Example 1, except for the dosage.

[0095] According to formulas (2) and (3), the calculated value of the amount of admixture used to achieve complete encapsulation of silt in comparative examples 1-4 is 3.93% (take 4%).

[0096] Using the same testing standards as Example 1, the 28-day compressive strength and permeability coefficient of the solidified silt soil obtained with different amounts of solidifying agent in Comparative Examples 1-4 are shown in Table 2.

[0097] Table 2

[0098] Dosage (%) Compressive strength (MPa) Permeability coefficient (cm / s) Comparative Example 1 2 1.37 <![CDATA[3.4×10 -6 ]]> Comparative Example 2 3 1.66 <![CDATA[6.5×10 -7 ]]> Comparative Example 3 4 1.89 <![CDATA[2.7×10 -7 <!-- 7 -->]]> Comparative Example 4 5 2.11 <![CDATA[1.4×10 -7 ]]>

[0099] Comparative Example 5: Solid Waste Component Solidifying Agent

[0100] The only difference from Example 1 is that a single solid waste component solidifying agent (carbide slag, gypsum, and mineral powder) is used.

[0101] According to formula (3), the encapsulation degree is approximately 1. At this time, the mass of the curing agent is approximately 67.2g, and the curing agent dosage is approximately 6.72%. The mass ratio of carbide slag, gypsum and mineral powder is 15:15:70.

[0102] Using the same testing standards as in Example 1, the results showed that the 28-day compressive strength of the solidified silt was 1.43 MPa, and the permeability coefficient was 3.8 × 10⁻⁶. -6 .

[0103] Comparative Example 6: Agar Curing Agent

[0104] The only difference from Example 1 is that the solid waste component solidifier is replaced with an equal mass of agar.

[0105] Using the same testing standards as in Example 1, the results showed that the 28-day compressive strength of the solidified silt was 1.61 MPa, and the permeability coefficient was 5.5 × 10⁻⁶. -7 .

[0106] Comparative Example 7: Chitosan and milk powder replace xanthan gum and casein

[0107] The only difference from Example 1 is that the organic curing component curing agent is replaced with an equal mass of chitosan and milk powder (mass ratio 1:1).

[0108] Using the same testing standards as in Example 1, the results showed that the 28-day compressive strength of the solidified silt was 0.96 MPa, and the permeability coefficient was 7.2 × 10⁻⁶. -7 .

[0109] Compared to cement and other organic cementitious materials, the composite curing agent of this invention has technical advantages and also exhibits certain strength advantages when fully encapsulated. Furthermore, the curing agent of this invention is universally applicable and environmentally friendly to soils with low strength, high water absorption, and poor impermeability. Based on the synergistic mechanism of the carbide slag-gypsum-mineral powder solid waste cementing system and xanthan gum-casein organic components, its encapsulation degree can be adapted to soils with different particle size environments (clay to sand) and densities. By dynamically adjusting the component ratio, it achieves full-scale encapsulation from nanoscale pore filling to macroscopic structural reinforcement.

[0110] The environmental benefits of this invention stem from the dual innovation of the green properties of bio-based materials and the resource utilization of solid waste. Casein, as a natural protein gelling component, can be completely mineralized through microbial metabolism, avoiding the environmental residue risks of chemically synthesized materials; the biocompatibility of xanthan gum further ensures the ecological safety of the system. Compared to the high carbon emissions of cement production, the recycling of industrial by-products such as carbide slag and gypsum can reduce the carbon footprint of gelling materials by more than 60%, forming a closed-loop technical path of "solid waste value-added - low-carbon solidification - ecological restoration". Using this composite solidifying agent as a gelling material to solidify soil, even if the soil structure changes later or it is discarded, it will not cause long-term environmental pollution like some non-degradable organic gelling materials, which is conducive to the restoration and protection of the ecological environment.

[0111] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A soil solidifier for sludge, characterized by comprising: The raw materials include a solid waste cementitious component and an organic reinforcing component; The solid waste cementitious component includes carbide slag, gypsum and mineral powder; the organic reinforcing component includes xanthan gum and casein; The mass ratio of the carbide slag, gypsum and mineral powder is 13-17:13-17:66-74; the mass ratio of the xanthan gum and casein is 1:0.8-1.2; The mass ratio of the solid waste cementitious component and the organic reinforcing component is 7:2.5-3.

5.

2. The method for preparing a soil solidifying agent according to claim 1, wherein The method comprises the following steps: Mixing the solid waste cementitious component and the organic reinforcing component in water to obtain the sludge soil solidifying agent.

3. The sludge soil solidifying agent of claim 1 in the application of sludge soil solidification.

4. A method for solidifying a sludge soil, characterized by, The method comprises the following steps: Mixing the sludge soil solidifying agent of claim 1 with sludge soil to achieve the solidification of the sludge soil.

5. The method of claim 4, wherein, The dry mass ratio of the sludge soil solidifying agent to the sludge soil is 5-6:

100.

6. A solidified sludge, characterized by, The sludge soil solidifying agent is prepared by the solidification method of claim 4.

7. A method for calculating the amount of the soil solidifying agent of claim 1 to be mixed in the silt soil based on the degree of wrapping, characterized in that, The dosage of the sludge soil solidifying agent in the sludge soil is calculated according to a wrapping degree calculation formula; The wrapping degree calculation formula is: In the formula, m is the solidifying agent dosage, m0 is the sludge soil mass, ρ is the sludge soil density, ρ1 is the solid waste cementitious component density, ρ2 is the xanthan gum density, ρ3 is the casein density, and α = 0.95; Wherein, the wrapping degree P = 0-1.

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