Gypsum slag-based super-retarding material and preparation method thereof
By preparing gypsum slag-based super-retarded setting materials, and utilizing TPEG-modified polycarboxylic acid ethers and composite activators to form dense films and complexes, the problems of insufficient retarding performance, low mechanical strength, and poor storage stability were solved, achieving excellent retarding performance, strength, and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG HENGJIAN ENG INSPECTION CO LTD
- Filing Date
- 2026-05-12
- Publication Date
- 2026-06-12
AI Technical Summary
Existing gypsum slag-based ultra-retarded materials suffer from insufficient retarding performance, low mechanical strength, and poor storage stability.
The raw materials, by weight, consist of desulfurized gypsum, slag powder, composite activator, carbide slag, silica fume, and fly ash. By preparing TPEG-modified polycarboxylic acid ether and composite activator, a dense polymer hydration film and a stable complex are formed, which prevents the hydration reaction from being too fast, prolongs the setting time, and improves the strength and stability.
An ultra-retarded material with excellent retarding properties, high mechanical strength, and good storage stability was prepared. The initial setting time was extended to 3914-3927 minutes, the final setting time was extended to 4925-4936 minutes, the 7-day compressive strength was 21.2-23.5 MPa, the 28-day compressive strength was 52.6-56.3 MPa, and the storage stability was excellent.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials technology, specifically to a gypsum slag-based super-retarded setting material and its preparation method. Background Technology
[0002] Super-retarded setting materials play an irreplaceable role in large-volume concrete projects, ultra-long-distance concrete transportation construction, emergency rescue and disaster relief temporary support, and special engineering layered pouring scenarios. Their core requirement is to significantly extend the initial setting time to adapt to complex construction conditions while ensuring the later strength development of the material.
[0003] Currently, existing retarding materials are mainly divided into two categories: chemical retarder and industrial waste-based composite retarder. While chemical retarders offer direct retarding effects, controlling ultra-retardation is difficult, and excessive addition can lead to problems such as later-stage strength reduction in concrete and unstable hydration products. Industrial waste-based materials, on the other hand, have become a research hotspot due to their environmental friendliness and low cost. Gypsum and slag, as major industrial solid wastes, have hydration products with good strength development potential and have been explored for use in preparing retarding materials. Existing technology with publication number CN117228970A discloses a gypsum-slag-based ultra-retarded cementitious binder and its preparation method. This technology uses sodium dihydrogen phosphate in combination with soluble calcium salts to reduce the pH value of the binder in the initial hydration stage, thus reducing the alkalinity of the hydration system. By adjusting the ratio and amount of cement, composite activator, and quicklime, the alkalinity and reaction rate of the initial hydration reaction slurry can be changed, significantly extending the setting time of the binder. However, this existing technology still suffers from insufficient ultra-retarding performance, limited retarding effect, and insufficient synergy between retarding and strength, and it does not address storage stability.
[0004] In summary, although the existing technical solutions have improved some properties of gypsum slag-based super-retarded materials to a certain extent, the following technical problems still exist: insufficient retardation performance, low mechanical strength, and poor storage stability. Summary of the Invention
[0005] In order to solve the above-mentioned problems in the prior art, the present invention provides a gypsum slag-based super-retarded setting material and its preparation method, and achieves the following objectives: to prepare a super-retarded setting material with excellent retarding performance, high mechanical strength and good storage stability.
[0006] To achieve the above objectives, the following technical solution is adopted: A gypsum slag-based super-retarded setting material, by weight, comprises: 15-20 parts desulfurized gypsum, 60-70 parts slag powder, 1-2 parts composite activator, 1-2 parts carbide slag, 1-3 parts silica fume, and 3-6 parts fly ash.
[0007] The composite activator uses raw materials including TPEG-modified polycarboxylic acid ether, sodium pyrophosphate, and sodium citrate.
[0008] The slag powder used is S95 grade slag powder with a specific surface area ≥400 m². 2 / kg.
[0009] The fly ash used is Grade I fly ash.
[0010] The silica content of the silica ash is ≥90%.
[0011] The desulfurized gypsum has a calcium sulfate dihydrate content of ≥90%.
[0012] The calcium oxide content of the carbide slag is ≥70%.
[0013] This invention also provides a method for preparing gypsum slag-based super-retarded setting material, including the steps of preparing TPEG-modified polycarboxylic acid ether, preparing a composite activator, and obtaining the super-retarded setting material.
[0014] The preparation of TPEG-modified polycarboxylic acid ether involves: mixing acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water to obtain a mixed monomer solution; heating and maintaining the isopentenyl alcohol polyoxyethylene ether solution; then simultaneously adding the mixed monomer solution, initiator solution, and reducing agent solution; after the addition is complete, maintaining the temperature for reaction; after the reaction is complete, cooling and adjusting the pH value to obtain TPEG-modified polycarboxylic acid ether.
[0015] Further, the mass ratio of acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water is (8-12):(2-3):(0.1-0.12):(20-25). The isopentenyl alcohol polyoxyethylene ether solution is an aqueous solution of isopentenyl alcohol polyoxyethylene ether with a mass fraction of 50-55%. The molecular weight of the isopentenyl alcohol polyoxyethylene ether is 2400-3000.
[0016] Furthermore, the mass ratio of the mixed monomer solution, initiator solution, reducing agent solution, and isopentenyl alcohol polyoxyethylene ether solution is (4-4.5):(0.6-0.8):(0.6-0.8):(4.5-5).
[0017] The initiator solution is an aqueous solution of ammonium persulfate with a mass fraction of 8-10%.
[0018] The reducing agent solution is an aqueous solution of sodium bisulfite with a mass fraction of 8-10%.
[0019] The sodium hydroxide solution has a mass fraction of 20%.
[0020] Further, the preparation of TPEG-modified polycarboxylate ether involves: mixing acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water to obtain a mixed monomer solution. The isopentenyl alcohol polyoxyethylene ether (TPEG) solution is heated to 55-60℃ and held at this temperature for 15-20 min; then, the mixed monomer solution, initiator solution, and reducing agent solution are simultaneously added dropwise. The dropwise addition time for the mixed monomer solution is 150-180 min, and the dropwise addition time for the initiator solution and reducing agent solution is 160-190 min. After the addition is complete, the temperature is raised to 65-68℃ and the reaction is held at this temperature for 90-120 min. After the reaction is complete, the temperature is lowered to 40-50℃, and sodium hydroxide solution is added dropwise to adjust the pH to 6-7. The mixture is then passed through a 200-mesh sieve to obtain the TPEG-modified polycarboxylate ether.
[0021] The preparation of the composite activator involves: pulverizing sodium pyrophosphate and sodium citrate; adding TPEG-modified polycarboxylic acid ether to a mixer, then adding sodium pyrophosphate and sodium citrate, and stirring; then adjusting the viscosity with deionized water, allowing it to stand, and obtaining the composite activator.
[0022] Furthermore, the mass ratio of the TPEG modified polycarboxylic acid ether, sodium pyrophosphate, and sodium citrate is (9-11):(2-4):(1-2).
[0023] Further, the preparation of the composite activator involves: pulverizing sodium pyrophosphate and sodium citrate and passing them through a 200-mesh sieve; adding TPEG-modified polycarboxylic acid ether to a mixer, starting the mixer at 700-900 rpm, then adding sodium pyrophosphate and sodium citrate in 3-4 portions, stirring for 10-20 minutes after each addition; then adjusting the viscosity to 600-900 mPa·s with deionized water, testing the viscosity at 25℃, and allowing it to stand for 10-15 minutes to obtain the composite activator.
[0024] The super-retarded setting material is prepared by adding a composite activator to deionized water and stirring to obtain an activator-water mixture; then adding slag powder and fly ash, then adding silica fume, and finally adding desulfurized gypsum and carbide slag, stirring evenly to obtain the super-retarded setting material.
[0025] Furthermore, the mass ratio of the composite activator to deionized water is 1:(18-20).
[0026] Furthermore, the preparation of the super-retarded material involves: adding the composite activator to deionized water and stirring for 15-20 minutes at a stirring speed of 300-400 rpm to obtain an activator-water mixture, maintaining the temperature of the activator-water mixture at 20-30℃. Then, slag powder and fly ash are added and stirred for 8-10 minutes at a stirring speed of 200-250 rpm; then, silica fume is added, and the stirring speed is increased to 300-350 rpm for 10-12 minutes; finally, desulfurized gypsum and carbide slag are added and stirred evenly to obtain the super-retarded material.
[0027] The beneficial effects of this invention are as follows: In this invention, the carboxyl and hydroxyl groups on the TPEG-modified polycarboxylic acid ether molecular chain can be adsorbed onto the surface of slag and gypsum particles, forming a dense polymer hydration film. On one hand, this physically blocks the diffusion channels of hydrated ions, inhibiting the initial formation rate of core hydration products such as calcium hydroxide and ettringite. On the other hand, the polymer molecular chain effectively prevents particles from agglomerating, significantly reducing the water demand of the slurry and ensuring that the hydration reaction proceeds uniformly within the system, avoiding performance imbalances caused by excessively rapid local reactions. Pyrophosphate and citrate groups affect the Ca... 2+ Al 3+ Metal ions possess extremely strong complexing abilities. In the early stages of hydration, they can adsorb and coat the surface of slag and gypsum particles, and interact with free Ca in the solution. 2+ Al 3+ The rapid formation of stable complexes significantly slows down the formation and growth of crystal nuclei in hydration products such as calcium hydroxide and ettringite. Furthermore, the adsorption layer formed on the particle surface hinders the contact between water and active components, further reducing the dissolution-precipitation reaction rate. Simultaneously, these complexes can act as "ion carriers," slowly releasing the complexed metal ions in the later stages of hydration, promoting the formation of a more uniform and dense structure of the hydration products.
[0028] (2) The gypsum slag-based super-retarded setting material of the present invention has excellent retarding performance. The standard consistency water consumption of the super-retarded setting material is 20.2-21.4%, the initial setting time is 3914-3927 min, and the final setting time is 4925-4936 min.
[0029] (3) The gypsum slag-based super-retarded setting material of the present invention has high mechanical strength. The 7-day compressive strength of the super-retarded setting material is 21.2-23.5 MPa, the 28-day compressive strength is 52.6-56.3 MPa, the 7-day flexural strength is 6.2-6.7 MPa, and the 28-day flexural strength is 10.2-10.9 MPa.
[0030] (4) The gypsum slag-based super-retarded setting material of the present invention has excellent storage stability. The initial setting time of the prepared super-retarded setting material after 7 days of storage is 1.2-2.8%, the initial setting time after 14 days of storage is 4.1-5.5%, the final setting time after 7 days of storage is 1.5-2.3%, and the final setting time after 14 days of storage is 3.4-6.2%. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.
[0032] Example 1: A gypsum slag-based super-retarded setting material and its preparation method A gypsum-slag-based super-retarded setting material, by weight, comprises: 15 parts desulfurized gypsum, 70 parts slag powder, 1 part composite activator, 2 parts carbide slag, 1 part silica fume, and 6 parts fly ash.
[0033] A method for preparing a gypsum slag-based super-retarded setting material includes the following steps: Step 1: Preparation of TPEG-modified polycarboxylic acid ether Acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water were mixed thoroughly to obtain a mixed monomer solution. The isopentenyl alcohol polyoxyethylene ether solution was heated to 55°C and held at this temperature for 20 min. Then, the mixed monomer solution, initiator solution, and reducing agent solution were simultaneously added dropwise over 150 min, and the initiator and reducing agent solutions over 160 min. After the addition was complete, the temperature was raised to 65°C and the reaction was held at this temperature for 120 min. After the reaction was complete, the temperature was lowered to 40°C, and sodium hydroxide solution was added dropwise to adjust the pH to 6. The mixture was then passed through a 200-mesh sieve to obtain TPEG-modified polycarboxylic acid ether.
[0034] The mass ratio of acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water is 8:2:0.1:20.
[0035] The isopentenyl alcohol polyoxyethylene ether solution is a 50% (w / w) aqueous solution of isopentenyl alcohol polyoxyethylene ether. The molecular weight of the isopentenyl alcohol polyoxyethylene ether is 2400-3000.
[0036] The initiator solution is an 8% (w / w) aqueous solution of ammonium persulfate.
[0037] The reducing agent solution is an 8% sodium bisulfite aqueous solution.
[0038] The mass ratio of the mixed monomer solution, initiator solution, reducing agent solution, and isopentenyl alcohol polyoxyethylene ether solution is 4:0.6:0.6:4.5.
[0039] The sodium hydroxide solution has a mass fraction of 20%.
[0040] Step 2: Preparation of composite activator Sodium pyrophosphate and sodium citrate were pulverized and passed through a 200-mesh sieve. TPEG-modified polycarboxylic acid ether was added to a mixer and stirred at 700 rpm. Sodium pyrophosphate and sodium citrate were then added in three portions, and stirred for 20 minutes after each addition. The viscosity was then adjusted to 600 mPa·s using deionized water, and the viscosity was tested at 25°C. The mixture was allowed to stand for 10 minutes to obtain the composite activator.
[0041] The mass ratio of the TPEG-modified polycarboxylic acid ether, sodium pyrophosphate, and sodium citrate is 9:2:1.
[0042] Step 3: Obtaining the super-retarded setting material The composite activator was added to deionized water and stirred for 15 minutes at a stirring speed of 400 rpm to obtain an activator-water mixture. The mass ratio of the composite activator to deionized water was 1:18, and the temperature of the activator-water mixture was maintained at 20℃. Then, slag powder and fly ash were added and stirred for 8 minutes at a stirring speed of 250 rpm. Next, silica fume was added, and the stirring speed was increased to 350 rpm for 10 minutes. Finally, desulfurized gypsum and carbide slag were added and stirred evenly to obtain the ultra-retarded setting material.
[0043] Example 2: A gypsum slag-based super-retarded setting material and its preparation method A gypsum slag-based super-retarded setting material, by weight, comprises the following raw materials: 18 parts desulfurized gypsum, 65 parts slag powder, 1.5 parts composite activator, 1.5 parts carbide slag, 2 parts silica fume, and 4.5 parts fly ash.
[0044] A method for preparing a gypsum slag-based super-retarded setting material includes the following steps: Step 1: Preparation of TPEG-modified polycarboxylic acid ether Acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water were mixed thoroughly to obtain a mixed monomer solution. The isopentenyl alcohol polyoxyethylene ether solution was heated to 60°C and held at this temperature for 20 min. Then, the mixed monomer solution, initiator solution, and reducing agent solution were simultaneously added dropwise over 170 min, and the initiator and reducing agent solutions were added over 180 min. After the addition was complete, the temperature was raised to 68°C and the reaction was held at this temperature for 110 min. After the reaction was complete, the temperature was lowered to 45°C, and sodium hydroxide solution was added dropwise to adjust the pH to 6.5. The mixture was then passed through a 200-mesh sieve to obtain TPEG-modified polycarboxylic acid ether.
[0045] The mass ratio of acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water is 10:2.5:0.1:20.
[0046] The isopentenyl alcohol polyoxyethylene ether solution is a 50% (w / w) aqueous solution of isopentenyl alcohol polyoxyethylene ether. The molecular weight of the isopentenyl alcohol polyoxyethylene ether is 2400-3000.
[0047] The initiator solution is a 9% (w / w) aqueous solution of ammonium persulfate.
[0048] The reducing agent solution is a 9% sodium bisulfite aqueous solution.
[0049] The mass ratio of the mixed monomer solution, initiator solution, reducing agent solution, and isopentenyl alcohol polyoxyethylene ether solution is 4.5:0.7:0.7:5.
[0050] The sodium hydroxide solution has a mass fraction of 20%.
[0051] Step 2: Preparation of composite activator Sodium pyrophosphate and sodium citrate were pulverized and passed through a 200-mesh sieve. TPEG-modified polycarboxylic acid ether was added to a mixer and stirred at 800 rpm. Sodium pyrophosphate and sodium citrate were then added in three portions, and stirred for 15 minutes after each addition. The viscosity was then adjusted to 800 mPa·s using deionized water and tested at 25°C. The mixture was allowed to stand for 15 minutes to obtain the composite activator.
[0052] The mass ratio of the TPEG-modified polycarboxylic acid ether, sodium pyrophosphate, and sodium citrate is 10:3:1.5.
[0053] Step 3: Obtaining the super-retarded setting material The composite activator was added to deionized water and stirred for 18 minutes at a stirring speed of 400 rpm to obtain an activator-water mixture. The mass ratio of the composite activator to deionized water was 1:19, and the temperature of the activator-water mixture was maintained at 25°C. Then, slag powder and fly ash were added and stirred for 10 minutes at a stirring speed of 250 rpm. Next, silica fume was added, and the stirring speed was increased to 350 rpm for 12 minutes. Finally, desulfurized gypsum and carbide slag were added and stirred evenly to obtain the ultra-retarded setting material.
[0054] Example 3: A gypsum slag-based super-retarded setting material and its preparation method A gypsum slag-based super-retarded setting material, by weight, comprises: 20 parts desulfurized gypsum, 60 parts slag powder, 2 parts composite activator, 1 part carbide slag, 3 parts silica fume, and 3 parts fly ash.
[0055] A method for preparing a gypsum slag-based super-retarded setting material includes the following steps: Step 1: Preparation of TPEG-modified polycarboxylic acid ether Acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water were mixed thoroughly to obtain a mixed monomer solution. The isopentenyl alcohol polyoxyethylene ether solution was heated to 60°C and held at that temperature for 15 min. Then, the mixed monomer solution, initiator solution, and reducing agent solution were simultaneously added dropwise over 180 min, and the initiator and reducing agent solutions were added over 190 min. After the addition was complete, the temperature was raised to 68°C and the reaction was held at that temperature for 90 min. After the reaction was complete, the temperature was lowered to 50°C, and sodium hydroxide solution was added dropwise to adjust the pH to 7. The mixture was then passed through a 200-mesh sieve to obtain TPEG-modified polycarboxylic acid ether.
[0056] The mass ratio of acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water is 12:3:0.12:25.
[0057] The isopentenyl alcohol polyoxyethylene ether solution is a 55% (w / w) aqueous solution of isopentenyl alcohol polyoxyethylene ether. The molecular weight of the isopentenyl alcohol polyoxyethylene ether is 2400-3000.
[0058] The initiator solution is a 10% (w / w) aqueous solution of ammonium persulfate.
[0059] The reducing agent solution is a 10% sodium bisulfite aqueous solution.
[0060] The mass ratio of the mixed monomer solution, initiator solution, reducing agent solution, and isopentenyl alcohol polyoxyethylene ether solution is 4.5:0.8:0.8:5.
[0061] The sodium hydroxide solution has a mass fraction of 20%.
[0062] Step 2: Preparation of composite activator Sodium pyrophosphate and sodium citrate were pulverized and passed through a 200-mesh sieve. TPEG-modified polycarboxylic acid ether was added to a mixer and stirred at 900 rpm. Sodium pyrophosphate and sodium citrate were then added in four portions, and stirred for 10 minutes after each addition. The viscosity was then adjusted to 900 mPa·s using deionized water and tested at 25°C. The mixture was allowed to stand for 15 minutes to obtain the composite activator.
[0063] The mass ratio of the TPEG-modified polycarboxylic acid ether, sodium pyrophosphate, and sodium citrate is 11:4:2.
[0064] Step 3: Obtaining the super-retarded setting material The composite activator was added to deionized water and stirred for 20 minutes at a stirring speed of 300 rpm to obtain an activator-water mixture. The mass ratio of the composite activator to deionized water was 1:20, and the temperature of the activator-water mixture was maintained at 30℃. Then, slag powder and fly ash were added and stirred for 10 minutes at a stirring speed of 200 rpm. Next, silica fume was added, and the stirring speed was increased to 300 rpm for 12 minutes. Finally, desulfurized gypsum and carbide slag were added and stirred evenly to obtain the ultra-retarded setting material.
[0065] Comparative Example 1 A gypsum slag-based super-retarded setting material, by weight, comprises the following raw materials: 18 parts desulfurized gypsum, 65 parts slag powder, 1.5 parts composite activator, 1.5 parts carbide slag, 2 parts silica fume, and 4.5 parts fly ash.
[0066] A method for preparing a gypsum slag-based super-retarded setting material includes the following steps: Step 1: Preparation of composite activator Sodium pyrophosphate and sodium citrate were pulverized and passed through a 200-mesh sieve. Sodium pyrophosphate and sodium citrate were added to a mixer, and the mixer was turned on at 800 rpm for 15 minutes. Then, the viscosity was adjusted to 800 mPa·s with deionized water, and the viscosity was tested at 25℃. After standing for 15 minutes, the composite activator was obtained.
[0067] The mass ratio of sodium pyrophosphate to sodium citrate is 3:1.5.
[0068] Step 2: Obtaining the super-retarded setting material This step is the same as the "Preparation of Ultra-Retarded Material" step in Example 2.
[0069] Example 4 Performance Test (a) The retarding performance of the super-retarded materials prepared in Examples 1-3 and Comparative Example 1 was tested. The standard consistency water consumption, initial setting time, and final setting time were tested according to the test method specified in GB / T1346-2011. The specific test results are shown in Table 1.
[0070] Table 1 As shown in Table 1, the standard consistency water requirement of the ultra-retarded setting materials prepared in Examples 1-3 is 20.2-21.4%, the initial setting time is 3914-3927 min, and the final setting time is 4925-4936 min. This demonstrates that the ultra-retarded setting materials prepared in this invention have excellent retarding properties.
[0071] (II) The mechanical properties of the ultra-retarded materials prepared in Examples 1-3 and Comparative Example 1 were tested. Mortar test blocks were prepared according to the test methods specified in GB / T17671-2021, and cured for 7 days and 28 days, and the compressive strength and flexural strength were tested. The specific test results are shown in Table 2.
[0072] Table 2 As shown in Table 2, the super-retarded setting materials prepared in Examples 1-3 have a 7-day compressive strength of 21.2-23.5 MPa, a 28-day compressive strength of 52.6-56.3 MPa, a 7-day flexural strength of 6.2-6.7 MPa, and a 28-day flexural strength of 10.2-10.9 MPa. This demonstrates that the super-retarded setting materials prepared in this invention have high mechanical strength.
[0073] (III) Storage stability tests were conducted on the ultra-retarded materials prepared in Examples 1-3 and Comparative Example 1. After 7 days and 14 days of sealed storage, the initial setting / final setting time was tested, and the change rate was calculated as: (storage time - initial time) / initial time × 100%. The specific test results are shown in Table 3.
[0074] Table 3 As shown in Table 3, the initial setting time of the ultra-retarded materials prepared in Examples 1-3 changed by 1.2-2.8% after 7 days of storage, 4.1-5.5% after 14 days of storage, 1.5-2.3% after 7 days of storage, and 3.4-6.2% after 14 days of storage. This demonstrates the excellent storage stability of the ultra-retarded materials prepared in this invention.
[0075] The specific parameters of the raw materials used in this invention are as follows: The slag powder used is S95 grade slag powder with a specific surface area ≥400 m². 2 / kg.
[0076] The fly ash used is Grade I fly ash.
[0077] The silica content of the silica ash is ≥90%.
[0078] The desulfurized gypsum has a calcium sulfate dihydrate content of ≥90%.
[0079] The calcium oxide content of the carbide slag is ≥70%.
[0080] Obviously, there are many other possible implementation methods under the concept of this invention. It should be stated here that any changes made under the inventive concept of this invention will fall within the protection scope of this invention.
Claims
1. A gypsum slag-based super-retarded setting material, characterized in that: The raw materials for the ultra-retarded setting material include desulfurized gypsum, slag powder, composite activator, carbide slag, silica fume, and fly ash; The preparation method of the super-retarded setting material includes the steps of preparing TPEG-modified polycarboxylic acid ether, preparing a composite activator, and obtaining the super-retarded setting material. The preparation of TPEG-modified polycarboxylic acid ether involves: mixing acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water to obtain a mixed monomer solution; heating and maintaining the temperature of the isopentenyl alcohol polyoxyethylene ether solution; then simultaneously adding the mixed monomer solution, initiator solution, and reducing agent solution; after the addition is complete, maintaining the temperature for reaction; after the reaction is complete, cooling and adjusting the pH value to obtain TPEG-modified polycarboxylic acid ether. The preparation of the composite activator involves: pulverizing sodium pyrophosphate and sodium citrate; adding TPEG-modified polycarboxylic acid ether to a mixer, then adding sodium pyrophosphate and sodium citrate, and stirring; then adjusting the viscosity with deionized water, allowing it to stand, and obtaining the composite activator. The super-retarded setting material is prepared by adding a composite activator to deionized water and stirring to obtain an activator-water mixture; then adding slag powder and fly ash, then adding silica fume, and finally adding desulfurized gypsum and carbide slag, stirring evenly to obtain the super-retarded setting material.
2. The gypsum slag-based super-retarded setting material according to claim 1, characterized in that: The raw material composition by weight of the ultra-retarded setting material is as follows: 15-20 parts desulfurized gypsum, 60-70 parts slag powder, 1-2 parts composite activator, 1-2 parts calcium carbide slag, 1-3 parts silica fume, and 3-6 parts fly ash.
3. The gypsum slag-based super-retarding material according to claim 1, characterized in that: In the step of preparing TPEG modified polycarboxylic acid ether, the mass ratio of acrylic acid, hydroxypropyl acrylate, mercaptoacetic acid, and deionized water is (8-12):(2-3):(0.1-0.12):(20-25).
4. The gypsum slag-based super-retarded setting material according to claim 1, characterized in that: The isopentenyl alcohol polyoxyethylene ether solution is an aqueous solution of isopentenyl alcohol polyoxyethylene ether with a mass fraction of 50-55%; the molecular weight of the isopentenyl alcohol polyoxyethylene ether is 2400-3000.
5. The gypsum slag-based super-retarded setting material according to claim 1, characterized in that: The initiator solution is an aqueous solution of ammonium persulfate with a mass fraction of 8-10%.
6. The gypsum slag-based super-retarded setting material according to claim 1, characterized in that: The reducing agent solution is an aqueous solution of sodium bisulfite with a mass fraction of 8-10%.
7. The gypsum slag-based super-retarded setting material according to claim 1, characterized in that: In the step of preparing TPEG modified polycarboxylic acid ether, the mass ratio of the mixed monomer solution, initiator solution, reducing agent solution and isopentenyl alcohol polyoxyethylene ether solution is (4-4.5):(0.6-0.8):(0.6-0.8):(4.5-5).
8. The gypsum slag-based super-retarded setting material according to claim 1, characterized in that: To adjust the pH value: add sodium hydroxide solution dropwise to adjust the pH value to 6-7.
9. The gypsum slag-based super-retarded setting material according to claim 1, characterized in that: In the step of preparing the composite activator, the mass ratio of TPEG modified polycarboxylic acid ether, sodium pyrophosphate, and sodium citrate is (9-11):(2-4):(1-2).
10. The gypsum slag-based super-retarded setting material according to claim 1, characterized in that: In the step of preparing the super-retarded coagulation material, the mass ratio of the composite activator to deionized water is 1:(18-20).