Super high-rise pumping pipeline moistening cement paste

Abstract

The invention relates to the field of pumping concrete, and particularly discloses a super high-rise pumping pipeline moistening cement paste. The super high-rise pumping pipeline moistening pipe neat cement paste comprises the following components in parts by weight: 1000-1400 parts of cement, 1-10 parts of a rheology modifier, 400-600 parts of water, 5-15 parts of a water reducing agent and 200-400 parts of fly ash. The preparation method comprises the following steps: stirring and mixing the cement and the fly ash to obtain a dry mixture, adding the water into a stirring container, and continuously stirring to form uniform slurry; and adding the weighed water reducing agent and rheological modifier into the slurry, and stirring for 20-30 minutes to form the uniform and particle-free cement paste. The super high-rise pumping pipeline moistening neat cement paste has the advantages that a layer of lubricating film can be formed on the inner wall of a pumping pipeline, so that the resistance of concrete in the pumping process is reduced, and pipe blockage is prevented.

Description

Technical Field

[0001] The present application relates to the field of pumping concrete, and more specifically, to a cement slurry for lubricating super-high-rise pumping pipelines. Background Art

[0002] With the continuous development of urban construction, more and more high-rise buildings stand in major cities. They have become the symbol and business card of the city with their towering and spectacular image. However, in the construction of high-rise buildings, concrete construction is a major technical problem. Due to the high height of the building, the traditional concrete transportation and pouring methods can no longer meet the construction needs. Therefore, super high-rise pumping concrete technology came into being and became the key technology to solve this problem.

[0003] Super high-rise pumping concrete technology mainly uses concrete pumps to transport concrete to high altitudes through conveying pipes, which can greatly shorten the concrete delivery time, improve construction efficiency, shorten the construction period, and avoid workers working at high altitudes, reducing safety risks and improving construction safety. However, due to the long length and many bends of the pumping pipes used in the construction of super high-rise buildings, the concrete mortar has a large flow resistance inside the pumping pipe. In order to overcome the large conveying resistance, the pumping equipment needs to consume more energy, and the conveying resistance will reduce the pumping speed, thereby affecting the construction efficiency. After the pumping pipe has been used many times and the concrete adhered to the pipe wall solidifies, the pumping resistance will increase further and easily cause blockage.

[0004] Therefore, there is a need for a pumping concrete auxiliary product that can form a lubricating film on the inner wall of a pumping pipeline to reduce the resistance of concrete during pumping and prevent pipe blockage. Summary of the invention

[0005] In order to provide a product that can form a lubricating film on the inner wall of a pumping pipeline to reduce the resistance of concrete during the pumping process, the present application provides a cement slurry for lubricating super-high-rise pumping pipelines.

[0006] The present application provides a super high-rise pumping pipeline lubrication cement slurry adopts the following technical solution: A cement slurry for lubricating a super high-rise pumping pipeline comprises, by weight, 1000-1400 parts of cement, 1-10 parts of a rheology regulator, 400-600 parts of water, 5-15 parts of a water reducing agent and 200-400 parts of fly ash.

[0007] By adopting the above technical solution, the use of rheology regulator and water reducer ensures the uniform distribution of the slurry during the pumping process, reduces the risk of accumulation and solidification of the slurry in the pipeline, and thus prevents the occurrence of pipe blockage. The addition of fly ash and water reducer gives the slurry better fluidity and self-cleaning function, effectively cleans the inner wall of the pipeline, and prevents the accumulation of concrete residues. The ultra-high-rise pumping pipeline lubricating cement slurry of the present application optimizes the water-cement component ratio. During construction, the lubricating cement slurry is first pumped, so that a lubricating film is effectively formed on the inner wall of the pumping pipeline, which significantly reduces the flow resistance of the subsequent concrete during the pumping process, and reduces the adhesion of concrete mortar to the inner wall, preventing pipe blockage.

[0008] Optionally, the rheology regulator includes 30-50 parts of carbomer resin and 20-30 parts of polyoxyethylene sorbitan fatty acid ester by weight.

[0009] By adopting the above technical solution, the addition of carbopol resin makes the pure slurry have a higher viscosity, ensuring that the slurry remains in a stable state when flowing in the pipeline, and is not prone to stratification and segregation. The surfactant function provided by polyoxyethylene sorbitan fatty acid ester further enhances the lubrication effect of the slurry and reduces the friction between the inner wall of the pipeline and the slurry. Due to the comprehensive synergistic effect of these two components, the pure slurry can evenly cover the inner wall of the pumping pipeline to form a continuous lubricating film, preventing the concrete from blocking the pipe due to increased friction resistance during the pumping process. At the same time, it can also reduce the sticky residue of concrete on the inner wall.

[0010] Optionally, the rheology regulator further comprises 1-5 parts by weight of sodium alginate.

[0011] By adopting the above technical solution, the addition of sodium alginate significantly enhances the viscoelasticity of the slurry, further optimizes the rheological properties of the slurry, prevents stratification and segregation of the slurry during pumping, and ensures that the lubricating slurry is evenly covered on the inner wall of the pipeline.

[0012] Optionally, the invention further comprises 20-40 parts by weight of polyurethane-modified nitrocellulose.

[0013] Optionally, the preparation method of the polyurethane modified nitrocellulose is: 5-15 parts of nitrocellulose by weight are added to 80-100 parts of acetone and stirred evenly to obtain a nitrocellulose solution. Under continuous stirring, a polyurethane prepolymer containing an isocyanate group is added to the nitrocellulose solution at a rate of 1-2 L / min, wherein the mass ratio of the polyurethane prepolymer to the nitrocellulose is (1-3):1 to obtain a mixed solution; 0.01-0.1 parts of dibutyltin dilaurate are added to the mixed solution, the mixed solution is maintained at 30-50°C, and the reaction time is 8-24 hours. After the reaction is completed, the mixed solution is poured into 300-500 parts of anhydrous ethanol and allowed to stand for precipitation. The precipitate is separated and dried in a vacuum drying oven at 60-80°C to obtain polyurethane modified nitrocellulose.

[0014] By adopting the above technical solution, the isocyanate group (-NCO) in the polyurethane reacts chemically with the hydroxyl group (-OH) in the nitrocellulose to form a cross-linked network with high strength and good toughness. This network structure can effectively wrap the solid particles in the cement paste to form a dense film layer, which can significantly improve the lubricity and wear resistance of the cement paste, thereby enhancing its lubrication effect in super-high-rise pumping pipelines, reducing the resistance of concrete during pumping, reducing the risk of blockage, and effectively reducing the wear of the inner wall of the pipeline.

[0015] Optionally, the water reducing agent comprises, by weight, 100-120 parts of maleic anhydride, 250-300 parts of polyethylene glycol monoacrylate, 1-10 parts of sodium propylene sulfonate, and 5-15 parts of potassium persulfate.

[0016] Optionally, the preparation method of the water reducing agent is: Dissolving maleic anhydride and polyethylene glycol monoacrylate in acetone to obtain component A, and dissolving sodium propylene sulfonate and potassium persulfate in deionized water to obtain component B; Under stirring conditions, component A and component B are mixed and transferred to a reaction vessel, and heated to 85-90° C., 1-3% of the total mass of the reaction solution is added with dodecyl mercaptan, and the reaction is continued for 4-6 hours; After the reaction is completed, impurities are removed by filtration, and the reaction solution is concentrated and dried to obtain a water reducing agent.

[0017] By adopting the above technical solution, this water reducer can significantly improve the fluidity and water retention of cement paste, reduce bleeding and segregation, and improve the working performance of cement paste. Maleic anhydride, polyethylene glycol monoacrylate and sodium propylene sulfonate, as the main components of the water reducer, can be effectively adsorbed on the surface of cement particles, reduce the agglomeration between cement particles through charge repulsion and steric hindrance effects, and then release more free water, significantly improving the fluidity and pumpability of the cement paste for lubricating pipes.

[0018] In a second aspect, the present application provides a method for preparing cement slurry for lubricating super high-rise pumping pipelines, which adopts the following technical solution: A method for preparing cement slurry for lubricating a super high-rise pumping pipeline comprises the following steps: First, cement and fly ash are stirred and mixed to obtain a dry mix, and then water is added to the mixing container while continuously stirring to form a uniform slurry; Add the weighed water reducer and rheology regulator into the slurry and stir for 20-30 minutes to form a uniform, particle-free cement slurry.

[0019] Optionally, polyurethane-modified nitrocellulose is also added to the slurry.

[0020] By adopting the above technical scheme, cement and fly ash are first stirred and mixed to obtain a dry mix, and then mixed with water to form a slurry. Such a preparation method helps to evenly mix cement and fly ash, avoiding the problems of caking and uneven particles. Subsequently, a water reducer and a rheology modifier are added, and stirring is continued for 20-30 minutes, which can further adjust the fluidity and viscosity of the slurry to make it more suitable for the requirements of super-high-rise pumping pipelines. The water reducer can effectively reduce the amount of water used in the cement slurry, thereby improving the fluidity and pumpability of the slurry. The raw materials used in this preparation method are all environmentally friendly materials, such as cement, fly ash, water reducer and rheology modifier, etc., which will not cause pollution to the environment.

[0021] In summary, this application has the following beneficial effects: 1. Since this application ensures uniform distribution of the slurry during pumping by adding rheology regulator and water reducer, reduces the risk of blockage, and uses the combination of fly ash and water reducer to enhance the fluidity and self-cleaning ability of the slurry, effectively cleaning the inner wall of the pipe. The optimized water-cement composition ratio enables the pipe-lubricating cement slurry to form a lubricating film on the inner wall of the pipe, significantly reducing the flow resistance of subsequent concrete pumping, preventing the concrete mortar from sticking, and effectively preventing the occurrence of pipe blockage.

[0022] 2. In this application, the addition of carbopol resin is preferably used to give the slurry high viscosity, ensuring that it remains stable when flowing in the pipeline to prevent stratification and segregation; while polyoxyethylene sorbitan fatty acid ester is used as a surfactant to enhance the lubricity of the slurry and reduce friction with the inner wall of the pipeline. The synergistic effect of the two enables the slurry to evenly cover the inner wall of the pumping pipeline, forming a continuous lubricating film, effectively preventing pipe blockage caused by increased friction resistance, and reducing the sticky residue of concrete on the inner wall.

[0023] 3. The present application forms a tough cross-linked network structure by chemically reacting the isocyanate groups in the polyurethane with the hydroxyl groups in the nitrocellulose. This structure can not only effectively wrap the solid particles in the cement paste to form a dense lubricating film layer, enhance the lubricity and wear resistance of the cement paste, significantly improve the lubrication effect in the super-high-rise pumping pipeline, reduce the concrete pumping resistance, reduce the risk of pipe blockage, but also effectively reduce the wear of the inner wall of the pipeline and extend the service life of the pipeline. DETAILED DESCRIPTION

[0024] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0025] Preparation example of polyurethane modified nitrocellulose Preparation Example 1 Preparation of polyurethane modified nitrocellulose: Add 90 kg of acetone into a clean reactor, add 10 kg of nitrocellulose with a purity of ≥98% into the acetone, stir while adding until the nitrocellulose is completely dissolved to obtain a nitrocellulose solution, add 10 kg of a polyurethane prepolymer containing an isocyanate group into the nitrocellulose solution, stir continuously at a speed of 80 r / min, and control the addition speed of the polyurethane prepolymer to be 1-2 L / min, and stir evenly to obtain a mixed solution; 0.05 kg of dibutyltin dilaurate was added to the mixed solution, and the reactor was heated to 40°C and then kept warm for 16 hours. After the reaction, the reaction solution was naturally cooled to room temperature, and the mixed solution was poured into 400 kg of anhydrous ethanol and allowed to settle. After the precipitate was separated by a filter, the precipitate was dried at a constant temperature of 70°C in a vacuum drying oven to obtain polyurethane modified nitrocellulose.

[0026] Preparation Example 2 Preparation of polyurethane modified nitrocellulose: Add 90 kg of acetone into a clean reactor, add 10 kg of nitrocellulose with a purity of ≥98% into the acetone, stir while adding until the nitrocellulose is completely dissolved to obtain a nitrocellulose solution, add 20 kg of a polyurethane prepolymer containing an isocyanate group into the nitrocellulose solution, continue stirring at a speed of 80 r / min, and control the addition speed of the polyurethane prepolymer to be 1-2 L / min. Stir evenly to obtain a mixed solution; 0.05 kg of dibutyltin dilaurate was added to the mixed solution, and the reactor was heated to 40°C and then kept warm for 16 hours. After the reaction, the reaction solution was naturally cooled to room temperature, and the mixed solution was poured into 400 kg of anhydrous ethanol and allowed to settle. After the precipitate was separated by a filter, the precipitate was dried at a constant temperature of 70°C in a vacuum drying oven to obtain polyurethane modified nitrocellulose.

[0027] Preparation Example 3 Preparation of polyurethane modified nitrocellulose: Add 90 kg of acetone into a clean reactor, add 10 kg of nitrocellulose with a purity of ≥98% into the acetone, stir while adding until the nitrocellulose is completely dissolved to obtain a nitrocellulose solution, add 30 kg of a polyurethane prepolymer containing an isocyanate group into the nitrocellulose solution, continue stirring at a speed of 80 r / min, and control the addition speed of the polyurethane prepolymer to be 1-2 L / min. Stir evenly to obtain a mixed solution; 0.05 kg of dibutyltin dilaurate was added to the mixed solution, and the reactor was heated to 40°C and then kept warm for 16 hours. After the reaction, the reaction solution was naturally cooled to room temperature, and the mixed solution was poured into 400 kg of anhydrous ethanol and allowed to settle. After the precipitate was separated by a filter, the precipitate was dried at a constant temperature of 70°C in a vacuum drying oven to obtain polyurethane modified nitrocellulose.

[0028] Preparation Example 4 Preparation of polyurethane-modified nitrocellulose: The difference from Preparation Example 2 is that 5 kg of polyurethane prepolymer containing isocyanate groups is added to the nitrocellulose solution.

[0029] Preparation Example 5 Preparation of polyurethane-modified nitrocellulose: The difference from Preparation Example 2 is that 40 kg of polyurethane prepolymer containing isocyanate groups is added to the nitrocellulose solution.

[0030] Preparation Example 6 Preparation of polyurethane modified nitrocellulose: The difference from Preparation Example 2 is that no dibutyltin dilaurate is added.

[0031] Preparation example of water reducing agent Preparation Example 7 Preparation of water reducing agent: 10 kg of maleic anhydride and 25 kg of polyethylene glycol monoacrylate were dissolved in 50 kg of acetone and stirred evenly with a stirrer to obtain component A; 0.1 kg of sodium propylene sulfonate and 0.5 kg of potassium persulfate were dissolved in 5 kg of deionized water and stirred evenly to obtain component B; Add component A and component B into a clean reactor and stir evenly with a stirrer, heat the reaction solution to 90°C, add 1-3% dodecyl mercaptan of the total mass of the reaction solution, and continue the reaction for 5 hours; After the reaction is completed, the solid impurities are removed by filtering through a filter, the reaction solution is heated and concentrated, and the concentrated reaction product is vacuum dried at 60° C. to obtain a water reducing agent.

[0032] Preparation Example 8 Preparation of water reducing agent: 11 kg of maleic anhydride and 28 kg of polyethylene glycol monoacrylate were dissolved in 50 kg of acetone and stirred evenly with a stirrer to obtain component A; 0.5 kg of sodium propylene sulfonate and 1 kg of potassium persulfate were dissolved in 5 kg of deionized water and stirred evenly to obtain component B; Add component A and component B into a clean reactor and stir evenly with a stirrer, heat the reaction solution to 90°C, add 1-3% dodecyl mercaptan of the total mass of the reaction solution, and continue the reaction for 5 hours; After the reaction is completed, the solid impurities are removed by filtering through a filter, the reaction solution is heated and concentrated, and the concentrated reaction product is vacuum dried at 60° C. to obtain a water reducing agent.

[0033] Preparation Example 9 Preparation of water reducing agent: 12 kg of maleic anhydride and 30 kg of polyethylene glycol monoacrylate were dissolved in 50 kg of acetone and stirred evenly with a stirrer to obtain component A; 1 kg of sodium propylene sulfonate and 1.5 kg of potassium persulfate were dissolved in 5 kg of deionized water and stirred evenly to obtain component B; Add component A and component B into a clean reactor and stir evenly with a stirrer, heat the reaction solution to 90°C, add 1-3% dodecyl mercaptan of the total mass of the reaction solution, and continue the reaction for 5 hours; After the reaction is completed, the solid impurities are removed by filtering through a filter, the reaction solution is heated and concentrated, and the concentrated reaction product is vacuum dried at 60° C. to obtain a water reducing agent.

[0034] Preparation Example 10 Preparation of water reducing agent: The difference from Preparation Example 8 is that 15 kg of maleic anhydride and 24 kg of polyethylene glycol monoacrylate are dissolved in 50 kg of acetone, and stirred evenly with a stirrer to obtain component A. Example

[0035] Example 1 A method for preparing cement slurry for super high-rise pumping pipeline lubrication: First, 1200kg 42.5R Portland cement and 300kg Grade II fly ash were put into a mixer for mixing to obtain a dry mix, and then 500kg water was added to the mixer while continuously mixing to form a uniform slurry; Add 10 kg of water reducer and 5 kg of rheology regulator into the slurry and stir for 25 minutes to form a uniform, particle-free cement slurry.

[0036] Among them, the rheology regulator contains 3 kg of carbomer resin and 2 kg of polyoxyethylene sorbitan fatty acid ester, and the water reducer is prepared by Preparation Example 8.

[0037] Example 2 A method for preparing cement slurry for super high-rise pumping pipeline lubrication: First, 1200 kg of cement, 300 kg of fly ash and 30 kg of polyurethane modified nitrocellulose were put into a mixer for mixing to obtain a dry mix, and then 500 kg of water was added to the mixer while continuously stirring to form a uniform slurry; Add 10 kg of water reducer and 5 kg of rheology regulator into the slurry and stir for 25 minutes to form a uniform, particle-free cement slurry.

[0038] Among them, the rheology regulator contains 3kg of carbomer resin and 2kg of polyoxyethylene sorbitan fatty acid ester, the water reducer is prepared by Preparation Example 8, and the polyurethane modified nitrocellulose is prepared by Preparation Example 2.

[0039] Example 3 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 2 is that the rheology regulator contains 2.9 kg of carbomer resin, 1.8 kg of polyoxyethylene sorbitan fatty acid ester and 0.3 kg of sodium alginate.

[0040] Example 4 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 3 is that the polyurethane-modified nitrocellulose is prepared by Preparation Example 1.

[0041] Example 5 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 3 is that the polyurethane-modified nitrocellulose is prepared by Preparation Example 3.

[0042] Example 6 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 3 is that the water reducing agent is prepared by Preparation Example 7.

[0043] Example 7 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 3 is that the water reducing agent is prepared by Preparation Example 9.

[0044] Comparative Example Comparative Example 1 A method for preparing cement slurry for super high-rise pumping pipeline lubrication: First, 900 kg of cement, 300 kg of fly ash and 30 kg of polyurethane modified nitrocellulose were put into a mixer for mixing to obtain a dry mix, and then 500 kg of water was added to the mixer while continuously stirring to form a uniform slurry; Add 10 kg of water reducer and 5 kg of rheology regulator into the slurry and stir for 25 minutes to form a uniform, particle-free cement slurry.

[0045] Among them, the rheology regulator contains 3kg of carbomer resin and 2kg of polyoxyethylene sorbitan fatty acid ester, the water reducer is prepared by Preparation Example 8, and the polyurethane modified nitrocellulose is prepared by Preparation Example 2.

[0046] Comparative Example 2 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 3 is that the polyurethane-modified nitrocellulose is prepared by Preparation Example 4.

[0047] Comparative Example 3 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 3 is that the polyurethane-modified nitrocellulose is prepared by Preparation Example 5.

[0048] Comparative Example 4 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 3 is that the polyurethane-modified nitrocellulose is prepared by Preparation Example 6.

[0049] Comparative Example 5 A method for preparing cement slurry for lubricating super-high-rise pumping pipelines: the difference from Example 3 is that the water reducing agent is prepared by Preparation Example 10.

[0050] Performance testing Detection Methods The viscosity of the pipe lubrication slurry was measured by a Brookfield viscometer.

[0051] Add 500kg of pipe lubricating slurry to the pumping equipment and run the pumping system to cover the inner wall of the pipe. Use 1 ton of concrete to conduct an actual 100m pumping test and record the pressure during the pumping process to evaluate the lubricity.

[0052] Pour the pipe lubricating slurry into a transparent container and let it stand for 24 hours. Observe whether the pipe lubricating slurry shows any stratification, precipitation or water separation.

[0053] Table 1 Summary of test data It can be seen from Example 3 and Comparative Example 1 and Table 1 that a pipe-lubricating slurry with better lubrication effect can be achieved by using the water-cement ratio in the present application.

[0054] Combining Example 3 and Comparative Examples 2-4 with Table 1, it can be seen that in the preparation process of polyurethane-modified nitrocellulose, adding too little polyurethane prepolymer will affect the modification effect, resulting in poor film-forming effect, while adding too much polyurethane prepolymer will increase the impurity products of the product, which will also affect its use effect. Dibutyltin dilaurate is beneficial to the speed of the modification reaction. In the same time, the product after adding dibutyltin dilaurate has better use effect.

[0055] It can be seen from Example 3 and Comparative Example 5 and Table 1 that the composition ratio of the water reducing agent in the present application is optimal.

[0056] It can be seen from Examples 1-3 and Table 1 that the polyurethane-modified nitrocellulose forms a dense film layer, which can significantly improve the lubricity and wear resistance of cement paste, thereby enhancing its lubrication effect in super-high-rise pumping pipelines, reducing the resistance of concrete during pumping and reducing the risk of blockage. The addition of sodium alginate significantly enhances the viscoelasticity of the slurry, further optimizes the rheological properties of the slurry, prevents stratification and segregation of the slurry during pumping, and ensures that the lubricating slurry is evenly covered on the inner wall of the pipeline.

[0057] Combining Examples 3-7 and Table 1, it can be seen that the polyurethane modified nitrocellulose obtained in Preparation Example 2 has the best film-forming effect, while the water reducing agent obtained in Preparation Example 8 has the best effect.

[0058] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A cement slurry for lubricating super high-rise pumping pipelines. It is characterized in that The invention comprises 1000-1400 parts of cement, 1-10 parts of rheology regulator, 400-600 parts of water, 5-15 parts of water reducing agent and 200-400 parts of fly ash in parts by weight.

2. The cement slurry for lubricating the super high-rise pumping pipeline according to claim 1, Features: The rheology regulator comprises 30-50 parts of carbomer resin and 20-30 parts of polyoxyethylene sorbitan fatty acid ester by weight.

3. The cement slurry for lubricating the super high-rise pumping pipeline according to claim 2, Features: The rheology regulator also includes 1-5 parts by weight of sodium alginate.

4. The cement slurry for lubricating the super high-rise pumping pipeline according to claim 1, Features: The invention also comprises 20-40 parts by weight of polyurethane modified nitrocellulose.

5. The cement slurry for lubricating the super high-rise pumping pipeline according to claim 4, Features: The preparation method of the polyurethane modified nitrocellulose is: 5-15 parts of nitrocellulose by weight are added to 80-100 parts of acetone and stirred evenly to obtain a nitrocellulose solution. Under continuous stirring, a polyurethane prepolymer containing an isocyanate group is added to the nitrocellulose solution at a rate of 1-2 L / min, wherein the mass ratio of the polyurethane prepolymer to the nitrocellulose is (1-3):1 to obtain a mixed solution; 0.01-0.1 parts of dibutyltin dilaurate are added to the mixed solution, the mixed solution is maintained at 30-50°C, and the reaction time is 8-24h. After the reaction is completed, the mixed solution is poured into 300-500 parts of anhydrous ethanol and allowed to stand for precipitation. The precipitate is separated and dried in a vacuum drying oven at 60-80°C to obtain polyurethane modified nitrocellulose.

6. The cement slurry for lubricating the super high-rise pumping pipeline according to claim 1, Features: The water reducing agent comprises, by weight, 100-120 parts of maleic anhydride, 250-300 parts of polyethylene glycol monoacrylate, 1-10 parts of sodium propylene sulfonate, and 5-15 parts of potassium persulfate.

7. The cement slurry for lubricating the super high-rise pumping pipeline according to claim 6, Features: The preparation method of the water reducing agent is: Dissolving maleic anhydride and polyethylene glycol monoacrylate in acetone to obtain component A, and dissolving sodium propylene sulfonate and potassium persulfate in deionized water to obtain component B; Under stirring conditions, component A and component B are mixed and transferred to a reaction vessel, and heated to 85-90° C., 1-3% of the total mass of the reaction solution is added with dodecyl mercaptan, and the reaction is continued for 4-6 hours; After the reaction is completed, impurities are removed by filtration, and the reaction solution is concentrated and dried to obtain a water reducing agent.

8. A method for preparing cement slurry for lubricating super high-rise pumping pipelines according to any one of claims 1 to 7, Features: The following steps are involved: First, cement and fly ash are stirred and mixed to obtain a dry mix, and then water is added to the mixing container while continuously stirring to form a uniform slurry; Add the weighed water reducer and rheology regulator into the slurry and stir for 20-30 minutes to form a uniform, particle-free cement slurry.

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