Preparation method of organic interface coupling composite activator and super-sulfated cement thereof

Abstract

The application relates to the field of cement building materials, in particular to a preparation method of an organic interface coupling composite activator and super-sulphate cement thereof. The method comprises the following steps: (1) mixing calcium carbide slag and water to form slurry a, then mixing the slurry a with a tannic acid aqueous solution to react, drying and crushing after the reaction, and thus tannic acid modified calcium carbide slag is obtained; (2) mixing steel slag and water to form slurry b, then mixing the slurry b with an amine interface agent aqueous solution to react, drying and crushing after the reaction, and thus amine interface modified steel slag is obtained; (3) adding the tannic acid modified calcium carbide slag and the amine interface modified steel slag into water to form a composite slurry, stirring and dispersing the composite slurry, and grinding, then adjusting the pH of the system and standing, and finally spray-drying the obtained slurry, and thus the organic interface coupling composite activator is obtained. The calcium carbide slag and the steel slag are modified, and thus the early strength and setting performance of the super-sulphate cement with high gypsum content are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of cement building materials, specifically to a method for preparing an organic interface coupling composite activator and its supersulfate cement. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Supersulfate cement (SSC) is a type of low-carbon cementitious material formed by the combined action of granulated blast furnace slag as the main cementing material and sulfates (such as gypsum) and alkaline activating components. Compared with traditional silicate cement, it has advantages such as lower clinker consumption and lower carbon dioxide emissions, and has good application prospects in the fields of solid waste resource utilization and low-carbon building materials. Desulfurization gypsum is a typical industrial by-product generated during the flue gas desulfurization process of coal-fired power plants, characterized by large production volume and concentrated emissions. With the widespread application of flue gas desulfurization technology in coal-fired power plants, the production of desulfurization gypsum continues to increase, and its resource utilization is receiving increasing attention. Using desulfurization gypsum as a component of supersulfate cement not only helps to activate the slag and promote the formation of ettringite, but also realizes the resource utilization of desulfurization gypsum.

[0004] Currently, supersulfate cement typically uses cement clinker, lime, or other alkaline substances as activating components to dissolve slag in an alkaline environment and form hydration products. In recent years, some studies have attempted to replace some traditional alkaline activating components with solid wastes such as carbide slag and steel slag to reduce costs and improve solid waste utilization. However, the inventors have found that under high gypsum content conditions, simply increasing alkaline components or using multiple solid wastes is insufficient to stably control the early reaction process, easily leading to problems such as prolonged setting time, slow early strength development, uneven reaction, and performance fluctuations. The main reason is that the activating components in the above methods usually exist as independent particles, randomly dispersed during mixing, making it difficult to achieve stable synergy at the microscale. This results in uneven local ionic environments, mismatched reaction zones, and disordered formation of early hydration products, thus limiting effective control of the early reaction pathway. Therefore, how to construct structural units capable of controlling the reaction behavior of activating components at the microscale, matching the alkaline release process with the solid particle reaction process, and adapting to the complex ionic environment of high gypsum systems, has become a technical problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a method for preparing an organic interface-coupled composite activator and its associated hypersulfate cement. By modifying carbide slag and steel slag and coupling their interfaces, the method achieves synergistic regulation of the alkaline release process, the steel slag's participation in the reaction process, and the nucleation process under high gypsum content conditions, effectively improving the early strength and setting performance of the hypersulfate cement. Specifically, the technical solution of this invention is as follows.

[0006] In a first aspect, the present invention provides a method for preparing an organic interface coupling composite activator, comprising the following steps: (1) Mix carbide slag with water to form slurry a, then mix it with tannic acid aqueous solution to react. After the reaction is completed, dry and crush it to obtain tannic acid modified carbide slag for later use.

[0007] (2) Mix steel slag with water to form slurry b, then mix it with an aqueous solution of amine interface agent to react. After the reaction is completed, dry and crush it to obtain amine interface modified steel slag for later use.

[0008] (3) The composite slurry formed by adding the tannic acid-modified carbide slag and the amine-modified steel slag to water is stirred and dispersed, and then ground. After completion, the pH of the system is adjusted and allowed to stand, and then the resulting slurry is spray-dried to obtain the organic interface coupling composite activator.

[0009] Further, in step (1), the ratio of carbide slag to water is 1g:2~6mL. Optionally, the two are mixed and stirred for 10~30min to obtain the slurry a.

[0010] Further, in step (1), the tannic acid in the tannic acid aqueous solution is 0.05~1.0% of the mass of carbide slag. Optionally, the mass fraction of the tannic acid aqueous solution is 0.1~2.0%.

[0011] Further, in step (1), the reaction temperature is 20~50℃, and the reaction time is 20~90min. During this process, the tannic acid reacts with the Ca on the surface of the carbide slag particles. 2+ Adsorption and complexation occur, thereby forming an organic complex adsorption layer containing polyphenol groups on the surface of carbide slag particles.

[0012] Furthermore, in step (1), the drying temperature is 60~105℃ and the drying time is 6~24h.

[0013] Further, in step (2), the ratio of steel slag to water is 1g:1~5mL. Optionally, the two are mixed and stirred for 10~30min to obtain the slurry b.

[0014] Further, in step (2), the amine interface agent in the aqueous solution is 0.02~0.8% of the mass of the steel slag. Optionally, the mass fraction of the aqueous solution of the amine interface agent is 0.1~3.0%.

[0015] Further, in step (2), the amine interface agent includes one or more of polyethyleneimine, polylysine, etc.

[0016] Furthermore, in step (2), the reaction temperature is 20~50℃, and the reaction time is 20~90min. During this process, the amine-based interface agent is used to construct an amine-rich interface layer on the surface of the steel slag particles.

[0017] Furthermore, in step (2), the drying temperature is 70~95℃ and the drying time is 8~16h.

[0018] Furthermore, in step (3), the mass ratio of the tannic acid-modified carbide slag to the amine-modified steel slag is 1~5:1~3.

[0019] Furthermore, in step (3), the solid content of the composite slurry is 25~45 wt.%.

[0020] Further, in step (3), the stirring and dispersion treatment time is 5~15 min, and the stirring rate is 3000~8000 rpm.

[0021] Furthermore, in step (3), the grinding process takes 10 to 40 minutes.

[0022] Further, in step (3), the pH is 8~10. Optionally, the pH can be adjusted by adding acid or alkali.

[0023] Furthermore, in step (3), the settling time is 20-40 minutes. During this process, the tannic acid-modified carbide slag and the amine-modified steel slag form composite particles through interfacial coupling, constructing a composite excitation structure that can regulate the local reaction environment, improve the early product precipitation position, and reduce the coverage and passivation.

[0024] Furthermore, in step (3), the inlet air temperature of the spray dryer is 150~220℃ and the outlet air temperature is 70~110℃.

[0025] Furthermore, in step (3), the particle size of the organic interface coupling composite activator is 10~150μm.

[0026] Secondly, the present invention provides a supersulfate cement comprising the following components in the following proportions: 30-60 parts by weight of mineral powder, 30-60 parts by weight of solid waste gypsum, 1-10 parts by weight of the organic interface coupling composite activator, 10-20 parts by weight of aluminate cement, 0.1-5 parts by weight of accelerator, 0.1-1 parts by weight of water-reducing agent, and a water-cement ratio of 0.35-0.45, wherein the "cement" refers to the sum of the above-mentioned mineral powder, solid waste gypsum, organic interface coupling composite activator, and aluminate cement.

[0027] Furthermore, the solid waste gypsum includes at least one of desulfurization gypsum, phosphogypsum, fluorogypsum, etc.

[0028] Furthermore, the quick-setting agent includes one or more of the following: aluminum sulfate, nano-alumina, nano-silica, and nano-calcium carbonate.

[0029] Furthermore, the water-reducing agent includes one or more of the following: polycarboxylate water-reducing agents, naphthalene-based water-reducing agents, and lignin sulfonate water-reducing agents.

[0030] Compared with the prior art, the present invention has at least the following beneficial technical effects: This invention employs tannic acid and an amino-based interfacial agent to modify the surfaces of carbide slag particles and steel slag particles, respectively, and then forms a composite activator through interfacial coupling between the two. On one hand, the polyphenol groups in the tannic acid react with the CaO on the surface of the carbide slag particles... 2+ The formed organic complex adsorption layer enables the carbide slag to reduce the instantaneous release rate of alkaline components in the initial stage of mixing while maintaining its alkaline activation ability, and improves the dispersion stability of carbide slag particles in cement paste, thereby reducing local high pH and local Ca2+. 2+ The uneven reaction caused by enrichment is beneficial to the smooth start-up of the early hydration reaction process in the high gypsum system.

[0031] On the other hand, when the steel slag is used in this invention to assist in the local alkaline environment and calcium-containing reaction conditions of the system as a component participating in the early reaction process, the contact state between the surface of the steel slag particles and the aqueous phase and the local ionic environment will affect the stability and consistency of its above-mentioned effects. This is not conducive to its effective participation in the reaction in the early stage, nor to the formation of a stable synergy between it and the carbide slag. However, by using an amine-based interfacial agent to construct an amine-rich interfacial layer on the surface of the steel slag particles, not only can the wetting and dispersion state of the steel slag particles in the aqueous system be improved, but the contact conditions between the surface of the steel slag particles and the cement paste can also be improved. This is conducive to the steel slag participating more stably in the early reaction process in the alkaline environment, and provides favorable conditions for the synergistic matching between the alkaline release process of the carbide slag and the reaction process of the steel slag in the composite activator of this invention.

[0032] Furthermore, by constructing a composite structure from the tannic acid-modified carbide slag and the amine-modified steel slag through interfacial coupling, the release of alkaline components and Ca from the carbide slag can be effectively prevented. 2+ The problem that the active phase in the steel slag initially enters the surrounding pore fluid and diffuses outwards, making it difficult to preferentially act on the surface of the steel slag particles, means that the surface activation, initial dissolution, and subsequent participation in the reaction process of the active phase in the steel slag still mainly depend on the alkalinity and ionic composition of the pore fluid at its location. It is difficult to form a locally high alkalinity and Ca²⁺ concentration in the vicinity of the particles. 2+ The process involves a continuous reaction from the establishment of enrichment conditions and the activation of steel slag particle surfaces to the preferential precipitation of early products. The composite structure enables the formation of stable composite structural units at the particle scale between carbide slag and steel slag, consisting of polyphenol-amine coupling interfaces. These units can facilitate the release of locally high alkalinity and Ca from the carbide slag. 2+ Enrichment conditions preferentially act on the surfaces of adjacent steel slag particles and are first absorbed by the adjacent steel slag interface. This constructs an organic-inorganic bridging near-field activation interface between the two types of particles. This allows the auxiliary reactions of the steel slag and the participation of some active phases in the process to occur preferentially in the vicinity of the particles, forming an activation zone in the near field of the composite particles. This further transforms into a preferential nucleation / growth interface for early hydration products, making early products such as AFt more likely to precipitate preferentially near the composite structural unit, rather than directly and rapidly precipitating locally on the surface of mineral powder or solid waste gypsum and forming a capping layer. This mitigates the adverse effects of localized concentrated distribution, delayed hydration, and uneven local reactions of steel slag particles. Therefore, the role of potential reactive components in the steel slag changes from a later, discrete release to a relatively dispersed and more uniform participation in the process in the early stages, which to some extent helps reduce the volume stability risk that may be caused by localized delayed reactions of the steel slag.

[0033] In addition, this invention constructs an organic interface coupling composite activator to achieve localized high alkalinity and Ca2+. 2+ The enrichment conditions, steel slag particle surface activation, and early product precipitation processes can be carried out more orderly in the vicinity of the particles. This can improve the problems of insufficient early strength and excessive setting time of hypersulfate cement under high gypsum content conditions, so that the system still has good early strength development and relatively stable setting performance. It is especially suitable for the regulation of the early reaction process of hypersulfate cement in high sulfate environment. Attached Figure Description

[0034] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings, wherein: Figure 1 The image shows a sample of the organic interface coupling composite activator prepared in Example 1 below.

[0035] Figure 2 The following diagram shows the compressive strength test results of the supersulfate cement specimens from Example 1.

[0036] Figure 3 The image shows the microstructure of the supersulfate cement specimen from Example 1 below under a scanning electron microscope (SEM). Detailed Implementation

[0037] The present invention is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods in the art or as per the product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention.

[0039] Example 1 1. A method for preparing an organic interface coupling composite activator, comprising the following steps: (1) Mix carbide slag powder and water at a ratio of 1g:4mL and stir for 20min to form slurry a. Then add 0.5% tannic acid aqueous solution to the slurry at a ratio of 0.5% of the mass of carbide slag powder and stir at 30℃ for 45min. After completion, heat to 80℃ and dry for 12h. Crush the resulting block to obtain tannic acid modified carbide slag for later use.

[0040] (2) Steel slag and water were mixed at a ratio of 1g:3mL and stirred for 20min to form slurry b. Then, an aqueous solution of 0.5% amine interface agent (polyethyleneimine) was added to the slurry at a ratio of 0.3% of the amine interface agent by mass of the steel slag, and stirred at 35℃ for 40min. After the reaction was completed, the mixture was heated to 85℃ and dried for 10h. The resulting block was then crushed to obtain amine interface modified steel slag for later use.

[0041] (3) The tannic acid-modified carbide slag and amine-modified steel slag were added to water at a mass ratio of 3:2 and stirred evenly to form a composite slurry with a solid content of 35%. Then, the slurry was sheared and dispersed at a high speed of 5000 rpm for 10 min, followed by grinding for 20 min. After completion, the pH of the system was adjusted to 9, and the mixture was allowed to stand for 30 min. The resulting slurry was then spray-dried (inlet air temperature set to 200℃, outlet air temperature set to 90℃). After sieving, an organic interface coupling composite activator with a particle size distribution between 10 and 150 μm was obtained, such as... Figure 1 As shown.

[0042] 2. A method for preparing supersulfate cement, comprising the following steps: (S1) Take the following components in the following proportions: 45 parts by weight of mineral powder, 45 parts by weight of desulfurized gypsum powder, 5 parts by weight of the organic interface coupling composite activator prepared in this embodiment, 10 parts by weight of aluminate cement, 0.5 parts by weight of quick-setting agent (aluminum sulfate), 0.3 parts by weight of polycarboxylate superplasticizer, and 44 parts by weight of mixing water; the aluminate cement is sulfoaluminate cement.

[0043] (S2) First, add the mineral powder, desulfurized gypsum powder, composite activator, and aluminate cement to a mixer and dry mix at a rate of 300 r / min for 10 min. Then add the quick-setting agent and water-reducing agent and mix for 2 min. Finally, add the mixing water and mix at a rate of 500 r / min for 120 s. After stopping for 15 s, mix at a rate of 1000 r / min for 120 s to obtain supersulfate cement.

[0044] Performance testing: (1) The setting time of the supersulfate cement specimens of this embodiment was tested according to GB / T 1346-2024. (2) The supersulfate cement of this embodiment was poured into a mold to make specimens, and the compressive strength of the specimens at curing ages of 1d, 3d, and 28d was tested according to GB / T 17671-2021. The 28d compressive strength test diagram is shown in the figure. Figure 2 As shown in Table 1 below, the test results for each of the above performance indicators are as follows.

[0045] Figure 3 The image shows the microstructure of the 3-day-old specimen under a scanning electron microscope (SEM). It can be seen that numerous needle-like and rod-like hydration products are formed internally, interwoven and overlapping with gel-like hydration products. Some pores are filled with hydration products, resulting in a dense matrix structure. This indicates that the organic interface coupling composite activator of this embodiment can effectively promote the formation of a continuous network structure of early hydration products in the high-gypsum system, thereby improving early strength.

[0046] Table 1 Test Results 135min 210min 7.2MPa 20.3MPa 46.5MPa Example 2 1. A method for preparing an organic interface coupling composite activator, comprising the following steps: (1) Mix carbide slag powder and water at a ratio of 1g:2mL and stir for 30min to form slurry a. Then, add 0.1% tannic acid aqueous solution to the slurry at a ratio of 0.05% of the carbide slag powder mass and stir at 50℃ for 20min. After completion, heat to 60℃ and dry for 24h. Crush the resulting block to obtain tannic acid modified carbide slag for later use.

[0047] (2) Steel slag and water were mixed at a ratio of 1g:1mL and stirred for 30min to form slurry b. Then, an aqueous solution of 0.1% amine interface agent (polylysine) was added to the mixture at a ratio of 0.02% of the amine interface agent by mass of the steel slag, and stirred at 50℃ for 20min. After the reaction was completed, the mixture was heated to 70℃ and dried for 16h. The resulting block was then crushed to obtain amine interface modified steel slag for later use.

[0048] (3) The tannic acid-modified carbide slag and amine-modified steel slag were added to water at a mass ratio of 5:3 and stirred evenly to form a composite slurry with a solid content of 45%. Then, the slurry was sheared and dispersed at a high speed of 8000 rpm for 15 min, and then ground for 10 min. After completion, the pH of the system was adjusted to 8 and allowed to stand for 40 min. Then, the obtained slurry was spray-dried (the inlet air temperature was set to 220℃ and the outlet air temperature was set to 110℃). After sieving, an organic interface coupling composite activator with a particle size distribution between 10 and 150 μm was obtained.

[0049] 2. A method for preparing supersulfate cement, comprising the following steps: (S1) Take the following components in the following proportions: 30 parts by weight of mineral powder, 60 parts by weight of desulfurized gypsum powder, 1 part by weight of the organic interface coupling composite activator prepared in this embodiment, 15 parts by weight of aluminate cement, 0.1 parts by weight of quick-setting agent (nano alumina), 0.1 parts by weight of polycarboxylate superplasticizer, and 37.1 parts by weight of mixing water; the aluminate cement is sulfoaluminate cement.

[0050] (S2) First, add the mineral powder, desulfurized gypsum powder, composite activator, and aluminate cement to a mixer and dry mix at a rate of 300 r / min for 10 min. Then add the quick-setting agent and water-reducing agent and mix for 2 min. Finally, add the mixing water and mix at a rate of 500 r / min for 120 s. After stopping for 15 s, mix at a rate of 1000 r / min for 120 s to obtain supersulfate cement.

[0051] Performance testing: The various performance indicators of the supersulfate cement in this embodiment were tested using the same method as in Example 1 above, and the results are shown in Table 2 below.

[0052] Table 2 Test Results 115min 190min 8.6MPa 22.4MPa 48.7MPa Example 3 1. A method for preparing an organic interface coupling composite activator, comprising the following steps: (1) Mix carbide slag powder and water at a ratio of 1g:6mL and stir for 10min to form slurry a. Then, add 2% tannic acid aqueous solution to the slurry at a ratio of 1% of the mass of carbide slag powder and stir at 20℃ for 90min. After completion, heat to 105℃ and dry for 6h. Crush the resulting block to obtain tannic acid modified carbide slag for later use.

[0053] (2) Steel slag and water were mixed at a ratio of 1g:5mL and stirred for 10min to form slurry b. Then, an aqueous solution of 3% amine interface agent (polylysine) was added to the mixture at a ratio of 0.8% of the amine interface agent by weight of the steel slag, and the mixture was stirred at 20℃ for 90min. After the reaction was completed, the mixture was heated to 95℃ and dried for 8h. The resulting block was then crushed to obtain amine interface modified steel slag for later use.

[0054] (3) The tannic acid-modified carbide slag and amine-modified steel slag were added to water at a mass ratio of 1:1 and stirred evenly to form a composite slurry with a solid content of 25%. Then, the slurry was sheared and dispersed at a high speed of 3000 rpm for 5 min, and then ground for 40 min. After completion, the pH of the system was adjusted to 10 and allowed to stand for 20 min. Then, the obtained slurry was spray-dried (the inlet air temperature was set to 150℃ and the outlet air temperature was set to 70℃). After sieving, an organic interface coupling composite activator with a particle size distribution between 10 and 150 μm was obtained.

[0055] 2. A method for preparing supersulfate cement, comprising the following steps: (S1) Take the following components in the following proportions: 60 parts by weight of mineral powder, 30 parts by weight of phosphogypsum powder, 10 parts by weight of the organic interface coupling composite activator prepared in this embodiment, 20 parts by weight of aluminate cement, 5 parts by weight of quick-setting agent (nano silica), 1 part by weight of naphthalene-based water-reducing agent, and 54 parts by weight of mixing water; the aluminate cement is sulfoaluminate cement.

[0056] (S2) First, add the mineral powder, phosphogypsum powder, composite activator, and aluminate cement to a mixer and dry mix at a rate of 300 r / min for 10 min. Then add the quick-setting agent and water-reducing agent and mix for 2 min. Finally, add the mixing water and mix at a rate of 500 r / min for 120 s. After stopping for 15 s, mix at a rate of 1000 r / min for 120 s to obtain supersulfate cement.

[0057] Performance testing: The various performance indicators of the supersulfate cement in this embodiment were tested using the same method as in Example 1 above, and the results are shown in Table 3 below.

[0058] Table 3 Test Results 105min 175min 9.1MPa 23.6MPa 49.8MPa Example 4 A method for preparing supersulfate cement is the same as in Example 1 above, except that the composite activator prepared by the following method is used instead of the organic interface coupling composite activator in Example 1: carbide slag powder and steel slag powder are mixed at a mass ratio of 3:2 and then ground. After grinding, the mixture is sieved to obtain a composite activator with a particle size distribution between 10 and 150 μm.

[0059] Performance testing: The various performance indicators of the supersulfate cement in this embodiment were tested using the same method as in Example 1 above. The results are shown in Table 4 below.

[0060] Table 4 Test Results 210min 315min 4.2MPa 14.6MPa 39.4MPa Example 5 A method for preparing supersulfate cement, similar to Example 1 above, differs in that the organic interface coupling composite activator in this example is prepared using the following steps: (1) Steel slag and water were mixed at a ratio of 1g:3mL and stirred for 20min to form slurry b. Then, an aqueous solution of 0.5% amine interface agent (polyethyleneimine) was added to the slurry at a ratio of 0.3% of the amine interface agent by mass of the steel slag, and stirred at 35℃ for 40min. After the reaction was completed, the mixture was heated to 85℃ and dried for 10h. The resulting block was then crushed to obtain amine interface modified steel slag for later use.

[0061] (2) Unmodified calcium carbide slag powder and the amine-modified steel slag of this embodiment were added to water at a mass ratio of 3:2 and stirred evenly to form a composite slurry with a solid content of 35%. Then, the slurry was sheared and dispersed at a high speed of 5000 rpm for 10 min, and then ground for 20 min. After completion, the pH of the system was adjusted to 9 and allowed to stand for 30 min. The resulting slurry was then spray-dried (the inlet air temperature was set to 200℃ and the outlet air temperature was set to 90℃). After sieving, an organic interface coupling composite activator with a particle size distribution between 10 and 150 μm was obtained.

[0062] Performance testing: The various performance indicators of the supersulfate cement in this embodiment were tested using the same method as in Example 1 above, and the results are shown in Table 5 below.

[0063] Table 5 Test Results 165min 245min 5.8MPa 17.1MPa 42.6MPa Example 6 A method for preparing supersulfate cement is the same as in Example 2 above, except that the organic interface coupling composite activator in this example is prepared using the following steps: (1) Mix carbide slag powder and water at a ratio of 1g:2mL and stir for 30min to form slurry a. Then, add 0.1% tannic acid aqueous solution to the slurry at a ratio of 0.05% of the carbide slag powder mass and stir at 50℃ for 20min. After completion, heat to 60℃ and dry for 24h. Crush the resulting block to obtain tannic acid modified carbide slag for later use.

[0064] (2) The tannic acid-modified carbide slag of this embodiment and the unmodified steel slag powder were added to water at a mass ratio of 5:3 and stirred evenly to form a composite slurry with a solid content of 45%. Then, the slurry was sheared and dispersed at a high speed of 8000 rpm for 15 min, and then ground for 10 min. After completion, the pH of the system was adjusted to 8 and allowed to stand for 40 min. Then, the obtained slurry was spray-dried (the inlet air temperature was set to 220℃ and the outlet air temperature was set to 110℃). After sieving, an organic interface coupling composite activator with a particle size distribution between 10 and 150 μm was obtained.

[0065] Performance testing: The various performance indicators of the supersulfate cement in this embodiment were tested using the same method as in Example 1 above. The results are shown in Table 6 below.

[0066] Table 6 Test Results 155min 240min 6.3MPa 18.5MPa 44.1MPa Example 7 A method for preparing supersulfate cement is the same as in Example 3 above, except that the organic interface coupling composite activator in this example is prepared using the following steps: (1) Mix carbide slag powder and water at a ratio of 1g:6mL and stir for 10min to form slurry a. Then, add 2% tannic acid aqueous solution to the slurry at a ratio of 1% of the mass of carbide slag powder and stir at 20℃ for 90min. After completion, heat to 105℃ and dry for 6h. Crush the resulting block to obtain tannic acid modified carbide slag for later use.

[0067] (2) Steel slag and water were mixed at a ratio of 1g:5mL and stirred for 10min to form slurry b. Then, an aqueous solution of 3% amine interface agent (polylysine) was added to the mixture at a ratio of 0.8% of the amine interface agent by weight of the steel slag, and the mixture was stirred at 20℃ for 90min. After the reaction was completed, the mixture was heated to 95℃ and dried for 8h. The resulting block was then crushed to obtain amine interface modified steel slag for later use.

[0068] (3) The tannic acid modified carbide slag and the amine interface modified steel slag are mixed at a mass ratio of 1:1 and stirred evenly for 5 minutes to make the two evenly mixed. After sieving, an organic interface coupling composite activator with a particle size distribution between 10 and 150 μm is obtained.

[0069] Performance testing: The various performance indicators of the supersulfate cement in this embodiment were tested using the same method as in Example 1 above. The results are shown in Table 7 below.

[0070] Table 7 Test Results 140min 215min 7.0MPa 20.1MPa 45.7MPa The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an organic interfacial coupling composite activator, characterized in that, Includes the following steps: (1) Mix carbide slag with water to form slurry a, then mix it with tannic acid aqueous solution to react. After the reaction is completed, dry and crush it to obtain tannic acid modified carbide slag for later use. (2) Mix steel slag with water to form slurry b, then mix it with an aqueous solution of amine interface agent to react. After the reaction is completed, dry and crush it to obtain amine interface modified steel slag for later use. (3) The composite slurry formed by adding the tannic acid modified carbide slag and the amine interface modified steel slag to water is stirred and dispersed, and then ground. After completion, the pH of the system is adjusted and allowed to stand. Then the obtained slurry is spray-dried to obtain the organic interface coupling composite activator. In step (1), the tannic acid in the tannic acid aqueous solution is 0.05~1.0% of the mass of carbide slag; In step (2), the amine interface agent in the aqueous solution is 0.02-0.8% of the mass of the steel slag; the amine interface agent includes one or more of polyethyleneimine and polylysine. In step (3), the mass ratio of the tannic acid-modified carbide slag to the amine-modified steel slag is 1~5:1~3, and the pH is 8~10.

2. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (1), the ratio of carbide slag to water is 1g:2~6mL.

3. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (1), the carbide slag is mixed with water and stirred for 10-30 minutes to obtain the slurry a.

4. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (1), the mass fraction of the tannic acid aqueous solution is 0.1~2.0%.

5. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (1), the reaction temperature is 20~50℃ and the reaction time is 20~90min.

6. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (1), the drying temperature is 60~105℃ and the drying time is 6~24h.

7. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (2), the ratio of steel slag to water is 1g:1~5mL.

8. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (2), the steel slag is mixed with water and stirred for 10-30 minutes to obtain the slurry b.

9. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (2), the mass fraction of the aqueous solution of the amine interfacial agent is 0.1~3.0%.

10. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (2), the reaction temperature is 20~50℃ and the reaction time is 20~90min.

11. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (2), the drying temperature is 70~95℃ and the drying time is 8~16h.

12. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (3), the solid content of the composite slurry is 25~45 wt.%.

13. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (3), the stirring and dispersion treatment time is 5 to 15 minutes and the stirring rate is 3000 to 8000 rpm.

14. The method for preparing the organic interface coupling composite activator according to claim 1, characterized in that, In step (3), the grinding process takes 10 to 40 minutes.

15. The method for preparing the organic interface coupling composite activator according to any one of claims 1-14, characterized in that, In step (3), the settling time is 20-40 minutes.

16. The method for preparing the organic interface coupling composite activator according to any one of claims 1-14, characterized in that, In step (3), the inlet air temperature of the spray dryer is 150~220℃ and the outlet air temperature is 70~110℃.

17. The method for preparing the organic interface coupling composite activator according to any one of claims 1-14, characterized in that, In step (3), the particle size of the organic interface coupling composite activator is 10~150μm.

18. A supersulfate cement, characterized in that, The composition comprises the following components in the following proportions: 30-60 parts by weight of mineral powder, 30-60 parts by weight of solid waste gypsum, 1-10 parts by weight of organic interface coupling composite activator obtained by the preparation method according to any one of claims 1-17, 10-20 parts by weight of aluminate cement, 0.1-5 parts by weight of quick-setting agent, and 0.1-1 parts by weight of water-reducing agent, with a water-cement ratio of 0.35-0.

45. The "cement" refers to the sum of the above-mentioned mineral powder, solid waste gypsum, organic interface coupling composite activator, and aluminate cement.

19. The supersulfate cement according to claim 18, characterized in that, The solid waste gypsum includes at least one of the following: desulfurization gypsum, phosphogypsum, and fluorogypsum.

20. The supersulfate cement according to claim 18, characterized in that, The quick-setting agent includes one or more of the following: aluminum sulfate, nano-alumina, nano-silica, and nano-calcium carbonate.

21. The supersulfate cement according to claim 18, characterized in that, The water-reducing agent includes one or more of the following: polycarboxylate water-reducing agent, naphthalene-based water-reducing agent, and lignin sulfonate water-reducing agent.

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