A sludge cohesive solidified soil pumping anti-sticking agent

Abstract

This invention discloses a pumping anti-sticking agent for silt-based cohesive solidified soil. It is a specialized anti-sticking agent for pumping cohesive solidified soil. The material consists of two parts: a foaming agent for pipe wall adhesion and a modified foaming agent. The foaming agent for pipe wall adhesion contains, by weight percentage: 20%-30% PAO (polyalphaolefin), 70-80% polyether synthetic oil, and 10-15% talc. The anti-sticking foaming agent, by weight percentage: 10.0-15.0% foaming agent, 4.0-10.0% foam stabilizer, 2.5-5.0% dispersant, and 70-83.5% water. This anti-sticking agent for silt-based cohesive solidified soil solves the problem of preventing adhesion of silt-based cohesive fluid solidified soil in a closed environment. During the pumping process, it reduces the adhesion force of the cohesive soil to the pipe wall, preventing the solidified soil from adhering to the pipe wall, increasing the pumping speed, and thus reducing maintenance costs.

Description

Technical Field

[0001] This invention relates to the technical field of geotechnical engineering, and more particularly to an anti-sticking agent for pumping silt-based cohesive fluidized solidified soil. Background Technology

[0002] The silty cohesive fluidized solidified soil filling technology is an emerging ex-situ soft soil solidification technology that has been widely used in soft soil solidification in coastal and lake areas. It achieves the plastic-to-fluid transition of the cohesive solidified soil by adjusting the water-cement ratio of the solidifying material or adding chemical dispersants. Once it reaches a pumpable state, the silty cohesive fluidized solidified soil is pumped to the pouring location using ordinary mud pumps or high-pressure concrete pumps for filling construction. This technology has been widely applied in engineering fields such as road and railway backfilling, pavement base course backfilling, underground pipe gallery foundation backfilling, deep foundation pit backfilling, and underground mining area filling. During the pumping and pouring process, the inventors discovered that the cohesive fluidized solidified soil easily adheres to the inner wall of the mud pump and high-pressure pump mud delivery pipe, causing the inner diameter of the delivery pipe to become increasingly smaller, reducing construction efficiency. Furthermore, due to the agglomeration of the cohesive fluidized solidified soil, it is difficult to clean the inner wall of the delivery pipe afterward, causing problems for large-scale construction of cohesive fluidized solidified soil. To solve the above problems, it is necessary to invent a material that adheres to the inner wall of the pumping pipe before pumping construction. This material can form an isolation layer between the viscous fluidized solidified soil and the inner wall of the pumping pipe. This material layer is hydrophobic and fully utilizes the material's own large-scale effect to effectively overcome the van der Waals forces between fine particles of the viscous fluidized solidified soil, eliminate the agglomeration of the viscous solidified soil on the inner wall, thereby solving the adhesion problem during the transportation of viscous solidified soil and forming a truly effective anti-adhesion agent. Engineering experience shows that foaming agents can form an isolation layer on the inner surface of the pipe wall. Through the large-size effect provided by the foaming action, the foaming agent prevents the cohesive solidified soil from fully contacting and adhering to the inner wall during transport. This method prevents the formation of adhesive "mud cakes" on the rotating cutterhead during tunneling. However, the cutterhead working face in tunnel boring machines is open, making it easy to deliver and replenish the foaming agent. Therefore, the requirements for foaming rate and half-life are low. In contrast, the working face of pipelines transporting silty, cohesive, fluidized solidified soil is closed, making it impossible to simultaneously replenish foaming agent and pump the fluidized solidified soil. Therefore, higher requirements are placed on the foaming rate and the foaming agent itself. Furthermore, the foaming agent needs to be delivered to the pipe wall and adhere to it for foaming. An adhesion carrier material needs to be added to the pipe wall. This carrier material has adhesive properties for the foaming agent and also regulates its foaming process, ensuring continuous foaming performance during the transport of silty, fluidized solidified soil. Summary of the Invention

[0003] Based on the shortcomings of the existing technology, the technical problem solved by this invention is to provide an anti-sticking agent for pumping silty, viscous, fluidized solidified soil. The anti-sticking agent of this invention comprises two parts: an attachment carrier material and a foaming material. First, the attachment liquid material is transported into the pumping pipe and flushed multiple times within the pipe, thus forming an attachment carrier for the foaming agent on the inner wall of the pipe. Then, the foaming agent is injected into the pumping pipe, adhering to the inner wall and initiating foaming, which is then used for pumping silty, viscous, fluidized solidified soil. The attachment material involved in this invention has stable performance and excellent adhesion properties to the foaming material. The anti-sticking foaming agent involved in this invention has excellent performance and low production cost, effectively separating the viscous, fluidized solidified soil from the pipe wall, reducing the adhesion force of the clay to the pipe wall, improving conveying efficiency, preventing blockage of the pumping pipe channel, and increasing pumping speed, thus possessing significant practical application value.

[0004] To solve the above-mentioned technical problems, the present invention provides a pumping anti-sticking agent for silt and cohesive solidified soil. This material consists of two parts: a foaming agent pipe wall adhesion material and a foaming material. The foaming agent pipe wall adhesion material is a group of industrial oils and, by weight percentage, contains the following components: PAO (polyalphaolefin): 20%-30%, polyether synthetic oil 60-80%, talc 10-15%.

[0005] The foamed material contains the following components by weight percentage: Foaming agent 10.0-15.0%, foam stabilizer 4.0-10.0%, dispersant 2.5-5.0%, water 70-83.5%. As a preferred embodiment of the above technical solution, the anti-sticking agent for pumping silt-cohesive solidified soil provided by the present invention further includes some or all of the following technical features: As an improvement to the above technical solution, the foaming agent is an anionic surfactant.

[0006] As an improvement to the above technical solution, the anionic surfactant is a mixture of SAS, AOS, or AES. It can effectively reduce the surface tension of the liquid, and the anionic surfactant has a high foaming rate, producing rich, fine foam with good biodegradability.

[0007] As an improvement to the above technical solution, the mass ratio of SAS to AOS or AES is in the range of 0.5 to 1.5.

[0008] As an improvement to the above technical solution, the foam stabilizer is a silicone resin polyether emulsion, which has a significant foam stabilizing effect, is easy to use, and has significant thickening and foam stabilizing properties. It can prolong the foam stabilization time and extend the foam collapse half-life under high pressure conditions.

[0009] As an improvement to the above technical solution, the dispersant is modified sodium lignosulfonate with a molecular weight in the range of 4000 to 10000. Modified sodium lignosulfonate is green and environmentally friendly, biodegradable in nature, abundant in resources, and inexpensive. It not only has a good dispersing effect, but also has the functions of anti-precipitation and protecting colloids.

[0010] Furthermore, sodium lignosulfonate also serves as a water quality stabilizer in this system. The dispersant sodium lignosulfonate not only has a dispersing effect, but it can also form stable complexes with scale-forming substances such as calcium and magnesium ions in the water. It is easily soluble in water, exhibiting good chelation, dispersion, and corrosion inhibition effects, preventing scale formation and loosening old scale layers for easier cleaning. It is also a good water quality stabilizer.

[0011] As an improvement to the above technical solution, the water is deionized water.

[0012] As an improvement to the above technical solution, the temperature of the deionized water is from room temperature to 45°C; preferably, the temperature of the deionized water is 35-45°C.

[0013] This invention also includes a method for preparing the anti-sticking agent for pumping silt-cohesive solidified soil as described above, specifically comprising the following steps: Step 1, preparation method of foaming material: Take 30% of the total added water, add foaming agent, foam stabilizer and dispersant under stirring conditions, stir until uniform, then add the remaining water, and continue stirring to obtain the anti-sticking agent foaming material; the water is deionized water, and the water temperature of the deionized water is maintained at 35-45℃ during the stirring process; Step 2, Preparation method of foaming agent pipe wall adhesion material: PAO polyalphaolefin, polyether synthetic oil, and talc are mixed to obtain foaming agent pipe wall adhesion material; The mass ratio of foaming material to foaming agent adhering material on the pipe wall is 5:1. As an improvement to the above technical solution, the water is deionized water, and the temperature of the deionized water is maintained at 35-45°C during the stirring process.

[0014] As an improvement to the above scheme, during use, the foaming agent pipe wall adhering material needs to be stirred a second time to ensure a more thorough mixing of talc powder and industrial oil. First, a mud pump is used to pump the foaming agent pipe wall adhering material into the pipe, adhering a layer of industrial oil (foaming agent pipe wall adhering material) to the entire inner wall of the delivery pipe. Excess industrial oil (foaming agent pipe wall adhering material) is then collected and stored in a tank for later use. Next, a mud pump is used to pump the anti-sticking agent into the pipe, where it adheres to the pipe wall and begins to stabilize and foam. Finally, a mud pump is used to pump the silty, viscous, fluidized solidified soil.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The anti-adhesion material solves the problem of fixing foaming agents in enclosed working spaces. In enclosed working spaces, higher requirements are placed on the foaming rate, strength, and stability of the anti-adhesion agent. The anti-adhesion agent obtained in this invention is a composite foaming agent consisting of a foaming agent, a foam stabilizer, a dispersant, and a water quality stabilizer. It is an environmentally friendly anti-adhesion agent for silt and cohesive soil, effectively improving the quality of foaming agents, exhibiting good foam stabilization performance, and strong corrosion resistance.

[0016] This invention provides an anti-foaming agent for silt-stabilized clay with high foaming rate, producing rich, fine, and uniformly distributed foam with small air bubble pores. After the dispersant molecules in the foaming agent come into contact with the clay particles, they are adsorbed onto the surface of the clay particles through electrostatic repulsion. Then, through penetration, the dispersant molecules quickly enter the soil, rapidly dispersing and separating the soil. This reduces the adhesion of the silt-stabilized clay to the pipe wall, prevents channel blockage, increases pumping speed, and thus reduces maintenance costs.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, the following detailed description is provided in conjunction with preferred embodiments. Detailed Implementation

[0018] The specific embodiments of the present invention are described in detail below, which are part of this specification. The principles of the present invention are illustrated by means of examples, and other aspects, features and advantages of the present invention will become apparent from this detailed description.

[0019] Example 1 Prepare 100g each of the silt-cohesive soil anti-adhesion agent and the anti-adhesion agent. The content of each component is as follows: Anti-adhesive fixing material: PAO (polyalphaolefin): 20g Polyether synthetic oil 70, 10g of talcum powder.

[0020] Anti-adhesive: SAS: 6.0g AOS: 7.0g Silicone polyether emulsion: 5g Sodium lignosulfonate: 5.0g Water: 77g.

[0021] Mix all components thoroughly at room temperature. The foaming agent is 10.0–15.0%, the foam stabilizer is 4.0–10.0%, the dispersant is 2.5–5.0%, and the water is 70–83.5%.

[0022] Example 2 Prepare 100g each of the silt-cohesive soil anti-adhesion agent and the anti-adhesion agent. The content of each component is as follows: Anti-adhesive fixing material: PAO (polyalphaolefin): 25g 60g of polyether synthetic oil 15g of talcum powder.

[0023] Anti-adhesive: SAS: 5.0g AES: 9.0g Silicone polyether emulsion: 6g Sodium lignosulfonate: 5g Water: 75g.

[0024] Simply mix and stir all components thoroughly at room temperature.

[0025] Example 3 Prepare 100g each of the silt-cohesive soil anti-adhesion agent and the anti-adhesion agent. The content of each component is as follows: Anti-adhesive fixing material: PAO (polyalphaolefin): 30g 60g of polyether synthetic oil 10g of talcum powder.

[0026] Anti-adhesive: AOS: 6.0g AES: 6.0g Silicone polyether emulsion: 7g Sodium lignosulfonate: 5.0g Water: 76g.

[0027] Simply mix and stir all components thoroughly at room temperature.

[0028] Example 4 Prepare 100g each of the silt-cohesive soil anti-adhesion agent and the anti-adhesion agent. The content of each component is as follows: Anti-adhesive fixing material: PAO (polyalphaolefin): 28g 64g of polyether synthetic oil 13g of talcum powder.

[0029] Anti-adhesive: SAS: 8.0g AES: 6.0g Silicone polyether emulsion: 6g Sodium lignosulfonate: 5.0g Water: 75g.

[0030] Simply mix and stir all components thoroughly at room temperature.

[0031] Example 5 (Comparative Example) Prepare 100g each of the silt-cohesive soil anti-adhesion agent and the anti-adhesion agent. The content of each component is as follows: Anti-adhesive fixing material: PAO (polyalphaolefin): 28g 64g of polyether synthetic oil 13g of talcum powder.

[0032] Anti-adhesive: SAS: 8g AES: 6g Silicone polyether emulsion: 6g Water: 75g.

[0033] Simply mix and stir all components thoroughly at room temperature.

[0034] This example is a comparative example. No dispersant is added in this example, and the content of other components, except for water, is the same as in Example 4.

[0035] Example 6 Performance testing of clay-based soil stabilizers and anti-adhesion materials: The prepared anti-sticking agent was divided into 5 groups, with 3 portions in each group. Groups 1 to 4 correspond to Examples 1 to 4 of the present invention, and Group 5 is Example 5, i.e., the comparative example, and they were labeled accordingly. Each group of samples was diluted with deionized water at a ratio of 4%, and foamed using an indoor foaming device. The foaming device was adjusted to obtain the required foam, and this state was kept stable.

[0036] The prepared anti-adhesive materials were divided into 5 groups, with 3 points in each group. Groups 1 to 4 corresponded to Examples 1 to 4 of this invention, and Group 5 was Example 5, i.e., the comparative example, and were labeled accordingly. The adhesion amount of the corresponding anti-adhesive materials was tested, and the adhesion ability of the anti-adhesive materials was evaluated by the mass ratio of the anti-adhesive to the adhesion material.

[0037] 1. Foaming rate experiment The foaming rate refers to the ratio of the volume of foam produced by a given volume of foaming agent solution to the volume of foam produced by the foaming agent solution; that is, the volume of foam produced per volume of foaming agent solution. After the foaming device maintains a stable foaming state, the initial volume of the foaming agent solution is recorded. The produced foam is collected using a graduated measuring cup, and the final volume of the foaming agent solution is recorded after the measuring cup is filled with foam. Each experiment is repeated three times, and the experimental results are compiled and averaged.

[0038] 2. Stability test The stability of foam can be measured by its half-life, which is the time required for half the volume of liquid displaced from the foam to equal the total volume of liquid before displacement. Each experiment was repeated three times, and the experimental results were compiled and averaged.

[0039] 3. Test on the adhesion amount of anti-adhesive material The experimental method is as follows: First, a test tube is prepared. The adhering material is first fed into the test tube, and the mass of the adhering material adhering to the tube wall is obtained by subtracting the mass after the material was fed from its initial mass. Then, a foaming agent is fed into the test tube, and the mass of the foaming agent adhering to the test tube is obtained by subtracting the mass after the material was fed from its initial mass. The ratio of the amount of foaming agent adhering to the mass of the adhering material is the adhesion rate. For the corresponding anti-adhesive material, the adhesion amount of the corresponding anti-adhesive is tested, and the adhesion ability of the anti-adhesive material is evaluated by using the ratio of the mass of the anti-adhesive to the mass of the adhering material. Each experiment is repeated three times, and the experimental results are compiled and averaged.

[0040] The experimental results are shown in Table 1: Table 1. Comparison of Anti-adhesive Tests

[0041] As can be seen from Table 1, the foaming rates of the anti-sticking agents in Examples 1 to 4 of the present invention are not significantly different and are all higher than those in the comparative example, indicating that under the same foaming conditions, the foaming performance of the anti-sticking agent of the present invention is higher than that of the comparative sample.

[0042] The foam-forming half-life of the anti-sticking agents in Examples 1-4 of this invention is longer than that of the comparative examples, indicating that the foam-forming stability of the anti-sticking agents of this invention is superior to that of the comparative samples.

[0043] The adhesion rates of the anti-adhesive materials in Examples 1-4 of this invention to the anti-adhesive are not significantly different and are all higher than those of the comparative sample, indicating that under the same foaming conditions, the adhesion rate of the anti-adhesive materials of this invention to the anti-adhesive is higher than that of the comparative sample.

[0044] Example 7 The prepared anti-adhesion agent was divided into 5 groups, with 3 portions in each group. Groups 1 to 4 correspond to Examples 1 to 4 of this invention, respectively, and Group 5 corresponds to Example 5 and Comparative Example 1. Comparative Example 6, which did not use the anti-adhesion agent, was also tested. Marine silty, cohesive, fluidized solidified soil was selected for pumping tests. The pumping efficiency of the fluidized solidified soil was compared in the field, with the maximum pumping velocity and duration used as the basic evaluation indicators. The test results are shown in Table 2.

[0045] Table 2. Comparison of Anti-adhesive Tests

[0046] As can be seen from Table 1, the maximum pumping flow rate and the duration of the maximum pumping flow rate in Examples 1 to 4 of the present invention are not much different, and are all higher than Comparative Example 1 and much higher than Comparative Example 2, indicating that the anti-sticking agent greatly improves the conveying efficiency and working stability of the pumping pipe.

[0047] All the raw materials listed in this invention, as well as the upper and lower limits and ranges of the raw materials and the upper and lower limits and ranges of the process parameters (such as temperature, time, etc.), can realize this invention. Examples are not listed one by one here.

[0048] The above description is merely a preferred embodiment of the present invention, and should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A pumping anti-sticking agent for silt-based cohesive soil, characterized in that, The anti-adhesion agent for pumping silt cohesive solidified soil is composed of foaming agent pipe wall adhesion material and foaming material, with a mass ratio of foaming material to adhesion material of 5:

1. The foaming agent pipe wall adhesion material belongs to a group of industrial oils, and by weight percentage, it contains the following components: PAO (polyalphaolefin): 20%-30%, polyether synthetic oil: 60-80%, talc powder: 10-15%; The foamed material contains the following components by weight percentage: Foaming agent 10.0-15.0%, foam stabilizer 4.0-10.0%, dispersant 2.5-5.0%, water 70-83.5%.

2. The anti-sticking agent for pumping silt-cohesive solidified soil as described in claim 1, characterized in that: The foaming agent is an anionic surfactant.

3. The anti-sticking agent for pumping silt-cohesive solidified soil as described in claim 2, characterized in that: The anionic surfactant is a mixture of SAS, AOS, or AES.

4. The anti-sticking agent for pumping silt-cohesive solidified soil as described in claim 3, characterized in that: The ratio of SAS to AOS or AES is in the range of 0.5-1.

5.

5. The anti-sticking agent for pumping silt-cohesive solidified soil as described in claim 1, characterized in that: The foam stabilizer is a silicone polyether emulsion.

6. The anti-sticking agent for pumping silt-cohesive solidified soil as described in claim 1, characterized in that: The dispersant is sodium lignosulfonate with a molecular weight in the range of 4,000 to 10,000.

7. The anti-sticking agent for pumping silt-cohesive solidified soil as described in claim 1, characterized in that: The water is deionized water.

8. The anti-sticking agent for pumping silt-cohesive solidified soil as described in claim 7, characterized in that: The temperature of the deionized water is between room temperature and 45°C.

9. The method for preparing the anti-sticking agent for pumping silt-cohesive solidified soil as described in any one of claims 1-8, characterized in that, It includes the following steps: Step 1, preparation method of foaming material: Take 30% of the total added water, add foaming agent, foam stabilizer and dispersant under stirring conditions, stir until uniform, then add the remaining water, and continue stirring to obtain anti-sticking foaming material; the water is deionized water, and the temperature of the deionized water is kept at 35-45℃ during the stirring process; Step 2, Preparation method of foaming agent pipe wall adhesion material: PAO polyalphaolefin, polyether synthetic oil, and talc are mixed to obtain foaming agent pipe wall adhesion material; The mass ratio of foaming material to foaming agent adhering material on the pipe wall is 5:

1.

10. A method for using the anti-sticking agent for pumping silt-based cohesive solidified soil as described in any one of claims 1-9, characterized in that, It includes the following steps: 1) After thoroughly mixing the foaming agent pipe wall adhering material, use a mud pump to pump the foaming agent pipe wall adhering material into the pipe, so that a layer of foaming agent pipe wall adhering material is attached to the entire inner wall of the conveying pipe, and the excess foaming agent pipe wall adhering material is recycled to the storage tank for later use. 2) The anti-sticking agent is pumped into the pipe using a mud pump. The anti-sticking agent adheres to the pipe wall and begins to foam steadily. 3) Use a mud pump to pump silty, viscous, fluidized solidified soil.

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