Industrial ash gradient utilization and carbon reduction synergistic system
The industrial ash cascade utilization and carbon reduction system has solved the problem of full-component utilization of ash and carbon dioxide emissions, and achieved efficient resource utilization and low-cost production of calcium carbonate and zeolite molecular sieves, reducing energy consumption and costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG UNIV
- Filing Date
- 2025-04-08
- Publication Date
- 2026-04-21
AI Technical Summary
Existing technologies make it difficult to achieve efficient utilization of all components of industrial ash and slag, and the direct emission of carbon dioxide from flue gas exacerbates the global greenhouse effect.
An industrial ash cascade utilization and carbon reduction system is adopted. Through fly ash pretreatment, CO2 mineralization and zeolite synthesis unit, the high-value utilization of calcium and silicon-aluminum components and carbon dioxide fixation are realized. The fly ash silicon-aluminum components are activated by amino acid-mediated cyclic leaching-mineralization process combined with the mechanochemical action of high-energy ball milling.
It achieves high-value utilization of all components of fly ash, with CO2 emission reduction efficiency up to 80%, energy consumption reduced by 50%, and cost reduced by 40%. It is adaptable to ash residues with different silicon-aluminum ratios, realizing efficient resource utilization and low-cost production of calcium carbonate and zeolite molecular sieves.
Smart Images
Figure CN224143147U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of solid waste resource utilization and environmental protection technology, specifically relating to a synergistic carbon reduction system for the cascade utilization of industrial ash and slag. Background Technology
[0002] With the rapid development of industrialization, the output of industrial ash (including fly ash from coal-fired power plants and fly ash from waste incineration) has continued to rise. It is estimated that by 2024, the national output of fly ash will reach 830 million tons, while the output of fly ash from waste incineration will reach 9.6 million tons. These ash residues are rich in beneficial elements such as calcium (Ca), silicon (Si), and aluminum (Al), but also contain small amounts of heavy metals and harmful components, making their treatment quite challenging. Traditionally, fly ash treatment mainly relies on landfill or solidification / stabilization technologies, but these methods have drawbacks such as low resource utilization, large land occupation, high treatment costs, and significant environmental risks. In recent years, some studies have begun to explore the possibility of using fly ash as a building material raw material, soil conditioner, or adsorbent material, but these attempts usually only utilize a single component of fly ash and have not yet achieved efficient utilization of all components. Furthermore, industrial flue gas contains a large amount of carbon dioxide (CO2), and its direct emissions will exacerbate the global greenhouse effect.
[0003] In light of this, we propose an innovative system that utilizes all components (Ca, Si, Al) in fly ash to synergistically treat CO2 in flue gas. This approach not only enables the resource utilization of solid waste but also effectively reduces carbon emissions, which is of great significance for both environmental protection and economic development. Utility Model Content
[0004] To address at least one of the aforementioned problems, this invention provides a synergistic carbon reduction system for the cascade utilization of industrial ash and slag.
[0005] To achieve the above objectives, the present invention employs the following technical means:
[0006] This utility model provides a cascade utilization and synergistic carbon reduction system for industrial ash and slag, comprising:
[0007] Fly ash pretreatment unit: includes a fly ash raw material silo, a washing tank, a first centrifuge, a sedimentation tank, a filter press, and a calcium-containing filtrate storage tank connected in sequence; the sedimentation tank is connected to a chemical precipitant tank, the first centrifuge performs solid-liquid separation on the washed fly ash from the washing tank to obtain fly ash sludge and calcium-rich washing liquid, the calcium-rich washing liquid enters the sedimentation tank, reacts with the chemical precipitant to remove heavy metals and then precipitates, the filter press performs solid-liquid separation, the filtrate enters the calcium-containing filtrate storage tank, and the filter residue enters the zeolite synthesis unit;
[0008] The CO2 mineralization unit includes a carbonation tower, a second centrifuge, and a first dryer connected in sequence. The carbonation tower is connected to the calcium-containing filtrate storage tank of the fly ash pretreatment unit. The carbonation tower is also equipped with a flue gas inlet pipe. The second centrifuge separates the calcium carbonate slurry obtained from the carbonation tower. The filtrate from the second centrifuge enters the filtrate recycling tank, and the calcium carbonate enters the first dryer. The CO2-containing flue gas enters the carbonation tower through the flue gas inlet pipe. The calcium-containing filtrate received by the carbonation tower absorbs the CO2 in the flue gas to obtain calcium carbonate slurry. Specifically, the reaction is that calcium carbonate ions dissolved in the liquid phase react to form calcium carbonate.
[0009] Amino acid storage tank: connected to the water washing tank and filtrate reuse tank of the fly ash pretreatment unit; the amino acid storage tank is connected to the water washing tank, which receives fly ash for water washing, desalination and detoxification treatment, and extracts calcium ions through selective complexation leaching of amino acids;
[0010] Zeolite synthesis unit: includes a ball mill, a third centrifuge and a second dryer connected in sequence. The third centrifuge separates the zeolite molecular sieve slurry obtained after ball milling. The solid enters the second dryer and the liquid is returned to the activator storage tank. The ball mill is connected to the filter press of the fly ash pretreatment unit to receive the silica-alumina residue in the filter press.
[0011] In some embodiments of this utility model, a sludge storage tank is also included, which is connected to the first centrifuge and is used to store fly ash sludge.
[0012] In some embodiments of this utility model, the ball mill is connected to the activator storage tank via a screw conveyor; the silicon-aluminum residue and activator received in the ball mill tank activate the silicon-aluminum components of fly ash through the mechanical force and chemical action of the ball mill to obtain zeolite molecular sieves.
[0013] In some embodiments of this utility model, the ball mill and the filter press are connected by a screw conveyor.
[0014] In some embodiments of this utility model, a carbon dioxide enrichment device is provided on the flue gas inlet pipe; the carbon dioxide enrichment device is used to enrich carbon dioxide in the flue gas of the waste incineration power plant to a concentration of ≥15%.
[0015] In some embodiments of this utility model, a bubble generator is also provided between the carbon dioxide enrichment device and the carbonation tower to circulate and generate carbon dioxide micro-nano bubbles, thereby enhancing the gas-liquid reaction for synthesizing calcium carbonate.
[0016] In some embodiments of this utility model, the washing tank is equipped with a metering pump for metering the added amino acids to ensure the concentration of amino acids in the aqueous solution.
[0017] In some embodiments of this utility model, the first centrifuge, the second centrifuge, and the third centrifuge are horizontal spiral centrifuges. The first centrifuge is connected to a washing tank and is used to separate the fly ash sludge and calcium-rich washing liquid after washing; the second centrifuge is connected to a carbonation tower and is used to receive and separate the calcium carbonate slurry obtained from the carbonation tower; the third centrifuge is connected to a ball mill and is used to receive and separate the zeolite molecular sieve slurry obtained from the ball mill.
[0018] In some embodiments of this utility model, the filter press is a plate and frame filter press; the ball mill is a high-energy vibrating ball mill; the dryer is a drum dryer; the first dryer is used to dry calcium carbonate slurry; and the second dryer is used to dry zeolite molecular sieve slurry.
[0019] Beneficial effects of this utility model
[0020] Compared with existing technologies, this invention has the following beneficial effects: This invention provides a cascade utilization and synergistic carbon reduction system for industrial fly ash. Through a cascade utilization approach, the calcium component in industrial fly ash is mineralized using CO2 to generate high-purity calcium carbonate, and the silicon and aluminum components in industrial fly ash are synthesized into zeolite molecular sieves through mechanochemical processes. In one system, high-value utilization of all fly ash components (calcium, silicon, and aluminum) and efficient CO2 fixation are achieved. In this system, through an amino acid-mediated cyclic leaching-mineralization process, a mineralization efficiency of ≥80% is achieved, CO2 emission reduction of ≥0.12 tons / ton of fly ash is achieved, and glycine regeneration rate of ≥85% is achieved, reducing carbon emissions, energy consumption, and raw material costs. The high-energy ball milling process directly activates the silica-alumina components in fly ash without requiring high-temperature and high-pressure hydrothermal conditions. This reduces energy consumption by 50% and zeolite synthesis costs by 40% compared to traditional hydrothermal methods. Furthermore, the activator components in the filtrate are recycled. Differentiated alkaline activators are used for fly ash with different silica-alumina ratios (high silica-alumina ratio in fly ash and low silica-alumina ratio in waste incineration fly ash), resulting in a wide range of process adaptability. Attached Figure Description
[0021] Figure 1 A schematic diagram of a synergistic carbon reduction system for the cascade utilization of industrial ash and slag is shown. Detailed Implementation
[0022] The following examples are used to illustrate preferred embodiments of the present invention. Those skilled in the art will understand that the techniques disclosed in the following examples represent technologies discovered by the inventor that can be used to implement the present invention, and therefore can be considered preferred embodiments for implementing the present invention. However, those skilled in the art should understand from this specification that many modifications can be made to the specific embodiments disclosed herein, still yielding the same or similar results, without departing from the spirit or scope of the present invention.
[0023] 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 invention pertains, and all materials disclosed herein and referenced therein are incorporated herein by reference. Many equivalent techniques of the particular embodiments of the invention described herein will be recognized or understood by those skilled in the art through conventional experimentation. These equivalents will be included in the claims.
[0024] The technical solution of this application will be further described in detail below with reference to specific embodiments.
[0025] Example 1
[0026] A cascade utilization and synergistic carbon reduction system for industrial ash and slag includes:
[0027] Fly ash pretreatment unit: includes a fly ash raw material silo, a washing tank, a first centrifuge, a sedimentation tank, a filter press, and a calcium-containing filtrate storage tank connected in sequence; the sedimentation tank is connected to a chemical precipitant tank, the first centrifuge performs solid-liquid separation on the washed fly ash from the washing tank to obtain fly ash sludge and calcium-rich washing liquid, the calcium-rich washing liquid enters the sedimentation tank, reacts with the chemical precipitant to remove heavy metals and then precipitates, the filter press performs solid-liquid separation, the filtrate enters the calcium-containing filtrate storage tank, and the filter residue is conveyed by a screw conveyor to the ball mill in the zeolite synthesis unit; the sludge storage tank is connected to the first centrifuge and is used to store fly ash sludge;
[0028] The CO2 mineralization unit includes a carbonation tower, a second centrifuge, and a first dryer connected in sequence. The carbonation tower is connected to the calcium-containing filtrate storage tank of the fly ash pretreatment unit. A flue gas inlet pipe is also installed on the carbonation tower. The second centrifuge separates the calcium carbonate slurry obtained from the carbonation tower. The filtrate from the second centrifuge enters the filtrate recycling tank, and the calcium carbonate enters the first dryer. The CO2-containing flue gas enters the carbonation tower through the flue gas inlet pipe. The calcium-containing filtrate received by the carbonation tower absorbs the CO2 in the flue gas to obtain calcium carbonate slurry. Specifically, the reaction is that calcium carbonate ions dissolved in the liquid phase react to form calcium carbonate.
[0029] Amino acid storage tank: connected to the water washing tank and filtrate reuse tank of the fly ash pretreatment unit; the amino acid storage tank is connected to the water washing tank, which receives fly ash for water washing, desalination and detoxification treatment, and extracts calcium ions through selective complexation leaching of amino acids;
[0030] Zeolite synthesis unit: includes a ball mill, a third centrifuge and a second dryer connected in sequence. The third centrifuge separates the zeolite molecular sieve slurry obtained after ball milling. The solid enters the second dryer. The ball mill is connected to the filter press of the fly ash pretreatment unit to receive the silica-alumina residue in the filter press. The ball mill is connected to the activator storage tank through a screw conveyor.
[0031] The washing tank is equipped with a metering pump to measure the added amino acids and ensure the concentration of amino acids in the aqueous solution. The first, second, and third centrifuges are horizontal screw centrifuges. The first centrifuge is connected to the washing tank and separates the fly ash sludge and calcium-rich washing liquid after washing; the second centrifuge is connected to the carbonation tower and receives and separates the calcium carbonate slurry obtained from the carbonation tower; the third centrifuge is connected to the ball mill and receives and separates the zeolite molecular sieve slurry obtained from the ball mill; the filter press is a plate and frame filter press; the ball mill is a high-energy vibrating ball mill; and the dryer is a drum dryer. The first dryer is used to dry the calcium carbonate slurry; the second dryer is used to dry the zeolite molecular sieve slurry.
[0032] Example 2
[0033] The other structures are the same as in Example 1, except that a carbon dioxide enrichment device is installed on the flue gas inlet pipe; the carbon dioxide enrichment device is used to enrich the carbon dioxide in the flue gas of the waste incineration power plant to a concentration of ≥15%.
[0034] Example 3
[0035] The other structures are the same as in Example 1, except that a bubble generator is further installed between the carbon dioxide enrichment device and the carbonization tower. Carbon dioxide is injected into the bubble generator at a flow rate of 1.5 L / min to process the carbon dioxide into carbon dioxide micro-nano bubbles (bubble particle size <100 μm). The resulting milky white bubble water is used for the mineralization of fly ash to synthesize calcium carbonate.
[0036] Example 4
[0037] Based on the industrial ash cascade utilization and synergistic carbon reduction system of Example 1, a method for the full-component cascade utilization of fly ash based on CO2 mineralization is provided, the steps of which are as follows:
[0038] S1, fly ash (CaO=12%, Si / Al=2.8) collected from fly ash raw material silo is sent to the water washing tank for water washing, desalination and detoxification treatment. Glycine in amino acid storage tank is transported to water washing tank. Calcium ions are extracted by glycine complexation. Glycine solution is added at a liquid-to-solid ratio of 10:1, and the amino acid concentration is ensured to be 1.5 mol / L.
[0039] S2, using the first centrifuge to separate the calcium-rich washing solution after washing in step S1;
[0040] S3, use a sedimentation tank to physically precipitate the calcium-rich washing liquid obtained in step S2, and add sodium sulfide from the chemical precipitant tank to the sedimentation tank to remove heavy metals from the washing liquid by adding sodium sulfide.
[0041] S4. Use a filter press to separate the solid and liquid components of the suspension treated in step S3 to obtain calcium-containing filtrate and silica-alumina residue.
[0042] S5, the carbonation tower receives the calcium-containing filtrate obtained in step S4 and the flue gas from the coal-fired power plant. The received calcium-containing filtrate absorbs CO2 from the flue gas in the carbonation tower to obtain calcium carbonate slurry.
[0043] S61, the calcium carbonate slurry obtained in step S5 is received by the second centrifuge and centrifuged to obtain calcium carbonate residue and glycine filtrate.
[0044] S62, the glycine filtrate obtained after mineralization separation in step S61 is received by the filtrate recycling tank, and the glycine is recovered to the amino acid storage tank for recycling.
[0045] S7, use the first dryer to dry the calcium carbonate slag obtained in step S61, and dry it at 110°C to obtain calcium carbonate product.
[0046] S81, the silicon-aluminum residue obtained in step S4 and the 2 mol / L sodium hydroxide solution in the activator storage tank are transported to the ball mill in a ratio of 1 g: 10 mL using a screw conveyor;
[0047] S82, the silicon-aluminum residue obtained in step S81 and the alkaline activator compound are mechanically ball-milled using a ball mill with ball mill speed of 400 rpm, ball milling time of 3 hours and ball-to-material mass ratio of 10:1 to obtain zeolite molecular sieve slurry.
[0048] S9. The zeolite molecular sieve slurry obtained in step S82 is received by the third centrifuge and centrifuged to obtain zeolite molecular sieve residue and waste liquid.
[0049] S10, the zeolite molecular sieve residue obtained in step S9 is dried using a second dryer at 110°C to obtain the zeolite molecular sieve product.
[0050] Example 5
[0051] The steps are the same as in Example 4, except that:
[0052] In step S1, the amino acid storage tank contains an aspartic acid solution with a concentration of 1 mol / L.
[0053] In step S81, the activator in the activator storage tank is a 3 mol / L sodium hydroxide solution.
[0054] Example 6
[0055] The steps are the same as in Example 4, except that:
[0056] In step S1, the fly ash from the waste incineration has the following composition: CaO = 38%, Si / Al = 1.56; the amino acid storage tank contains an aspartic acid solution with a concentration of 1.5 mol / L.
[0057] In step S5, the power plant flue gas is enriched to 15% CO2 by a carbon dioxide enrichment device.
[0058] In step S81, the activator in the activator storage tank is a 2 mol / L sodium silicate solution, which is delivered to the ball mill at a Si / Al ratio of 2.5.
[0059] In step S82, the ball mill speed is 600 rpm.
[0060] Example 7
[0061] The steps are the same as in Example 6, except that in step S5, the power plant flue gas is enriched to 15% by a carbon dioxide enrichment device; the enriched CO2 is processed into carbon dioxide micro-nano bubbles (bubble particle size <100 μm) by a bubble generator, and the flow rate of carbon dioxide injected into the bubble generator is 1.5 L / min.
[0062] The calcium carbonate products prepared in Examples 4-7 were pulverized, and the CaCO3 content in the products was tested according to GB / T 19281-2014 "Analytical Methods for Calcium Carbonate". Heavy metal leaching tests were carried out according to standard HJ / T 300-2007 "Leaching Toxicity of Solid Waste - Acetic Acid Buffer Solution Method". The specific surface area of the samples was analyzed using a fully automated specific surface area and porosity analyzer (BET). The CEC was used to measure the total cation adsorption capacity of the zeolite molecular sieve, which was determined according to the US Environmental Protection Agency 9081 method. Generally, the larger the CEC, the better the performance of the zeolite.
[0063] The performance test results of the calcium carbonate products in Examples 4-7 are shown in Table 1.
[0064] Table 1. Performance Test Results of Calcium Carbonate Products
[0065]
[0066] The performance test results of the zeolite products in Examples 4-7 are shown in Table 2.
[0067] Table 2. Performance Test Results of Zeolite Products
[0068]
[0069] As shown in Table 1, the calcium carbonate product prepared by this invention has high purity, and the heavy metal content in the product meets the standard of "Ordinary Industrial Precipitated Calcium Carbonate" (HG / T 2226-2019), making it suitable for rubber, coatings, papermaking, plastics and other fields.
[0070] As shown in Table 2, the P-type zeolite product prepared by this invention has a high specific surface area and strong ion exchange capacity, making it suitable for VOCs treatment, wastewater treatment and other fields, thus expanding the application scenarios of fly ash resource utilization.
[0071] All documents mentioned in this invention are incorporated herein by reference as if each document were individually incorporated by reference. Furthermore, it should be understood that after reading the foregoing teachings of this invention, those skilled in the art can make various alterations or modifications to this invention, and these equivalent forms also fall within the scope defined by this application.
Claims
1. A cascade utilization and synergistic carbon reduction system for industrial ash and slag, characterized in that, include: Fly ash pretreatment unit: includes a fly ash raw material silo, a washing tank, a first centrifuge, a sedimentation tank, a filter press, and a calcium-containing filtrate storage tank connected in sequence; the sedimentation tank is connected to a chemical precipitant tank, the first centrifuge performs solid-liquid separation on the washed fly ash from the washing tank to obtain fly ash sludge and calcium-rich washing liquid, the calcium-rich washing liquid enters the sedimentation tank, reacts with the chemical precipitant to remove heavy metals and then precipitates, the filter press performs solid-liquid separation, the filtrate enters the calcium-containing filtrate storage tank, and the filter residue enters the zeolite synthesis unit; CO2 mineralization unit: includes a carbonation tower, a second centrifuge and a first dryer connected in sequence. The carbonation tower is connected to the calcium-containing filtrate storage tank of the fly ash pretreatment unit. The carbonation tower is also equipped with a flue gas inlet pipe. The second centrifuge separates the calcium carbonate slurry obtained from the carbonation tower. The filtrate of the second centrifuge enters the filtrate recycling tank, and the solid calcium carbonate enters the first dryer. Amino acid storage tank: connected to the washing tank and filtrate reuse tank of the fly ash pretreatment unit; Zeolite synthesis unit: includes a ball mill, a third centrifuge and a second dryer connected in sequence. The third centrifuge separates the zeolite molecular sieve slurry obtained after ball milling. The solid enters the second dryer and the liquid is returned to the activator storage tank. The ball mill is connected to the filter residue output end of the filter press of the fly ash pretreatment unit.
2. The industrial ash cascade utilization synergic decarburization system according to claim 1, characterized in that, It also includes a sludge storage tank, which is connected to the first centrifuge and is used to store fly ash sludge.
3. The industrial ash cascade utilization synergic decarburization system according to claim 1, characterized in that, The ball mill is connected to the activator storage tank via a screw conveyor.
4. The industrial ash cascade utilization synergic decarburization system according to claim 3, characterized in that, The ball mill and the filter press are connected by a screw conveyor.
5. The industrial ash cascade utilization synergic decarburization system according to claim 1, characterized in that, A carbon dioxide enrichment device is installed on the flue gas inlet pipe.
6. The industrial ash cascade utilization synergic decarburization system according to claim 5, characterized in that, A bubble generator is also installed between the carbon dioxide enrichment device and the carbonization tower.
7. The industrial ash cascade utilization synergic decarburization system according to claim 1, characterized in that, The washing tank is equipped with a metering pump for measuring the added amino acids.
8. The industrial ash and slag cascade utilization and synergistic carbon reduction system according to claim 1, characterized in that, The first centrifuge, the second centrifuge, and the third centrifuge are horizontal spiral centrifuges.
9. The industrial ash cascade utilization synergic decarburization system according to claim 1, characterized in that, The filter press is a plate and frame filter press.
10. The industrial ash cascade utilization synergic decarburization system according to claim 1, characterized in that, The ball mill is a high-energy vibratory ball mill.