A dense phase steel slag carbonization device

Abstract

The application discloses a dense-phase steel slag carbonization device, which comprises a bucket elevator, a dense-phase carbonization tower, a spraying device, an intermediate bin, a finished product bin and a monitoring module; carbon dioxide-containing flue gas enters a reaction cavity from a flue gas inlet of the dense-phase carbonization tower; the bucket elevator is used for conveying steel slag powder from a first conveying device into the dense-phase carbonization tower; the spraying device is used for spraying water and additives into the reaction cavity of the dense-phase carbonization tower; the intermediate bin is used for screening and collecting the steel slag output with the flue gas; the reaction cavity is used for carrying out a three-phase carbonization reaction of the steel slag, water and carbon dioxide entering the dense-phase carbonization tower; the reacted flue gas is discharged from a flue gas outlet; the reacted carbonized steel slag is discharged from the flue gas and then enters the intermediate bin; the monitoring module is used for monitoring the water content and carbon dioxide concentration of the steel slag in the dense-phase carbonization tower, and adjusting the adding amount of water, additives and / or steel slag powder in real time according to the monitoring result; and the finished product bin is used for collecting the carbonized steel slag from an ash bucket and the intermediate bin. The application realizes large-scale continuous steel slag carbonization reaction and efficient recycling of the steel slag.

Description

Technical Field

[0001] This invention relates to the field of industrial waste treatment technology, and in particular to a dense phase steel slag carbonization device. Background Technology

[0002] China's annual crude steel production in 2023 is approximately 1 billion tons, accounting for more than 50% of the global total. Steel slag, as a byproduct of the steelmaking process, accounts for about 15% to 20% of crude steel emissions.

[0003] Steel slag contains approximately 40% calcium (Ca), making it suitable as a substitute for cement and natural aggregates in concrete. The Ca in steel slag exists as free calcium oxide and calcium silicate, which react with CO2 to form CaCO3. The dissolution of free calcium oxide is beneficial for the stabilization of steel slag and improves its utilization performance. Therefore, steel slag carbonization technology not only solidifies a large amount of CO2 but also enables the effective utilization of secondary resources. Building materials such as bricks and tiles prepared using this technology have advantages such as high strength, low price, and good stability.

[0004] Current steel slag carbonization technology mainly involves placing steel slag into bricks and then carbonizing them in a CO2 curing chamber (CN111763786A, CN116514476A, CN113955999A). On the one hand, this method has drawbacks such as long reaction time, poor carbon fixation ability, complex carbonization process, and high requirements for temperature and atmosphere. On the other hand, the formed brick products are not suitable for road and underground mine filling scenarios, which limits the widespread use of carbonized steel slag. Summary of the Invention

[0005] In view of this, the present application provides a dense phase steel slag carbonization device to solve at least one problem existing in the background art, so as to achieve efficient steel slag powder carbonization and realize large-scale continuous steel slag carbonization reaction.

[0006] In a first aspect, one embodiment of this application provides a dense-phase steel slag carbonization apparatus, comprising:

[0007] Bucket elevator, dense phase carbonization tower, spraying device, intermediate silo, finished product silo, and monitoring module;

[0008] The dense phase carbonization tower includes a flue gas inlet, a reaction chamber, a flue gas outlet, and an ash hopper; carbon dioxide-containing flue gas enters the reaction chamber from the flue gas inlet;

[0009] The bucket elevator is used to feed steel slag powder from the first conveying device into the dense phase carbonization tower;

[0010] The spraying device is used to spray water and additives into the reaction chamber of the dense phase carbonization tower;

[0011] The intermediate silo is located between the flue gas outlet and the finished product silo, and is used to screen and collect the steel slag output with the flue gas.

[0012] The reaction chamber is used to cause a three-phase carbonization reaction between the steel slag, water, and carbon dioxide entering the dense phase carbonization tower; the flue gas after the reaction is discharged from the flue gas outlet; the carbonized steel slag after the reaction is discharged with the flue gas and enters the intermediate silo.

[0013] The monitoring module is used to monitor the moisture content and carbon dioxide concentration of the steel slag in the dense phase carbonization tower, and adjust the amount of water, additives and / or steel slag powder added in real time according to the moisture content and carbon dioxide concentration.

[0014] The finished product bin is used to collect carbide steel slag from the ash hopper and the intermediate bin.

[0015] In conjunction with the first aspect of this application, in an optional embodiment, the dense-phase carbonization tower includes a rectification zone, a main reaction zone, a dynamic adjustment zone, and a reaction adjustment zone; the rectification zone is provided with a guide plate to ensure a uniform and stable flow field when flue gas and materials pass through the guide plate; the main reaction zone is used to complete most of the carbonization reaction; the dynamic adjustment zone is used for monitoring and optimizing the amount of reactants added; in the reaction adjustment zone, the monitoring module automatically adjusts the amount of reactants added based on the calculated amount of materials added.

[0016] In conjunction with the first aspect of this application, in an optional embodiment, the injection ports of the spray device are respectively located at the top, middle and bottom of the reaction chamber.

[0017] In conjunction with the first aspect of this application, in an optional embodiment, a dust collector is further included, which is connected to the intermediate chamber and is used to remove dust from the flue gas discharged from the intermediate chamber and discharge clean flue gas.

[0018] In conjunction with the first aspect of this application, in an optional embodiment, a chimney is further included, connected to the dust collector via a fan, for discharging the dust-collected flue gas.

[0019] In conjunction with the first aspect of this application, in an optional embodiment, a flexible stirring device is further included, disposed within the reaction chamber, for fully reacting the water, the additive, and / or the steel slag powder.

[0020] In conjunction with the first aspect of this application, in an optional embodiment, a fluidization device is further included, connected between the chimney and the bottom ash hopper of the dense phase carbonization tower, for recirculating a portion of the flue gas discharged from the chimney back to the ash hopper.

[0021] In conjunction with the first aspect of this application, in an optional embodiment, the first conveying device is disposed below the dense phase carbonization tower for conveying the steel slag powder discharged from the bottom ash hopper of the dense phase carbonization tower back to the bucket elevator.

[0022] In conjunction with the first aspect of this application, in an optional embodiment, a second conveying device is provided below the dust collector for conveying the carbide steel slag collected by the dust collector to the finished product silo.

[0023] In conjunction with the first aspect of this application, in an optional embodiment, the monitoring module is connected to a flow meter, a regulating valve, a water pump, and a bucket elevator control device, respectively, for controlling the water output of the spraying device, the solvent flow rate, and the steel slag conveying speed of the bucket elevator.

[0024] A dense-phase carbonization tower was used to perform a three-phase carbonization reaction on steel slag powder, achieving large-scale continuous carbon fixation of steel slag, efficient recycling of steel slag, and reduction of carbon emissions. It has advantages such as fast reaction rate, less stringent requirements on reaction atmosphere and temperature, simple equipment, and no secondary pollution. A monitoring module monitors the moisture content and carbon dioxide concentration of the steel slag inside the tower, and adjusts the injection rates of water and additives, as well as the steel slag delivery rate, in real time, further improving the carbonization effect.

[0025] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0027] Figure 1 This is a schematic diagram of the structure of a dense phase steel slag carbonization device provided in an embodiment of this application. Detailed Implementation

[0028] To make the technical solutions and beneficial effects of this application more apparent and understandable, the technical solutions in the embodiments of this application are clearly and completely described below by listing specific examples. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Unless otherwise defined, 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 application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0030] It should be noted that the terms "first," "second," etc., used in this application may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element, and not to describe a specific order or sequence.

[0031] It is understood that in the context of this application, "connection" means that there is an electrical signal or data transmission between the connected end and the connected end, which can be understood as "electrical connection", "communication connection", etc. In the context of this application, "A and B are directly connected" means that there are no other components between A and B except for wires.

[0032] This application provides a dense phase steel slag carbonization device, including: a bucket elevator 3, a dense phase carbonization tower 4, a spraying device 6, an intermediate silo, a finished product silo 18, and a monitoring module 8. The bucket elevator 3 is used to feed steel slag powder from a first conveying device 23 into the dense phase carbonization tower. The bucket elevator 3 lifts the steel slag powder 17 to the top of the dense phase carbonization tower 4 and feeds it into the dense phase carbonization tower 4 through a steel slag inlet 42. The bucket elevator 3 is selected from types such as ring chain bucket elevators, plate chain bucket elevators, or belt bucket elevators. The bucket elevator 3 is controlled by a bucket elevator control device to control the steel slag conveying speed.

[0033] The dense-phase carbonization tower 4 includes a flue gas inlet 41, a steel slag inlet 42, a reaction chamber 40, a flue gas outlet 45, and an ash hopper. The flue gas inlet 41, steel slag inlet 42, and spray device 6 are located at the top of the carbonization tower 4. An intermediate chamber 16 is located between the flue gas outlet 45 and the finished product chamber 18, used for screening and collecting the steel slag output with the flue gas. The dense-phase carbonization tower 4 is used to ensure sufficient reaction between the steel slag and the flue gas. Optionally, the dense-phase carbonization tower 4 is cylindrical.

[0034] Carbon dioxide-containing flue gas enters the reaction chamber 40 through the flue gas inlet 41. The spray device 6 sprays water and additives into the dense-phase carbonization tower 4 to slurry the steel slag, thereby improving carbonization efficiency. The reaction chamber 40 is used to allow the steel slag, water, and carbon dioxide entering the dense-phase carbonization tower 4 to undergo a three-phase carbonization reaction. The reacted flue gas is discharged from the flue gas outlet 45. The reacted carbonized steel slag, after being discharged from the flue gas outlet 45 with the flue gas, enters the intermediate chamber 16. Preferably, the spray device 6 has multiple injection ports, respectively located at the top, middle, and bottom of the reaction chamber 40 of the dense-phase carbonization tower 4, to further improve carbonization efficiency.

[0035] The dense-phase carbonization tower 4 contains flexible stirring devices 7 located within the reaction chamber 40. These devices ensure the thorough reaction of water, additives, and / or steel slag powder. The flexible stirring devices 7 drive the steel slag powder slurry to rotate and flow, ensuring a thorough and uniform reaction between the gas and the rotating slurry. This prevents slurry accumulation and agglomeration, and also prevents turbulence. The stirring paddles of the flexible stirring devices 7 are mounted on a stirring shaft, and the number of paddles can be one, two, or more. The flexible stirring devices 7 can be selected from anchor type, propeller type, disc type, turbine type, ribbon type, paddle type, etc.

[0036] The monitoring module 8 is used to monitor the moisture content and carbon dioxide concentration of the steel slag in the dense phase carbonization tower 4, and to adjust the amount of water, additives, and / or steel slag powder added in real time according to the moisture content and carbon dioxide concentration to achieve the best steel slag carbonization effect. Preferably, the monitoring module 8 is set in the middle and lower part of the dense phase carbonization tower 4 to improve the accuracy of monitoring. The monitoring module 8 set in the middle is used to monitor the carbon dioxide concentration and steel slag moisture, and feeds back to the bucket elevator 3 and water flow meter 14 to adjust the steel slag feeding speed and humidification amount. The monitoring module 8 set in the lower part is used to monitor the steel slag moisture to ensure that the steel slag is in a dry state when it enters the intermediate silo 16. The bottom of the dense phase carbonization tower 4 is connected to part of the flue gas outlet of the chimney 10, so that the bottom steel slag can react fully again and prevent steel slag caking. The steel slag deposited in the carbonization tower 4 is returned to the bucket elevator 3 via the first conveying device 23.

[0037] The monitoring module 8 is connected to the flow meter 14, the regulating valve 13, the water pump 12, and the bucket elevator control device. The monitoring module 8 controls the water output and solvent flow of the spray device 6 based on the flow meter 14. The water pump 12 is connected to the water tank 11 and the solvent tank 15, which are connected in parallel.

[0038] Dust collector 1 is used to separate the dust from the flue gas containing steel slag powder. Optionally, dust collector 1 includes an electrostatic precipitator or a bag filter. The size of dust collector 1 is selected according to the flue gas volume.

[0039] The second conveying device 24 is located below the dust collector 1 and is used to transport steel slag powder to the finished product silo 18. Optionally, the second conveying device 24 includes belt conveyor, screw conveyor, pipeline conveyor, etc.

[0040] The fluidization device 21 is located around the bottom ash hopper of the dense phase carbonization tower 4. Part of the flue gas emitted from the chimney returns to the dense phase carbonization tower 4 through the root valve 19 and check valve 20, regulating the flue gas flow rate to fluidize the steel slag falling into the ash hopper and prevent caking. Optionally, the fluidization device 21 includes a hopper fluidizer, a disc fluidizer, or a dish fluidizer. If the steel slag solvent in the bottom ash hopper of the dense phase carbonization tower 4 accumulates and cakings, it will affect system operation and reduce carbonization efficiency. The fluidization device 21 draws part of the flue gas from the chimney outlet back into the ash hopper, causing the steel slag to re-fluidize and, after sufficient carbonization, enter the intermediate silo 16. The angle of repose of the steel slag is generally 50-60°, therefore the ash hopper angle is greater than or equal to 60°.

[0041] The steel slag adding device 22 is used to add steel slag into the first conveying device 23. Optionally, a magnetic separator can be added to the front end of the steel slag adding device 22. The first conveying device 23 conveys the steel slag to the bucket elevator 3.

[0042] The dense phase carbonization tower 4 and the dust collector 1 are connected by an intermediate chamber 16. The intermediate chamber 16 serves as an inertial settling device to classify particles by size and extend the service life of the dust collector. During the process of flue gas and steel slag being sent from the dense phase carbonization tower 4 into the dust collector 1, the carbonized steel slag falls into the intermediate chamber 16 due to gravity as it passes through it. Different intermediate chambers 16 at different locations can collect carbonized steel slag with different particle size distributions.

[0043] The dust collector 1 is also connected to the chimney 10 via a fan 9. The fan 9 can increase the gas pressure to facilitate gas discharge.

[0044] The finished product silo 18 is used to collect carbonized steel slag from the bottom ash hopper of the dense phase carbonization tower 4 and the intermediate silo 16. The carbonized steel slag collected in the ash hopper by the dust collector 1 is transported to the finished product silo 18 for storage via the second conveying device 24.

[0045] The reaction chamber 40 of the dense phase carbonization tower 4 includes five areas: rectification zone 401, main reaction zone 402, dynamic adjustment zone 403, reaction adjustment zone 404, and fluidization zone 405. The water output, solvent flow rate and steel slag conveying speed of the bucket elevator 3 are controlled by the monitoring module 8, thereby dynamically adjusting the reaction conditions.

[0046] The rectifying zone is equipped with guide vanes to ensure a uniform and stable flow field as flue gas and materials pass through, minimizing eddies. The main reaction zone completes most of the carbonization reaction. The dynamic adjustment zone monitors and optimizes the amount of reactants added. The monitoring module calculates the actual required amounts of water, additives, and steel slag to ensure optimal carbonization efficiency with minimal energy and material consumption. In the reaction adjustment zone, the monitoring module automatically adjusts the reactant addition amount based on the calculated material addition amount to ensure the steel slag at the flue gas outlet is dry.

[0047] The working principle of the dense phase steel slag carbonization device in this application embodiment is as follows:

[0048] After dust removal, the flue gas discharged from the sintering machine enters the dense phase carbonization tower 4 through flue gas inlet 41. Simultaneously, a bucket elevator 3 lifts steel slag powder to the top of the dense phase carbonization tower 4. Water and solvent additives pass sequentially through a water pump 12, a regulating valve 13, and a flow meter 14 before being injected into the dense phase carbonization tower 4 via a spray device 6. The injection points are the top and sides of the carbonization tower, and multiple spraying points can be arranged according to production needs.

[0049] The spraying point at the top, through continuous addition of water and solvent additives, mixes and reacts with steel slag powder, which then undergoes a carbonization reaction with carbon dioxide in the flue gas to achieve decarbonization.

[0050] The flue gas and solid reactants flow in the same direction, from the top of the tower to the bottom. The dust-laden flue gas after decarbonization enters the intermediate silo 16 and falls into the ash hopper of the intermediate silo 16 in stages according to the particle size from large to small, resulting in carbonized steel slag.

[0051] Dust-laden flue gas enters the dust collector 1 from the intermediate silo 16 and is then discharged. Steel slag powder falling into the lower ash hopper of the dense phase carbonization tower 4 is periodically cleaned and then enters the first conveying device 23, before re-entering the bucket elevator 3 for the next cycle. Through multiple cycles of carbonization, the carbonization effect of the steel slag is improved.

[0052] The monitoring module 8 is located inside the carbonization tower and is used to monitor the moisture content and carbon dioxide concentration of the steel slag inside the tower. It feeds back the data to the flow meter 14 and the bucket elevator 3, and adjusts the injection volume of water and solvent additives and the conveying volume of steel slag in real time to achieve the best steel slag carbonization effect.

[0053] The flexible stirring device 7 inside the dense phase carbonization tower 4 has a power source at its upper end. The power source drives the stirring device 7 inside the carbonization tower to start stirring. The stirring device 7 drives the steel slag powder slurry to rotate and flow. The plate-type stirring blades on the stirring device 7 diffuse the gas again, and then react fully and evenly with the rotating slurry. The rotating slurry forms a vortex as it passes through the inner wall of the carbonization tower, and reacts evenly with the gas again. The slurry and gas pass through the rectification zone 401, the main reaction zone 402, the dynamic adjustment zone 403, and the reaction adjustment zone 404 in sequence. At the same time, the humidity, the amount of additive injected, and the steel slag feed rate are adjusted to ensure the best carbonization effect.

[0054] The carbonized steel slag enters the intermediate silo 16 in descending order of particle size, while the gas enters the dust collector 1 and is discharged from the chimney by the fan. Part of the flue gas from the chimney outlet is guided back to the bottom of the dense phase carbonization tower 4 to fluidize the steel slag falling to the bottom of the dense phase carbonization tower 4, preventing the ash hopper from accumulating and caking, and ensuring that the steel slag is fully carbonized.

[0055] The carburized steel slag collected in the intermediate silo 16 and the dust collector 1 hopper eventually enters the finished product silo 18. The steel slag entering the bottom hopper of the dense phase carburization tower 4 is periodically cleaned and reintroduced into the bucket elevator 3.

[0056] Leveraging the advantages of dense-phase dry tower technology for complete gas-solid-water three-phase reaction, and considering the technical requirements of steel slag carbonization, a monitoring module 8 is added to simultaneously detect the moisture content and gaseous carbon dioxide content of the steel slag. Compared with the traditional steel slag curing box process, this device is more flexible, achieves a more complete and efficient carbonization reaction, and is more suitable for steel slag carbonization in industrial flue gas and industrial production processes, thus promoting the large-scale development and application of steel slag carbonization technology.

[0057] The relevant content of each unit in this embodiment can be referred to the relevant content of the units with the same reference numerals in any of the foregoing embodiments, and will not be repeated here.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A dense-phase steel slag carbonization device, characterized in that, include: Bucket elevator, dense phase carbonization tower, spraying device, intermediate silo, finished product silo, and monitoring module; The dense phase carbonization tower includes a flue gas inlet, a steel slag inlet, a reaction chamber, a flue gas outlet, and an ash hopper; carbon dioxide-containing flue gas enters the reaction chamber from the flue gas inlet; The bucket elevator is used to feed steel slag powder from the first conveying device into the dense phase carbonization tower; The spraying device is used to spray water and additives into the reaction chamber of the dense phase carbonization tower; The intermediate silo is located between the flue gas outlet and the finished product silo, and is used to screen and collect the steel slag output with the flue gas. The reaction chamber is used to cause a gas-solid-water three-phase carbonization reaction of steel slag powder, water and carbon dioxide entering the dense phase carbonization tower; the flue gas after the reaction is discharged from the flue gas outlet; the carbonized steel slag after the reaction is discharged with the flue gas and enters the intermediate silo. The monitoring module is used to monitor the moisture content and carbon dioxide concentration of the steel slag in the dense phase carbonization tower, and adjust the amount of water, additives and / or steel slag powder added in real time according to the moisture content and carbon dioxide concentration. The finished product bin is used to collect carbide steel slag from the ash hopper and the intermediate bin.

2. The dense-phase steel slag carbonization device according to claim 1, characterized in that, The dense phase carbonization tower includes a rectification zone, a main reaction zone, a dynamic adjustment zone, and a reaction adjustment zone; the rectification zone is equipped with a guide plate to ensure that the flow field is uniform and stable when the flue gas and materials pass through the guide plate; The main reaction zone is used to complete most of the carbonization reaction; the dynamic adjustment zone is used to monitor and optimize the amount of reactants added; in the reaction adjustment zone, the monitoring module automatically adjusts the amount of reactants added based on the calculated amount of materials added.

3. The dense-phase steel slag carbonization device according to claim 1, characterized in that, The injection ports of the spray device are respectively located at the top, middle and bottom of the reaction chamber.

4. The dense-phase steel slag carbonization device according to claim 1, characterized in that, It also includes a dust collector, which is connected to the intermediate chamber, for removing dust from the flue gas discharged from the intermediate chamber and discharging clean flue gas.

5. The dense-phase steel slag carbonization device according to claim 4, characterized in that, It also includes a chimney, which is connected to the dust collector via a fan, for discharging the dust-collected flue gas.

6. The dense-phase steel slag carbonization device according to claim 1, characterized in that, It also includes a flexible stirring device, which is disposed in the reaction chamber to ensure that the water, the additive and / or the steel slag powder react fully.

7. The dense-phase steel slag carbonization device according to claim 5, characterized in that, It also includes a fluidization device connected between the chimney and the bottom ash hopper of the dense phase carbonization tower, for returning a portion of the flue gas discharged from the chimney to the ash hopper.

8. The dense-phase steel slag carbonization device according to claim 1, characterized in that, The first conveying device is located below the dense phase carbonization tower and is used to convey the steel slag powder discharged from the bottom ash hopper of the dense phase carbonization tower back to the bucket elevator.

9. The dense-phase steel slag carbonization device according to claim 4, characterized in that, A second conveying device is provided below the dust collector for conveying the carbide steel slag collected by the dust collector to the finished product silo.

10. The dense-phase steel slag carbonization device according to claim 1, characterized in that, The monitoring module is connected to the flow meter, regulating valve, water pump and bucket elevator control device respectively, and is used to control the water output of the spraying device, the solvent flow rate and the steel slag conveying speed of the bucket elevator.

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