Vertical mineralization reactor, system and method for preparing artificial aggregates from CO2

Abstract

The present application relates to a vertical mineralization reactor, system and method for preparing artificial aggregate from mineralized CO2, the reactor comprising a body provided with a shaped green body inlet, a mineralized aggregate outlet, a flue gas inlet and a tail gas outlet; a moving bed and a fixed bed are arranged in the reaction cavity, the shaped green body entering the reaction cavity passes through the moving bed and then enters the fixed bed; the moving bed comprises a plurality of inclined and staggered sieve trays, and the shaped green body moves step by step on the sieve trays. The moving bed can slow down the impact of the green body, prolong the flow path of the shaped green body and CO2, increase the gas-solid two-phase countercurrent contact time to promote the mass transfer process, and improve the product qualification rate; the fixed bed can ensure the uniformity and mechanical properties of the product. The vertical reactor can save space, and the system integrated with the reactor can realize low-cost carbon capture and utilization by directly mineralizing low-concentration flue gas CO2 from solid waste, low-temperature micro-positive pressure mineralization curing can reduce the operation energy consumption, and fresh flue gas and atomized water can improve the mineralization efficiency.

Description

Technical Field

[0001] This invention relates to the resource utilization of industrial solid waste, specifically to the field of carbon dioxide utilization and storage technology, and particularly to a vertical mineralization reactor, system and method for preparing artificial aggregates from mineralized CO2. Background Technology

[0002] CO2 mineralization technology achieves CO2 utilization and storage by simulating and accelerating the natural carbon sequestration process, creating economically valuable products. It has significant application potential in the synergistic treatment of carbon emission reduction and solid waste reduction. Currently, the key parameters (reaction temperature, reaction pressure, reaction time, curing time, CO2 concentration and pressure, etc.) and reaction mechanisms of CO2 mineralization technology for preparing green building materials from industrial solid waste have been studied to a certain extent. Existing technical solutions mostly use high-purity CO2 after capture, which is costly; mineralization curing is carried out under high temperature or high pressure conditions, resulting in high energy consumption; the key equipment, the mineralization reactor, is mostly an intermittent mineralization curing vessel modified from a horizontal autoclave, which occupies a large area; the contact between CO2 gas and solid waste in the mineralization reactor is poor, resulting in low mineralization efficiency, and the mass transfer process of the mineralization reaction needs to be further enhanced.

[0003] Invention CN115677248B provides a carbon-fixed lightweight aggregate and its preparation method, utilizing powdered solid waste such as fly ash and construction waste residue to prepare recycled aggregate. This process simultaneously disposes of the solid waste and solidifies CO2. The mineralization curing temperature is 480~510 ℃. In the mineralization reactor, the lightweight aggregate green body moves in opposite directions to the hot flue gas, and the lightweight aggregate is transported using a conveyor belt or screw. This method requires relatively high energy consumption. Invention CN119591372A provides a carbon-mineralized artificial stone based on solid waste and its preparation process. This method employs pre-mineralization and staged mineralization methods, with a mineralization pressure of 0.1~0.7 MPa. The process is relatively complex and requires a larger area. Therefore, there is an urgent need to develop a low-energy, low-cost CO2 mineralization method and a corresponding compact and efficient continuous mineralization reactor.

[0004] Therefore, it is necessary to propose more reasonable technical solutions to address the technical problems existing in the current technology. Summary of the Invention

[0005] To address some of the problems existing in the prior art, this invention discloses a vertical mineralization reactor, system, and method for preparing artificial aggregates from mineralized CO2. By directly mineralizing and capturing CO2 from flue gas using industrial solid waste, a pre-forming and post-curing process is adopted. Atomized water is used to humidify fresh flue gas, providing a timely liquid phase environment to accelerate the mineralization reaction and improve mineralization efficiency. Mineralization and curing are carried out under low temperature and micro-positive pressure, avoiding the high energy consumption and high cost of flue gas capture.

[0006] To achieve the above objectives, the vertical mineralization reactor disclosed in this invention can adopt the following scheme:

[0007] A vertical mineralization reactor for preparing artificial aggregate from CO2 mineralization includes a main body forming a reaction chamber. A preform inlet and a tail gas outlet are located above the main body, while a mineralized aggregate outlet and a flue gas inlet are located below the main body. Within the reaction chamber, a flow path for the preform from top to bottom and a flow path for CO2 from bottom to top are formed. A moving bed and a fixed bed are arranged within the reaction chamber. The preform entering the reaction chamber passes through the moving bed and then enters the fixed bed. The moving bed includes several inclined, staggered perforated trays, along which the preform moves downwards to the next perforated tray.

[0008] The disclosed vertical mineralization reactor enables continuous feeding and processing. Molded feedstock and CO2 continuously undergo countercurrent contact reaction within the reactor to generate the final mineralized aggregate. By guiding the molten feedstock sequentially through a moving bed and a fixed bed, primary and secondary mineralization processes are achieved, ultimately yielding the mineralized aggregate. During this process, the inclined, staggered perforated trays limit the descent rate of the molten feedstock, causing it to travel along a zigzag flow path. This also guides the flow path of CO2, extending its travel time within the reaction chamber and allowing for more thorough contact and reaction with the molten feedstock. This enhances the mineralization degree of the molten feedstock, thereby improving the quality and efficiency of CO2 flue gas treatment and ensuring the quality and uniformity of the mineralized aggregate product. Furthermore, the entire process can be carried out under conventional temperature and pressure conditions without prior CO2 enrichment, achieving low-cost carbon capture and utilization through direct mineralization of solid waste to capture low-concentration CO2 in flue gas, making it simpler and more convenient.

[0009] Furthermore, the perforated tray is used to guide the formed material and CO2 and facilitate their mineralization reaction. Its specific arrangement can employ various schemes and is not limited to a single one. Here, we optimize and propose one feasible option: the perforated tray extends from the inner wall of the reaction chamber toward the interior of the chamber and deflects downwards by 1°~5°. Several perforations are formed on the perforated tray, with a consistent aperture ranging from 2mm to 4mm. These perforations are randomly distributed on the perforated tray. With this scheme, the perforations on each perforated tray are smaller than the particle size of the formed material and are randomly distributed in multiple locations. Some CO2 can pass through the perforated tray and mix with the formed material to react.

[0010] Furthermore, to guide more CO2 to countercurrent contact with the formed material and reduce CO2 directly passing through the sieve holes, the distribution of the sieve holes can be limited. Here, optimization is proposed, and one feasible option is to gradually increase the sieve hole density on a single sieve tray along the flow direction of the formed material. Using this scheme increases the contact time between CO2 and the formed material, thereby improving the degree of mineralization reaction. Further, to further control the flow rate of the formed material and reduce its impact on the sieve tray, the structure of the sieve tray can be improved. Here, optimization is proposed, and one feasible option is to install several vertical plates on the sieve tray surface, which are staggered to form a continuous obstruction for the downward movement of the formed material, thereby slowing down the rate at which the formed material moves down the sieve tray to the next sieve tray. When the above scheme is adopted, the vertical plate is set upright on the sieve tray, forming a blocking structure on the sieve tray. When the forming material passes through, it is blocked and guided to change its travel path. The forming material forms a Z-shaped travel path along the vertical plate on the sieve tray, thereby slowing down the travel speed of the forming material and avoiding its excessive speed, which may cause it to collide and break when it reaches the next sieve tray.

[0011] In some designs, the height of the upright plate is 5mm to 30mm.

[0012] Furthermore, the specific arrangement of the vertical plates can adopt various schemes, and its structure is not limited to one. Here, we optimize and propose one feasible option: the vertical plates are arranged in an alternating Z-shaped cross structure on the upper surface of the sieve tray to guide the flow path of the formed material and CO2 flue gas. When the above scheme is adopted, a certain gap is formed between the vertical plates to allow the formed material to pass through. When the formed material passes through the gap between the vertical plates, it forms a Z-shaped travel trajectory on the sieve tray, thereby extending the path of the formed material and the mineralization reaction time.

[0013] Furthermore, after the initial mineralization treatment in the moving bed, the formed material blank will continue to enter the fixed bed below for secondary mineralization. After the initial mineralization, the mineralized aggregate entering the fixed bed needs to be distributed as evenly as possible. This can be achieved by setting a distribution structure to ensure uniform distribution of the mineralized aggregate into the fixed bed. Here, we propose an optimization and one feasible option: an aggregate distributor is set between the moving bed and the fixed bed. The aggregate distributor includes a conical distribution surface with several distribution holes formed on the distribution surface. The distribution holes are spaced apart on the distribution surface to form several layers of annular distribution structures. After the formed material blank is mineralized in the moving bed, it becomes mineralized aggregate. The mineralized aggregate falls from the moving bed to the aggregate distributor, slides down the distribution surface, and falls through the distribution holes to the fixed bed for secondary mineralization. In the above scheme, the aggregate distributor is a convex cone shape. After the mineralized aggregate reaches the distribution surface, it slides down the distribution surface and falls into the fixed bed through the distribution holes during the slide.

[0014] Furthermore, when the mineralized aggregate is discharged from the fixed bed and the main body, the residence time of the mineralized aggregate in the fixed bed can be controlled by controlling the output rate. This can be achieved through various schemes; here, we optimize and propose one feasible option: an electrically controlled valve is installed at the mineralized aggregate outlet to control the opening degree of the outlet and adjust the discharge rate. In this scheme, the electrically controlled valve is connected to a controller, and the opening degree is adjusted by the controller's commands. The controller can be manually operated to generate commands, or it can automatically generate corresponding control commands based on system settings.

[0015] The above-described vertical mineralization reactor is disclosed. This invention also discloses a system for preparing artificial aggregates from mineralized CO2, integrating the aforementioned vertical mineralization reactor for preparing artificial aggregates from mineralized CO2, comprising:

[0016] The raw material pretreatment component is used to crush, grind, weigh, mix, and convey raw materials for granulation to obtain shaped material blanks;

[0017] A vertical mineralization reactor is used to receive shaped material blanks and use the shaped material blanks to mineralize CO2 to obtain mineralized aggregates.

[0018] The CO2 supply assembly is connected to the vertical mineralization reactor and used to supply CO2.

[0019] The exhaust gas treatment assembly is connected to the vertical mineralization reactor and used to treat the exhaust gas;

[0020] The feeding assembly is connected to the vertical mineralization reactor to process mineralized aggregates. It conveys qualified mineralized aggregates to the downstream for further application and conveys unqualified mineralized aggregates to the raw material pretreatment assembly as secondary raw materials.

[0021] The system disclosed above, after the raw materials are processed by the raw material pretreatment component, continues to carry out the mineralization reaction in the vertical mineralization reactor. The corresponding CO2 is introduced into the reactor for the reaction. After the mineralization reaction, the tail gas of the reaction is treated by gas-solid separation through the tail gas treatment component before being discharged, while the solid mineralized aggregate is screened and processed separately at the feeding component.

[0022] Furthermore, various configuration schemes for vertical mineralization reactors can be adopted, and their structure is not limited to a single one. Here, we optimize and propose one feasible option: the number of vertical mineralization reactors is greater than one, with multiple vertical mineralization reactors connected in series or in parallel. Using this scheme, setting up multiple vertical mineralization reactors can increase the degree of mineralization or the yield of mineralized aggregates. Specifically, connecting them in series increases the degree of mineralization reaction, while connecting them in parallel increases aggregate yield. Simultaneously, the vertical structure of the reactors saves floor space compared to traditional horizontal reactor structures, which is more conducive to the rational layout planning of the system.

[0023] This invention also discloses a method for preparing artificial aggregates, specifically a method for preparing artificial aggregates by mineralizing CO2, using the system for preparing artificial aggregates by mineralizing CO2 described above, including:

[0024] Raw material pretreatment: The raw materials to be treated are processed separately to obtain powders with a set particle size range;

[0025] Mixing process: Select pre-treated raw materials according to the set mass ratio, and select auxiliary materials according to the set ratio to mix them to obtain intermediate materials. Add an appropriate amount of process water during the mixing process.

[0026] Molding process: The intermediate material is granulated, and water is added during the granulation process to obtain the shaped material blank;

[0027] Mineralization curing: The shaped material is fed into a vertical mineralization reactor, and after passing through a moving bed multi-layer sieve tray, it falls into the fixed bed below; at the same time, CO2 with a concentration of 10%~30% is introduced from the bottom of the vertical mineralization reactor. After being moistened with 5~30% atomized water, the CO2 reacts with the shaped material in a countercurrent manner to obtain mineralized aggregate.

[0028] Discharge processing: The tail gas from the vertical mineralization reactor undergoes gas-solid separation treatment before being discharged, while the mineralized aggregates are screened. Qualified products are transported out for subsequent applications, while unqualified products are returned to the pretreatment section for reuse in production.

[0029] The above-disclosed method involves mineralization curing at 40℃~140℃, requiring no external heat source and exhibiting low energy consumption. The CO2 temperature is 60℃~120℃. The auxiliary materials used have a mass fraction of less than or equal to 5%, a particle size of 50μm~250μm, and the moisture required for the granulation process is approximately 10~30% of the intermediate material mass. The resulting granulated material has a solid particle size of 5mm~30mm.

[0030] Furthermore, in the specific reaction, the effect of mineralization reaction can be improved by controlling the reaction conditions in the reactor. Here, we optimize and propose one feasible option: during the reaction of CO2 with the molding material, the pressure in the reaction chamber is positive pressure of 5kPa~50kPa, and the reaction time is 0.5h~2h.

[0031] Compared with the prior art, some of the beneficial effects of the technical solution disclosed in this invention include:

[0032] The vertical mineralization reactor of this invention has a vertical structure, which saves space. Its internal moving bed can extend the flow path between the formed material and CO2, increase the contact time, promote the mass transfer mineralization reaction, improve the quality of the mineralized aggregate product, and enable continuous production. The system integrating this reactor can achieve low-cost carbon capture application by directly mineralizing low-concentration flue gas CO2 through solid waste. The use of low-temperature micro-positive pressure mineralization curing reduces operating energy consumption. The fresh flue gas and atomized water humidification process improves mineralization efficiency. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of the internal structure of a vertical mineralization reactor for preparing artificial aggregates from mineralized CO2.

[0035] Figure 2 This is a top view of a portion of the perforated tray.

[0036] Figure 3 Schematic diagram of the system and method for preparing artificial aggregates from mineralized CO2;

[0037] In the above attached figures, the meanings of each label are as follows:

[0038] 1. Main body; 2. Moving bed; 3. Perforated tray; 4. Aggregate distributor; 5. Fixed bed; 6. Condensate outlet; 7. Vertical plate; 8. Reinforcing ribs. Detailed Implementation

[0039] The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this embodiment.

[0040] In view of the many shortcomings of the existing CO2 mineralization technology, the following embodiments are optimized and overcome the defects of the existing technology.

[0041] Example 1

[0042] like Figure 1 , Figure 2 As shown, this embodiment provides a vertical mineralization reactor for preparing artificial aggregates from mineralized CO2. It includes a body 1 forming a reaction chamber. A preform inlet and a tail gas outlet are provided above the body 1, and a mineralized aggregate outlet and a flue gas inlet are provided below the body 1. A flow path for the preform from top to bottom and a flow path for CO2 from bottom to top are formed in the reaction chamber. A moving bed 2 and a fixed bed 5 are provided in the reaction chamber. The preform entering the reaction chamber passes through the moving bed 2 and then enters the fixed bed 5. The moving bed 2 includes several inclined and staggered sieve trays 3. The preform moves downward along the sieve trays 3 to the next sieve tray 3.

[0043] Preferably, in this embodiment, the reactor combines a moving bed 2 and a fixed bed 5 structure, with a height-to-diameter ratio of 3 to 10.

[0044] The vertical mineralization reactor disclosed in this embodiment guides the shaped material pellets sequentially through a moving bed 2 and a fixed bed 5, achieving primary and secondary mineralization treatments respectively, ultimately yielding mineralized aggregates. During this process, the inclined, staggered screen plates 3 limit the downward flow rate of the shaped material pellets, causing them to travel along a Z-shaped flow path. Simultaneously, the flow path of CO2 is guided, also causing CO2 to travel along a Z-shaped path. Some CO2 flows upward through the screen holes, extending its travel time within the reaction chamber. This results in a larger contact area between the shaped material pellets and CO2, allowing for more thorough contact and reaction, thus enhancing the mineralization degree of the pellets. This improves the treatment quality and efficiency of CO2 flue gas. Furthermore, the entire process can be carried out under conventional temperature and slightly positive pressure conditions without prior CO2 enrichment. Direct mineralization of solid waste to capture low-concentration CO2 in flue gas achieves low-cost carbon capture and utilization, making it simpler and more convenient.

[0045] The perforated tray 3 is used to guide the formed material and CO2 and facilitate their mineralization reaction. Its specific arrangement can employ various schemes and is not limited to a single one. This embodiment optimizes and adopts one feasible option: the perforated tray 3 extends from the inner wall of the reaction chamber toward the interior of the chamber and deflects downwards by 1°~5°. Several perforations are formed on the perforated tray 3, with a consistent aperture ranging from 2mm to 4mm. The perforations are randomly distributed on the perforated tray 3. With this scheme, the perforations on each perforated tray 3 are smaller than the particle size of the formed material and are randomly distributed in multiple locations. Some CO2 can pass through the perforated tray 3 through the perforations and mix with the formed material to react.

[0046] To guide more CO2 to countercurrent contact with the molded blank and reduce CO2 directly passing through the sieve holes, the distribution of the sieve holes can be limited. This embodiment optimizes this by adopting one feasible option: such as... Figure 2 As shown, the sieve aperture density on a single sieve tray 3 gradually increases along the flow direction of the formed material. This design increases the contact time between CO2 and the formed material, thereby enhancing the degree of mineralization reaction.

[0047] To further control the flow rate of the formed material and reduce its impact on the perforated tray 3, the structure of the perforated tray 3 can be improved. This embodiment optimizes this by employing one feasible option: several vertical plates 7 are provided on the perforated tray 3. These plates are staggered on the surface of the perforated tray 3 to continuously obstruct the downward movement of the formed material, thereby slowing down its movement to the next perforated tray 3. With this scheme, the vertical plates 7 are erected on the perforated tray 3, forming a blocking structure. When the formed material passes through, it is blocked and guided to change its path. The formed material forms a Z-shaped path along the vertical plates on the perforated tray, thus slowing down its movement and preventing it from colliding and breaking upon reaching the next perforated tray.

[0048] In some designs, the height of the upright plate 7 is 5mm to 30mm.

[0049] Preferably, in this embodiment, a reinforcing rib 8 is provided at the sieve plate 3 to connect the sieve plate 3 with the inner wall of the reaction chamber.

[0050] The specific arrangement of the vertical plates 7 can adopt various schemes, and its structure is not limited to one. This embodiment optimizes and adopts one feasible option: the vertical plates 7 are arranged in an alternating Z-shaped cross structure on the upper surface of the sieve tray 3 to guide the flow path of the formed material and CO2 flue gas. When the above scheme is adopted, a certain gap is formed between the vertical plates 7 to allow the formed material to pass through. When the formed material passes through the gap between the vertical plates 7, it forms a Z-shaped travel trajectory on the sieve tray 3, thereby prolonging the path of the formed material and the mineralization reaction time.

[0051] After the initial mineralization treatment in the moving bed 2, the formed material blank will continue to the fixed bed 5 below for secondary mineralization treatment. After the initial mineralization, the mineralized aggregate entering the fixed bed 5 needs to be distributed as evenly as possible. This can be achieved by setting a distribution structure to ensure the uniform distribution of mineralized aggregate into the fixed bed 5. This embodiment optimizes and adopts one feasible option: an aggregate distributor 4 is set between the moving bed 2 and the fixed bed 5. The aggregate distributor 4 includes a conical distribution surface with several distribution holes formed on the distribution surface. The distribution holes are spaced apart on the distribution surface to form several layers of annular distribution structures. After the formed material blank is mineralized in the moving bed 2, it becomes mineralized aggregate. The mineralized aggregate falls from the moving bed 2 to the aggregate distributor 4, slides down the distribution surface, and falls through the distribution holes to the fixed bed 5 for secondary mineralization. In the above scheme, the aggregate distributor 4 is a convex cone shape. After the mineralized aggregate reaches the distribution surface, it slides down the distribution surface and falls onto the fixed bed 5 through the distribution holes during the slide.

[0052] Preferably, the diameter of the distribution holes on the aggregate distributor 4 is 5 mm to 30 mm.

[0053] Preferably, in this embodiment, a condensate outlet 6 is also provided below the main body 1 to discharge the condensate generated in the reaction chamber after a series of reactions.

[0054] When the mineralized aggregate is discharged from the fixed bed 5 and the main body, the residence time of the mineralized aggregate in the fixed bed 5 can be controlled by controlling the output rate. This can be achieved through various schemes. This embodiment optimizes and adopts one feasible option: an electrically controlled valve is installed at the mineralized aggregate outlet to control the opening degree of the mineralized aggregate outlet and adjust the discharge rate. When the above scheme is adopted, the electrically controlled valve is connected to a controller, and the opening degree is adjusted by the controller's instructions. The controller can be manually operated to generate instructions, or it can automatically generate corresponding control instructions according to the system settings.

[0055] In this embodiment, the continuous vertical mineralization reactor is a vertical reactor, which can significantly reduce the floor space by 25% to 40% compared to the traditional horizontal mineralization and curing kettle, which is beneficial for the engineering application of the technology.

[0056] Based on the solution provided in this embodiment, a practical case is given here for illustration.

[0057] Case 1

[0058] Fresh, low-concentration flue gas CO2 from industrial engineering is mixed with atomized water and enters the continuous vertical mineralization reactor through the side inlet pipe at the bottom, flowing upwards. It first passes through the aggregate layer of fixed bed 5; the unreacted shaped material continues to capture fresh flue gas CO2, improving product quality uniformity. After passing through fixed bed 5, some gas flows out through the holes in the perforated tray 3, reacting with the counter-flowing shaped material as it rolls; another portion flows through the gap between the perforated tray 3 and the reactor cylinder to the next tray, following a reverse "Z" shaped flow path. After multiple rolling contact reactions with the shaped material, the flue gas CO2 is discharged from the top after dust removal and purification.

[0059] The granulated material, after being pelletized, enters the upper moving bed reaction layer from the upper left feed inlet of the continuous vertical mineralization reactor via a conveyor belt or other conveyor device. The moving bed reaction layer contains multiple layers of alternating inclined perforated sieve trays 3. Under gravity, the granulated material falls slowly and orderly along a "Z"-shaped arrangement of stainless steel plates to the next stage tray. The material flows in a "Z"-shaped path in both the perforated sieve trays 3 and the moving bed layer 2 to increase its residence time in the reactor. After the granulated material and flue gas CO2 have fully contacted and reacted through the N-stage perforated sieve trays 3, it falls into the fixed bed layer 5, and then falls into the fixed bed layer 5 via the aggregate distributor 4 above it, continuing to undergo a secondary mineralization reaction with fresh, humidified flue gas CO2. An electrically controlled valve at the bottom of the reactor regulates the discharge rate, ensuring the continuity of the reaction process by controlling the feed and discharge rates of the mineralized aggregate. The condensate formed in the continuous vertical mineralization reactor is discharged through the bottom drain outlet.

[0060] Example 2

[0061] The above content discloses a vertical mineralization reactor, such as... Figure 3 As shown, this embodiment discloses a system for preparing artificial aggregates by mineralizing CO2, which integrates the vertical mineralization reactor for preparing artificial aggregates by mineralizing CO2 described above, including:

[0062] The raw material pretreatment component is used to crush, grind, weigh, mix, and convey raw materials for granulation to obtain shaped material blanks.

[0063] Preferably, the raw material pretreatment assembly includes a crusher, a ball mill, a weighing feeder, a mixer, a screw feeder, and a disc granulator connected in sequence.

[0064] A vertical mineralization reactor is used to receive shaped material blanks and use the shaped material blanks to mineralize CO2 to obtain mineralized aggregates.

[0065] The CO2 supply assembly is connected to the vertical mineralization reactor and used to supply CO2.

[0066] Preferably, the CO2 supply component includes a low-concentration CO2 gas source and an atomizing water component. When the low-concentration CO2 gas source supplies gas to the reactor, the atomizing water component can simultaneously humidify the CO2.

[0067] The exhaust gas treatment assembly is connected to the vertical mineralization reactor and used to treat the exhaust gas.

[0068] Preferably, the exhaust gas treatment component includes a bag filter, which performs gas-solid separation on the exhaust gas, collects the dust in the exhaust gas, and discharges the separated gas.

[0069] The feeding assembly is connected to the vertical mineralization reactor to process mineralized aggregates. It conveys qualified mineralized aggregates to the downstream for further application and conveys unqualified mineralized aggregates to the raw material pretreatment assembly as secondary raw materials.

[0070] Preferably, the feeding assembly includes a screening machine, which is used to screen out qualified products and unqualified products.

[0071] The system disclosed in this embodiment, after the raw material pretreatment component processes the raw material, continues to carry out the mineralization reaction in the vertical mineralization reactor. The corresponding CO2 is introduced into the reactor for the reaction. After the mineralization reaction, the tail gas of the reaction is treated by gas-solid separation through the tail gas treatment component before being discharged, while the solid mineralized aggregate is screened and processed separately at the feeding component.

[0072] There are various possible configuration schemes for vertical mineralization reactors, and their structure is not limited to a single one. This embodiment optimizes and adopts one feasible option: the number of vertical mineralization reactors is greater than one, and multiple vertical mineralization reactors are arranged in series or in parallel. Using the above scheme, setting up multiple vertical mineralization reactors can improve the mineralization effect; specifically, series connection increases the degree of mineralization reaction, while parallel connection increases aggregate yield. Simultaneously, the vertical structure of the reactors saves floor space compared to traditional horizontal reactor structures, which is more conducive to the rational layout planning of the system.

[0073] Example 3

[0074] like Figure 3 As shown, this embodiment discloses a method for preparing artificial aggregates. Specifically, the method for preparing artificial aggregates by mineralizing CO2 uses the system for preparing artificial aggregates by mineralizing CO2 described above, including:

[0075] S01. Raw material pretreatment: The raw materials to be treated are processed separately to obtain powders with a set particle size range;

[0076] S02. Mixing process: Select pre-treated raw materials according to the set mass ratio, and select auxiliary materials according to the set ratio to mix them to obtain intermediate materials. Add an appropriate amount of process water during the mixing process.

[0077] S03, Molding process: Granulation of intermediate material, with water added during granulation to obtain shaped material blank;

[0078] S04, mineralization curing: The shaped material is fed into the vertical mineralization reactor, and after reacting through the moving bed multi-layer sieve tray 3, it falls into the fixed bed 5 below; at the same time, CO2 with a concentration of 10%~30% is introduced from the bottom of the vertical mineralization reactor. After being moistened with 5~30% atomized water, the CO2 reacts with the shaped material in countercurrent contact to obtain mineralized aggregate.

[0079] S05. Discharge treatment: The tail gas of the vertical mineralization reactor is treated by gas-solid separation before being discharged. The mineralized aggregate is screened. Qualified products are transported out for subsequent applications, while unqualified products are returned to the pretreatment section for reuse in production.

[0080] The method disclosed in this embodiment involves mineralization curing at 40℃~140℃, requiring no external heat source and exhibiting low energy consumption. The CO2 temperature is 60℃~120℃. The auxiliary materials used have a mass fraction of less than or equal to 5%, a particle size of 50μm~250μm, and the moisture required for the granulation process of molding treatment is approximately 10~30% of the intermediate material mass. The solid particle size of the granulated material embryo is 5mm~30mm.

[0081] In the specific reaction, controlling the reaction conditions in the reactor can help improve the mineralization reaction effect. This embodiment optimizes and adopts one of the feasible options: during the reaction of CO2 with the molding material, the pressure in the reaction chamber is a slight positive pressure of 5kPa to 50kPa, and the reaction time is 0.5h to 2h.

[0082] According to the method disclosed in this embodiment, Case 2 is provided here for further explanation.

[0083] The first step is raw material pretreatment: One or more types of industrial solid waste transported from the stockpile are pretreated by a crusher and a ball mill to obtain solid powder with the particle size required for the mineralization reaction. The industrial solid waste can be desulfurization ash, steel slag, carbide slag, etc., with a particle size of 50μm~250μm and good reactivity.

[0084] After processing according to this step, a solid powder with a particle size of 50μm~250μm is obtained.

[0085] The second step is mixing: calculate the required mass of each type of industrial solid waste, add solid waste raw materials and auxiliary materials in a certain proportion, with the auxiliary material mass fraction being less than or equal to 5%. After weighing by a weighing feeder, add the materials to the mixer for mixing, and add a small amount of process water at the same time to reduce dust at the discharge.

[0086] In this step, solid waste raw materials are prepared according to a mixing ratio of 0.5 to 3 parts coal ash to 1 part coal slag.

[0087] The third step is forming: the uniformly mixed solid waste raw materials are fed into a granulator by a screw feeder for granulation, while the required moisture is provided at the same time. Granulation methods include molding, extrusion, disc granulation, extrusion-spheronization, etc., with a water-to-solid mass ratio of 0.1~0.3 and a pellet size of 5mm~30mm.

[0088] Step 4, mineralization curing: The shaped material is added from above the continuous vertical mineralization reactor via a conveyor belt or similar device. After reacting counter-currently with CO2 in the multi-layer tray structure, it falls orderly into the fixed-bed reactor below, where it is evenly distributed to the fixed-bed layer 5 via aggregate distributor 4 for a secondary mineralization reaction. A 15% CO2 solution and atomized water are mixed and introduced from the bottom side of the reactor at a humidification ratio of 5% to 30%, ensuring counter-current contact between the shaped material and the flue gas. The mineralization reaction temperature is 40℃ to 140℃, the reaction pressure is slightly positive (5kPa to 50kPa), and the residence time of the shaped material in the continuous mineralization reactor is 0.5h to 2h. The low-concentration CO2 source can be a coal-fired power plant, steel plant, cement kiln, or other large industrial emission source, with a CO2 concentration of 10% to 30% and a temperature of 60℃ to 120℃.

[0089] Step 5, Discharge: After curing, the dust-laden gas exiting the mineralization reactor enters a bag filter for gas-solid separation and is then sent back to the chimney for emission. The mineralized aggregate is screened from below the continuous mineralization reactor and transported to the product stockpile. Unqualified solid particles are returned to the pretreatment section for reprocessing.

[0090] The above are the embodiments listed in this example; however, this example is not limited to the optional embodiments described above; those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments; anyone can derive other various forms of embodiments under the guidance of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example; the scope of protection of this example should be determined by the claims.

Claims

1. A vertical mineralization reactor for preparing artificial aggregates by mineralizing CO2, characterized in that: The reaction chamber includes a main body (1) forming a reaction chamber. A molding material inlet and a tail gas outlet are provided above the main body (1), and a mineralized aggregate outlet and a flue gas inlet are provided below the main body (1). A flow path for the molding material from top to bottom and a flow path for CO2 from bottom to top are formed in the reaction chamber. A moving bed (2) and a fixed bed (5) are provided in the reaction chamber. The molding material entering the reaction chamber passes through the moving bed (2) and then enters the fixed bed (5). The moving bed (2) includes several inclined and staggered sieve trays (3). The molding material moves down along the sieve trays (3) to the next level sieve tray (3). The sieve plate (3) extends from the inner wall of the reaction chamber toward the inside of the reaction chamber and deflects downward by 1°~5°. Several sieve holes are formed on the sieve plate (3). The sieve hole diameter is consistent and takes a value within 2mm~4mm. The sieve holes are randomly distributed on the sieve plate (3). An aggregate distributor (4) is provided between the moving bed (2) and the fixed bed (5). The aggregate distributor (4) includes a conical distribution surface with several distribution holes formed on the distribution surface. The distribution holes are spaced apart on the distribution surface and form several layers of annular distribution structure. When the molded material blank passes through the moving bed (2) and is mineralized, mineralized aggregate is obtained. The mineralized aggregate falls from the moving bed (2) to the aggregate distributor (4), slides down along the distribution surface and falls from the distribution holes to the fixed bed (5) for remineralization.

2. The vertical mineralization reactor for preparing artificial aggregates from mineralized CO2 according to claim 1, characterized in that: The sieve hole density on a single sieve tray (3) gradually increases along the flow direction of the formed material.

3. The vertical mineralization reactor for preparing artificial aggregates from mineralized CO2 according to claim 1, characterized in that: The perforated tray (3) is provided with several vertical plates (7). The vertical plates (7) are arranged alternately on the surface of the perforated tray (3) to form a continuous obstruction for the downward movement of the forming material blank, so as to slow down the rate at which the forming material blank moves down the perforated tray (3) to the next level perforated tray (3).

4. The vertical mineralization reactor for preparing artificial aggregates from mineralized CO2 according to claim 3, characterized in that: The vertical plates (7) are arranged in an alternating pattern on the upper surface of the perforated tray (3) to form a Z-shaped cross structure, which is used to guide the flow path of the molding blank and CO2.

5. A system for preparing artificial aggregates by mineralizing CO2, integrating the vertical mineralization reactor for preparing artificial aggregates by mineralizing CO2 as described in any one of claims 1 to 4, characterized in that, include: The raw material pretreatment component is used to crush, grind, weigh, mix, and convey raw materials for granulation to obtain shaped material blanks; A vertical mineralization reactor is used to receive shaped material blanks and use the shaped material blanks to mineralize CO2 to obtain mineralized aggregates. The CO2 supply assembly is connected to the vertical mineralization reactor and used to supply CO2. The exhaust gas treatment assembly is connected to the vertical mineralization reactor and used to treat the exhaust gas; The feeding assembly is connected to the vertical mineralization reactor to process mineralized aggregates. It conveys qualified mineralized aggregates to the downstream for further application and conveys unqualified mineralized aggregates to the raw material pretreatment assembly as secondary raw materials.

6. The system for preparing artificial aggregate by mineralizing CO2 according to claim 5, characterized in that: The number of vertical mineralization reactors is greater than one, and multiple vertical mineralization reactors are arranged in series or in parallel.

7. A method for preparing artificial aggregates by mineralizing CO2, using the system for preparing artificial aggregates by mineralizing CO2 as described in claim 5 or 6, characterized in that, include: Raw material pretreatment: The raw materials to be treated are processed separately to obtain powders with a set particle size range; Mixing process: Select pre-treated raw materials according to the set mass ratio, and select auxiliary materials according to the set proportion to mix them to obtain intermediate material. Add an appropriate amount of process water during the mixing process. Molding process: The intermediate material is granulated, and water is added during the granulation process to obtain the shaped material blank; Mineralization curing: The shaped material is fed into the vertical mineralization reactor, and after reacting through the moving bed multi-layer sieve tray (3), it falls into the fixed bed (5) below; at the same time, CO2 with a concentration of 10~30% is introduced from the bottom of the vertical mineralization reactor. After being moistened with 5~30% atomized water, the CO2 reacts with the shaped material in countercurrent contact to obtain mineralized aggregate. Discharge processing: The tail gas from the vertical mineralization reactor undergoes gas-solid separation treatment before being discharged, while the mineralized aggregates are screened. Qualified products are transported out for subsequent applications, while unqualified products are returned to the pretreatment section for reuse in production.

8. The method for preparing artificial aggregate by mineralizing CO2 according to claim 7, characterized in that: During the reaction of CO2 with the molding blank, the pressure inside the reaction chamber is positive pressure of 5kPa~50kPa, and the reaction time is 0.5h~2h.

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