A method for the coupled mineralization and resource utilization of modified steel slag and its application.

Abstract

This application provides a method for the resource utilization of modified steel slag coupled with mineralization. The method utilizes solid waste and tail gas from steel production. By using dopants and optimizing the composition, the activity and carbon fixation efficiency of steel slag are significantly improved, the energy consumption of the processing process is reduced, and the mechanical strength of the mineralized products is improved. The resource-based products prepared by this method can well meet the requirements of the rail transit and building materials industries. Furthermore, the processing technology is simple and effective and can be used in the activation, mineralization, or resource utilization of steel slag.

Description

Technical Field

[0001] This invention relates to the field of waste mineralization, and more particularly to a method for the resource utilization of modified steel slag through coupled mineralization and its application. Background Technology

[0002] The most prominent solid waste generated in steel production is steel slag. However, due to factors such as large particle size, unstable slag composition, and low activity, steel slag has not been effectively utilized, with a comprehensive utilization rate of only about 3%. In addition, a large amount of exhaust gas is emitted during industrial production, which contains 10-20% carbon dioxide. With the introduction of the "dual carbon" target, carbon dioxide emission reduction has become a hot issue that has received widespread attention and urgently needs to be addressed both domestically and internationally.

[0003] Chinese patent CN106145878A discloses a method for preparing lightweight building materials from mineralized steel slag. This method uses steel slag, waste gas, and expanded perlite as main raw materials. Through vacuum heating and humidification carbonization, lightweight steel slag building materials with certain heat insulation functions are prepared. However, the humidification process causes the solid components to agglomerate and the surface to condense, which not only hinders the absorption of carbon dioxide in the waste gas, but also leads to the problem of unstable quality of the prepared materials. Chinese patent CN101851071A discloses a method for CO2 fixation and the digestion of free calcium oxide in steel slag powder. In this method, steel slag is ball-milled to peel off the surface of the unreacted calcium carbonate, increasing the content of soluble calcium. However, this process requires a lot of energy and has a low degree of mineralization. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention first provides a method for the coupled mineralization and resource utilization of modified steel slag.

[0005] Furthermore, the method for the coupled mineralization and resource utilization of modified steel slag includes the following steps:

[0006] (1) In the steelmaking process, after the molten iron is released and before the temperature is reduced, a dopant is added to the high-temperature steel slag to obtain high-temperature mixed steel slag.

[0007] (2) After the high-temperature mixed steel slag is stirred in a sealed manner, it is cooled to room temperature to obtain modified steel slag;

[0008] (3) The modified steel slag, silicoaluminous solid waste and water are mixed and stirred to obtain a mixture;

[0009] (4) The mixture is fed into a digestion system for digestion, and then pressed into shape under a pressure of 5-50 MPa to obtain a green body;

[0010] (5) Load the green billet into the reactor, introduce carbon dioxide flue gas, control the pressure inside the reactor to 0.2-2 MPa, and after mineralization for 4-48 hours, discharge the flue gas inside the reactor to atmospheric pressure. Cool the reactor to below 80°C and then take out the sample.

[0011] Furthermore, the dopant includes at least one or a combination of several compounds containing element B, alkali metal elements, and alkaline earth metal elements.

[0012] Preferably, in step (1), the dopant includes compounds containing element B, including but not limited to one or a combination of boric acid, metaboric acid, borates, boron oxides, borides, borates, and borates.

[0013] Furthermore, the dopant includes, but is not limited to, one or more combinations of boric acid, boron trioxide, ammonium borate, lithium borate, sodium borate, borax, potassium borate, lithium metaborate, sodium metaborate, potassium metaborate, magnesium metaborate, ammonium metaborate, boron sulfide, titanium boride, and zirconium boride.

[0014] In a preferred embodiment, the dopant is any one or a combination of several of boric acid, sodium borate, potassium borate, borax, and ammonium borate.

[0015] Calcium or magnesium in steel slag is difficult to dissolve and mineralize under mild conditions, limiting the mineralization efficiency of steel slag. Traditional technologies use ultrafine grinding and high temperature and pressure to increase the reaction degree between mineralizable calcium or magnesium and carbon dioxide. However, this application only requires the addition of a dopant. The dopant in this application is a boron-containing compound that exists in the system as [BO4] and replaces [SiO4] in C2S or C3S, partially reducing the boron content. 3+ Ions can also replace Ca 2+ This causes lattice distortion in C2S and C3S crystals in solid waste, forming crystals with the general formula Ca. (2-x) B x (SiO4) (1-x) (BO4) x The solid solution increases the reactivity of mineralizable calcium or magnesium, thereby improving the mineralization activity of steel slag.

[0016] Furthermore, this application does not impose strict requirements on the amount of dopant used, and adjustments can be made accordingly based on the requirements of mineralization activity.

[0017] Preferably, element B is used as the basis for dopant measurement, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is (0.03-0.18):1.

[0018] Furthermore, the dopant also includes at least one of an alkali metal and / or alkaline earth metal salt, halide, or hydroxide.

[0019] This application unexpectedly discovered that when the dopant also includes salts, halides, or hydroxides of alkali metals and / or alkaline earth metals, it not only improves the mineralization efficiency of steel slag but also significantly enhances the mechanical strength of the steel slag resource products. Based on this, the applicant analyzes the reason as follows: when alkali metals or alkaline earth metals are doped into the system, boron mainly exists in the form of [BO3], and the solid solution composition at this time is Ca. (2-x) M x (SiO4) (1-x) (BO3) x M is an alkali metal or alkaline earth metal; it has a triangular planar structure, which makes the structure of the mineralized product more stable and its mechanical strength higher than the original four-cornered planar structure.

[0020] Furthermore, this application does not impose strict regulations on the content of alkali metal and / or alkaline earth metal salts, halides or hydroxides in the dopant, and the amount added can be adjusted accordingly based on the hardness of the subsequent steel slag resource products.

[0021] Preferably, the compound containing element B in the dopant is denoted as n1 based on the molar content of B; the salt, halide or hydroxide of alkali metal and / or alkaline earth metal element is denoted as n2 based on the molar content of alkali metal and / or alkaline earth metal, wherein n1:n2 is 1:(0-2.5).

[0022] Preferably, the ratio of n1:n2 is 1:(0-1.5); more preferably, the ratio of n1:n2 is 1:(0.25-1.5); and even more preferably, it is 1:(0.5-1.5).

[0023] Furthermore, the salts of the alkali metal or alkaline earth metal include, but are not limited to, any one or a combination of several of their carbonates, nitrates, acetates, and nitrates.

[0024] Preferably, the alkali metal or alkaline earth metal salt is a carbonate and / or acetate.

[0025] Preferably, the alkali metal or alkaline earth metal salt is a carbonate.

[0026] Furthermore, the alkali metal or alkaline earth metal halide is any one or a combination of several of chlorides, bromides, and iodides.

[0027] Furthermore, the alkali metal or alkaline earth metal is selected from any one or more combinations of lithium, sodium, potassium, rubidium, cesium, francium-beryllium, magnesium, calcium, strontium, barium, and radium.

[0028] Furthermore, this application does not strictly specify the source of the compounds containing element B, salts of alkali metals and / or alkaline earth metals, halides or hydroxides in the dopant. The dopant can be the aforementioned substances directly, or it can be solid waste and waste liquid containing the aforementioned substances.

[0029] Furthermore, the C2S and C3S content in the steel slag is greater than 20 wt.%.

[0030] Preferably, the C2S and C3S content in the steel slag is greater than 30 wt.%.

[0031] Preferably, the cooling method in step (2) is gradient cooling.

[0032] Preferably, step (2) specifically involves: stirring the high-temperature mixed steel slag obtained in step (1) in a closed system for 20-30 minutes until the material is homogeneous, then stopping the stirring; subsequently, the mixed steel slag is subjected to a gradient cooling in three temperature ranges: 750-900℃ for 5-15 minutes, 450-600℃ for 5-15 minutes, and 50-250℃ for 5-15 minutes, until it reaches room temperature, thus obtaining modified steel slag.

[0033] Preferably, in step (2), the temperature is lowered sequentially according to a temperature gradient of 750-850℃, 450-550℃, and 50-150℃.

[0034] Furthermore, the silica-alumina solid waste in step (3) includes, but is not limited to, any one or more combinations of mineral powder, silica fume, fly ash, cement kiln ash, kaolin, coal gangue, construction waste, and sludge.

[0035] Further, in step (3), the mass ratio of modified steel slag, silicoaluminous solid waste and water is (16-50):(40-70):(5-20).

[0036] Further, in step (3), the mass ratio of modified steel slag, silicoaluminous solid waste and water is (25-50): (40-70): (5-15).

[0037] Furthermore, the digestion time in step (4) is 25-65 min.

[0038] Furthermore, the molding pressure is 6-42 MPa.

[0039] Furthermore, in step (5), the green blank occupies 5-60% of the space in the reactor, preferably 20-60%.

[0040] Furthermore, the carbon dioxide-containing flue gas includes, but is not limited to, one or more types of dust removal flue gas from steel plants, coal-fired power plants, lime kilns, chemical plants, and cement plants.

[0041] Furthermore, the volume fraction of carbon dioxide in the carbon dioxide-containing flue gas is 10-99%.

[0042] Preferably, the volume fraction of carbon dioxide in the carbon dioxide-containing flue gas is 20-99%.

[0043] Preferably, the pressure inside the vessel in step (5) is 0.2-1 MPa.

[0044] Secondly, this application also provides the application of the modified steel slag coupled mineralization and resource utilization method, which is used in the process of steel slag activation, mineralization or resource utilization.

[0045] Beneficial effects

[0046] 1. The modified steel slag coupled mineralization and resource utilization method of this application not only solves the problem of low activity of steel slag in the resource utilization process, but also solves the problems of low quality of its resource products and high energy consumption of the process.

[0047] 2. The method provided in this application effectively utilizes the waste heat of the steelmaking reaction in the front-end process, reducing energy loss and consumption, and making resource-based use of the exhaust gas emitted by steel, coal, power plants, cement plants, etc., which not only reduces pollution emissions, but also further reduces the cost of exhaust gas treatment.

[0048] 3. In the method provided in this application, the use of dopants fundamentally changes the crystal structure of C2S and C3S in solid waste, improves its mineralization reactivity and carbon dioxide absorption; in addition, the addition of alkali metals or alkaline earth metals further improves the performance of mineralized products to meet the requirements of industries such as building materials, effectively promoting my country's development towards low-carbon and energy-saving directions. Attached Figure Description

[0049] Figure 1 XRD patterns of steel slag before and after modification with dopants in Example 2; the lower curve is the XRD pattern of steel slag before modification, and the upper curve is the XRD pattern of steel slag after modification (S: ferrocalcite Ca2Fe2O5, M: calcium aluminate Ca). 12 Al 14 O 33 L: clinoptilolite (Ca2SiO4), C: dicalcium silicate (Ca2SiO4), A: alumina (Al2O3). Detailed Implementation

[0050] Example

[0051] Example 1

[0052] This embodiment provides a method for the resource utilization of modified steel slag through coupled mineralization, including the following steps:

[0053] (1) In the steelmaking process, after the molten iron is precipitated and before cooling, a dopant is added to the high-temperature steel slag to obtain high-temperature mixed steel slag; the dopant includes boric acid and potassium chloride, the boric acid is calculated based on the molar content of element B, the potassium chloride is calculated based on the molar content of element K, and the molar ratio of boric acid to potassium chloride is 1:1.5; the dopant is based on element B as the measurement basis, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is 0.03:1;

[0054] (2) Stir the high-temperature mixed steel slag in a sealed container for 30 minutes. After the mixture is uniform, stop stirring. Cool the high-temperature mixed steel slag in sequence according to the temperature gradient of 850℃ (maintain for 10 minutes), 550℃ (maintain for 10 minutes), and 150℃ (maintain for 10 minutes) until it is cooled to room temperature to obtain the modified steel slag.

[0055] (3) The modified steel slag, construction waste and water are mixed and stirred in a mass ratio of 40:50:10 to obtain a mixture;

[0056] (4) The mixture is fed into the digestion system and digested for 25 minutes. Then the mixture is placed in the mold and pressed into shape under a pressure of 11.5 MPa to obtain the green body.

[0057] (5) Load the green billet into the reactor. The filling amount of the green billet is 45% of the reactor space. Introduce flue gas containing carbon dioxide (the volume fraction of carbon dioxide in the flue gas is 70%). Control the pressure inside the reactor to 0.2 MPa. After mineralization for 40 hours, discharge the flue gas inside the reactor to atmospheric pressure. Cool the reactor to below 80°C and take out the sample.

[0058] Example 2

[0059] This embodiment provides a method for the resource utilization of modified steel slag through coupled mineralization, including the following steps:

[0060] (1) In the steelmaking process, after the molten iron is precipitated and before cooling, a dopant is added to the high-temperature steel slag to obtain high-temperature mixed steel slag; the dopant includes boric acid and barium carbonate, the boric acid is calculated based on the molar content of element B, the barium carbonate is calculated based on the molar content of element Ba, and the molar ratio of boric acid to barium carbonate is 1:0.5; the dopant is based on element B, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is 0.18:1;

[0061] (2) Stir the high-temperature mixed steel slag in a sealed container for 30 minutes. After the mixture is evenly mixed, stop stirring. Cool the high-temperature mixed steel slag in sequence according to the temperature gradient of 800℃ (maintain for 10 minutes), 500℃ (maintain for 10 minutes), and 100℃ (maintain for 10 minutes) until it is cooled to room temperature to obtain the modified steel slag.

[0062] (3) The modified steel slag, construction waste and water are mixed and stirred in a mass ratio of 40:50:10 to obtain a mixture;

[0063] (4) The mixture is fed into the digestion system and digested for 65 minutes. Then the mixture is placed in the mold and pressed into shape under a pressure of 11.5 MPa to obtain the green body.

[0064] (5) Load the green body into the reactor. The green body filling amount is 45% of the reactor space. Introduce flue gas containing carbon dioxide (the volume fraction of carbon dioxide in the flue gas is 70%). Control the pressure inside the reactor to 1 MPa. After mineralization for 4 hours, discharge the flue gas inside the reactor to atmospheric pressure. Cool the reactor to below 80°C and take out the sample.

[0065] Example 3

[0066] This embodiment provides a method for the resource utilization of modified steel slag through coupled mineralization, including the following steps:

[0067] (1) In the steelmaking process, after the molten iron is precipitated and before cooling, a dopant is added to the high-temperature steel slag to obtain high-temperature mixed steel slag; the dopant includes boric acid and sodium carbonate, the boric acid is calculated based on the molar content of element B, the sodium carbonate is calculated based on the molar content of element Na, and the molar ratio of boric acid to sodium carbonate is 1:1; the dopant is based on element B as the measurement basis, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is 0.12:1;

[0068] (2) Stir the high-temperature mixed steel slag in a sealed container for 30 minutes. After the mixture is evenly mixed, stop stirring. Cool the high-temperature mixed steel slag in sequence according to the temperature gradient of 800℃ (maintain for 10 minutes), 500℃ (maintain for 10 minutes), and 100℃ (maintain for 10 minutes) until it is cooled to room temperature to obtain the modified steel slag.

[0069] (3) The modified steel slag, construction waste and water are mixed and stirred in a mass ratio of 40:50:10 to obtain a mixture;

[0070] (4) The mixture is fed into the digestion system and digested for 30 minutes. Then the mixture is placed in the mold and pressed into shape under a pressure of 11.5 MPa to obtain the green body.

[0071] (5) Load the green billet into the reactor. The green billet filling amount is 45% of the reactor space. Introduce flue gas containing carbon dioxide (the volume fraction of carbon dioxide in the flue gas is 70%). Control the pressure inside the reactor to 0.6 MPa. After mineralization for 8 hours, discharge the flue gas inside the reactor to atmospheric pressure. Cool the reactor to below 80°C and take out the sample.

[0072] Example 4

[0073] It is basically the same as Example 3, except that: the dopant is based on element B, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is 0.06:1.

[0074] Example 5

[0075] It is basically the same as Example 3, except that: the dopant is based on element B, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is 0.09:1.

[0076] Example 6

[0077] It is basically the same as Example 3, except that: the dopant is based on element B, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is 0.15:1.

[0078] Example 7

[0079] It is basically the same as Example 6, except that the dopant only includes boric acid.

[0080] Example 8

[0081] It is basically the same as Example 3, except that: the dopant includes boric acid and sodium carbonate, the boric acid is calculated by the molar content of element B, the sodium carbonate is calculated by the molar content of element Na, and the molar ratio of boric acid to sodium carbonate is 1:0.25.

[0082] Example 9

[0083] It is basically the same as Example 3, except that: the dopant includes boric acid and sodium carbonate, the boric acid is calculated by the molar content of element B, the sodium carbonate is calculated by the molar content of element Na, and the molar ratio of boric acid to sodium carbonate is 1:0.5.

[0084] Example 10

[0085] It is basically the same as Example 3, except that the dopant includes boric acid and sodium carbonate, with boric acid calculated by the molar content of element B and sodium carbonate calculated by the molar content of element Na, and the molar ratio of boric acid to sodium carbonate is 1:1.5.

[0086] Example 11

[0087] It is basically the same as Example 3, except that the amount of green blank filled in step (5) is 20% of the space of the reactor.

[0088] Example 12

[0089] It is basically the same as Example 3, except that the amount of green blank filled in step (5) is 30% of the space of the reactor.

[0090] Example 13

[0091] It is basically the same as Example 3, except that the amount of green blank filled in step (5) is 50% of the space of the reactor.

[0092] Comparative Example 1

[0093] It is basically the same as Example 3, except that: the dopant includes boric acid and sodium carbonate, the boric acid is calculated by the molar content of element B, the sodium carbonate is calculated by the molar content of element Na, and the molar ratio of boric acid to sodium carbonate is 1:1.8.

[0094] Comparative Example 2

[0095] It is basically the same as Example 3, except that the dopant only includes sodium carbonate.

[0096] Comparative Example 3

[0097] It is basically the same as Example 3, except that: the dopant is based on element B, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is 0.2:1.

[0098] Comparative Example 4

[0099] It is basically the same as Example 3, except that: the dopant is based on element B, and the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is 0.01:1.

[0100] Comparative Example 5

[0101] It is basically the same as Example 3, except that no dopant is added in the method.

[0102] Performance testing methods:

[0103] 1. Carbon dioxide absorption rate: The carbon dioxide content absorbed by the mineralized product is measured by the TG / DTG curve obtained from the test example. The absorption rate is (mass of absorbed carbon dioxide / mass of mineralized product) × 100%.

[0104] 2. Compressive strength: The samples obtained in the examples were tested in accordance with the test methods for concrete blocks and bricks specified in GB / T 4111-2013.

[0105] 3. XRD characterization: The XRD patterns of the steel slag in Example 2 before and after modification with dopants are shown in the figure. Figure 1 As shown in the figure, the characteristic peaks of dicalcium silicate (represented by C in the figure) in steel slag changed significantly before and after modification. The characteristic peaks at 31, 32.4 and 36 shifted significantly to the left, and the width of the characteristic peak at 36 increased significantly. This is because the doping of boron and barium caused lattice distortion of dicalcium silicate. In addition, due to the low doping of boron and barium, the characteristic peaks of boron and barium compounds were almost invisible in the spectrum.

[0106] Performance test results:

[0107] Table 1

[0108]

[0109] Analyze the above results:

[0110] The mineralized products prepared in Examples 1-3 have high carbon dioxide absorption rates and high compressive strength, which can meet the application requirements.

[0111] Comparing Examples 3 and 4-6, it can be seen that within a certain range, when the amount of dopant increases, the absorption rate of carbon dioxide in the mineralization reaction and the compressive strength of the mineralized product are significantly improved. However, when too much dopant is added, the absorption rate of carbon dioxide and the compressive strength of the mineralized product decrease. The reason for this is that when the additive content is too high, the modified steel slag undergoes a large amount of lattice distortion, and carbon dioxide can react with the modified steel slag more quickly. Under certain temperature and pressure, mineralization is more likely to occur on the surface, and the generated carbonate fills the pores, making it difficult for carbon dioxide to enter the interior of the billet, thus leading to a decrease in the absorption rate and the strength of the mineralized product.

[0112] Comparing Examples 3 and 8-10, and Examples 6 and 7, it can be seen that the addition of sodium will significantly improve the mechanical strength of the mineralized product and the absorption rate of carbon dioxide during the mineralization process. However, when too much sodium is added, it will lead to a decrease in mechanical strength. The reason is speculated to be that when the sodium content increases, the eutectic formed by sodium reacts with carbon dioxide in a mineralization reaction. However, the carbonate formed by sodium is not conducive to strength enhancement. Excessive accumulation of sodium carbonate in the product will lead to a significant decrease in the strength of the final product.

[0113] Comparing Examples 3 and 11-13, it can be seen that when the amount of green body filling increases, the absorption of carbon dioxide also increases, but this increase is not positively correlated. This is because the amount of green body filling affects the temperature inside the reactor. Increasing the amount of filling helps to raise the temperature inside the reactor, which is conducive to increasing the disturbance of carbon dioxide and increasing the carbon dioxide absorption rate, thereby improving the mechanical strength and carbon fixation rate of the mineralized product. However, excessive increase leads to a decrease in the above indicators. The reason is speculated to be that excessive filling makes the mineralization reaction violent, the temperature inside the reactor rises rapidly, the mineralization reaction is concentrated on the surface of the green body, and carbon dioxide is difficult to enter the interior of the green body, which reduces the carbon dioxide absorption rate and the compressive strength of the product.

[0114] Comparing Example 3 and Comparative Examples 1-5, it can be seen that the addition of element B in the dopant can effectively improve the mineralization activity of steel slag, and the addition of element sodium can further improve the mechanical strength of the mineralized products, but the effective addition amount should be controlled within a suitable range; the addition of dopant helps to improve the carbon dioxide absorption rate and compressive strength, but the dosage range needs to be controlled.

Claims

1. A method for modifying steel slag coupling mineralization resource utilization, characterized in that, Includes the following steps: (1) In the steelmaking process, after the molten iron is released and before the temperature is reduced, a dopant is added to the high-temperature steel slag to obtain high-temperature mixed steel slag. (2) After the high-temperature mixed steel slag is stirred in a sealed manner, it is cooled to room temperature to obtain modified steel slag; (3) The modified steel slag, silicoaluminous solid waste and water are mixed and stirred to obtain a mixture; (4) The mixture is fed into a digestion system for digestion, and then pressed into shape under a pressure of 5-50 MPa to obtain a green body; (5) Load the green body into the reactor, introduce carbon dioxide flue gas, control the pressure inside the reactor to 0.2-2 MPa, and after mineralization for 4-48 hours, discharge the flue gas inside the reactor to atmospheric pressure. Cool the reactor to below 80°C and then take out the sample. The dopant includes compounds containing element B; the dopant also includes at least one of salts or hydroxides of alkali metals and / or alkaline earth metals. The compound containing element B in the dopant is denoted as n1 based on the molar content of B; the salt or hydroxide of alkali metal and / or alkaline earth metal is denoted as n2 based on the molar content of alkali metal and / or alkaline earth metal, wherein n1:n2 is 1:(0.25-1.5).

2. The method of claim 1, wherein, The ratio of n1 to n2 is 1:(0.5-1.5).

3. The method according to claim 1, characterized in that, Using element B as the basis for dopant measurement, the molar ratio of the dopant to the total amount of C2S and C3S in the steel slag is (0.03-0.18):

1.

4. The method according to claim 1, characterized in that, The cooling method in step (2) is gradient cooling.

5. The method according to claim 4, characterized in that, The specific steps (2) are as follows: the high-temperature mixed steel slag obtained in step (1) is stirred in a closed system for 20-30 minutes. After the material is homogeneous, the stirring is stopped. Then, the mixed steel slag is cooled in a gradient according to three temperature ranges: 750-900℃ for 5-15 minutes, 450-600℃ for 5-15 minutes, and 50-250℃ for 5-15 minutes, until it reaches room temperature, thus obtaining modified steel slag.

6. The method according to claim 1, characterized in that, The C2S and C3S content in the steel slag is greater than 20 wt.%.

7. The method according to claim 1, characterized in that, In step (3), the mass ratio of modified steel slag, silicoaluminous solid waste and water is (16-50): (40-70): (5-20).

8. The method according to claim 1, characterized in that, In step (5), the green body occupies 5-60% of the space in the reactor.

9. The method according to claim 1, characterized in that, The volume fraction of carbon dioxide in the carbon dioxide-containing flue gas is 10-99%.

10. The application of the method according to any one of claims 1-9 in the resource utilization process of steel slag.

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