Method for carbon sequestration by using sintering machine head ash to modify steel slag

Abstract

The application discloses a method for carbon fixation by using sintering machine head ash modified steel slag, and belongs to the technical field of industrial solid waste treatment and environmental protection. The carbon fixation method disclosed by the application first breaks and screens the steel slag to obtain steel slag powder, then grinds the steel slag powder and the sintering machine head ash according to a certain proportion to obtain modified steel slag powder, and finally uses the modified steel slag powder for direct carbon fixation. By adopting the technical scheme, the carbon fixation capacity of the steel slag can be significantly improved, the purpose of capturing CO2 by using the steel slag is effectively achieved, and meanwhile, a good way for utilization of the steel slag and the sintering machine head ash is provided.

Description

Technical Field

[0001] This invention belongs to the field of industrial solid waste treatment and environmental protection technology, and more specifically, relates to a method for carbon fixation using modified steel slag from sintering machine head ash. Background Technology

[0002] With the development and progress of human industrialization, CO2 emissions have continued to increase, leading to increasingly serious global warming problems. How to reduce carbon emissions and curb global warming has become a hot issue of concern for humanity.

[0003] Carbonation of steel slag not only allows for the local use of steel plant solid waste to fix CO2 in exhaust gases, but also significantly reduces free oxides in steel slag, promoting its utilization in building materials and achieving "waste treatment and recycling." However, the active components in steel slag that can react with CO2 through carbonation are metal oxides such as f-CaO, but their total content is low, making it impossible to achieve large-scale and effective capture of CO2.

[0004] A search revealed relevant patents regarding the use of steel slag for carbon fixation, such as Chinese patent application No. 202211142705.8, which discloses a steel slag carbon fixation device and its usage method. This application simply increases the contact time between steel slag powder and CO2 through the carbon fixation device to achieve steel slag carbon fixation, resulting in a low carbon fixation capacity.

[0005] For example, Chinese Patent Application No. 202210599827.3 discloses a method and application for carbon fixation and emission reduction of steel slag by wet grinding in steel plants. The application involves crushing steel slag into powder, then preparing steel slag slurry, and finally feeding the steel slag slurry, stabilizer and flue gas into a ball mill for wet grinding to fix CO2. However, this method is complex and has a low carbon fixation capacity.

[0006] Meanwhile, in existing technologies, the carbonation reaction between 2CaO·SiO2 and CaO·SiO2 in steel slag is not readily achieved. The main active components in steel slag that react with CO2 for carbonation are CaO and Ca(OH)2, and the content of these two components in steel slag is much lower than that of silicates. This results in a limited carbon fixation capacity of steel slag, restricting its large-scale application for carbon fixation. Therefore, improving the carbon fixation capacity of steel slag is of great significance for capturing CO2 and realizing the resource utilization of steel slag. Summary of the Invention

[0007] 1. The problem to be solved

[0008] In view of the shortcomings of existing technologies that use steel slag for carbon fixation, such as low carbon fixation capacity and amount, this invention provides a method for carbon fixation using sintering machine head ash to modify steel slag. By using sintering machine head ash to modify steel slag, the above-mentioned problems are effectively solved.

[0009] 2. Technical Solution

[0010] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0011] This invention provides a method for carbon fixation of modified steel slag using sintering machine head ash. First, the steel slag is crushed and sieved to obtain steel slag powder. Then, the steel slag powder and sintering machine head ash are ground in a certain ratio to obtain modified steel slag powder. Finally, the modified steel slag powder is calcined, and CO2 is introduced during calcination to further fix the carbon. By adopting the technical solution of this invention, the carbon fixation capacity of steel slag can be significantly improved, effectively achieving the purpose of using steel slag to capture CO2. Simultaneously, it also provides a good pathway for the digestion of steel slag.

[0012] Specifically, the carbon fixation method of the present invention includes the following steps:

[0013] Step 1: Raw Material Preparation

[0014] (1) Preparation of steel slag powder

[0015] The steel slag is crushed, ground, and sieved to obtain steel slag powder with a particle size of 100-200 mesh.

[0016] (2) Ash screening at the sintering machine head

[0017] The sintering machine head ash is screened to remove large particles of impurities, resulting in sintering machine head ash with a particle size ≤100 mesh.

[0018] Step 2: Preparation of modified steel slag powder

[0019] The steel slag powder processed in step one is ground with sintering machine head ash to obtain modified steel slag powder.

[0020] Step 3: Calcination and carbon fixation of modified steel slag powder

[0021] Modified steel slag powder was roasted under the influence of CO2.

[0022] The steel slag used in this invention comprises: CaO 36.60–65.85%, SiO2 2.17–24.94%, Al2O3 2.91–28.85%, MgO 2.99–7.61%, Fe2O3 1.74–28.22%, P2O5 0.05–2.50%, with the remainder being unavoidable impurities. When steel slag is used directly for carbon fixation, its poor activity and low carbon fixation capacity prevent the effective capture of large amounts of CO2. This invention proposes incorporating sintering machine head ash into the steel slag, optimizing the amount added, and grinding the sintering machine head ash and steel slag together to modify the steel slag, thereby improving its carbon fixation capacity. The composition of the sintering head ash used includes: Fe 10-40%, K2O 5-30%, Na2O 0.6-5%, MgO 0.5-3%, SiO2 0.3-5%, CaO 1-12%, Al2O3 1-4%, Cl 5-25%, with the remainder being unavoidable impurities.

[0023] The applicant, through extensive research, discovered that mixing sintering machine head ash into steel slag and then grinding it can modify the steel slag, thereby enhancing its carbon fixation capacity. This is mainly reflected in:

[0024] (1) The sintering machine head ash contains a large amount of metal K. The change in atomic size at the K doping modification site will cause the lattice to shrink or expand, change the calcium-oxygen bond length, and thus affect the band gap, changing the electronic conductivity and electronic mobility.

[0025] (2) The intrusion of heteroatoms reduces the lattice stability of C2S;

[0026] (3) Formation of lattice chemical defects, such as doping defects and oxygen vacancy defects, increases ion mobility and accelerates the reaction of unreacted Ca. 2+ The diffusion rate of the CaCO3 product layer on the surface promotes the gas-solid reaction.

[0027] Therefore, by adding sintering machine head ash to steel slag, K modification can effectively reduce the structural stability of C2S in the steel slag, promote the reaction of C2S with CO2, and enhance the carbon fixation capacity of steel slag, thereby achieving the goal of treating waste with waste and recycling resources.

[0028] As a further preferred embodiment of the present invention, in step two, the mass of sintering mill head ash added is 1% of the mass of steel slag powder. If the amount of sintering mill head ash added is too low, K... + Insufficient amounts are unlikely to reduce the structural stability of C2S in steel slag; excessive amounts of sintering machine head ash will lead to K... + Excess, hindering Ca 2+ The diffusion of carbon dioxide inhibits the gas-solid reaction, which in turn reduces the carbon fixation capacity of steel slag.

[0029] As a further preferred embodiment of the present invention, in step two, a planetary ball mill is used for grinding, with the rotation speed controlled at 500-800 r / min and the grinding time at 0.5-1.5 h.

[0030] As a further preferred embodiment of the present invention, in step three, the flow rate of the introduced CO2 is 500-1000 mL / min.

[0031] As a further preferred embodiment of the present invention, in step three, the carbonization temperature is 650–750°C, and the carbonization time is 1–2 hours. The carbonization temperature affects the carbonization capacity of the steel slag. During carbonization in modified steel slag, CaO reacts with CO2 to generate CaCO3. When the carbonization temperature is below the range required by the present invention, the carbonization reaction may not proceed or may be incomplete, affecting the carbonization effect. Conversely, if the carbonization temperature is above the required range, CaCO3 will decompose and generate CO2 again.

[0032] 3. Beneficial effects

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] The present invention discloses a method for carbon fixation of steel slag modified with sintering machine head ash. By modifying the steel slag with sintering machine head ash, the carbon fixation capacity of the steel slag is significantly improved, and the processing cost is low, making it suitable for large-scale industrial application.

[0035] Meanwhile, by using sintering machine head ash as a steel slag modifier, a new approach suitable for the resource-based disposal of sintering machine head ash, a waste from steel plants, has been found, realizing waste treatment and recycling. Detailed Implementation

[0036] The present invention will be further described below with reference to specific embodiments.

[0037] Example 1

[0038] This embodiment describes a method for carbon fixation using modified steel slag from sintering machine head ash. The specific steps are as follows:

[0039] Step 1: Raw Material Preparation

[0040] (1) Preparation of steel slag powder

[0041] The steel slag was crushed using a jaw crusher, and after grinding and screening, steel slag powder with a particle size of 200 mesh was obtained.

[0042] (2) Ash screening at the sintering machine head

[0043] The sintering machine head ash was sieved using a 100-mesh sieve to remove large particles of impurities, resulting in sintering machine head ash with a particle size ≤100 mesh.

[0044] In this embodiment, both the steel slag and sintering machine head ash are solid wastes generated by steel plants. The steel slag has the following composition by mass percentage: CaO 47.7%, SiO2 13.3%, Al2O3 3.0%, MgO 6.4%, Fe2O3 24.4%, P2O5 1.47%, with the remainder being unavoidable impurities. The sintering machine head ash has the following main chemical composition by mass percentage: Fe 25.18%, K 18.46%, Na 8.29%, Pb 1.42%, Zn 0.28%, Cu 0.15%, Ca 4.91%, Cl 25.18%, with the remainder being unavoidable impurities.

[0045] Step 2: Preparation of modified steel slag powder

[0046] Steel slag powder and sintering mill head ash were fed into a planetary ball mill for grinding. The mass of the sintering mill head ash was 3% of the mass of the steel slag powder. The planetary ball mill rotated at 650 r / min, and the grinding time was 1 hour. Modified steel slag powder was obtained after grinding.

[0047] Step 3: Use modified steel slag powder for carbon fixation and test its carbon fixation capacity.

[0048] (1) Take 1g of modified steel slag powder and place it in a corundum crucible. Weigh the total mass of the modified steel slag powder and the corundum crucible using a balance and record it as m1. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 700℃ for calcination. At the same time, introduce N2 into the muffle furnace at a flow rate of 500mL / min. The calcination time is 1h. After calcination, allow the crucible to cool naturally and weigh it, recording its mass as m2. The mass difference before and after calcination is recorded as m. a That is, m a =m2-m1. This operation can avoid the influence of the modified steel slag's own burn-off on its quality changes before and after carbon fixation.

[0049] (2) Take 1g of modified steel slag powder and place it in an alumina crucible. Weigh the total mass of the modified steel slag powder and the alumina crucible using a balance and record it as m3. Then place the crucible containing the modified steel slag powder in a muffle furnace at 700℃, and simultaneously introduce CO2 into the muffle furnace at a flow rate of 500mL / min for 1h of carbon fixation. After carbon fixation is completed, allow the crucible to cool naturally and weigh it, recording its mass as m4. The mass difference before and after carbon fixation is recorded as m. b That is, m b =m3-m4, then the final weight increase m after carbon fixation of modified steel slag powder is... f =m a +m b m f This refers to a fixed mass of CO2. In this embodiment, the experimental results were recorded as shown in Table 1 after the experiment.

[0050] Example 2

[0051] This embodiment describes a method for carbon fixation using modified steel slag from sintering machine head ash. The specific steps are as follows:

[0052] Step 1: Raw Material Preparation

[0053] (1) Preparation of steel slag powder

[0054] The steel slag is crushed using a jaw crusher, and after grinding and screening, steel slag powder with a particle size of 100-200 mesh is obtained.

[0055] (2) Ash screening at the sintering machine head

[0056] The sintering machine head ash was sieved using a 100-mesh sieve to remove large particles of impurities, resulting in sintering machine head ash with a particle size ≤100 mesh.

[0057] In this embodiment, both the steel slag and sintering machine head ash are solid wastes generated by steel plants. The steel slag has the following composition by mass percentage: CaO 47.7%, SiO2 13.3%, Al2O3 3.0%, MgO 6.4%, Fe2O3 24.4%, P2O5 1.47%, with the remainder being unavoidable impurities. The sintering machine head ash has the following main chemical composition by mass percentage: Fe 25.18%, K 18.46%, Na 8.29%, Pb 1.42%, Zn 0.28%, Cu 0.15%, Ca 4.91%, Cl 25.18%, with the remainder being unavoidable impurities. However, it should be noted that this embodiment only uses the above-mentioned specific raw material composition as an example, and the specific composition of each raw material is not limited to this embodiment.

[0058] Step 2: Preparation of modified steel slag powder

[0059] Steel slag powder and sintering mill head ash were fed into a planetary ball mill for grinding. The mass of the sintering mill head ash was 1% of the mass of the steel slag powder. The planetary ball mill rotated at 500 r / min, and the grinding time was 1.5 h. Modified steel slag powder was obtained after grinding.

[0060] Step 3: Use modified steel slag powder for carbon fixation and test its carbon fixation capacity.

[0061] (1) Take 1g of modified steel slag powder and place it in a corundum crucible. Weigh the total mass of the modified steel slag powder and the corundum crucible using a balance and record it as m1. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 700℃ for calcination. At the same time, introduce N2 into the muffle furnace at a flow rate of 500mL / min. The calcination time is 1h. After calcination, allow the crucible to cool naturally and weigh it, recording its mass as m2. The mass difference before and after calcination is recorded as m. a That is, m a=m2-m1. This operation can avoid the influence of the modified steel slag's own burn-off on its quality changes before and after carbon fixation.

[0062] (2) Take 1g of modified steel slag powder and place it in an alumina crucible. Weigh the total mass of the modified steel slag powder and the alumina crucible using a balance and record it as m3. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 700℃ for calcination. Simultaneously, introduce CO2 into the muffle furnace at a flow rate of 500mL / min for 1 hour for carbon fixation. After carbon fixation, allow the crucible to cool naturally and weigh it, recording its mass as m4. The mass difference before and after calcination is recorded as m. b That is, m b =m3-m4, then the final weight increase m after carbon fixation of modified steel slag powder is... f =m a +m b m f This refers to a fixed mass of CO2. In this embodiment, the experimental results were recorded as shown in Table 1 after the experiment.

[0063] Example 3

[0064] This embodiment describes a method for carbon fixation using modified steel slag from sintering machine head ash. The specific steps are as follows:

[0065] Step 1: Raw Material Preparation

[0066] (1) Preparation of steel slag powder

[0067] The steel slag is crushed using a jaw crusher, and after grinding and screening, steel slag powder with a particle size of 100-200 mesh is obtained.

[0068] (2) Ash screening at the sintering machine head

[0069] The sintering machine head ash was sieved using a 100-mesh sieve to remove large particles of impurities, resulting in sintering machine head ash with a particle size ≤100 mesh.

[0070] In this embodiment, both the steel slag and sintering machine head ash are solid wastes generated by steel plants. The steel slag has the following composition by mass percentage: CaO 47.7%, SiO2 13.3%, Al2O3 3.0%, MgO 6.4%, Fe2O3 24.4%, P2O5 1.47%, with the remainder being unavoidable impurities. The sintering machine head ash has the following main chemical composition by mass percentage: Fe 25.18%, K 18.46%, Na 8.29%, Pb 1.42%, Zn 0.28%, Cu 0.15%, Ca 4.91%, Cl 25.18%, with the remainder being unavoidable impurities. However, it should be noted that this embodiment only uses the above-mentioned specific raw material composition as an example, and the specific composition of each raw material is not limited to this embodiment.

[0071] Step 2: Preparation of modified steel slag powder

[0072] Steel slag powder and sintering mill head ash were fed into a planetary ball mill for grinding. The mass of the sintering mill head ash was 10% of the mass of the steel slag powder. The planetary ball mill rotated at 800 r / min, and the grinding time was 0.5 h. Modified steel slag powder was obtained after grinding.

[0073] Step 3: Use modified steel slag powder for carbon fixation and test its carbon fixation capacity.

[0074] (1) Take 1g of modified steel slag powder and place it in a corundum crucible. Weigh the total mass of the modified steel slag powder and the corundum crucible using a balance and record it as m1. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 700℃ for calcination. At the same time, introduce N2 into the muffle furnace at a flow rate of 500mL / min. The calcination time is 1h. After calcination, allow the crucible to cool naturally and weigh it, recording its mass as m2. The mass difference before and after calcination is recorded as m. a That is, m a =m2-m1. This operation can avoid the influence of the modified steel slag's own burn-off on its quality changes before and after carbon fixation.

[0075] (2) Take 1g of modified steel slag powder and place it in an alumina crucible. Weigh the total mass of the modified steel slag powder and the alumina crucible using a balance and record it as m3. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 700℃ for calcination. Simultaneously, introduce CO2 into the muffle furnace at a flow rate of 500mL / min for 1 hour for carbon fixation. After carbon fixation, allow the crucible to cool naturally and weigh it, recording its mass as m4. The mass difference before and after calcination is recorded as m. b That is, m b =m3-m4, then the final weight increase m after carbon fixation of modified steel slag powder is... f =m a +m b m f This refers to a fixed mass of CO2. In this embodiment, the experimental results were recorded as shown in Table 1 after the experiment.

[0076] Example 4

[0077] This embodiment describes a method for carbon fixation using modified steel slag from sintering machine head ash. The specific steps are as follows:

[0078] Step 1: Raw Material Preparation

[0079] (1) Preparation of steel slag powder

[0080] The steel slag is crushed using a jaw crusher, and after grinding and screening, steel slag powder with a particle size of 100-200 mesh is obtained.

[0081] (2) Ash screening at the sintering machine head

[0082] The sintering machine head ash was sieved using a 100-mesh sieve to remove large particles of impurities, resulting in sintering machine head ash with a particle size ≤100 mesh.

[0083] In this embodiment, both the steel slag and sintering machine head ash are solid wastes generated by steel plants. The steel slag has the following composition by mass percentage: CaO 47.7%, SiO2 13.3%, Al2O3 3.0%, MgO 6.4%, Fe2O3 24.4%, P2O5 1.47%, with the remainder being unavoidable impurities. The sintering machine head ash has the following main chemical composition by mass percentage: Fe 25.18%, K 18.46%, Na 8.29%, Pb 1.42%, Zn 0.28%, Cu 0.15%, Ca 4.91%, Cl 25.18%, with the remainder being unavoidable impurities. However, it should be noted that this embodiment only uses the above-mentioned specific raw material composition as an example, and the specific composition of each raw material is not limited to this embodiment.

[0084] Step 2: Preparation of modified steel slag powder

[0085] Steel slag powder and sintering mill head ash were fed into a planetary ball mill for grinding. The mass of the sintering mill head ash was 1% of the mass of the steel slag powder. The planetary ball mill rotated at 650 r / min, and the grinding time was 1 h. Modified steel slag powder was obtained after grinding.

[0086] Step 3: Use modified steel slag powder for carbon fixation and test its carbon fixation capacity.

[0087] (1) Take 1g of modified steel slag powder and place it in an alumina crucible. Weigh the total mass of the modified steel slag powder and the alumina crucible using a balance, and record it as m1. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 650℃ for calcination. At the same time, introduce N2 into the muffle furnace at a flow rate of 500mL / min. The calcination time is 1h. After calcination, allow the crucible to cool naturally and weigh it, recording its mass as m2. The mass difference before and after calcination is recorded as m. a That is, m a =m2-m1. This operation can avoid the influence of the modified steel slag's own burn-off on its quality changes before and after carbon fixation.

[0088] (2) Take 1g of modified steel slag powder and place it in an alumina crucible. Weigh the total mass of the modified steel slag powder and the alumina crucible using a balance and record it as m3. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 650℃ for calcination. Simultaneously, introduce CO2 into the muffle furnace at a flow rate of 500mL / min for 1 hour for carbon fixation. After carbon fixation, allow the crucible to cool naturally and weigh it, recording its mass as m4. The mass difference before and after calcination is recorded as m. b That is, m b=m3-m4, then the final weight increase m after carbon fixation of modified steel slag powder is... f =m a +m b m f This refers to a fixed mass of CO2. In this embodiment, the experimental results were recorded as shown in Table 1 after the experiment.

[0089] Example 5

[0090] This embodiment describes a method for carbon fixation using modified steel slag from sintering machine head ash. The specific steps are as follows:

[0091] Step 1: Raw Material Preparation

[0092] (1) Preparation of steel slag powder

[0093] The steel slag is crushed using a jaw crusher, and after grinding and screening, steel slag powder with a particle size of 100-200 mesh is obtained.

[0094] (2) Ash screening at the sintering machine head

[0095] The sintering machine head ash was sieved using a 100-mesh sieve to remove large particles of impurities, resulting in sintering machine head ash with a particle size ≤100 mesh.

[0096] In this embodiment, both the steel slag and sintering machine head ash are solid wastes generated by steel plants. The steel slag has the following composition by mass percentage: CaO 47.7%, SiO2 13.3%, Al2O3 3.0%, MgO 6.4%, Fe2O3 24.4%, P2O5 1.47%, with the remainder being unavoidable impurities. The sintering machine head ash has the following main chemical composition by mass percentage: Fe 25.18%, K 18.46%, Na 8.29%, Pb 1.42%, Zn 0.28%, Cu 0.15%, Ca 4.91%, Cl 25.18%, with the remainder being unavoidable impurities. However, it should be noted that this embodiment only uses the above-mentioned specific raw material composition as an example, and the specific composition of each raw material is not limited to this embodiment.

[0097] Step 2: Preparation of modified steel slag powder

[0098] Steel slag powder and sintering mill head ash were fed into a planetary ball mill for grinding. The mass of the sintering mill head ash was 1% of the mass of the steel slag powder. The planetary ball mill rotated at 650 r / min, and the grinding time was 1 h. Modified steel slag powder was obtained after grinding.

[0099] Step 3: Use modified steel slag powder for carbon fixation and test its carbon fixation capacity.

[0100] (1) Take 1g of modified steel slag powder and place it in an alumina crucible. Weigh the total mass of the modified steel slag powder and the alumina crucible using a balance and record it as m1. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 750℃ for calcination. At the same time, introduce N2 into the muffle furnace at a flow rate of 500mL / min. The calcination time is 1h. After calcination, allow the crucible to cool naturally and weigh it, recording its mass as m2. The mass difference before and after calcination is recorded as m. a That is, m a =m2-m1. This operation can avoid the influence of the modified steel slag's own burn-off on its quality changes before and after carbon fixation.

[0101] (2) Take 1g of modified steel slag powder and place it in an alumina crucible. Weigh the total mass of the modified steel slag powder and the alumina crucible using a balance and record it as m3. Then, place the crucible containing the modified steel slag powder in a muffle furnace at 750℃ for calcination. Simultaneously, introduce CO2 into the muffle furnace at a flow rate of 500mL / min for 1 hour for carbon fixation. After carbon fixation, allow the crucible to cool naturally and weigh it, recording its mass as m4. The mass difference before and after calcination is recorded as m. b That is, m b =m3-m4, then the final weight increase m after carbon fixation of modified steel slag powder is... f =m a +m b m f This refers to a fixed mass of CO2. In this embodiment, the experimental results were recorded as shown in Table 1 after the experiment.

[0102] Example 6

[0103] This embodiment describes a method for carbon fixation using modified steel slag from sintering machine head ash. The steps are basically the same as in Embodiment 1, except that the steel slag and sintering machine head ash used have different compositions. Specifically, the steel slag used in this embodiment has the following composition:

[0104] CaO 36.60%, SiO 23.14%, Al 2O 328.85%, MgO 7.61%, Fe 2O 32.6%, P 2O 52.50%, with the remainder being unavoidable impurities.

[0105] The composition of the sintering machine head ash is as follows:

[0106] Fe 40%, K2O30%, Na2O4%, MgO 0.5%, SiO20.3%, CaO12%, Al2O34%, Cl 15%.

[0107] Example 8

[0108] This embodiment describes a method for carbon fixation using modified steel slag from sintering machine head ash. The steps are basically the same as in Embodiment 1, except that the steel slag and sintering machine head ash used have different compositions. Specifically, the steel slag used in this embodiment has the following composition:

[0109] CaO 36.8%, SiO2 24.94%, Al2O3 3.12%, MgO 2.99%, Fe2O3 28.22%, P2O5 0.15%, with the remainder being unavoidable impurities.

[0110] The composition of the sintering machine head ash is as follows:

[0111] Fe 20%, K2O28%, Na2O5%, MgO3%, SiO23%, CaO8%, Al2O32%, Cl 5%.

[0112] Comparative Example 1

[0113] The method of carbon fixation using steel slag in this comparative example differs from that in Example 1 in that: no sintering head ash is added, and steel slag after crushing and screening is directly used for carbon fixation by roasting under the condition of CO2 introduction. After the experiment, the experimental results are recorded as shown in Table 1.

[0114] Comparative Example 2

[0115] The method of carbon fixation using steel slag in this comparative example differs from that in Example 1 in that: no sintering head ash is added, but the steel slag powder is ground separately, and finally CO2 is introduced into the ground steel slag for roasting and carbon fixation. After the experiment, the experimental results are recorded as shown in Table 1.

[0116] Comparative Example 3

[0117] The method of carbon fixation using steel slag in this comparative example differs from that in Example 1 in that sintering machine head ash is added, but the steel slag and sintering machine head ash are not ground; instead, they are directly mixed. After the experiment, the experimental results are recorded as shown in Table 1.

[0118] Comparative Example 4

[0119] The method of carbon fixation using steel slag in this comparative example differs from that in Example 1 in that the amount of sintering head ash added is different. Specifically, the mass of sintering head ash added in this comparative example accounts for 0.5% of the mass of steel slag. After the experiment, the experimental results are recorded as shown in Table 1.

[0120] Comparative Example 5

[0121] The method of carbon fixation using steel slag in this comparative example differs from that in Example 1 in that the amount of sintering head ash added is different. Specifically, the mass of sintering head ash added in this comparative example accounts for 11% of the mass of steel slag. After the experiment, the experimental results are recorded as shown in Table 1.

[0122] Table 1. Carbon fixation data for each embodiment and comparative example of the present invention.

[0123] Example 1 15.221 15.218 0.003 15.221 15.246 0.025 0.028 28 Example 2 15.221 15.219 0.002 15.221 15.244 0.023 0.025 25 Example 3 15.221 15.216 0.005 15.221 15.243 0.022 0.027 27 Example 4 15.221 15.219 0.002 15.221 15.244 0.023 0.025 25 Example 5 15.221 15.219 0.002 15.221 15.243 0.022 0.024 24 Example 6 15.221 15.217 0.004 15.221 15.243 0.022 0.026 26 Example 7 15.221 15.218 0.003 15.221 15.242 0.021 0.024 24 Example 8 15.221 15.219 0.002 15.221 15.246 0.025 0.027 27 Comparative Example 1 15.221 15.218 0.003 15.221 15.229 0.008 0.011 11 Comparative Example 2 15.221 15.217 0.004 15.221 15.230 0.009 0.013 13 Comparative Example 3 15.221 15.218 0.003 15.221 15.235 0.014 0.017 17 Comparative Example 4 15.221 15.219 0.002 15.221 15.231 0.010 0.012 12 Comparative Example 5 15.221 15.216 0.005 15.221 15.225 0.004 0.009 9

[0124] More specifically, although exemplary embodiments of the invention have been described herein, the invention is not limited to these embodiments, but includes any and all embodiments modified, omitted, such as combinations between various embodiments, adaptive changes, and / or substitutions, as would be apparent to those skilled in the art from the foregoing detailed description. The limitations in the claims are to be interpreted broadly as used in the language of the claims and are not limited to the examples described in the foregoing detailed description or during the implementation of this application, which should be considered non-exclusive. Any step listed in any method or process claim may be performed in any order and is not limited to the order set forth in the claims. Therefore, the scope of the invention should be determined solely by the appended claims and their legal equivalents, and not by the description and examples given above.

[0125] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of conflict, the definitions in this specification shall prevail. When a rate, pressure, temperature, time, or other value or parameter is expressed as a range, preferred range, or a range defined by a series of upper and lower preferred values, this shall be understood to specifically disclose all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether such range is disclosed individually. For example, the range 1-50 should be understood to include any number, combination of numbers, or subrange selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50, as well as all decimal values ​​between the integers mentioned above, such as 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, and 1.9. Regarding subranges, specifically consider "nested subranges" extending from any endpoint of the range. For example, nested sub-ranges of the exemplary range 1-50 may include 1-10, 1-20, 1-30 and 1-40 in one direction, or 50-40, 50-30, 50-20 and 50-10 in another direction.

Claims

1. A method for carbon fixation using modified steel slag from sintering machine head ash, characterized in that: The steel slag is crushed and screened, and the resulting steel slag powder is ground with sintering machine head ash to obtain modified steel slag powder. The modified steel slag powder is then roasted, and CO2 is introduced during roasting to fix carbon. Step 1: Raw Material Preparation (1) Preparation of steel slag powder The steel slag is crushed, ground, and sieved to obtain steel slag powder with a particle size of 100-200 mesh. (2) Ash screening at the sintering machine head The sintering machine head ash is screened to remove large particles of impurities, resulting in sintering machine head ash with a particle size ≤100 mesh. Step 2: Preparation of modified steel slag powder The steel slag powder processed in step one is ground with sintering machine head ash to obtain modified steel slag powder. The mass of sintering machine head ash added is 1-10% of the mass of steel slag powder. Grinding is carried out using a planetary ball mill with a speed control of 500-800 r / min and a grinding time of 0.5-1.5 h. Step 3: Carbon fixation using modified steel slag powder CO2 is introduced at a certain temperature to directly fix modified steel slag powder with carbon. The carbon fixation temperature is 650~750℃ and the carbon fixation time is 1~2h.

2. The method for carbon fixation using modified steel slag from sintering machine head ash according to claim 1, characterized in that: In step three, the flow rate of CO2 introduced is 500~1000 mL / min.

3. A method for carbon fixation using modified steel slag from sintering machine head ash according to any one of claims 1 to 2, characterized in that: The composition of steel slag includes: CaO 36.60~65.85%, SiO2 2.17~24.94%, Al2O3 2.91~28.85%, MgO 2.99~7.61%, Fe2O3 1.74~28.22%, P2O5 0.05~2.50%, with the remainder being unavoidable impurities.

4. A method for carbon fixation using modified steel slag from sintering machine head ash according to any one of claims 1 to 2, characterized in that: The composition of sintering machine head ash includes: Fe 10~40%, K2O 5~30%, Na2O 0.6~5%, MgO 0.5~3%, SiO2 0.3~5%, CaO 1~12%, Al2O3 1~4%, Cl 5~25%, and the remainder are unavoidable impurities.