Metallurgical slag composite micropowder cementitious material without efflorescence and preparation method and application thereof

Abstract

The present application relates to the technical field of building materials, in particular to a no efflorescence metallurgical slag composite micro-powder cementitious material, a preparation method and application thereof.A preparation method of a no efflorescence metallurgical slag composite micro-powder cementitious material, the steel slag micro-powder is reacted with acid for the first time, then the slag is added for the second reaction, and then the water glass solution is added to obtain the no efflorescence metallurgical slag composite micro-powder cementitious material.The preparation method of the no efflorescence metallurgical slag composite micro-powder cementitious material in the present application improves the easy efflorescence of the steel slag, which is beneficial to the subsequent steel slag resource recycling.The preparation method of the no efflorescence metallurgical slag composite micro-powder cementitious material in the present application uses strong alkali as an activator, promotes the release of the internal cementitious activity of the steel slag, and widens the subsequent steel slag utilization field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a no efflorescence metallurgical slag composite micro-powder cementitious material and a preparation method and application thereof. BACKGROUND

[0002] The steel industry is one of the important industries of the pillar of the national economy, and in the production process of steelmaking, there are many by-products such as steel slag, blast furnace slag, etc. But at present, the effective utilization rate of these industrial wastes in China is very low, and usually mainly adopts landfill, stockpile and other ways for treatment. In recent years, with the continuous emission and accumulation of solid waste, a large amount of agricultural land has been occupied, and serious pollution and damage to the surrounding ecological environment have been caused. How to effectively deal with the problem of continuously accumulating solid waste has become a difficult problem restricting the further development of society.

[0003] Steel slag is the molten slag discharged from the steelmaking furnace. From the chemical composition, the steel slag also belongs to silicate minerals, and theoretically the steel slag also has high application potential. However, due to the high temperature in the steelmaking furnace, which is as high as 1600℃, which is much higher than the formation temperature of portland cement 1450℃, the high temperature leads to more dense mineral crystallization of steel slag, and the grain is also larger, resulting in poor cementitious activity of steel slag.

[0004] In addition, due to the low Al2O3 content and high FeO content in the steel slag, the melting point of the steel slag is high, the viscosity is also large, the cooling process of the molten slag is slow, the internal mineral crystal development degree is good, and the crystal is complete, resulting in low glass content in the steel slag, and poor potential activity of the steel slag.

[0005] On the other hand, due to the production process requirements, a large amount of limestone, dolomite, iron ore and other slagging raw materials are often added during steel smelting. Under the high temperature environment in the furnace, these slagging raw materials will cause a large amount of CaO, MgO and other alkaline oxides to be generated in the steel slag. During the crushing and grinding process of the steel slag, due to the dense and hard structure of these overburned oxides, the crushed particles often have these overburned oxides as boundaries, and the dense surface structure delays the overall hydration process of the steel slag. Therefore, the steel slag will hydrate in the later stage of resource utilization, resulting in the production of calcium hydroxide and magnesium hydroxide, and the efflorescence phenomenon.

[0006] Although the efflorescence behavior does not have a serious impact on the mechanical properties of the raw materials, it will seriously damage the appearance of the steel slag resource utilization products, causing serious consumption of municipal products, which is contrary to the original intention of green resource utilization of metallurgical slag. SUMMARY

[0007] In view of the problems existing in the prior art, the present application provides a no-alkali-blooming metallurgical slag composite micro-powder cementitious material and a preparation method thereof, and the treatment method provided by the present application can improve the steel slag cementitious activity and effectively improve the alkali blooming of the steel slag.

[0008] A preparation method of a no-alkali-blooming metallurgical slag composite micro-powder cementitious material, wherein steel slag micro-powder is subjected to a first reaction with acid, then slag is added for a second reaction, and then water glass solution is added to obtain the no-alkali-blooming metallurgical slag composite micro-powder cementitious material.

[0009] The present application promotes the release of the internal cementitious activity of the steel slag micro-powder through the acid-alkali synergistic treatment of the steel slag micro-powder, effectively improves the alkali blooming of the steel slag, and applies the steel slag as a cementitious material. Since the cementitious activity of the steel slag depends on the existence of a strong alkali environment, in order to ensure that the steel slag cementitious activity is effectively excited, the present application adopts the treatment method of acid first and then alkali.

[0010] If the treatment method of alkali first and then acid is adopted, the test piece will be retarded, and the reason is that the alkali excitation effect is reduced due to the acid treatment. The development of the performance of the alkali-excited cementitious material seriously depends on the excitation of the strong alkali excitation agent to the potential cementitious activity of the solid waste. When the acid is added into the alkali-excited slurry, the acid and the alkali will immediately react after meeting, which seriously affects the excitation effect of the strong alkali excitation agent, thereby causing the hydration reaction rate of the material to decrease and the setting and hardening time of the material to be prolonged.

[0011] Since the development of the cementitious activity of the solid waste seriously depends on the strong alkali environment, in order to ensure the excitation effect of the alkali excitation agent, the addition of the acid must be earlier than the addition of the alkali excitation agent.

[0012] Preferably, it comprises at least one of the following technical features:

[0013] A1) the particle size of the steel slag micro-powder is ≤45 μm;

[0014] A2) the preparation method of the steel slag micro-powder is: drying, cooling, crushing and grinding the steel slag;

[0015] A3) the mass ratio of the steel slag micro-powder to the slag is (3:2) to (4:2);

[0016] A4) the steel slag micro-powder comprises one or more of CaO, MgO, Al2O3, Fe2O3 and SiO2.

[0017] Preferably, it comprises at least one of the following technical features:

[0018] A21) in feature A2), the drying temperature is 85-95℃;

[0019] A22) In feature A2), the cooling to room temperature;

[0020] A23) In feature A2), the crushing device is a jaw crusher;

[0021] A24) In feature A2), the grinding device is a ball mill;

[0022] A25) In feature A2), the grinding time is 30-60 min;

[0023] A26) In feature A2), the grinding is to a particle size of the steel slag micro-powder of ≤45 μm;

[0024] A41) In feature A4), the mass fraction of Al2O3 is 5-15%; preferably, 8.39%;

[0025] A42) In feature A4), the mass fraction of MgO is 3-10%; preferably, 5.04%;

[0026] A43) In feature A4), the mass fraction of SiO2 is 20-50%; preferably, 27.23%;

[0027] A44) In feature A4), the mass fraction of Fe2O3 is 5-25%; preferably, 13.99%;

[0028] A45) In feature A4), the mass fraction of CaO is 20-50%; preferably, 32.10%.

[0029] Preferably, at least one of the following technical features is included:

[0030] B1) The acid is selected from one or more of sulfuric acid and hydrochloric acid; preferably, the mass concentration of the sulfuric acid is 95%-99%, preferably, 98%, and the mass concentration of the hydrochloric acid is 30-40%, preferably, 30%;

[0031] Since industrial solid wastes such as steel slag contain mineral components such as calcium salt, carbonate, metal oxide, etc. in different amounts that can react with acid, this composition feature provides the reaction basis for acid treatment of steel slag. After treatment with strong acids such as hydrochloric acid and sulfuric acid, the composition structure of the mineral particles of steel slag, slag, etc. will change significantly. The acid dissolves and corrodes the mineral particles from the outside to the inside by reacting with the mineral particles, destroys the structural compactness and integrity of the particles, and makes the originally dense mineral particles become loose and porous. The acid-base cooperation further improves the physical and mechanical properties of alkali-activated cementitious materials and the serious alkali bleeding behavior.

[0032] B2) The mass ratio of the acid to the steel slag micro-powder is 0.03-0.04.

[0033] Preferably, at least one of the following technical features is included:

[0034] C1) when the first reaction is performed, a first stirring is performed.

[0035] C2) when the slag is added, a second stirring is performed;

[0036] C3) the second reaction is performed for 1h-1.5h;

[0037] C4) the slag comprises one or more of CaO, MgO, AI2O3, Fe2O3, SiO2.

[0038] Preferably, at least one of the following technical features is included:

[0039] C21) in feature C2), after the second stirring is performed to be uniform, a sealing is performed;

[0040] C41) in feature C4), the mass fraction of AI2O3 is 10-25%; preferably, 18.65%;

[0041] C42) in feature C4), the mass fraction of MgO is 1-15%; preferably, 5.04%;

[0042] C43) in feature C4), the mass fraction of SiO2 is 15-50%; preferably, 31.35%;

[0043] C44) in feature C4), the mass fraction of Fe2O3 is 0-15%; preferably, 0.57%;

[0044] C45) in feature C4), the mass fraction of CaO is 20-50%; preferably, 34.65%.

[0045] Preferably, at least one of the following technical features is included:

[0046] D1) the solvent of the water glass solution has a molecular formula of Na2O-nSiO2, n is selected from any value in 1.0-1.5, and the n is the modulus of the water glass solution.

[0047] Generally, the solid waste itself has no or very poor cementitious activity, and only under the excitation of strong alkaline activator, the cementitious activity contained in the material is activated and released. The reaction process of alkali-activated cementitious material mainly includes three stages of dissolution-reconstruction-polycondensation. First, the silicon-aluminum mineral components in the raw materials are dissolved in the high-alkali solution, releasing free silicon-aluminum monomers. Then, the free monomers dissolved are restructured to form silicon-aluminum complex short chains. Finally, the restructured monomers are polycondensed to form a dense and stable three-dimensional network structure, and the material establishes physical and mechanical strength. Through a large number of experiments, it is found that among many alkaline substances, the water glass solution activator has better excitation effect.

[0048] D2) the modulus of the water glass solution is 1.0-1.5;

[0049] D3) the mass ratio of the water glass solution to the steel slag micro-powder is (0.1-0.15):1.

[0050] The second aspect of the present application provides a no-alkali-blooming metallurgical slag composite micro-powder cementitious material prepared by the above no-alkali-blooming metallurgical slag composite micro-powder cementitious material preparation method.

[0051] The third aspect of the present application provides an application of the no-alkali-blooming metallurgical slag composite micro-powder cementitious material, which is applied to low-carbon non-clinker cementitious material.

[0052] The present application has the following beneficial effects:

[0053] 1) The preparation method of the no-alkali-blooming metallurgical slag composite micro-powder cementitious material improves the easy-alkali-blooming condition of the steel slag, which is beneficial to the subsequent resource recycling of the steel slag.

[0054] 2) In the preparation method of the no-alkali-blooming metallurgical slag composite micro-powder cementitious material, strong alkali is used as an activator to promote the release of the cementitious activity in the steel slag, which widens the subsequent utilization field of the steel slag.

[0055] 3) The no-alkali-blooming metallurgical slag composite micro-powder cementitious material provided by the present application can be widely applied to low-carbon non-clinker cementitious material in the field of municipal engineering, which promotes the further utilization of steel slag solid waste resources in China. DETAILED DESCRIPTION

[0056] The embodiments of the present application are illustrated by the following specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosed content.

[0057] It is to be understood that the structure, proportion, size, etc. of the present application are only used to cooperate with the content disclosed in the specification, so as to be understood and read by those skilled in the art, and are not used to limit the limited conditions that the present application can be implemented, so it does not have technical significance, any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that the present application can produce, should still fall within the scope of the technology disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" in the specification are only for the convenience of clear description, and are not used to limit the scope of the present application, the change or adjustment of relative relationship is also regarded as the implementation of the present application without changing the technical content.

[0058] The main raw materials used in the embodiments of the present application are steel slag powder (Baosteel Steel Plant), slag (Guolun Zhonghe Company), water glass solution (modulus is 1.25), standard sand (Aiseo Co., Ltd.), sulfuric acid (analytical pure), hydrochloric acid (analytical pure);

[0059] The mixing amount of water glass refers to the mass ratio of water glass solution to steel slag powder;

[0060] The water-cement ratio refers to the mass ratio of the total mass of steel slag and slag to water;

[0061] The cement-sand ratio refers to the mass ratio of the total mass of steel slag and slag to cement-sand;

[0062] Comparative Example 1

[0063] 1. Crushing and grinding

[0064] (1) First, the raw materials are placed in an oven (95℃), and after the raw materials are dried to a constant weight (dry state), the oven is turned off. After the raw materials are cooled to room temperature, a jaw crusher is used to repeatedly crush the larger volume blocks into smaller particles.

[0065] (2) The crushed small particles of raw materials are put into a ball mill and ground for 30 min. The ground raw materials are passed through a 45 μm square screen, and the screen residue particles with a particle size greater than 45 μm are continuously ground, and the screened powder meeting the fineness requirement is taken for standby.

[0066] 2. 270 g of steel slag powder is weighed in a beaker, and the remaining 180 g of slag is slowly poured in and continuously stirred. After stirring uniformly and thoroughly, the plastic container is immediately sealed to avoid water vapor evaporation loss due to reaction heat.

[0067] 3. Finally, the steel slag slurry was poured into a stirring pot and stirred evenly, then water glass with a dosage of 13.33%, 1.25 modulus water glass solution and 1200g standard sand were added in sequence to prepare the steel slag mortar specimen. The specimen was cured by film curing, and the compressive strength values of the specimen at 3d, 7d and 28d were tested.

[0068] Example 1

[0069] 1. Crushing and grinding

[0070] (1) First, the raw materials were placed in an oven (95°C) and dried until the weight of the raw materials was constant (dry state), and then the oven was turned off. After the raw materials cooled to room temperature, a jaw crusher was used to repeatedly crush the larger blocks into smaller particles.

[0071] (2) The crushed raw materials were placed in a ball mill and ground for 30 minutes. The ground raw materials were passed through a 45μm sieve, and the particles with a particle size greater than 45μm were further ground. The sieved powder meeting the fineness requirement was reserved for use.

[0072] 2. 270g of steel slag powder was weighed in a beaker, then 90% concentrated sulfuric acid solution was slowly poured in while stirring with a glass rod. After the sulfuric acid solution was completely poured in and stirred evenly and sufficiently, the remaining 180g of slag was slowly poured in and continued to be stirred. After stirring evenly and sufficiently, the plastic container was immediately sealed to avoid water vapor loss due to heat generated by the reaction. The mixture was left to stand for 1h under natural conditions to allow the steel slag and sulfuric acid to fully react.

[0073] 3. Finally, the acid-treated steel slag slurry was poured into a stirring pot and stirred evenly, then water glass with a dosage of 13.33%, 1.25 modulus water glass solution and 1200g standard sand were added in sequence to prepare the steel slag mortar specimen. The specimen was cured by film curing, and the compressive strength values of the specimen at 3d, 7d and 28d were tested. The specific composition of the specimen in this example is shown in Table 1, and the compressive strength values of the specimen at 3d, 7d and 28d are shown in Table 2.

[0074] Table 1 Specific composition of the specimen

[0075]

[0076]

[0077] Table 2 Compressive strength values of the specimen at 3d, 7d and 28d

[0078] 3d compressive strength / MPa 7d compressive strength / MPa 28 compressive strength / MPa Comparative Example 1 19.40 24.45 32.05 Example 1 22.21 33.81 38.32

[0079] Example 2:

[0080] 1. Crushing and grinding

[0081] (1) First, the raw materials are placed in an oven (95°C), and after the raw materials reach a constant weight (dry state), the oven is turned off. After the raw materials cool to room temperature, they are repeatedly broken using a jaw crusher until the larger blocks are broken into smaller particles.

[0082] (2) The broken raw materials are placed in a ball mill and ground for 30 min. The ground raw materials are passed through a 45 μm square screen, and the particles with a particle size greater than 45 μm are further ground. The screened powder that meets the fineness requirement is reserved for use.

[0083] 2. 270 g of steel slag powder is weighed in a beaker, then 90% concentrated sulfuric acid solution is slowly poured in while stirring with a glass rod. After the sulfuric acid solution is completely poured in and stirred evenly and sufficiently, the remaining 180 g of slag is slowly poured in and continues to be stirred. After stirring evenly and sufficiently, the plastic container is immediately sealed to avoid water vapor loss due to heat release. It is naturally placed for 1 h to allow the steel slag and sulfuric acid to fully react.

[0084] 3. Finally, the acid-treated steel slag slurry is poured into a stirring pot and stirred evenly, then 13.33% water glass content, 1.25 modulus water glass solution, and 1200 g of standard sand are sequentially added to prepare steel slag mortar specimens. The specimens are cured by film curing, and the compressive strength values of the specimens at 3d, 7d, and 28d ages are tested. The specific composition of the specimens in this example is shown in Table 3, and the compressive strength values of the specimens at 3d, 7d, and 28d ages are shown in Table 4.

[0085] Table 3 Specific composition of the specimens

[0086]

[0087] Table 4 Compressive strength values of the specimens at 3d, 7d, and 28d ages

[0088] 3d compressive strength / MPa 7d compressive strength / MPa 28 compressive strength / MPa Comparative Example 1 19.40 24.45 32.05 Example 2 23.76 34.03 38.16 Example 3

[0089] 1. Breaking and grinding

[0090] (1) First, the raw materials are placed in an oven (95°C), and after the raw materials reach a constant weight (dry state), the oven is turned off. After the raw materials cool to room temperature, they are repeatedly broken using a jaw crusher until the larger blocks are broken into smaller particles.

[0091] (2) The broken raw materials are placed in a ball mill and ground for 30 min. The ground raw materials are passed through a 45 μm square screen, and the particles with a particle size greater than 45 μm are further ground. The screened powder that meets the fineness requirement is reserved for use.

[0092] 2. 270 g of steel slag powder was weighed in a beaker, then 30% mass concentration hydrochloric acid solution was slowly poured in while continuously stirring with a glass rod. After the hydrochloric acid solution was completely poured in and stirred evenly and sufficiently, the remaining 180 g of slag was slowly poured in and continued to be stirred. After stirring evenly and sufficiently again, the plastic container was immediately sealed to avoid water vapor loss due to reaction heat. It was naturally placed for 1 h to allow the steel slag to fully react with the hydrochloric acid.

[0093] 3. Finally, the acid-treated steel slag slurry was poured into a stirring pot and stirred evenly, then 13.33% water glass content, 1.25 modulus water glass solution and 1200 g of standard sand were sequentially added to prepare steel slag mortar specimens. Film curing was adopted during the curing of the specimens, and the compressive strength values of the specimens at 3d, 7d and 28d were tested. The specific composition of the specimens in this example is shown in Table 5, and the compressive strength values of the tested specimens at 3d, 7d and 28d are shown in Table 6.

[0094] Table 5 Specific composition of the specimens

[0095]

[0096] Table 6 Compressive strength values of the tested specimens at 3d, 7d and 28d

[0097] 3d compressive strength / MPa 7d compressive strength / MPa 28 compressive strength / MPa Comparative Example 1 19.40 24.45 32.05 Example 3 17.05 31.35 36.84

[0098] Example 4

[0099] 1. Crushing and grinding

[0100] (1) First, the raw materials were placed in an oven (95°C) and dried until the weight of the raw materials was constant (dry state), then the oven was turned off. After the raw materials cooled to room temperature, a jaw crusher was used to repeatedly crush the larger blocks into smaller particles.

[0101] (2) The crushed raw materials were placed in a ball mill and ground for 30 min. The ground raw materials were passed through a 45 μm sieve, and the sieve residue particles with a particle size greater than 45 μm were further ground. The sieved powder meeting the fineness requirement was reserved for use.

[0102] 2. 270 g of steel slag powder was weighed in a beaker, then 30% mass concentration hydrochloric acid solution was slowly poured in while continuously stirring with a glass rod. After the hydrochloric acid solution was completely poured in and stirred evenly and sufficiently, the remaining 180 g of slag was slowly poured in and continued to be stirred. After stirring evenly and sufficiently again, the plastic container was immediately sealed to avoid water vapor loss due to reaction heat. It was naturally placed for 1 h to allow the steel slag to fully react with the hydrochloric acid.

[0103] 3. Finally, the acid-treated steel slag slurry was poured into a mixing pot and stirred evenly. Then, water glass solutions with a content of 13.33% and a modulus of 1.25, along with 1200g of standard sand, were added sequentially to prepare steel slag mortar specimens. The specimens were cured with a film covering, and the compressive strength values ​​of the specimens at 3d, 7d, and 28d were tested sequentially. The specific composition of the specimens in the examples is shown in Table 7, and the compressive strength values ​​of the specimens at 3d, 7d, and 28d are shown in Table 8.

[0104] Table 7 Specific Composition of the Specimens

[0105]

[0106] Table 8. Compressive strength values ​​of test specimens at 3d, 7d, and 28d.

[0107] 3d compressive strength / MPa 7d compressive strength / MPa 28 compressive strength / MPa Comparative Example 1 19.40 24.45 32.05 Example 4 17.48 30.38 34.65 The data in the tables of the four examples above show that acid treatment of steel slag samples does not affect their strength.

[0108] Small test specimens were prepared using the treatment methods described in the four embodiments and comparative examples above, and the degree of efflorescence on the test specimens was tested.

[0109] Prepare small specimens, each weighing 300g, following the steps described above. After curing with a film for 7 days, remove the specimens from the standard curing chamber and remove the surface plastic wrap. Then, place the specimens in a clean container, pour in 300mL of deionized water to completely submerge them, and immediately seal the container to prevent foreign matter from falling in. Soak under natural conditions for 5 days. After the specimens have reached the specified curing age, remove them and suspend them upright above the container to allow them to drain naturally. Then, place the container in an oven to accelerate drying until the soaking solution has completely evaporated. Finally, carefully collect and weigh the white sediment precipitated on the inner wall of the container using a brush. The results are shown in Table 9.

[0110] Table 9. Results of efflorescence degree of test specimens from the examples and comparative examples.

[0111]

[0112] The above data shows that the acid treatment is effective for inhibiting the efflorescence of the steel slag, and the effect of the sulfuric acid is more obvious. As can be seen from the above examples, the compressive strength of the 7d and 28d test pieces is strengthened, and the efflorescence degree is also significantly improved by the acid-alkali synergistic treatment method of acid first and alkali later. The above description is only a preferred embodiment of the present application, and does not limit the present application in any form and essence. It should be pointed out that, for ordinary skilled persons in the art, some improvements and supplements can be made without departing from the method of the present application, and these improvements and supplements should also be regarded as the protection scope of the present application. For those skilled in the art, some slight changes, modifications and equivalent changes made by utilizing the technical content disclosed above without departing from the spirit and scope of the present application are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above examples according to the essential technology of the present application are still within the scope of the technical solutions of the present application.

Claims

1. A method for preparing a non-alkali metallurgical slag composite micropowder cementitious material, characterized in that, The steel slag micro-powder and acid are subjected to a first reaction, then slag is added for a second reaction, and then water glass solution is added to obtain the alkali-free metallurgical slag composite micro-powder cementing material; the acid is selected from one or more of sulfuric acid and hydrochloric acid; the mass concentration of the sulfuric acid is 95%-99%, and the mass concentration of the hydrochloric acid is 30-40%; the mass ratio of the acid to the steel slag micro-powder is 0.03-0.04; the mass ratio of the water glass solution to the steel slag micro-powder is (0.1-0.15):1; and the mass ratio of the steel slag micro-powder to the slag is (3:2)-(4:2).

2. The method of claim 1, wherein the method is characterized by: At least one of the following technical features is included: A1) the particle size of the steel slag micro-powder is ≤45 μm; A2) the steel slag micro-powder is prepared by drying, cooling, crushing, and grinding the steel slag; A3) the steel slag micro-powder includes one or more of CaO, MgO, Al2O3, Fe2O3, and SiO2.

3. The method of claim 2, wherein the method is characterized by: At least one of the following technical features is included: A21) in feature A2), the drying temperature is 85-95 °C; A22) in feature A2), the cooling is to room temperature; A23) in feature A2), the crushing equipment is a jaw crusher; A24) in feature A2), the grinding equipment is a ball mill; A25) in feature A2), the grinding time is 30 min-60 min; A26) in feature A2), the grinding is to a particle size of the steel slag micro-powder ≤45 μm.

4. The preparation method of the efflorescence-free metallurgical slag composite micro-powder cementitious material according to claim 2, characterized in that, At least one of the following technical features is included: A31) in feature A3), the mass fraction of Al2O3 is 5-15%; A32) in feature A3), the mass fraction of MgO is 3-10%; A33) in feature A3), the mass fraction of SiO2 is 20-50%; A34) in feature A3), the mass fraction of Fe2O3 is 5-25%; A35) in feature A3), the mass fraction of CaO is 20-50%.

5. The preparation method of the alkali-free metallurgical slag composite micro-powder cementing material according to claim 1, characterized in that, C1) when the first reaction is performed, first stirring is performed; C2) when the slag is added, second stirring is performed; C3) the second reaction time is 1 h-1.5 h; C4) the slag includes one or more of CaO, MgO, Al2O3, Fe2O3, and SiO2.

6. The method of claim 5, wherein the method is characterized by: At least one of the following technical features is included: C21) in feature C2), after the second stirring is performed until uniform, sealing is performed; C41) in feature C4), the mass fraction of Al2O3 is 10-25%; C42) in feature C4), the mass fraction of MgO is 1-15%; C43) in feature C4), the mass fraction of SiO2 is 15-50%; C44) in feature C4), the mass fraction of Fe2O3 is 0-15%; C45) in feature C4), the mass fraction of CaO is 20-50%.

7. The method of claim 1, wherein the method is characterized by: The molecular formula of the solvent of the water glass solution is Na2O·nSiO2, and n is any value selected from 1.0-1.

5.

8. A non-soda-fugitive metallurgical slag composite micro-powder cementitious material, characterized in that, The method is used for preparing the composite micropowder cementing material of the metallurgical slag without efflorescence according to any one of claims 1-7.

9. Use of a non-soda-fugitive metallurgical slag composite micropowder cementitious material, characterized in that, The composite micropowder cementing material of the metallurgical slag without efflorescence according to claim 8 is applied to low-carbon non-clinker cementing material.

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