Preparation method of full-solid-waste nanometer synergistic self-compacting fluidized solidified soil solidifying agent
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG UNIV
- Filing Date
- 2026-05-22
- Publication Date
- 2026-06-19
AI Technical Summary
Existing fluidized solidified soil materials have poor anti-segregation performance under high fluidity, making it difficult to meet the requirements of self-compacting backfilling in narrow spaces. Furthermore, traditional silicate cement-based materials have high carbon emissions, making it difficult to achieve large-scale solid waste resource utilization and low-carbon green construction.
A method for preparing a solidified soil agent using nano-synergistic solid waste technology was adopted. Through multi-step modification treatment with nano-Si/Al oxide modifiers from solid waste sources, a structure was formed with an internal highly active nano-core, an intermediate organic modified layer, and an outer Ca/Fe/Al active shell, which enhanced the fluidity, anti-segregation performance, and mechanical stability of the solidified soil.
It significantly improves the fluidity and anti-segregation performance of solidified fluid under cement-free conditions, achieves the stability and self-compacting ability of slurry under high fluidity, reduces carbon emissions and costs, and meets the engineering quality requirements for construction in narrow spaces.
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Figure CN122233746A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials, specifically to a method for preparing a solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil. Background Technology
[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
[0003] With the rapid advancement of industrialization and urbanization in my country, the amount of industrial solid waste generated continues to rise. According to relevant statistics, the annual output of fly ash exceeds 600 million tons, blast furnace slag exceeds 250 million tons, and steel slag exceeds 120 million tons. Meanwhile, the total output of bulk solid wastes such as calcium carbide slag, desulfurization gypsum, waste incineration fly ash, and construction waste has exceeded 1 billion tons per year. This not only occupies a large amount of land resources but also causes environmental problems such as dust pollution and heavy metal leaching.
[0004] Traditional silicate cement-based fluidized bed solidification agents are widely used in projects such as foundation pit backfilling, pipe gallery construction, and shield tunneling grouting. However, they suffer from drawbacks such as high cement consumption (typically accounting for over 30% of the solidification agent), resulting in high carbon emissions (approximately 0.8-1.0 tons of carbon dioxide are emitted per ton of silicate cement produced) and low solid waste disposal rates, making it difficult to meet the demands of large-scale solid waste resource utilization and low-carbon green construction. Currently, although explorations have been conducted in the field of fluidized bed solidification using diverse solid wastes, significant technical bottlenecks still exist. First, the amount and types of solid waste are low: For example, the patent document with publication number CN113307591A discloses a multi-source solid waste composite high-fluidity backfill material and its preparation method and application, but the total proportion of solid waste is still less than 80%, and segregation is likely to occur within 72 hours, which cannot meet the self-compacting requirements.
[0005] Secondly, it has poor anti-segregation performance under high fluidity: For example, the patent document with publication number CN112142406A discloses a soil stabilizer for high fluidity solidified soil, but it still relies on cement cementitious materials with a proportion as high as 25-40%, which has a low solid waste content. When constructing in narrow spaces, the slurry is prone to particle settling, resulting in uneven backfill compaction and insufficient strength at the later stage.
[0006] Furthermore, in scenarios involving simultaneous grouting during tunnel boring, backfilling of irregularly shaped foundation pits, or narrow spaces in utility tunnels, it is difficult to simultaneously achieve both high fluidity and anti-segregation properties in fluidized solidified soil materials. Segregation of the slurry can easily lead to engineering quality issues such as voids, leakage, and structural inhomogeneity. However, reducing the water content to increase anti-segregation properties results in insufficient slurry fluidity, making it unsuitable for self-compacting backfilling of irregularly shaped foundation pits or narrow spaces in utility tunnels. Summary of the Invention
[0007] This invention provides a method for preparing a solid waste-based nano-synergistic self-compacting fluidized bed solidifier. This method, without relying on cementitious materials and using only solid waste as a binder, fundamentally solves the segregation problem of fluidized bed solidifiers under high fluidity through the synergistic effect of solid waste-sourced nano-Si / Al oxide modifiers, thus achieving the goal of preparing a high-performance fluidized bed solidifier using only solid waste. Specifically, the technical solution of this invention is as follows.
[0008] A method for preparing a solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil includes the following steps: (1) Add a strong alkaline solution to the mixed powder of fly ash and blast furnace slag and stir and extract under heating conditions. After completion, an extract rich in soluble aluminosilicates is obtained for later use.
[0009] (2) Add solid waste calcium ion source to the extract and adjust the system to alkaline. After the reaction is completed, separate the solid product and wash it to neutral to obtain nano Si / Al hydrated oxide precipitate slurry for later use.
[0010] (3) After adding a surfactant to the precipitated slurry, wet grinding is performed, followed by the addition of silane coupling agent and dopamine. After sealing, ultrasonic vibration is performed, and intermittent microwave heating is performed during this process. After completion, a modified slurry is obtained for later use.
[0011] (4) After adding steel slag powder to the modified slurry, continue wet grinding, dry after completion, and then carry out thermal modification and stabilization treatment to obtain solid waste source nano Si / Al oxide modifier for later use.
[0012] (5) First, fly ash, blast furnace slag powder, steel slag powder, calcium carbide slag powder, solid waste gypsum, waste incineration fly ash, and slag powder are mixed and ground. Then, a portion of the resulting multi-element solid waste mixed powder is mixed with the solid waste source nano-Si / Al oxide modifier and water to form a slurry. This slurry is then ground to obtain a nano-composite modified slurry. The remaining multi-element solid waste mixed powder is then used to coat the nano-composite modified slurry. After drying, the fluidized solidified soil solidifier is obtained.
[0013] Further, in step (1), the mass ratio of fly ash to blast furnace slag is 1:1~1.2.
[0014] Further, in step (1), the mass ratio of the mixed powder to the strong alkaline solution is 1:5~8. Optionally, the strong alkaline solution includes at least one of sodium hydroxide solution, potassium hydroxide solution, etc.
[0015] Furthermore, in step (1), the concentration of the strong alkali solution is 2~4 mol / L.
[0016] Further, in step (1), the heating temperature is 80~95℃, and the stirring and extraction time is 1.5~2.5h.
[0017] Further, in step (2), the pH of the reaction system is maintained between 9 and 11 using the solid waste calcium ion source. Optionally, the solid waste calcium ion source includes at least one of the following: calcium carbide slag leaching aqueous solution, steel slag leaching aqueous solution, desulfurized gypsum leaching aqueous solution, etc.
[0018] Furthermore, in step (2), the reaction time is 30~60 min.
[0019] Further, in step (3), the surfactant is 0.3~0.8% of the mass of the precipitated slurry. Optionally, the water content of the precipitated slurry is 20~35 wt.%.
[0020] Further, in step (3), the surfactant includes at least one of the following: sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, polyethylene glycol-400, Tween 80 (polysorbate 80), Span 80 (sorbitan monooleate), sodium dodecylbenzene sulfonate, etc.
[0021] Furthermore, in step (3), the linear speed of grinding is 12~15m / s, and the grinding time is 60~120min.
[0022] Further, in step (3), the silane coupling agent is 0.4~0.8% of the mass of the precipitated slurry. Optionally, the silane coupling agent includes at least one of KH-550, KH-560, KH570, KH-792, vinyltrimethoxysilane, γ-aminopropyltriethoxysilane, etc.
[0023] Further, in step (3), the dopamine is 0.5 to 1.0% of the mass of the precipitate slurry.
[0024] Furthermore, in step (3), the power of the ultrasonic oscillation is 300~500W and the time is 30~45min.
[0025] Furthermore, in step (3), the microwave power of the intermittent microwave heating treatment is 300~600W, and the heating is stopped for 5~10 minutes after each heating.
[0026] Further, in step (4), the steel slag powder accounts for 5-10% of the solid content in the modified slurry. Optionally, the specific surface area of the steel slag powder is ≥500m² / kg.
[0027] Furthermore, in step (4), the linear speed of the continued wet grinding is 12~15m / s, and the time is 10~20min.
[0028] Furthermore, in step (4), the temperature of the thermal modification and stabilization treatment is 80~120℃, and the time is 1~3 hours.
[0029] Further, in step (5), the weight proportions of each component are as follows: 25-30 parts of fly ash, 30-35 parts of blast furnace slag powder, 15-20 parts of steel slag powder, 12-15 parts of calcium carbide slag powder, 10-12 parts of solid waste gypsum, 5-8 parts of waste incineration fly ash, 3-5 parts of slag powder, and 1-3 parts of solid waste source nano-Si / Al oxide modifier.
[0030] Further, in step (5), the portion of the multi-component solid waste mixture powder is 15-25% of the total mass of the multi-component solid waste mixture powder. Optionally, in step (5), the moisture content of the slurry is 25-35%.
[0031] Furthermore, in step (5), the grinding linear speed is 10~12m / s and the time is 30~50min.
[0032] Furthermore, in step (5), the coating method includes spray coating, etc. Optionally, the spray pressure of the spray coating is 0.4~0.6MPa, and the mixing time is 10~20min.
[0033] Further, in step (5), the moisture content of the fluidized solidified soil curing agent is ≤0.5%. Optionally, the particle size of the fluidized solidified soil curing agent is ≤0.045mm.
[0034] Compared with the prior art, the present invention has at least the following beneficial technical effects: This invention utilizes a solid waste-sourced nano-Si / Al oxide modifier obtained through a multi-step extraction-nano-scale modification-multifunctional surface / shell modification process to achieve deep synergistic modification of a multi-component solid waste system at multiple scales, including micro-, nano-, and interfacial dimensions. This significantly improves the fluidity, anti-segregation performance, self-compacting ability, and mechanical / volume stability of the solidified soil material under cement-free conditions. To this end, the invention first uses a strong alkaline solution to extract aluminosilicates from a mixture of fly ash and blast furnace slag powder. Then, it further reacts with the solid waste calcium ion source to form nano-Si / Al hydrated oxide precipitates. Next, the invention employs a silane coupling agent and dopamine to perform dual modification on the nano-Si / Al hydrated oxide precipitates. Finally, the multi-component solid waste mixed powder, formed from all solid waste, is used to further coat the surface of the nano-Si / Al hydrated oxide precipitates, thus forming a solid waste-sourced nano-Si / Al oxide modifier with an "internal highly active nano-core, middle organic modification layer, and outer Ca / Fe / Al active shell." When added as a solidifying agent to fluidized solidified soil, on the one hand, the Ca / Fe / Al active shell of the modifier undergoes a multiphase secondary reaction with the carbide slag powder, solid waste gypsum, and other components to form gelling hydration products such as CASH and AFt. Simultaneously, the active shell provides additional adsorption sites, enabling the adsorption and solidification of trace heavy metals in the waste incineration fly ash within the gelling hydration products, overcoming the problem of pollution easily caused by the leaching of heavy metal elements from waste incineration fly ash. On the other hand, the organic modified layer, as an interfacial transition layer between the nano-Si / Al oxide core and the Ca / Fe / Al active shell, effectively enhances the interfacial compatibility and chemical bonding strength of the core-shell structure, enabling the modifier to form a stable multilayer composite structure in the multi-element solid waste system. During the mixing and hydration process of the fluidized solidified soil slurry, the organic modified layer, through the gradual activation of the core-shell structure, achieves an orderly synergistic effect between the modifier and the surrounding solid waste particles. This significantly improves the macroscopic rheological properties and microstructural uniformity of the slurry, enabling the fluidized solidified soil material of this invention to effectively suppress the sedimentation of heavy particles and the floating of light components under high fluidity conditions. It achieves the characteristics of long-term static standing without segregation or water bleeding, better meeting the requirements of self-compacting backfilling in narrow spaces. Furthermore, the highly active nano-cores can undergo secondary reactions with calcium ions provided by carbide slag powder, sulfate ions provided by solid waste gypsum, and active components in steel slag and blast furnace slag, generating more cementitious hydration products (such as CASH, ettringite AFt, etc.) to construct a stable three-dimensional network structure, effectively improving the long-term mechanical properties and volume stability of the fluidized solidified soil.The solid waste source nano-Si / Al oxide modifier of this invention breaks through the poor compatibility problem caused by the difference in activity and mismatch of particle characteristics of traditional multi-element solid wastes, and realizes the efficient synergistic effect of solid wastes such as fly ash, slag, steel slag, carbide slag, gypsum, waste incineration fly ash, and slag fine powder. It reduces the dependence on traditional cement and purchased chemical nanomaterials, and significantly reduces carbon emissions and costs. Attached Figure Description
[0035] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings, wherein: Figure 1 The image shows a sample of the nano-Si / Al oxide modifier from solid waste source in Example 1 below.
[0036] Figure 2 The image shows a sample of the curing agent for the fluidized solidified soil in Example 1 below.
[0037] Figure 3 The image shows a sample of the nano-Si / Al oxide modifier from solid waste source in Example 2 below.
[0038] Figure 4 The image below shows a sample of the curing agent for the fluidized solidified soil in Example 2.
[0039] Figure 5 The image shows a sample of the nano-Si / Al oxide modifier from solid waste source in Example 3 below.
[0040] Figure 6 The image shows a sample of the curing agent for the fluidized solidified soil in Example 3 below.
[0041] Figure 7 The image below shows a sample of the curing agent for the fluidized solidified soil in Comparative Example 1.
[0042] Figure 8 The image below shows a sample of nano-Si / Al oxide modifier from solid waste source, as shown in Comparative Example 2.
[0043] Figure 9 The image below shows a sample of nano-Si / Al oxide modifier from solid waste source, as shown in Comparative Example 3.
[0044] Figure 10 The image below shows a sample of nano-Si / Al oxide modifier from solid waste source, as shown in Comparative Example 4. Detailed Implementation
[0045] The present invention is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.
[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods in the art or as per the product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention.
[0047] Example 1 A method for preparing a solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil includes the following steps: (1) Fly ash (particle size distribution between 20~45μm) and granulated blast furnace slag powder (specific surface area 481.9m² / kg) were mixed at a mass ratio of 1:1 to form a mixed powder. Then, a 3mol / L sodium hydroxide solution was added to the mixed powder at a mass ratio of 1:7. The mixture was then heated to 90℃ and kept at that temperature for 2 hours for stirring and extraction. After the extraction was completed, the extract rich in soluble aluminosilicates was obtained by filtration and set aside for later use.
[0048] (2) While stirring, add the carbide slag extraction solution dropwise to the extract, and then maintain the reaction for 40 minutes. During this process, replenish the carbide slag extraction solution as needed to maintain the pH of the system at 10 ± 0.5. After completion, filter out the solid product and wash it with water until neutral to obtain a nano-Si / Al hydrated oxide precipitate with a water content of 28.3%, which is ready for use.
[0049] (3) After adding 0.5% by mass of surfactant (sodium dodecyl sulfate) to the precipitated slurry, wet grinding was performed (the grinding linear speed was 14 m / s, and the grinding time was 85 min). After completion, silane coupling agent (KH570) and dopamine were added, sealed, and subjected to ultrasonic vibration, while intermittent microwave heating was performed during the process. Wherein: the silane coupling agent and dopamine were 0.65% and 0.8% by mass of the precipitated slurry, respectively; the ultrasonic vibration power was 500 W, and the time was 30 min. The microwave power of the intermittent microwave heating was 450 W, and the heating was stopped for 8 min after every 8 min until the set ultrasonic vibration time was reached, thus obtaining the modified slurry for later use.
[0050] (4) Add 10% by weight of steel slag powder (specific surface area 521.6 m² / kg) to the modified slurry, and then continue wet milling for 15 min at a linear speed of 12 m / s. After completion, dry to remove moisture, and then heat to 80℃ and hold for 3 hours for thermal modification and stabilization treatment. After completion, a solid waste source nano-Si / Al oxide modifier (such as...) is obtained. Figure 1 (As shown), for later use.
[0051] (5) Take the following components in the following weight ratios: 26 parts fly ash, 32 parts granulated blast furnace slag powder, 17 parts steel slag powder, 13 parts calcium carbide slag powder, 11 parts desulfurized gypsum powder, 6.5 parts waste incineration fly ash, 4 parts slag powder, and 2.5 parts of the solid waste source nano Si / Al oxide modifier prepared in this embodiment.
[0052] First, the fly ash, granulated blast furnace slag powder, steel slag powder, calcium carbide slag powder, desulfurized gypsum powder, waste incineration fly ash, and slag powder are mixed and ground to obtain a multi-element solid waste mixed powder with a specific surface area of 511.4 m² / kg.
[0053] Then, take 20% of the total amount of the multi-component solid waste mixed powder, mix it with the solid waste source nano Si / Al oxide modifier and water to form a slurry with a water content of 30%, and then grind the slurry for 40 minutes at a grinding linear speed of 10 m / s. After completion, a nano-composite modified slurry is obtained.
[0054] The remaining multi-component solid waste powder is then spray-coated onto the nanocomposite modified slurry in a high-speed mixer at a spray pressure of 0.5 MPa for 15 minutes. After completion, the slurry is dried at 60°C in a fluidized bed until the moisture content is ≤0.5%. After grading by a vibrating screen, particles with a diameter distribution between 0.003 and 0.045 mm are collected to obtain the fluidized bed solidification agent (e.g., [missing information]). Figure 2 (As shown).
[0055] Performance test: 15% of the mass of the fluidized solidified soil solidifier of this embodiment was added to the engineering slag with a water content of 48.1%. Then, water was added at a water-to-solid ratio of 0.50 and mechanically stirred for 4 minutes to obtain the fluidized solidified soil material. Then: (1) The fluidity of the fluidized solidified soil material was tested according to GB / T 8077-2023, and the presence of segregation was observed after standing for 72 hours. The bleeding rate was also tested. (2) The 28-day compressive strength of the specimen prepared by the fluidized solidified soil material was tested according to "5 Compressive Strength Test" in GB / T 50081-2019. (3) The volume expansion rate of the specimen prepared by the fluidized solidified soil material was tested according to JC / T3132009. The results are shown in the table below. It can be seen that the fluidized solidified soil material maintains high fluidity and does not segregate or bleed after standing for a long time (bleeding rate <1%). At the same time, it has good mechanical strength and volume stability (expansion rate <0.5%, low shrinkage rate), thus maintaining better durability during service.
[0056] Performance indicators Flowability Segregation phenomenon Perfusion rate 28-day compressive strength Expansion rate Test Results 328mm none 0.8% 5.9MPa 0.42% Example 2 A method for preparing a solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil includes the following steps: (1) Fly ash (particle size distribution between 20~45μm) and granulated blast furnace slag powder (specific surface area 481.9m² / kg) were mixed at a mass ratio of 1:1.2 to form a mixed powder. Then, a sodium hydroxide solution with a concentration of 4mol / L was added to the mixed powder at a mass ratio of 1:5. The mixture was then heated to 80℃ and kept at that temperature for 2.5 hours for stirring and extraction. After the extraction was completed, the extract rich in soluble aluminosilicates was obtained by filtration and set aside for later use.
[0057] (2) While stirring, add the carbide slag extraction solution dropwise to the extract, and then maintain the reaction for 30 minutes. During this process, replenish the carbide slag extraction solution as needed to maintain the pH of the system at 9.5 ± 0.5. After completion, filter out the solid product and wash it with water until neutral to obtain a nano-Si / Al hydrated oxide precipitate with a water content of 20.1%, which is ready for use.
[0058] (3) After adding 0.8% by mass of surfactant (Tween 80) to the precipitated slurry, wet grinding is performed (grinding linear speed is 15 m / s, grinding time is 60 min). After completion, silane coupling agent (KH560) and dopamine are added, sealed, and subjected to ultrasonic vibration, with intermittent microwave heating during the process. Wherein: the silane coupling agent and dopamine are 0.4% and 0.5% by mass of the precipitated slurry, respectively; the ultrasonic vibration power is 300 W, and the time is 45 min. The microwave power of the intermittent microwave heating treatment is 300 W, and heating is stopped for 5 min after every 5 min until the set ultrasonic vibration time is reached, thus obtaining the modified slurry for later use.
[0059] (4) Add 7% by weight of steel slag powder (specific surface area 500.2 m² / kg) to the modified slurry, and then continue wet milling for 10 min at a linear speed of 15 m / s. After completion, dry to remove moisture, and then heat to 120℃ and hold for 1 hour for thermal modification and stabilization treatment. After completion, a solid waste source nano-Si / Al oxide modifier (such as...) is obtained. Figure 3 (As shown), for later use.
[0060] (5) Take the following components in the following weight ratio: 25 parts fly ash, 30 parts granulated blast furnace slag powder, 15 parts steel slag powder, 12 parts calcium carbide slag powder, 10 parts desulfurized gypsum powder, 5 parts waste incineration fly ash, 3 parts slag powder, and 1 part of the solid waste source nano Si / Al oxide modifier prepared in this embodiment.
[0061] First, the fly ash, granulated blast furnace slag powder, steel slag powder, calcium carbide slag powder, desulfurized gypsum powder, waste incineration fly ash, and slag powder are mixed and ground to obtain a multi-element solid waste mixed powder with a specific surface area of 452.6 m² / kg.
[0062] Then, 15% of the total amount of the multi-component solid waste mixed powder is taken and mixed with the solid waste source nano-Si / Al oxide modifier and water to form a slurry with a water content of 25%. The slurry is then ground for 50 minutes at a linear speed of 10 m / s. After completion, a nano-composite modified slurry (such as...) is obtained. Figure 4 (As shown).
[0063] The remaining multi-component solid waste powder is then spray-coated onto the nanocomposite modified slurry in a high-speed mixer at a spray pressure of 0.6 MPa for 10 minutes. After completion, the slurry is dried at 60°C in a fluidized bed until the moisture content is ≤0.5%. After grading by a vibrating screen, particles with a particle size distribution between 0.003 and 0.045 mm are collected to obtain the fluidized solidified soil solidifying agent.
[0064] Performance testing: The performance indicators of the fluidized solidified soil material prepared by the fluidized solidified soil solidifier of this embodiment were tested using the same method as in Example 1 above. The results are shown in the table below.
[0065] Performance indicators Flowability Segregation phenomenon Perfusion rate 28-day compressive strength Expansion rate Test Results 322mm none 1.1% 5.4MPa 0.51% Example 3 A method for preparing a solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil includes the following steps: (1) Fly ash (particle size distribution between 20~45μm) and granulated blast furnace slag powder (specific surface area 441.7m² / kg) were mixed at a mass ratio of 1:1.15 to form a mixed powder. Then, a 2mol / L potassium hydroxide solution was added to the mixed powder at a mass ratio of 1:8. The mixture was then heated to 95℃ and kept at that temperature for 1.5 hours for stirring and extraction. After the extraction was completed, the extract was filtered to obtain an extract rich in soluble aluminosilicates for later use.
[0066] (2) While stirring, add the steel slag powder extraction solution dropwise to the extract, and then maintain the reaction for 60 minutes. During this process, replenish the steel slag powder extraction solution as needed to maintain the pH of the system at 10.5 ± 0.5. After completion, filter out the solid product and wash it with water until neutral to obtain a nano-Si / Al hydrated oxide precipitate with a water content of 34.9%, which is ready for use.
[0067] (3) After adding 0.3% by mass of surfactant (sodium dodecylbenzenesulfonate) to the precipitated slurry, wet grinding was performed (the grinding linear speed was 12 m / s, and the grinding time was 120 min). After completion, silane coupling agent (KH-792) and dopamine were added, sealed, and subjected to ultrasonic vibration, while intermittent microwave heating was performed during the process. Wherein: the silane coupling agent and dopamine were 0.8% and 1.0% by mass of the precipitated slurry, respectively; the ultrasonic vibration power was 350 W, and the time was 40 min. The microwave power of the intermittent microwave heating was 600 W, and the heating was stopped for 10 min after every 10 min until the set ultrasonic vibration time was reached, thus obtaining the modified slurry for later use.
[0068] (4) Add 5% by weight of steel slag powder (specific surface area 551.7 m² / kg) to the modified slurry, and then continue wet milling for 20 min at a linear speed of 15 m / s. After completion, dry to remove moisture, and then heat to 90℃ and hold for 2 hours for thermal modification and stabilization treatment. After completion, a solid waste source nano-Si / Al oxide modifier (such as...) is obtained. Figure 5 (As shown), for later use.
[0069] (5) Take the following components in the following weight ratio: 30 parts fly ash, 35 parts granulated blast furnace slag powder, 20 parts steel slag powder, 15 parts calcium carbide slag powder, 12 parts desulfurized gypsum powder, 8 parts waste incineration fly ash, 5 parts slag powder, and 3 parts of the solid waste source nano Si / Al oxide modifier prepared in this embodiment.
[0070] First, the fly ash, granulated blast furnace slag powder, steel slag powder, calcium carbide slag powder, desulfurized gypsum powder, waste incineration fly ash, and slag powder are mixed and ground to obtain a multi-element solid waste mixed powder with a specific surface area of 481.7 m² / kg.
[0071] Then, take 25% of the total amount of the multi-component solid waste mixed powder, mix it with the solid waste source nano Si / Al oxide modifier and water to form a slurry with a water content of 35%, and then grind the slurry for 30 minutes at a grinding linear speed of 12 m / s. After completion, a nano-composite modified slurry is obtained.
[0072] The remaining multi-component solid waste powder is then spray-coated onto the nanocomposite modified slurry in a high-speed mixer at a spray pressure of 0.4 MPa for 20 minutes. After completion, the slurry is dried at 60°C in a fluidized bed until the moisture content is ≤0.5%. After grading by a vibrating screen, particles with a diameter distribution between 0.003 and 0.045 mm are collected to obtain the fluidized bed solidification agent (e.g., [missing information]). Figure 6 (As shown).
[0073] Performance testing: The performance indicators of the fluidized solidified soil material prepared by the fluidized solidified soil solidifier of this embodiment were tested using the same method as in Example 1 above. The results are shown in the table below.
[0074] Performance indicators Flowability Segregation phenomenon Perfusion rate 28-day compressive strength Expansion rate Test Results 336mm none 0.6% 6.3MPa 0.38% Comparative Example 1
[0075] A method for preparing a solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil includes the following steps: (1) Take the following components in the following weight ratio: 26 parts fly ash, 32 parts granulated blast furnace slag powder, 17 parts steel slag powder, 13 parts calcium carbide slag powder, 11 parts desulfurized gypsum powder, 6.5 parts waste incineration fly ash, and 4 parts slag powder.
[0076] (2) First, the fly ash, granulated blast furnace slag powder, steel slag powder, calcium carbide slag powder, desulfurized gypsum powder, waste incineration fly ash, and slag powder are mixed and ground. After being classified by a vibrating screen, particles with a particle size distribution between 0.003 and 0.045 mm are taken to obtain the fluidized solidified soil solidifying agent (such as...). Figure 7 (As shown).
[0077] Performance Testing: The performance indicators of the fluidized solidified soil material prepared by the fluidized solidified soil solidifier of this comparative example were tested using the same method as in Example 1 above. The results are shown in the table below. It can be seen that, due to the absence of a solid waste-source nano-Si / Al oxide modifier and the failure to form a structure with an "internal highly active nano-core, an intermediate organic modified layer, and an outer Ca / Fe / Al active shell," the fluidized solidified soil material of this comparative example exhibits high slurry yield stress and severe particle agglomeration, failing to maintain good anti-segregation stability under high fluidity conditions. Simultaneously, the reduced hydration product formation rate and loose microstructure lead to a clear deterioration in both mechanical properties and volumetric stability.
[0078] Performance indicators Flowability Segregation phenomenon Perfusion rate 28-day compressive strength Expansion rate Test Results 165mm Obvious particle sedimentation and segregation 4.5% 1.2MPa 0.85% Comparative Example 2
[0079] A method for preparing a solid waste nano-synergistic self-compacting fluidized solidified soil solidifier is the same as in Example 1 above, except that the solid waste source nano-Si / Al oxide modifier in this comparative example is prepared using the following steps: (1) Fly ash (particle size distribution between 20~45μm) and granulated blast furnace slag powder (specific surface area 481.9m² / kg) were mixed at a mass ratio of 1:1 to form a mixed powder. Then, a 3mol / L sodium hydroxide solution was added to the mixed powder at a mass ratio of 1:7. The mixture was then heated to 90℃ and kept at that temperature for 2 hours for stirring and extraction. After the extraction was completed, the extract rich in soluble aluminosilicates was obtained by filtration and set aside for later use.
[0080] (2) While stirring, add the carbide slag extraction solution dropwise to the extract, and then maintain the reaction for 40 minutes. During this process, replenish the carbide slag extraction solution as needed to maintain the pH of the system at 10 ± 0.5. After completion, filter out the solid product and wash it with water until neutral to obtain a nano-Si / Al hydrated oxide precipitate with a water content of 28.3%, which is ready for use.
[0081] (3) After adding 0.5% by mass of surfactant (sodium dodecyl sulfate) to the precipitated slurry, wet grinding was performed (the grinding linear speed was 14 m / s, and the grinding time was 85 min). After completion, silane coupling agent (KH570) and dopamine were added, sealed, and subjected to ultrasonic vibration, while intermittent microwave heating was performed during the process. Wherein: the silane coupling agent and dopamine were 0.65% and 0.8% by mass of the precipitated slurry, respectively; the ultrasonic vibration power was 500 W, and the time was 30 min. The microwave power of the intermittent microwave heating was 450 W, and the heating was stopped for 8 min after every 8 min until the set ultrasonic vibration time was reached, thus obtaining the modified slurry for later use.
[0082] (4) The modified slurry is dried to remove moisture, then heated to 80°C and kept at that temperature for 3 hours. After completion, a solid waste source nano-Si / Al oxide modifier (such as...) is obtained. Figure 8 (As shown).
[0083] Performance testing: The performance indicators of the fluidized solidified soil material prepared by the fluidized solidified soil solidifier of this comparative example were tested using the same method as in Example 1 above. The results are shown in the table below.
[0084] Performance indicators Flowability Segregation phenomenon Perfusion rate 28-day compressive strength Expansion rate Test Results 318mm slight 2.1% 5.1MPa 0.68% Comparative Example 3
[0085] A method for preparing a solid waste nano-synergistic self-compacting fluidized solidified soil solidifier is the same as in Example 2 above, except that the solid waste source nano-Si / Al oxide modifier in this comparative example is prepared using the following steps: (1) Fly ash (particle size distribution between 20~45μm) and granulated blast furnace slag powder (specific surface area 481.9m² / kg) were mixed at a mass ratio of 1:1.2 to form a mixed powder. Then, a sodium hydroxide solution with a concentration of 4mol / L was added to the mixed powder at a mass ratio of 1:5. The mixture was then heated to 80℃ and kept at that temperature for 2.5 hours for stirring and extraction. After the extraction was completed, the extract rich in soluble aluminosilicates was obtained by filtration and set aside for later use.
[0086] (2) While stirring, add the carbide slag extraction solution dropwise to the extract, and then maintain the reaction for 30 minutes. During this process, replenish the carbide slag extraction solution as needed to maintain the pH of the system at 9.5 ± 0.5. After completion, filter out the solid product and wash it with water until neutral to obtain a nano-Si / Al hydrated oxide precipitate with a water content of 20.1%, which is ready for use.
[0087] (3) Add 0.8% of the surfactant (Tween 80) to the precipitated slurry and then perform wet grinding (the grinding linear speed is 15m / s and the grinding time is 60min). After completion, a modified slurry is obtained and ready for use.
[0088] (4) Add 7% by weight of steel slag powder (specific surface area 500.2 m² / kg) to the modified slurry, and then continue wet milling for 10 min at a linear speed of 15 m / s. After completion, dry to remove moisture, and then heat to 120℃ and hold for 1 hour for thermal modification and stabilization treatment. After completion, a solid waste source nano-Si / Al oxide modifier (such as...) is obtained. Figure 9 (As shown).
[0089] Performance testing: The performance indicators of the fluidized solidified soil material prepared by the fluidized solidified soil solidifier of this comparative example were tested using the same method as in Example 1 above. The results are shown in the table below.
[0090] Performance indicators Flowability Segregation phenomenon Perfusion rate 28-day compressive strength Expansion rate Test Results 310mm slight 2.8% 4.9MPa 0.74% Comparative Example 4
[0091] A method for preparing a solid waste nano-synergistic self-compacting fluidized solidified soil solidifier is the same as in Example 3 above, except that the solid waste source nano-Si / Al oxide modifier in this comparative example is prepared using the following steps: (1) Fly ash (particle size distribution between 20~45μm) and granulated blast furnace slag powder (specific surface area 441.7m² / kg) were mixed at a mass ratio of 1:1.15 to form a mixed powder. Then, a 2mol / L potassium hydroxide solution was added to the mixed powder at a mass ratio of 1:8. The mixture was then heated to 95℃ and kept at that temperature for 1.5 hours for stirring and extraction. After the extraction was completed, the extract was filtered to obtain an extract rich in soluble aluminosilicates for later use.
[0092] (2) While stirring, add the steel slag powder extraction solution dropwise to the extract, and then maintain the reaction for 60 minutes. During this process, replenish the steel slag powder extraction solution as needed to maintain the pH of the system at 10.5 ± 0.5. After completion, filter out the solid product and wash it with water until neutral to obtain a nano-Si / Al hydrated oxide precipitate with a water content of 34.9%, which is ready for use.
[0093] (3) After adding 0.3% by mass of surfactant (sodium dodecylbenzenesulfonate) to the precipitated slurry, wet grinding was performed (the grinding linear speed was 12 m / s, and the grinding time was 120 min). After completion, silane coupling agent (KH-792) and dopamine were added, sealed, and subjected to ultrasonic vibration, while intermittent microwave heating was performed during the process. Wherein: the silane coupling agent and dopamine were 0.8% and 1.0% by mass of the precipitated slurry, respectively; the ultrasonic vibration power was 350 W, and the time was 40 min. The microwave power of the intermittent microwave heating was 600 W, and the heating was stopped for 10 min after every 10 min until the set ultrasonic vibration time was reached, thus obtaining the modified slurry for later use.
[0094] (4) Add 5% by weight of steel slag powder (specific surface area 551.7 m² / kg) to the modified slurry, and then continue wet milling for 20 min at a linear speed of 15 m / s. After completion, dry to remove moisture, and obtain a solid waste source nano-Si / Al oxide modifier (such as...). Figure 10 (As shown).
[0095] Performance testing: The performance indicators of the fluidized solidified soil material prepared by the fluidized solidified soil solidifier of this comparative example were tested using the same method as in Example 1 above. The results are shown in the table below.
[0096] Performance indicators Flowability Segregation phenomenon Perfusion rate 28-day compressive strength Expansion rate Test Results 329mm slight 1.6% 5.7MPa 0.55% The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil, characterized in that, Includes the following steps: (1) Add a strong alkaline solution to the mixed powder of fly ash and blast furnace slag and stir and extract under heating conditions. After completion, an extract rich in soluble aluminosilicates is obtained for later use. (2) Add solid waste calcium ion source to the extract and adjust the system to alkaline. After the reaction is complete, separate the solid product and wash it to neutral to obtain nano Si / Al hydrated oxide precipitate slurry for later use. (3) After adding a surfactant to the precipitated slurry, wet grinding is performed, then silane coupling agent and dopamine are added, and after sealing, ultrasonic vibration is performed. During this process, intermittent microwave heating is performed to obtain a modified slurry for later use. (4) After adding steel slag powder to the modified slurry, continue wet grinding, dry after completion, and then carry out thermal modification and stabilization treatment to obtain solid waste source nano Si / Al oxide modifier for later use; (5) First, fly ash, blast furnace slag powder, steel slag powder, carbide slag powder, solid waste gypsum, waste incineration fly ash and slag powder are mixed and ground. Then, part of the obtained multi-element solid waste mixed powder is mixed with the solid waste source nano Si / Al oxide modifier and water to form a slurry. After grinding, a nano-composite modified slurry is obtained. Then, the remaining multi-component solid waste mixed powder is used to coat the nanocomposite modified slurry, and after drying, the fluidized solidified soil solidifier is obtained.
2. The preparation method of the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to claim 1, characterized in that, In step (1), the mass ratio of fly ash to blast furnace slag is 1:1~1.2; Alternatively, in step (1), the strong alkaline solution includes at least one of sodium hydroxide solution and potassium hydroxide solution.
3. The preparation method of the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to claim 1, characterized in that, In step (1), the mass ratio of the mixed powder to the strong alkali solution is 1:5~8; Alternatively, in step (1), the concentration of the strong alkali solution is 2~4 mol / L; Alternatively, in step (1), the heating temperature is 80~95℃; Alternatively, in step (1), the stirring and extraction time is 1.5 to 2.5 hours.
4. The preparation method of the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to claim 1, characterized in that, In step (2), the pH of the reaction system is maintained between 9 and 11 by using the solid waste calcium ion source; Alternatively, in step (2), the solid waste calcium ion source includes at least one of the following: calcium carbide slag leaching aqueous solution, steel slag leaching aqueous solution, and desulfurized gypsum leaching aqueous solution; Alternatively, in step (2), the reaction time is 30 to 60 minutes.
5. The preparation method of the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to claim 1, characterized in that, In step (3), the surfactant is 0.3 to 0.8% of the mass of the precipitated slurry; or, in step (3), the water content of the precipitated slurry is 20 to 35 wt.%.
6. The preparation method of the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to claim 1, characterized in that, In step (3), the surfactant includes at least one of the following: sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, polyethylene glycol-400, Tween 80, Span 80, and sodium dodecylbenzene sulfonate. Alternatively, in step (3), the grinding linear speed is 12~15m / s and the grinding time is 60~120min; Alternatively, in step (3), the silane coupling agent is 0.4 to 0.8% of the mass of the precipitated slurry.
7. The preparation method of the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to claim 1, characterized in that, In step (3), the dopamine is 0.5-1.0% of the mass of the precipitated slurry; Alternatively, in step (3), the silane coupling agent includes at least one of KH-550, KH-560, KH570, KH-792, vinyltrimethoxysilane, and γ-aminopropyltriethoxysilane. Alternatively, in step (3), the power of the ultrasonic oscillation is 300~500W and the time is 30~45min; Alternatively, in step (3), the microwave power of the intermittent microwave heating treatment is 300~600W, and the heating is stopped for 5~10 minutes after each heating.
8. The preparation method of the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to claim 1, characterized in that, In step (4), the steel slag powder accounts for 5-10% of the solid content in the modified slurry; Alternatively, in step (4), the specific surface area of the steel slag powder is ≥500m² / kg; Alternatively, in step (4), the linear speed of the continued wet grinding is 12~15m / s, and the time is 10~20min; Alternatively, in step (4), the temperature of the thermal modification and stabilization treatment is 80~120℃ and the time is 1~3 hours.
9. The preparation method of the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to any one of claims 1-8, characterized in that, In step (5), the weight proportions of each component are as follows: 25-30 parts fly ash, 30-35 parts blast furnace slag powder, 15-20 parts steel slag powder, 12-15 parts calcium carbide slag powder, 10-12 parts solid waste gypsum, 5-8 parts waste incineration fly ash, 3-5 parts slag powder, and 1-3 parts solid waste source nano-Si / Al oxide modifier.
10. The method for preparing the solidifying agent for all-solid waste nano-synergistic self-compacting fluidized solidified soil according to any one of claims 1-8, characterized in that, In step (5), the portion of the multi-component solid waste mixture powder is 15-25% of the total mass of the multi-component solid waste mixture powder; Alternatively, in step (5), the moisture content of the slurry is 25-35%; Alternatively, in step (5), the grinding linear speed is 10~12m / s and the time is 30~50min; Alternatively, in step (5), the coating method includes spray coating, wherein the spray pressure of the spray coating is 0.4~0.6MPa and the mixing time is 10~20min; Alternatively, in step (5), the moisture content of the fluidized solidified soil solidifying agent is ≤0.5%; Alternatively, in step (5), the particle size of the fluidized solidified soil curing agent is ≤0.045mm.