Preparation method of multi-source sludge solidified soil

Abstract

The invention discloses a preparation method of multi-source sludge solidified soil. The preparation method comprises the following steps: S1, measuring the dry mass a of particulate matters of which the pore diameters are greater than 0.005 mm, the dry mass b of particulate matters of which the pore diameters are not greater than 0.005 mm and the mass of water in sludge; s2, measuring the mass of montmorillonite, illite, kaolinite and other particles in the dry mass b; s3, calculating the mass of the cement; s4, calculating the mass of the admixture; s5, calculating the mass of the exciting agent; s6, calculating the mass of the surfactant; s7, calculating the mass of the additive; s8, mixing the admixture, the excitant and the surfactant to obtain a mixture I; s9, controlling the moisture content of the mixture I; and S10, mixing the mixture I with cement, an additive and sludge to obtain the multi-source sludge solidified soil. In the process of preparing the solidified soil, the mass of clay particles and secondary minerals of the sludge is accurately measured, and then the addition amount of other components of the solidified soil is calculated according to measured data, so that the solidification effect on the sludge is guaranteed, and the method is suitable for solidification treatment of different types of sludge.

Description

Technical Field

[0001] The present invention relates to the field of sludge treatment, and more particularly to a method for preparing multi-source sludge solidified soil. Background Art

[0002] Silt is widely present in rivers, lakes, ports and various water conservancy projects and facilities. Silt has a complex composition and is prone to secondary pollution. Improper disposal will have an adverse impact on the ecological environment. Therefore, the treatment of dredged silt has become a common concern.

[0003] At present, the commonly used method for treating sludge is to use a curing agent or cement to solidify the sludge, so that a cementing effect is formed between the sludge particles, thereby improving the strength and stability of the sludge and facilitating subsequent treatment. However, in actual operation, the existing curing treatment method does not distinguish between the composition and source of the sludge. In fact, the composition of sludge from different sources varies greatly. The clay content in the sludge and the type and content of secondary minerals have a significant effect on the mechanical properties of the solidified sludge. When treating sludge, if the components and sources of the sludge are not distinguished, the same curing material is used to solidify sludge of different components, and the curing effect of the sludge cannot be guaranteed. In order to ensure the curing effect, it is often necessary to adjust the mix ratio of the curing material through a large number of experiments, resulting in unnecessary cost, manpower and material investment.

[0004] Therefore, in order to ensure the solidification effect of silt and reduce resource waste, it is urgently necessary to provide a preparation method of multi-source silt solidification soil to meet actual needs. Summary of the invention

[0005] Another object of the present invention is to provide a method for preparing multi-source silt solidified soil. In the process of preparing the solidified soil, the mass of clay and secondary minerals in the silt are first accurately measured, and then the addition amount of other components of the solidified soil is calculated based on the measured clay mass and secondary mineral mass, thereby ensuring a good solidification effect on the silt, and the method is suitable for solidification treatment of silt from different sources.

[0006] In order to achieve these purposes and other advantages according to the present invention, a method for preparing multi-source silt solidified soil is provided. The multi-source silt solidified soil is obtained by fully mixing silt with cement, admixture, activator, surfactant and additive. The method for preparing multi-source silt solidified soil comprises the following steps: S1. Take sludge of mass S and determine the dry mass a of particles with pore size greater than 0.005 mm, the dry mass b of particles with pore size not greater than 0.005 mm, and the mass c of water in the sludge; S2, measure the mass b1 of montmorillonite, the mass b2 of illite, the mass b3 of kaolinite, and the mass b4 of other particles in particles with a pore size not greater than 0.005 mm; S3. According to the dry mass a and b of the particles in S1 and the mass b1, b2, b3 and b4 of the particles in S2, the mass G of the cement is calculated according to the following formula: G=a*m*( b1*1.15+ b2*1.1+ b3*1.1+ b4*1.05) / b; Where: m is the cement adjustment coefficient, 0.05≤m≤0.2; S4. According to the mass b1, b2, b3, and b4 of the particles in S2, the mass D of the admixture is calculated according to the following formula: D= b1*λ1+ b2*λ2+ b3*λ3+ b4*λ4; Where: λ1, λ2, λ3, λ4 are the admixture adjustment coefficients, among which, 0.15≤λ1≤0.25; 0.1≤λ2≤0.2; 0.05≤λ3≤0.15; 0.05≤λ4≤0.1; S5. According to the mass G of cement in S3 and the mass D of admixture in S4, the mass E of activator is calculated according to the following formula: E=G* w1+D* w2; Where: w1, w2 are the exciter adjustment coefficients, where 0.01≤w1≤0.05; 0.1≤w2≤0.2; S6. According to the mass D of the admixture in S4 and the mass E of the activator in S5, the mass F of the surfactant is calculated according to the following formula: F=(D+ E)*u; Wherein, u is the surfactant adjustment coefficient, 0.0001≤u≤0.001; S7. According to the mass c of water in S1, the mass H of the additive is calculated according to the following formula: H = c * q; Where: q is the additive adjustment coefficient, 0.001≤q≤0.005; S8. Mix the above-mentioned admixture, activator and surfactant evenly and grind them to a specific surface area of ​​600~1000m 2 / kg, the mixture is obtained; S9. Control the moisture content of the mixture 1 between 60% and 120%; S10, mixing the mixture 1 in S9 with the above-mentioned mass of cement and additives to obtain a mixture 2, and mixing the mixture 2 with the above-mentioned mass of sludge to obtain multi-source sludge solidified soil.

[0007] Preferably, in S4, the admixture is one or a mixture of slag, fly ash, carbide slag, coal gangue and silica ash.

[0008] Preferably, in S5, the activator is one or a mixture of sodium carbonate, sodium hydroxide, potassium carbonate and potassium hydroxide.

[0009] Preferably, in S6, the surfactant is one or a mixture of triethanolamine, sodium acetate, sodium lignosulfonate.

[0010] Preferably, in S7, the additive is one or a mixture of phosphogypsum, desulfurized gypsum or industrial gypsum.

[0011] The present invention includes at least the following beneficial effects: the preparation method of multi-source silt solidified soil proposed in the present invention, in the process of preparing solidified soil, firstly accurately measures the mass of clay and secondary minerals in the silt, and then calculates the addition amount of other components of the solidified soil according to the measured mass of clay and secondary minerals, thereby ensuring a good solidification effect on the silt, the preparation process is simple, the solidified soil mix ratio design process is simplified, a large number of mix ratio tests are avoided, manpower, financial resources and material resources are greatly saved, and it is suitable for the solidification treatment of silt from different sources.

[0012] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0013] The present invention is described in further detail below so that those skilled in the art can implement it according to the description.

[0014] The present invention provides a method for preparing multi-source silt solidified soil. The multi-source silt solidified soil is obtained by fully mixing silt with cement, admixture, activator, surfactant and additive. The method for preparing multi-source silt solidified soil comprises the following steps: S1. Take sludge with a mass of S, put it into an oven, dry it at a temperature of 105-110°C to constant weight, put the dried sludge into a dryer and cool it to room temperature, and weigh its mass on a balance as M, that is, the mass of water c=SM; put the dried and cooled sludge to room temperature on a screening machine, and screen it with a sieve with an aperture of 0.005 mm. After the screening is completed, weigh the mass of the particles left on the sieve, which is the dry mass a of the particles with an aperture greater than 0.005 mm in the sludge, and weigh the mass of the particles passing through the sieve, which is the dry mass b of the particles with an aperture not greater than 0.005 mm; S2. Using X-ray diffraction analysis to determine the mass b1 of montmorillonite, the mass b2 of illite, and the mass b3 of kaolinite in the particles with a pore size not greater than 0.005 mm, and subtracting b1, b2, and b3 from the total mass b to obtain the mass b4 of the other particles; S3. According to the dry mass a and b of the particles in S1 and the mass b1, b2, b3 and b4 of the particles in S2, the mass G of cement is calculated according to the following formula. Ordinary Portland cement is used as the cement, and the calculation formula is as follows: G=a*m*( b1*1.15+ b2*1.1+ b3*1.1+ b4*1.05) / b; Where: m is the cement adjustment coefficient, 0.05≤m≤0.2; S4. According to the mass b1, b2, b3, and b4 of the particles in S2, the mass D of the admixture is calculated according to the following formula. The admixture is one or a mixture of slag, fly ash, carbide slag, coal gangue, and silica fume; the calculation formula is as follows: D= b1*λ1+ b2*λ2+ b3*λ3+ b4*λ4; Where: λ1, λ2, λ3, λ4 are the admixture adjustment coefficients, among which, 0.15≤λ1≤0.25; 0.1≤λ2≤0.2; 0.05≤λ3≤0.15; 0.05≤λ4≤0.1; S5. According to the mass G of cement in S3 and the mass D of admixture in S4, the mass E of activator is calculated according to the following formula. The activator is one or a mixture of sodium carbonate, sodium hydroxide, potassium carbonate and potassium hydroxide. The calculation formula is as follows: E=G* w1+D* w2; Where: w1, w2 are the exciter adjustment coefficients, where 0.01≤w1≤0.05; 0.1≤w2≤0.2; S6. According to the mass D of the admixture in S4 and the mass E of the stimulator in S5, the mass F of the surfactant is calculated according to the following formula. The surfactant is one or a mixture of triethanolamine, sodium acetate, and sodium lignosulfonate. The calculation formula is as follows: F=(D+ E)*u; Wherein, u is the surfactant adjustment coefficient, 0.0001≤u≤0.001; S7. According to the mass c of water in S1, the mass H of the additive is calculated according to the following formula. The additive is one or a mixture of phosphogypsum, desulfurized gypsum or industrial gypsum; the calculation formula is as follows: H = c * q; Where: q is the additive adjustment coefficient, 0.001≤q≤0.005; S8. Mix the above-mentioned admixture, stimulant and surfactant evenly and grind them to a specific surface area of ​​600-1000m 2 / kg, the mixture is obtained; S9. Control the moisture content of the mixture 1 between 60% and 120%. The moisture content of the mixture 1 is controlled between 60% and 120%, which can ensure that the strength of the subsequently prepared solidified soil meets various construction process requirements. In order to further improve the strength of the solidified soil, the moisture content of the mixture 1 can be controlled between 80% and 100%. Specifically: a moisture meter is used to detect the moisture content of the mixture 1. When the moisture content detected exceeds a set range, the mixture 1 is dried until the moisture content is within the set range; when the moisture content detected is lower than the set range, water is sprayed into the mixture 1 and stirred evenly to make the moisture content of the mixture 1 within the set range; S10, mixing mixture one with the above-mentioned mass of cement and additives to obtain mixture two, and mixing mixture two with the above-mentioned mass of sludge to obtain multi-source sludge solidified soil.

[0015] The preparation method of the present invention is used to solidify dredged sludge from five different sources. The sludge in Examples 1-5 is derived from riverbed dredged sludge in Shanghai, Zhejiang, Dalian, Shenzhen, and Zhenjiang, respectively. The sludge in Example 6 is derived from the same source as that in Example 1. After the sludge is solidified, the 28d non-lateral compressive strength of the solidified soil is measured, and the corresponding data are shown in Table 1: Table 1 In Table 1, the admixtures of Examples 1-6 are all prepared by mixing slag and fly ash; the activators are all prepared by mixing sodium carbonate and sodium hydroxide; the surfactants are all triethanolamine; and the additives are all industrial gypsum; the admixtures, activators, and surfactants are uniformly mixed and ground to a specific surface area of ​​650 m 2 / kg, and the moisture content of the mixture is controlled to be 90%; In Example 1, the cement adjustment coefficient m=0.08, the admixture adjustment coefficients λ1=0.15, λ2=0.1, λ3=0.05, λ4=0.05; the activator adjustment coefficients w1=0.01, w2=0.1; the surfactant adjustment coefficient u=0.0001, and the additive adjustment coefficient q=0.001; In Example 2, the cement adjustment coefficient m=0.08, the admixture adjustment coefficients λ1=0.25, λ2=0.2, λ3=0.15, λ4=0.1; the activator adjustment coefficients w1=0.01, w2=0.1; the surfactant adjustment coefficient u=0.0001, and the additive adjustment coefficient q=0.001; In Example 3, the cement adjustment coefficient m=0.08, the admixture adjustment coefficients λ1=0.25, λ2=0.2, λ3=0.15, λ4=0.1; the activator adjustment coefficients w1=0.01, w2=0.1; the surfactant adjustment coefficient u=0.0001, and the additive adjustment coefficient q=0.001; In Example 4, the cement adjustment coefficient m=0.08, the admixture adjustment coefficients λ1=0.15, λ2=0.1, λ3=0.05, λ4=0.05; the activator adjustment coefficients w1=0.01, w2=0.1; the surfactant adjustment coefficient u=0.0001, and the additive adjustment coefficient q=0.001; In Example 5, the cement adjustment coefficient m=0.08, the admixture adjustment coefficients λ1=0.2, λ2=0.15, λ3=0.1, λ4=0.075; the activator adjustment coefficients w1=0.01, w2=0.1; the surfactant adjustment coefficient u=0.0001, and the additive adjustment coefficient q=0.001; In Example 6, the cement adjustment coefficient m=0.05, the admixture adjustment coefficients λ1=0.15, λ2=0.1, λ3=0.05, λ4=0.05; the activator adjustment coefficients w1=0.025, w2=0.15; the surfactant adjustment coefficient u=0.0005, and the additive adjustment coefficient q=0.0025; The original silt contains a large amount of secondary minerals, among which the contents of illite, kaolinite and montmorillonite have a significant effect on the mechanical properties of the solidified silt. The content of clay in the silt will also affect the mechanical properties of the solidified silt. The traditional silt solidification method ignores the influence of secondary biological minerals and clay content on the solidification effect, which easily leads to the situation that a lot of solidification materials are added but the solidification effect is not ideal, and the solidification cost is high; therefore, the present invention proposes a preparation method for solidified soil suitable for silt from different sources. In the process of preparing the solidified soil, the mass of clay and the mass of secondary minerals in the silt are firstly accurately measured, and then the addition amount of other components required for the solidified soil is calculated according to the measured clay mass and secondary mineral mass, thereby ensuring a good solidification effect on the silt; based on It can be seen from Table 1 that for silts from different sources, the 28d unconfined compressive strength of the solidified soil obtained by the preparation method of the present invention meets the relevant requirements of the unconfined compressive strength of the solidified soil in different application scenarios. Therefore, the preparation method of the present invention can effectively ensure the unconfined compressive strength of the solidified soil without increasing the amount of the curing agent. The preparation process is simple, which simplifies the design process of the solidified soil mix ratio, avoids a large number of mix ratio tests, greatly saves manpower, financial resources, and material resources, and realizes the effective and high-value reuse of silt. It is a green recycling technology. The solidified soil prepared by the preparation method of the present invention has strong unconfined compressive strength and can be used for various foundation treatments, backfill projects and sea reclamation projects. It has broad application prospects and considerable benefits.

[0016] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A method for preparing multi-source silt-stabilized soil, wherein the multi-source silt-stabilized soil is obtained by fully mixing silt with cement, admixture, activator, surfactant and additive, characterized in that: The preparation method of multi-source silt solidified soil comprises the following steps: S1. Take sludge of mass S and determine the dry mass a of particles with pore size greater than 0.005 mm, the dry mass b of particles with pore size not greater than 0.005 mm, and the mass c of water in the sludge; S2, measure the mass b1 of montmorillonite, the mass b2 of illite, the mass b3 of kaolinite, and the mass b4 of other particles in particles with a pore size not greater than 0.005 mm; S3. According to the dry mass a and b of the particles in S1 and the mass b1, b2, b3 and b4 of the particles in S2, the mass G of the cement is calculated according to the following formula: G=a*m*( b1*1.15+ b2*1.1+ b3*1.1+ b4*1.05) / b; Where: m is the cement adjustment coefficient, 0.05≤m≤0.2; S4. According to the mass b1, b2, b3, and b4 of the particles in S2, the mass D of the admixture is calculated according to the following formula: D= b1*λ1+ b2*λ2+ b3*λ3+ b4*λ4; Where: λ1, λ2, λ3, λ4 are the admixture adjustment coefficients, among which, 0.15≤λ1≤0.25; 0.1≤λ2≤0.2; 0.05≤λ3≤0.15; 0.05≤λ4≤0.1; S5. According to the mass G of cement in S3 and the mass D of admixture in S4, the mass E of activator is calculated according to the following formula: E=G* w1+D* w2; Where: w1, w2 are the exciter adjustment coefficients, where 0.01≤w1≤0.05; 0.1≤w2≤0.2; S6. According to the mass D of the admixture in S4 and the mass E of the activator in S5, the mass F of the surfactant is calculated according to the following formula: F=(D+ E)*u; Wherein, u is the surfactant adjustment coefficient, 0.0001≤u≤0.001; S7. According to the mass c of water in S1, the mass H of the additive is calculated according to the following formula: H = c * q; Where: q is the additive adjustment coefficient, 0.001≤q≤0.005; S8. Mix the above-mentioned admixture, activator and surfactant evenly and grind them to a specific surface area of ​​600~1000m 2 / kg, the mixture is obtained; S9. Control the moisture content of the mixture 1 between 60% and 120%; S10, mixing the mixture 1 in S9 with the above-mentioned mass of cement and additives to obtain a mixture 2, and mixing the mixture 2 with the above-mentioned mass of sludge to obtain multi-source sludge solidified soil.

2. The method for preparing multi-source silt solidified soil according to claim 1, characterized in that: In S4, the admixture is one or a mixture of slag, fly ash, carbide slag, coal gangue and silica ash.

3. The method for preparing multi-source silt solidified soil according to claim 1, characterized in that: In S5, the activator is one or a mixture of sodium carbonate, sodium hydroxide, potassium carbonate, potassium hydroxide.

4. The method for preparing multi-source silt solidified soil according to claim 1, characterized in that: In S6, the surfactant is one or a mixture of triethanolamine, sodium acetate, sodium lignosulfonate.

5. The method for preparing multi-source silt solidified soil according to claim 1, characterized in that: In S7, the additive is one or a mixture of phosphogypsum, desulfurized gypsum or industrial gypsum.

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