A full-solid-waste carbon-negative cementitious material, a preparation method thereof and application thereof

Abstract

This invention relates to the field of building materials technology, specifically disclosing a solid waste negative carbon cementitious material, its preparation method, and its application. The cementitious material comprises the following components: 1-5 parts by weight of modified steel slag powder, 1-5 parts by weight of solid admixture containing sodalite structural alkali, 1-5 parts by weight of recycled building micro powder, 70-80 parts by weight of granulated blast furnace slag powder, 10-15 parts by weight of waste gypsum powder, and a certain amount of mixing water. The modified steel slag powder is prepared by the following method: [The method involves...] 2+ An aqueous solution of a carbonization accelerator for complexation is mixed with steel slag powder and stirred in a CO2 atmosphere. After the mixture is dried, the solid product is obtained. This invention not only overcomes the problem of poor volume stability caused by steel slag, but also improves the alkali activation ability of red mud, promoting the application of industrial solid waste.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a solid waste negative carbon cementitious material, its preparation method, and its application. 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] Cement, as an indispensable cementing material in the construction industry, consumes a lot of resources and energy in its production process, causing environmental pollution, especially the large-scale emission of CO2.

[0004] Meanwhile, industrial solid wastes such as steel slag, red mud, building powder, granulated blast furnace slag, and waste gypsum are inevitably generated during industrial production and building demolition. Their output is enormous, and stockpiling them not only occupies land resources but also causes varying degrees of environmental pollution to the surrounding areas. Currently, many scholars are attempting to utilize industrial solid waste to prepare all-solid-waste cementitious materials to replace traditional silicate cement, which not only helps reduce carbon emissions but also promotes the green development of the building materials industry. However, research has found that some industrial solid wastes are "unusable" or "unsuitable for use." For example, steel slag contains free calcium oxide (… f -CaO), free magnesium oxide ( f During hydration, MgO expands, leading to poor volume stability of the cementitious system and making it prone to cracking. This is one of the key issues limiting the large-scale application of steel slag. Red mud is often used as an alkaline activator in solid waste cementitious materials, but most of its alkaline substances exist in the form of structural alkalis, with too little alkaline substances released in the liquid phase. This insufficient alkalinity usually results in poor activation effects, limiting the application of red mud. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a carbon-negative cementitious material for solid waste, its preparation method, and its application. This material not only overcomes the poor volume stability problem caused by steel slag but also improves the alkali activation capacity of red mud, thus facilitating the application of these industrial solid wastes. Specifically, the technical solution of this invention is as follows.

[0006] First, this invention discloses a solid waste negative carbon cementitious material, comprising the following components: 1-5 parts by weight of modified steel slag powder, 1-5 parts by weight of solid admixture containing sodalite structural alkali, 1-5 parts by weight of recycled building micro powder, 70-80 parts by weight of granulated blast furnace slag powder, 10-15 parts by weight of waste gypsum powder, and a certain amount of mixing water. The modified steel slag powder is prepared by the following method: [The method involves] preparing a mixture containing Ca... 2+The water solution of the carbonation accelerator with complex effect is mixed with the steel slag powder, and then stirring treatment is carried out in a CO2 atmosphere, and after completion, the solid product is dried to obtain the product.

[0007] Further, the solid admixture containing sodalite structure alkali includes at least one of Bayer red mud, waste incineration fly ash and the like.

[0008] Further, the specific surface area of the recycled building micro powder is 300-500 m 2 / kg.

[0009] Further, the waste gypsum includes at least one of fluorogypsum, phosphogypsum, titanium gypsum and the like.

[0010] Further, the mixing water is 0.4-0.5 times of the total amount of the modified steel slag powder, the solid admixture, the recycled building micro powder, the granulated blast furnace slag powder and the waste gypsum powder, i.e. the water-cement ratio is 0.4-0.5.

[0011] Further, the carbonation accelerator includes at least one of EDTA-4Na, EDTA-2Na, triethanolamine, triisopropanolamine, diethanol mono-isopropanolamine and the like.

[0012] Further, the adding amount of the water solution of the carbonation accelerator is 3-5% of the mass of the steel slag powder.

[0013] Further, the steel slag powder includes at least one of converter steel slag, electric furnace steel slag, hot leaching steel slag, roller steel slag and the like. 2 Further, the specific surface area of the steel slag powder is 300-500 m

[0014] Further, the volume concentration of CO2 in the CO2 atmosphere is kept at 10-20%.

[0015] Further, the drying temperature is 100-130 DEG C, and the time is 4-6 h.

[0016] Secondly, the application discloses a preparation method of the full-solid-waste carbon-negative cementitious material.

[0017] (1) the modified steel slag powder, the solid admixture containing sodalite structure alkali, the recycled building micro powder, the granulated blast furnace slag powder and the waste gypsum powder are mixed and then grinded to obtain activated powder.

[0018] (2) Mix the activated powder with the mixing water to obtain the solid waste negative carbon cementitious material.

[0019] Further, in step (1), the grinding process is followed by passing through a 200-300 mesh sieve to obtain the activated powder.

[0020] Finally, this invention discloses the application of the all-solid waste negative carbon cementitious material in engineering fields such as construction, highways, bridges, and water conservancy and hydropower.

[0021] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0022] (1) In steel slag f -CaO, f -MgO easily causes poor volumetric stability in cementitious materials, leading to cracking and a decrease in the mechanical properties and carbonization resistance of the cementitious materials. Therefore, this invention utilizes CO2 to modify steel slag, thereby reducing its... f -CaO, f -MgO is converted into more stable calcium carbonate and magnesium carbonate, improving volume stability. However, the reaction rate is extremely slow when CO2 is directly used to treat steel slag. This is because the surface of the steel slag reacts with CO2 first to form a dense layer of calcium carbonate and magnesium carbonate passivation, which hinders the dissolution of calcium and magnesium ions inside the steel slag and also prevents the entry of external CO2. This not only results in a slow reaction but also a low degree of modification to the steel slag, which is not conducive to solving the volume stability problem. To address this, the present invention first applies a carbonization accelerator to the steel slag before treating it with CO2. The carbonization accelerator's complexation effect on calcium ions keeps the resulting reaction products in a loose state, effectively preventing the formation of a dense passivation layer. This allows CO2 to continuously contact the steel slag, enabling the reaction to proceed continuously. This not only more thoroughly eliminates the volume stability problem of the steel slag but also forms more micro- and nano-sized calcium carbonate and magnesium carbonate, which can act as micro-aggregate fillers and induce hydration nucleation in the cementitious material. They effectively fill the internal pores of the system and promote hydration, resulting in a denser structure after the cementitious material hardens, thus contributing to improved mechanical strength and carbonization resistance. Simultaneously, the aforementioned carbonization treatment also consumes carbon dioxide, indirectly reducing carbon emissions.

[0023] (2) Since the modified steel slag powder also contains residual unreacted carbonization accelerator, it can also promote the dissolution and hydration activity of the granulated blast furnace slag powder. This is because the carbonization accelerator can complex the Ca²⁺ on the surface of the granulated blast furnace slag powder particles, quickly open the glassy mineral structure in the slag, greatly promote the dissolution and hydration reaction of the slag, improve the degree of reaction, and promote the development of the mechanical strength of the cementitious material.

[0024] (3) The solid admixture contains a large amount of alkaline substances that are difficult to release directly, which mainly exist in sodalite (Na8Al6Si6O 24 Cl2) in the form of structural alkali. After modification, a large amount of unreacted C2S and C3S exists in the steel slag powder, and the calcium hydroxide produced by the hydration of the unreacted C2S and C3S can promote the hydrolysis of sodalite (Na8Al6Si6O 24 Cl2+H2O→Na + +H4SiO4+[Al(OH)4] - ) alkaline product [Al(OH)4] - , thereby increasing the alkalinity of the cementitious material system and further stimulating the dissolution and hydration reactions of the ground granulated blast furnace slag. At the same time, Ca(OH)2 in the building micro-powder also helps to promote the above reactions. In addition, [Al(OH)4] - and Ca(OH)2 in the solid admixture further react with carbon CO3 2- to form calcium aluminocarbonate (Al(OH)4 - +OH - + Ca 2+ +CO3 2- →Ca4Al2(OH) 12 CO3) with lower solubility, thereby continuously promoting the hydrolysis of sodalite and more quickly and completely releasing the alkalinity of structural alkali in the solid admixture. In addition, due to the different hydration rates of C2S and C3S in the modified steel slag powder, the hydration activity of C3S is high, and the hydration reaction of C3S starts earlier than that of C2S, thereby forming a hydration relay and continuously providing Ca(OH)2 to promote the hydration of sodalite in the solid admixture, so that the cementitious material system maintains a high alkalinity in the later hydration stage, provides the required alkaline environment for the hydration of the ground granulated blast furnace slag, and ensures the development of the strength of the cementitious material in the later stage. At the same time, the supply of Ca(OH)2 effectively increases the "alkali storage" in the solid waste cementitious system of the present application, and improves the carbonation resistance of the cementitious material. These additional Ca(OH)2 reacts with CO2 preferentially, consumes the invading CO2, effectively delays the further deepening of carbonation, and maintains a high pH value of the pore solution for a long time, thereby protecting the key strength phases such as AFt and C-(A)-S-H gel from decomposition, and improving the durability of the cementitious material. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form a part of the present description, are included to provide a further understanding of the present application and are not to be considered as part of the present application.

[0026] Figure 1 Figure of the modified steel slag powder sample prepared for the following Example 1.

[0027] Figure 2 SEM of modified steel slag powder prepared for the following Example 1.

[0028] Figure 3 28d compressive strength test chart for the following Example 1.

[0029] Figure 4 Carbonation depth test chart for the following Example 1.

[0030] Figure 5 28d compressive strength test chart for the following Example 2.

[0031] Figure 6 Carbonation depth test chart for the following Example 2.

[0032] Figure 7 28d compressive strength test chart for the following Example 3.

[0033] Figure 8 28d compressive strength test chart for the following Example 4.

[0034] Figure 9 Carbonation depth test chart for the following Example 4.

[0035] Figure 10 28d compressive strength test chart for the following Example 5.

[0036] Figure 11 Carbonation depth test chart for the following Example 5.

[0037] Figure 12 28d compressive strength test chart for the following Example 6.

[0038] Figure 13 28d compressive strength test chart for the following Example 7. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be further described below in combination with specific examples. It should be understood that these examples are only used to illustrate the present application and not used to limit the scope of the present application. The experimental methods in the following examples without specific conditions are usually performed according to the conventional conditions or according to the conditions suggested by the manufacturers.

[0040] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those familiar to one skilled in the art. The reagents or raw materials used in the present application can be purchased through conventional channels. Unless otherwise specified, the reagents or raw materials used in the present application are used according to the conventional methods in the art or according to the product instructions. The technical solutions of the present application will be further described in combination with the drawings and specific examples in the present application.

[0041] Example 1: A preparation method of the full-solid-waste carbon-negative cementitious material, comprising the following steps:

[0042] (1) Spraying a triethanolamine aqueous solution (concentration of 0.35 mol / L) with a mass of 4% in the converter steel slag powder with a specific surface area of 446.3 m 2 / kg, and stirring while spraying, and continuing to stir for 2 min after completion. Then, the obtained mixture is placed in a CO2 atmosphere with a volume concentration of CO2 maintained at 15%, and continuously stirred for 60 min, and the obtained solid product is dried at 110°C for 4.5 hours to obtain the modified steel slag powder, and the macroscopic sample picture and the microscopic morphology under scanning electron microscopy (SEM) are shown in Figure 1 、 Figure 2 respectively.

[0043] (2) Take the following proportions of components: 3 parts by weight of the modified steel slag powder of the present example, 2.5 parts by weight of solid admixture containing sodalite structure alkali (Bayer process red mud, with a sodalite content of 11.62 wt.%), 2.5 parts by weight of recycled building micro powder, 76 parts by weight of granulated blast furnace slag powder, and 12 parts by weight of waste gypsum (fluorogypsum) powder. Among them: the specific surface area of the solid admixture is 394.7 m 2 / kg, and the specific surface area of the recycled building micro powder is 473.2 m 2 / kg.

[0044] (3) Grind the modified steel slag powder, solid admixture, recycled building micro powder, granulated blast furnace slag powder, and waste gypsum powder in a ball mill for 50 min, then pass through a 200-mesh sieve to obtain activated powder.

[0045] (4) Mix the activated powder with mixing water according to a water-cement ratio of 0.44, and stir for 2 min to obtain the full-solid-waste carbon-negative cementitious material.

[0046] Performance test: 1. According to the "Cement Mortar Strength Test Method (ISO Method)" (GB / T 17671-2021), the compressive strength of the full-solid-waste carbon-negative cementitious material prepared in the present example at different ages (3d, 7d, 28d) is tested, and the 28d compressive strength test is shown in Figure 3 . 2. According to the "Cement Mortar Carbonation Test Method" (GB / T 42277-2022), the carbonation depth of the full-solid-waste carbon-negative cementitious material prepared in the present example is tested (as shown in Figure 4 ), and the results are shown in the following table:

[0047]

[0048] Example 2: A preparation method of the full-solid-waste carbon-negative cementitious material, comprising the following steps:

[0049] (1) Spraying 5% of EDTA-4Na aqueous solution (concentration of 0.1 mol / L) in the electric furnace slag powder with a specific surface area of 498.1 m 2 / kg, and stirring while spraying, and continuing to stir for 2 min after completion. Then, the obtained mixture is placed in a CO2 atmosphere with a CO2 volume concentration of 10%, and continuously stirred for 50 min, and the obtained solid product is dried at 130°C for 4 hours after completion, to obtain modified slag powder, which is ready for use.

[0050] (2) Take the following proportions of components: 5 parts by weight of the modified slag powder of the present embodiment, 5 parts by weight of solid admixture containing sodalite structure alkali (Bayer process red mud, with a sodalite content of 11.62 wt.%), 5 parts by weight of recycled building micro powder, 80 parts by weight of granulated blast furnace slag powder, and 15 parts by weight of waste gypsum (fluorogypsum) powder. Among them: the specific surface area of the solid admixture is 403.6 m 2 / kg, and the specific surface area of the recycled building micro powder is 311.8 m 2 / kg.

[0051] (3) Grind the modified slag powder, solid admixture, recycled building micro powder, granulated blast furnace slag powder, and waste gypsum powder in a ball mill for 50 min, and then pass through a 220-mesh sieve to obtain activated powder.

[0052] (4) Mix the activated powder with mixing water according to a water-cement ratio of 0.5, and stir for 2 min, to obtain a full-solid-waste carbon-negative cementitious material.

[0053] Performance test: The compressive strength (wherein the 28d compressive strength test is as shown in Figure 5 ) and carbonation depth (as shown in Figure 6 ) of the full-solid-waste carbon-negative cementitious material prepared in the present embodiment are tested by the same method as in the above-mentioned embodiment 1, and the results are shown in the following table:

[0054]

[0055] Embodiment 3: A preparation method of the full-solid-waste carbon-negative cementitious material, comprising the following steps:

[0056] (1) Spraying 3% of diethanol mono-isopropanolamine aqueous solution (concentration of 0.5 mol / L) in the hot leached slag powder with a specific surface area of 301.5 m 2 / kg, and stirring while spraying, and continuing to stir for 2 min after completion. Then, the obtained mixture is placed in a CO2 atmosphere with a CO2 volume concentration of 20%, and continuously stirred for 55 min, and the obtained solid product is dried at 100°C for 6 hours after completion, to obtain modified slag powder, which is ready for use.

[0057] (2) The following components are taken in the following proportions: 1 part by weight of the modified steel slag powder described in this embodiment, 1 part by weight of the solid admixture containing sodalite structural alkali (waste incineration fly ash, wherein the sodalite content is 9.84 wt.%), 1 part by weight of recycled building micro powder, 70 parts by weight of granulated blast furnace slag powder, and 10 parts by weight of waste gypsum (phosphogypsum) powder. Wherein: the specific surface area of ​​the solid admixture is 403.6 m². 2 / kg, the specific surface area of ​​the recycled building powder is 504.4m². 2 / kg.

[0058] (3) The modified steel slag powder, solid admixture, recycled building micro powder, granulated blast furnace slag powder and waste gypsum powder are placed in a ball mill and ground for 60 minutes, and then passed through a 300-mesh sieve to obtain activated powder.

[0059] (4) Mix the activated powder with the mixing water at a water-cement ratio of 0.4 and stir for 2 minutes to obtain the solid waste negative carbon cementitious material.

[0060] Performance testing: The compressive strength and carbonization depth (e.g., ) of the all-solid waste negative carbon cementitious material prepared in this embodiment were tested using the same method as in Example 1 above. Figure 7 (As shown), the results are shown in the table below:

[0061]

[0062] Example 4: A method for preparing the aforementioned all-solid waste negative carbon cementitious material, comprising the following steps:

[0063] (1) The following components are taken in the following proportions: 3 parts by weight of converter steel slag powder, 2.5 parts by weight of solid admixture containing sodalite structural alkali (Bayer process red mud, in which the sodalite content is 11.62 wt.%), 2.5 parts by weight of recycled building micro powder, 76 parts by weight of granulated blast furnace slag powder, and 12 parts by weight of waste gypsum (fluorogypsum) powder. Wherein: the specific surface area of ​​the converter steel slag powder is 446.3 m². 2 / kg, the specific surface area of ​​the solid admixture is 394.7m². 2 / kg, the specific surface area of ​​the recycled building powder is 473.2m². 2 / kg.

[0064] (2) The modified steel slag powder, solid admixture, recycled building micro powder, granulated blast furnace slag powder and waste gypsum powder are placed in a ball mill and ground for 50 minutes, and then passed through a 200-mesh sieve to obtain activated powder.

[0065] (3) Mix the activated powder with the mixing water at a water-cement ratio of 0.44 and stir for 2 minutes to obtain the solid waste negative carbon cementitious material.

[0066] Performance test: the compressive strength (wherein the 28d compressive strength test is as shown in Figure 8 , and carbonation depth (as shown in Figure 9 ) of the full solid waste carbon-negative cementitious material prepared in this embodiment were tested by the same method as in Example 1 above, and the results are shown in the following table:

[0067]

[0068] Example 5: A method for preparing the full solid waste carbon-negative cementitious material, comprising the following steps:

[0069] (1) Spray 4% of water by mass in the converter steel slag powder with specific surface area of 446.3 m 2 / kg, and stir while spraying, and continue stirring for 2 min after completion. Then place the obtained mixture in a CO2 atmosphere with a volume concentration of CO2 maintained at 15%, and continuously stir for 60 min, and after completion, dry the obtained solid product at 110°C for 4.5 hours to obtain modified steel slag powder, which is ready for use.

[0070] (2) Take the following proportions of components: 3 parts by weight of the modified steel slag powder of this embodiment, 2.5 parts by weight of solid admixture containing sodalite structure alkali (Bayer process red mud, wherein the sodalite content is 11.62wt.%), 2.5 parts by weight of recycled building micro powder, 76 parts by weight of granulated blast furnace slag powder, and 12 parts by weight of waste gypsum (fluorogypsum) powder. Among them: the specific surface area of the solid admixture is 394.7 m 2 / kg, and the specific surface area of the recycled building micro powder is 473.2 m 2 / kg.

[0071] (3) Grind the modified steel slag powder, solid admixture, recycled building micro powder, granulated blast furnace slag powder, and waste gypsum powder in a ball mill for 50 min, then pass through a 200 mesh sieve to obtain activated powder.

[0072] (4) Mix the activated powder with mixing water according to a water-cement ratio of 0.44 and stir for 2 min to obtain a full solid waste carbon-negative cementitious material.

[0073] Performance test: the compressive strength (wherein the 28d compressive strength test is as shown in Figure 10 ) and carbonation depth (as shown in Figure 11 ) of the full solid waste carbon-negative cementitious material prepared in this embodiment were tested by the same method as in Example 1 above, and the results are shown in the following table:

[0074]

[0075] Example 6: A method for preparing the full solid waste carbon-negative cementitious material, comprising the following steps:

[0076] (1) Take the following proportions of components: 5 parts by weight of the modified steel slag powder of Example 2 above, 5 parts by weight of recycled building micro powder, 80 parts by weight of granulated blast furnace slag powder, and 15 parts by weight of waste gypsum (fluorogypsum) powder. Among them: the specific surface area of the recycled building micro powder is 311.8 m 2 / kg.

[0077] (2) The modified steel slag powder, recycled building micro powder, granulated blast furnace slag powder, and waste gypsum powder are placed in a ball mill and ground for 50 min, then passed through a 220-mesh sieve to obtain activated powder.

[0078] (3) The activated powder is mixed with mixing water according to a water-cement ratio of 0.5 and stirred for 2 min to obtain a full-solid-waste carbon-negative cementitious material.

[0079] Performance test: The compressive strength (of which the 28d compressive strength test is as shown in Figure 12 ) and carbonation depth of the full-solid-waste carbon-negative cementitious material prepared in this example are tested by the same method as in Example 1 above, and the results are shown in the following table:

[0080]

[0081] Example 7: A method for preparing a full-solid-waste carbon-negative cementitious material, comprising the following steps:

[0082] (1) Take the following proportions of components: 1 part by weight of the modified steel slag powder of Example 3 above, 1 part by weight of a solid admixture containing alkali with sodalite structure (waste incineration fly ash, with a sodalite content of 9.84 wt.%), 70 parts by weight of granulated blast furnace slag powder, and 10 parts by weight of waste gypsum (phosphogypsum) powder. Among them: the specific surface area of the solid admixture is 403.6 m 2 / kg.

[0083] (2) The modified steel slag powder, solid admixture, granulated blast furnace slag powder, and waste gypsum powder are placed in a ball mill and ground for 60 min, then passed through a 300-mesh sieve to obtain activated powder.

[0084] (3) The activated powder is mixed with mixing water according to a water-cement ratio of 0.4 and stirred for 2 min to obtain a full-solid-waste carbon-negative cementitious material.

[0085] Performance test: The compressive strength (of which the 28d compressive strength test is as shown in Figure 13 ) and carbonation depth of the full-solid-waste carbon-negative cementitious material prepared in this example are tested by the same method as in Example 1 above, and the results are shown in the following table:

[0086]

[0087] The above merely describes some preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that modifications can be made to the foregoing embodiments, or some of the technical features thereof can be equivalently replaced, without departing from the spirit and principle of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A solid waste negative carbon cementitious material, characterized in that, The mixture comprises the following components: 1-5 parts by weight of modified steel slag powder, 1-5 parts by weight of solid admixture containing sodalite structural alkali, 1-5 parts by weight of recycled building micro powder, 70-80 parts by weight of granulated blast furnace slag powder, 10-15 parts by weight of waste gypsum powder, and a certain amount of mixing water; wherein: The modified steel slag powder is prepared by the following method: [The method involves] preparing steel slag powder containing Ca... 2+ The aqueous solution of the carbonization accelerator for complexation is mixed with steel slag powder and stirred in a CO2 atmosphere. After the mixture is dried, the solid product is obtained. The solid admixture containing sodalite structural alkali is waste incineration fly ash; the carbonization accelerator is selected from at least one of triethanolamine and triisopropanolamine; The waste gypsum includes at least one of the following: fluorogypsum, phosphogypsum, and titanium gypsum; The mixing water is 0.4 to 0.5 times the total amount of modified steel slag powder, solid admixtures, recycled building micro powder, granulated blast furnace slag powder, and waste gypsum powder.

2. The all-solid-waste negative carbon cementitious material according to claim 1, characterized in that, The specific surface area of ​​the recycled building powder is 300~500m². 2 / kg.

3. The all-solid-waste negative carbon cementitious material according to claim 1, characterized in that, The amount of the aqueous solution of the carbonization accelerator added is 3-5% of the mass of the steel slag powder.

4. The all-solid waste negative carbon cementitious material according to claim 1, characterized in that, The concentration of the aqueous solution of the carbonization accelerator is 0.1~0.5 mol / L.

5. The all-solid-waste negative carbon cementitious material according to claim 1, characterized in that, The specific surface area of ​​the steel slag powder is 300~500 m². 2 / kg.

6. The all-solid waste negative carbon cementitious material according to any one of claims 1-5, characterized in that, The volume concentration of CO2 in the CO2 atmosphere is maintained at 10-20%.

7. The all-solid waste negative carbon cementitious material according to any one of claims 1-5, characterized in that, The steel slag powder includes at least one of the following: converter steel slag, electric furnace steel slag, hot-quenched steel slag, and drum steel slag.

8. The all-solid waste negative carbon cementitious material according to any one of claims 1-5, characterized in that, The stirring process should take 50-60 minutes and can be carried out at room temperature.

9. The all-solid waste negative carbon cementitious material according to any one of claims 1-5, characterized in that, The drying temperature is 100~130℃, and the time is 4~6 hours.

10. The method for preparing the all-solid waste negative carbon cementitious material according to any one of claims 1-9, characterized in that, Includes the following steps: (1) The modified steel slag powder, solid admixture containing sodalite structural alkali, recycled building micro powder, granulated blast furnace slag powder and waste gypsum powder are mixed and ground to obtain activated powder. (2) Mix the activated powder with the mixing water to obtain the solid waste negative carbon cementitious material.

11. The method for preparing the all-solid waste negative carbon cementitious material according to claim 10, characterized in that, In step (1), the grinding process is followed by passing the material through a 200-300 mesh sieve to obtain the activated powder.

12. The application of the all-solid waste negative carbon cementitious material according to any one of claims 1-9, or the all-solid waste negative carbon cementitious material obtained by the preparation method according to any one of claims 10-11, in the fields of construction, highways, bridges, or water conservancy and hydropower engineering.

Images