A preparation method of multi-source silt solidified soil

Abstract

The present invention discloses a preparation method for multi-source silt solidified soil, comprising: S1, measuring the dry mass a of particulate matter with a pore diameter greater than 0.005 mm, the dry mass b of particulate matter with a pore diameter not greater than 0.005 mm, and the mass of water in the silt; S2, measuring the masses of montmorillonite, illite, kaolinite, and other particulate matter in the dry mass b; S3, calculating the mass of cement; S4, calculating the mass of admixture; S5, calculating the mass of activator; S6, calculating the mass of surfactant; S7, calculating the mass of additive; S8, mixing the admixture, activator, and surfactant to obtain mixture one; S9, controlling the moisture content of mixture one; S10, mixing mixture one with cement, additive, and silt to obtain multi-source silt solidified soil. In the process of preparing the solidified soil, the present invention accurately measures the masses of the clay particles and secondary minerals in the silt first, and then calculates the addition amounts of other components of the solidified soil according to the measured data, so as to ensure the solidification effect on the silt, and is applicable to the solidification treatment of different silts.

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:

[0007] 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;

[0008] S2. Determine the mass b1 of montmorillonite, the mass b2 of illite, the mass b3 of kaolinite, and the mass b4 of other particulate matters in particulate matters with a pore size not greater than 0.005 mm;

[0009] S3. According to the dry mass a and b of the particulate matters in S1, and the mass b1, b2, b3, and b4 of the particulate matters in S2, calculate the mass G of cement according to the following formula. The calculation formula is as follows:

[0010] G = a * m * (b1 * 1.15 + b2 * 1.1 + b3 * 1.1 + b4 * 1.05) / b;

[0011] In the formula: m is the cement adjustment coefficient, and 0.05 ≤ m ≤ 0.2;

[0012] S4. According to the mass b1, b2, b3, and b4 of the particulate matters in S2, calculate the mass D of the admixture according to the following formula. The calculation formula is as follows:

[0013] D = b1 * λ1 + b2 * λ2 + b3 * λ3 + b4 * λ4;

[0014] In the formula: λ1, λ2, λ3, and λ4 are the admixture adjustment coefficients, where 0.15 ≤ λ1 ≤ 0.25; 0.1 ≤ λ2 ≤ 0.2; 0.05 ≤ λ3 ≤ 0.15; 0.05 ≤ λ4 ≤ 0.1;

[0015] S5. According to the mass G of cement in S3 and the mass D of the admixture in S4, calculate the mass E of the activator according to the following formula. The calculation formula is as follows:

[0016] E = G * w1 + D * w2;

[0017] In the formula: w1 and w2 are the activator adjustment coefficients, where 0.01 ≤ w1 ≤ 0.05; 0.1 ≤ w2 ≤ 0.2;

[0018] S6. According to the mass D of the admixture in S4 and the mass E of the activator in S5, calculate the mass F of the surfactant according to the following formula. The calculation formula is as follows:

[0019] F = (D + E) * u;

[0020] In the formula, u is the surfactant adjustment coefficient, and 0.0001 ≤ u ≤ 0.001;

[0021] S7. According to the mass c of water in S1, calculate the mass H of the additive according to the following formula. The calculation formula is as follows:

[0022] H = c * q;

[0023] Where: q is the additive adjustment coefficient, 0.001 ≤ q ≤ 0.005;

[0024] S8. Mix the above-mentioned masses of admixtures, activators, and surfactants evenly and then grind them to a specific surface area between 600 and 1000 m 2 / kg to obtain Mixture 1;

[0025] S9. Control the moisture content of Mixture 1 between 60% and 120%;

[0026] S10. After mixing and stirring evenly Mixture 1 in S9, the above-mentioned mass of cement, and additives, obtain Mixture 2. After mixing and stirring evenly Mixture 2 and the above-mentioned mass of silt, multi-source silt solidified soil is obtained.

[0027] Preferably, in S4, the admixture is one or a mixture of several of slag, fly ash, carbide slag, coal gangue, silica fume.

[0028] Preferably, in S5, the activator is one or a mixture of several of sodium carbonate, sodium hydroxide, potassium carbonate, potassium hydroxide.

[0029] Preferably, in S6, the surfactant is one or a mixture of several of triethanolamine, sodium acetate, sodium lignosulfonate.

[0030] Preferably, in S7, the additive is one or a mixture of several of phosphogypsum, desulfurized gypsum, or industrial gypsum.

[0031] The present invention has at least the following beneficial effects: The preparation method of the multi-source silt solidified soil proposed by the present invention accurately measures the mass of clay particles and the mass of secondary minerals in the silt during the preparation of the solidified soil, and then calculates the addition amounts of other components of the solidified soil according to the measured mass of clay particles and the mass of secondary minerals, thereby ensuring a good solidification effect on the silt. The preparation process is simple, 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 is applicable to the solidification treatment of silts from different sources.

[0032] Other advantages, objectives, and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. Detailed Embodiments

[0033] The following further elaborates on the present invention in detail so that those skilled in the art can implement it with reference to the description in the specification.

[0034] The present invention provides a preparation method for 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 preparation method for the multi-source silt solidified soil includes the following steps:

[0035] S1. Take silt with a mass of S, put it into an oven, dry it to a constant weight at a temperature of 105 - 110°C, put the dried silt into a desiccator and cool it to room temperature, then weigh its mass with a balance as M. That is, the mass of water c = S - M. Put the silt that has been dried and cooled to room temperature on a screening machine, and screen it with a sieve with a pore size of 0.005 mm. After screening, weigh the mass of the particles remaining on the sieve, and this mass is the dry mass a of the particles with a pore size greater than 0.005 mm in the silt. Weigh the mass of the particles passing through the sieve, and this mass is the dry mass b of the particles with a pore size not greater than 0.005 mm.

[0036] S2. Use X-ray diffraction analysis method 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. Subtract b1, b2, and b3 from the total mass b to obtain the mass b4 of other particles.

[0037] S3. According to the dry masses a and b of the particles in S1, and the masses b1, b2, b3, and b4 of the particles in S2, calculate the mass G of cement as follows. The cement used is ordinary Portland cement, and the calculation formula is as follows:

[0038] G = a * m * (b1 * 1.15 + b2 * 1.1 + b3 * 1.1 + b4 * 1.05) / b;

[0039] In the formula: m is the cement adjustment coefficient, 0.05 ≤ m ≤ 0.2;

[0040] S4. According to the masses b1, b2, b3, and b4 of the particles in S2, calculate the mass D of the admixture as follows. The admixture is one or a mixture of slag, fly ash, carbide slag, coal gangue, silica fume, etc. The calculation formula is as follows:

[0041] D = b1 * λ1 + b2 * λ2 + b3 * λ3 + b4 * λ4;

[0042] In the formula: λ1, λ2, λ3, and λ4 are the admixture adjustment coefficients, where 0.15 ≤ λ1 ≤ 0.25; 0.1 ≤ λ2 ≤ 0.2; 0.05 ≤ λ3 ≤ 0.15; 0.05 ≤ λ4 ≤ 0.1;

[0043] S5. According to the mass G of cement in S3 and the mass D of admixture in S4, calculate the mass E of the activator 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:

[0044] E = G * w1 + D * w2;

[0045] In the formula: w1 and w2 are activator adjustment coefficients, where 0.01 ≤ w1 ≤ 0.05; 0.1 ≤ w2 ≤ 0.2;

[0046] S6. According to the mass D of admixture in S4 and the mass E of activator in S5, calculate the mass F of the surfactant 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:

[0047] F = (D + E) * u;

[0048] In the formula, u is the surfactant adjustment coefficient, 0.0001 ≤ u ≤ 0.001;

[0049] S7. According to the mass c of water in S1, calculate the mass H of the additive 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:

[0050] H = c * q;

[0051] In the formula: q is the additive adjustment coefficient, 0.001 ≤ q ≤ 0.005;

[0052] S8. Mix the above-mentioned masses of admixture, activator, and surfactant evenly and grind them to a specific surface area between 600 - 1000 m 2 / kg to obtain mixture one;

[0053] S9. Control the moisture content of mixture one between 60% and 120%; controlling the moisture content of mixture one between 60% and 120% can ensure that the strength of the subsequent prepared solidified soil meets the requirements of various construction processes. To further improve the strength of the solidified soil, the moisture content of mixture one can be controlled between 80% and 100%.

[0054] Specifically: Use a moisture meter to detect the moisture content of mixture one. When the detected moisture content exceeds the set range, dry mixture one until the moisture content is within the set range; when the detected moisture content is lower than the set range, spray water into mixture one and stir evenly to make the moisture content of mixture one within the set range;

[0055] S10. After uniformly mixing mixture one with the above-mentioned mass of cement and additives, mixture two is obtained. After uniformly mixing mixture two with the above-mentioned mass of silt, multi-source silt solidified soil is obtained.

[0056] The preparation method of the present invention is used to solidify dredged silt from 5 different sources. The silt in Examples 1-5 is respectively from the dredged silt at the bottom of a certain river in Shanghai, Zhejiang, Dalian, Shenzhen, and Zhenjiang. The source of the silt in Example 6 is the same as that in Example 1. After the silt is solidified, the unconfined compressive strength of the solidified soil at 28 days is measured, and the corresponding data is shown in Table 1:

[0057] Table 1

[0058]

[0059] In Table 1, the admixtures in 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; after the admixtures, activators, and surfactants are uniformly mixed, they are all ground to a specific surface area of 650 m 2 / kg, and the moisture content of the mixture is controlled at 90%;

[0060] 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;

[0061] 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;

[0062] 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;

[0063] 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;

[0064] 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;

[0065] 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;

[0066] The original silt contains more secondary minerals. The contents of illite, kaolinite, and montmorillonite among them have a significant impact on the mechanical properties of the solidified silt. The content of clay particles in the silt also affects the mechanical properties of the solidified silt. However, the traditional silt solidification method ignores the influence of secondary minerals and clay particle content on the solidification effect, which easily leads to the situation of adding a lot of solidification materials but with an unsatisfactory solidification effect and high solidification cost. Therefore, the present invention proposes a preparation method for solidified soil applicable to silts from different sources. During the preparation of the solidified soil, the mass of clay particles and the mass of secondary minerals in the silt are accurately measured first, and then the addition amounts of other components required for the solidified soil are calculated according to the measured mass of clay particles and the mass of secondary minerals, thereby ensuring a good solidification effect on the silt. According to Table 1, for silts from different sources, the 28-day unconfined compressive strength of the solidified soil obtained by using the preparation method of the present invention meets the relevant requirements of the unconfined compressive strength of the solidified soil under 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 dosage of the solidifying agent. The preparation process is simple, simplifies the design process of the solidified soil mix ratio, avoids numerous mix ratio tests, greatly saves manpower, financial resources, and material resources, realizes the effective and high-value reuse of silt, and is a green recycling technology. The solidified soil prepared by using the preparation method of the present invention has a strong unconfined compressive strength and can be used for various foundation treatment, backfilling projects, and reclamation projects, with broad application prospects and considerable benefits.

[0067] Although the embodiments of the present invention have been disclosed as above, it is not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, 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, and 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 stabilized 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.

Images