A kind of sludge solidification modifier and preparation method thereof

Abstract

The invention discloses a sludge solidification modifier and a preparation method thereof. The solidification modifier comprises, by weight, 30-40 parts of CaO, 35-55 parts of CaCO3, 6-12 parts of SiO2, 6-12 parts of Al2O3, 3-8 parts of Fe2O3, 0.1-0.3 parts of TiO2, 0.1-0.5 parts of calcium chloride, 0.4-4 parts of water reducing agent, and 0.5-1 parts of white carbon black. The sludge solidification modifier disclosed by the invention has a simple preparation process, is safe and environmentally friendly, and is applicable to a sludge system with a water content of up to 70%.

Description

Technical Field

[0001] The invention relates to the field of E01C3 / 04, and in particular to a sludge solidification modifier and a preparation method thereof. Background Art

[0002] With the modernization construction and development, the production of silt in coastal cities is increasing. Silt has the characteristics of high water content, low strength, poor permeability, etc. These characteristics lead to poor engineering properties and are not suitable for use as engineering materials. Adding silt solidification modifier to silt can reduce the water content and effectively improve the mechanical properties of silt. The modified silt can be used in highway construction to realize the resource utilization of waste.

[0003] CN102583952A discloses a sludge solidifying agent, comprising cement and organic bentonite, and used as a solidifying agent for treating roadbed sludge filler. The solidifying agent can effectively absorb free water in the sludge, increase the sludge strength, and improve the sludge road performance.

[0004] CN107522436B discloses a sludge solidifying agent and its preparation method and application method, wherein the raw materials for preparation include sodium polyacrylate, biomass activated carbon, sodium lignin sulfonate, polyrotaxane, cement and other components. The raw materials of the solidifying agent are non-toxic and harmless, can be used on a large scale, and can effectively reduce the moisture content of sludge, improve the strength of sludge, and effectively seal heavy metals and organic matter in sludge to avoid the risk of secondary exposure of pollutants.

[0005] However, the above-mentioned sludge solidifying agents are not suitable for use in sludge systems with a water content greater than 50%. Summary of the invention

[0006] In order to solve the above problems, the present invention discloses a sludge solidification modifier, which comprises 30-40 parts of CaO, 35-55 parts of CaCO 3 、6-12 parts SiO 2 , 6-12 parts Al 2 O 3 , 3-8 parts Fe 2 O 3 , 0.1-0.3 parts TiO 2 , 0.1-0.5 parts of calcium chloride, 0.4-4 parts of water reducer, 0.5-1 parts of white carbon black.

[0007] The water reducer is selected from one or more of a complex organic polymer having a three-dimensional network structure and a polycarboxylate water reducer.

[0008] The water reducer is a compound of a complex organic polymer with a three-dimensional network structure and a polycarboxylic acid water reducer, with a mass ratio of (1-1.5): (0.5-1).

[0009] Furthermore, the complex organic polymer with a three-dimensional network structure contains abundant aromatic ring structures, aliphatic and aromatic hydroxyl groups and quinone groups.

[0010] Furthermore, the complex organic polymer having a three-dimensional network structure also contains sulfonic acid groups.

[0011] Furthermore, the preparation method of the complex organic polymer having a three-dimensional network structure is:

[0012] S1: Oxidation: add 5-10 parts by mass of calcium lignin sulfonate and 1-2 parts by mass of hydrogen peroxide with a concentration of 8-10%, and react at 60-70° C. for 1-1.5 hours.

[0013] S2: Sulfonation: add 1-3 parts of sodium bisulfite with a mass concentration of 30-35% and 2-3 parts of formaldehyde with a mass concentration of 5-8%, adjust the pH to 9-10, raise the temperature to 90-100°C, and react for 3-4h to obtain a complex organic polymer with a three-dimensional network structure.

[0014] S3: Physical screening, using ultrafiltration to screen out complex organic polymers with a three-dimensional network structure with an average molecular weight of 5000-8000.

[0015] Under the oxidation of hydrogen peroxide, more active sites of calcium lignin sulfonate can be exposed. Under the action of sodium bisulfite, more sulfonic acid groups are introduced into calcium lignin sulfonate to improve hydrophilicity and enhance water reduction effect. At the same time, some hydroxyl groups can be oxidized into carboxyl groups to shorten the coagulation time. Adding formaldehyde in an alkaline environment can ensure that the condensation reaction of calcium lignin sulfonate continues to proceed, generating more complex organic polymers with a three-dimensional network structure with a high average molecular weight. In the subsequent physical screening process, more complex organic polymers with a three-dimensional network structure that meet the requirements of the present invention can be obtained. The applicant has found that the complex organic polymer with a three-dimensional network structure prepared by the above method can play a good water reduction role and shorten the coagulation time when added in small amounts.

[0016] The polycarboxylate water reducer was purchased from Shandong Wanshan Chemical Co., Ltd., model FDN-C.

[0017] The white carbon black is fumed silica.

[0018] Furthermore, the specific surface area of ​​the fumed silica is 350-400m 2 / g.

[0019] The fumed silica was purchased from Hubei Huifu Nanomaterials Co., Ltd., model HL-380.

[0020] Another aspect of the present invention discloses a method for preparing the sludge solidification modifier, which is prepared by mixing the raw materials in parts by mass.

[0021] Beneficial effects:

[0022] 1. The present invention adds 30-40 parts of CaO and 35-55 parts of CaCO by mass. 3 、6-12 parts SiO 2 , 6-12 parts Al 2 O 3 It can absorb a large amount of water and increase soil hardness.

[0023] 2. The present invention uses a complex organic polymer with a three-dimensional network structure and a polycarboxylic acid water reducer to compound three water reducers, which can solidify sludge with a water content of up to 70%, has a good solidification effect, and has an early strength effect. The construction effect decreases after 4 hours.

[0024] 3. The present invention uses a complex organic polymer with a three-dimensional network structure and adds fumed silica, which can improve fluidity. Before solidification, the slurry has good fluidity and a good construction effect.

[0025] 4. The preparation process of the sludge solidification modifier disclosed in the present invention is simple, safe and environmentally friendly. DETAILED DESCRIPTION

[0026] Example 1

[0027] In one aspect, this embodiment 1 discloses a sludge solidification modifier, which comprises 30 parts of CaO, 35 parts of CaCO 3 、6 parts SiO 2 , 6 parts Al 2 O 3 , 3 parts Fe 2 O 3 , 0.1 parts TiO 2 , 0.1 parts of calcium chloride, 0.4 parts of water reducing agent, and 0.5 parts of fumed silica.

[0028] The water reducer is a compound of a complex organic polymer with a three-dimensional network structure and a polycarboxylic acid water reducer, with a mass ratio of 1.5:0.5.

[0029] The method for preparing the complex organic polymer having a three-dimensional network structure is as follows:

[0030] S1: Oxidation: 5 parts by mass of calcium lignin sulfonate and 1 part by mass of 8% hydrogen peroxide are reacted at 70°C for 1 hour.

[0031] S2: Sulfonation: add 1 part of 30% sodium bisulfite and 2 parts of 5% formaldehyde by mass, adjust the pH to 9, raise the temperature to 100°C, and react for 4 hours to obtain a complex organic polymer with a three-dimensional network structure.

[0032] S3: Physical screening, using ultrafiltration to screen out complex organic polymers with a three-dimensional network structure with an average molecular weight of 5000-8000.

[0033] The polycarboxylate water reducer was purchased from Shandong Wanshan Chemical Co., Ltd., model FDN-C.

[0034] The fumed silica was purchased from Hubei Huifu Nanomaterials Co., Ltd., model HL-380, with a specific surface area of ​​380 m 2 / g.

[0035] On the other hand, this embodiment 1 discloses a method for preparing the sludge solidification modifier, which is obtained by mixing the raw materials in parts by mass.

[0036] Example 2

[0037] This embodiment 2 discloses a sludge solidification modifier, which comprises 40 parts of CaO, 55 parts of CaCO, 3 、12 parts SiO 2 , 12 parts Al 2 O 3 , 8 parts Fe 2 O 3 , 0.3 parts TiO 2 , 0.5 parts of calcium chloride, 4 parts of water reducing agent, and 1 part of fumed silica.

[0038] The water reducer is a compound of a complex organic polymer with a three-dimensional network structure and a polycarboxylic acid water reducer, with a mass ratio of 1:1.

[0039] The method for preparing the complex organic polymer having a three-dimensional network structure is as follows:

[0040] S1: Oxidation: add 10 parts by mass of calcium lignin sulfonate and 2 parts by mass of 10% hydrogen peroxide, react at 60°C for 1.5 hours.

[0041] S2: Sulfonation: add 3 parts by mass of 35% sodium bisulfite and 3 parts by mass of 8% formaldehyde, adjust the pH to 10, raise the temperature to 90°C, and react for 3 hours to obtain a complex organic polymer with a three-dimensional network structure.

[0042] S3: Physical screening, using ultrafiltration to screen out complex organic polymers with a three-dimensional network structure with an average molecular weight of 5000-8000.

[0043] The polycarboxylate water reducer was purchased from Shandong Wanshan Chemical Co., Ltd., model FDN-C.

[0044] The fumed silica was purchased from Hubei Huifu Nanomaterials Co., Ltd., model HL-380, with a specific surface area of ​​380 m 2 / g.

[0045] On the other hand, this embodiment 2 discloses a method for preparing the sludge solidification modifier, which is obtained by mixing the raw materials in parts by mass.

[0046] Example 3

[0047] In one aspect, this embodiment 3 discloses a sludge solidification modifier, which comprises 35 parts of CaO, 50 parts of CaCO, and 3 、10 parts SiO 2 , 8 parts Al 2 O 3 , 6 parts Fe 2 O 3 , 0.2 parts TiO 2 , 0.2 parts of calcium chloride, 2 parts of water reducer, and 0.5 parts of fumed silica.

[0048] The water reducer is a compound of a complex organic polymer with a three-dimensional network structure and a polycarboxylic acid water reducer, with a mass ratio of 1.2:0.8.

[0049] The method for preparing the complex organic polymer having a three-dimensional network structure is as follows:

[0050] S1: Oxidation: add 8 parts by mass of calcium lignin sulfonate and 1.8 parts by mass of 8% hydrogen peroxide, react at 65° C. for 1.5 hours.

[0051] S2: Sulfonation: add 2 parts of 35% sodium bisulfite and 2.5 parts of 6% formaldehyde, by mass, adjust the pH to 9.5, raise the temperature to 95°C, and react for 3.5 hours to obtain a complex organic polymer with a three-dimensional network structure.

[0052] S3: Physical screening, using ultrafiltration to screen out complex organic polymers with a three-dimensional network structure with an average molecular weight of 5000-8000.

[0053] The polycarboxylate water reducer was purchased from Shandong Wanshan Chemical Co., Ltd., model FDN-C.

[0054] The fumed silica was purchased from Hubei Huifu Nanomaterials Co., Ltd., model HL-380, with a specific surface area of ​​380 m 2 / g.

[0055] On the other hand, this embodiment 3 discloses a method for preparing the sludge solidification modifier, which is obtained by mixing the raw materials in parts by mass.

[0056] Comparative Example 1

[0057] The curing modifier includes 60 parts of CaO, 30 parts of CaCO 3 , No SiO added 2 and Al 2 O 3 , the rest is the same as in Example 3.

[0058] Comparative Example 2

[0059] The mass ratio of the complex organic polymer with a three-dimensional network structure and the polycarboxylate water-reducing agent is 1:10, and the rest is the same as in Example 3.

[0060] Comparative Example 3

[0061] The complex organic polymer with a three-dimensional network structure is calcium lignin sulfonate, and no fumed silica is added. The rest is the same as in Example 3.

[0062] Performance Testing

[0063] The sludge solidification modifiers of Examples 1-3 and Comparative Examples 1-3 were used to solidify soil, the soil moisture content was 70%, and the amount of the sludge solidification modifier added was 30% of the mass of the sludge. According to the standard of Highway Geotechnical Test Code (JTG E40-2007), the California bearing ratio test was carried out, and the results are shown in the following table:

[0064]

[0065] According to the "Testing Procedure for Stabilized Materials of Inorganic Binders for Highway Engineering" (JTG T0808-2009), the mechanical properties of the silt-stabilized soil of Examples 1-3 and Comparative Examples 1-3 after 7 days of curing were tested by (top surface method), and the results are shown in the following table:

[0066]

Claims

1. A sludge solidification modifier, characterized in that: In parts by mass, the curing modifier includes 30-40 parts of CaO, 35-55 parts of CaCO3, 6-12 parts of SiO2, 6-12 parts of Al2O3, 3-8 parts of Fe2O3, 0.1-0.3 parts of TiO2, 0.1-0.5 parts of calcium chloride, 0.4-4 parts of water reducing agent, and 0.5-1 parts of white carbon black; The water reducer is a compound of a complex organic polymer having a three-dimensional network structure and a polycarboxylate water reducer, with a mass ratio of (1-1.5): (0.5-1); The preparation method of the complex organic polymer having a three-dimensional network structure is: S1: Oxidation: add 5-10 parts by mass of calcium lignin sulfonate and 1-2 parts by mass of hydrogen peroxide with a concentration of 8-10%, and react at 60-70°C for 1-1.5 hours; S2: Sulfonation, add 1-3 parts of sodium bisulfite with a mass concentration of 30-35% and 2-3 parts of formaldehyde with a mass concentration of 5-8%, adjust the pH to 9-10, raise the temperature to 90-100°C, and react for 3-4h to obtain a complex organic polymer with a three-dimensional network structure; S3: Physical screening, using ultrafiltration to screen out complex organic polymers with a three-dimensional network structure with an average molecular weight of 5000-8000.

2. The sludge solidification modifier according to claim 1, characterized in that: The white carbon black is fumed silica.

3. The sludge solidification modifier according to claim 2, characterized in that: The specific surface area of ​​the fumed silica is 350-400 m 2 / g.

4. A method for preparing the sludge solidification modifier according to claim 1, characterized in that: The preparation method is obtained by mixing the raw materials in parts by mass.

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