Steel-based multi-solid waste synergistic consolidation agent and preparation method thereof

Abstract

This invention relates to the field of industrial solid waste resource utilization technology, specifically disclosing a steel-based multi-solid waste synergistic consolidation agent and its preparation method. The consolidation agent of this invention is prepared using steel slag, blast furnace slag, dust collector ash, and desulfurization gypsum from Tangshan area as main raw materials, combined with a low-alkali composite activator. The solid waste utilization rate of this consolidation agent is ≥85wt%, with a 28-day compressive strength of 20-28 MPa, exhibiting early strength, water resistance, salt resistance, and freeze-thaw resistance. It is suitable for soft soil along the Tangshan coast, road base courses, mining area backfilling, and solid waste storage site hardening. This invention enables large-scale resource utilization of Tangshan steel solid waste, achieving low carbon and low cost, excellent engineering performance, and significant economic and environmental benefits.

Description

Technical Field

[0001] This invention relates to the field of industrial solid waste resource utilization technology, and specifically discloses a steel-based multi-solid waste synergistic consolidation agent and its preparation method. Background Technology

[0002] Tangshan, a steel city in northern China, generates over 30 million tons of solid waste annually, including steel slag, blast furnace slag, dust collector ash, and desulfurization gypsum. This presents challenges such as large stockpiles, high costs, and significant environmental risks. Traditional cement-based solidification methods for the resource utilization of this type of solid waste suffer from drawbacks such as high costs, large carbon emissions, and incompatibility with the high-salt, soft soil of the coastal area. Existing solid waste solidification agents often use single raw materials, resulting in low activity, poor early strength, susceptibility to efflorescence, and poor water resistance. Furthermore, the soft soil and high-salt, alkaline environment along Tangshan's coast imposes specific requirements on roadbed construction, mining area backfilling, and stockpile hardening. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a steel-based multi-solid waste synergistic consolidation agent and its preparation method. Specifically targeting bulk solid wastes from the steel industry in Tangshan, such as steel slag, blast furnace slag, dust collector ash, and desulfurization gypsum, this invention prepares a low-cost, high-strength cementless consolidation agent suitable for soft soil, roadbeds, mine backfilling, and stockpile hardening in Tangshan and the North China coastal areas.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] In a first aspect, this invention provides a steel-based multi-solid waste synergistic consolidation agent, comprising the following raw materials in parts by weight: steel slag powder (converter / electric furnace steel slag): 30-45 parts, blast furnace slag powder (granulated slag): 25-40 parts, steel dust collector ash (sintering / blast furnace / converter ash): 8-18 parts, desulfurization gypsum: 4-8 parts, and composite activator: 5-10 parts; wherein the composite activator is made from the following raw materials: quicklime, low-modulus water glass, and sodium sulfate. The consolidation agent of this invention is a compound of various steel industry solid wastes and the composite activator.

[0006] The core components and physical properties of the above raw materials are as follows:

[0007] Steel slag (converter / electric furnace steel slag), core components and content: CaO 40%~45%, SiO2 12%~16%, Fe2O3 18%~22%, MgO 5%~8%, Al2O3 2%~4%; impurity control: P≤0.8%, S≤0.5%, free calcium oxide≤3%, to ensure the stability of the solidified body volume.

[0008] Blast furnace slag (granulated slag), conforming to GB / T 203-2008 standard, has the following core components: SiO2 32%~38%, CaO 32%~38%, Al2O3 8%~10%, MgO 5%~8%; MnO≤2.0%, TiO2≤2.0%, mass coefficient K≥1.2, glass content≥85%, and excellent hydration activity.

[0009] Dust collector ash, covering sintering, blast furnace and converter ash, has the following core components: TFe 30%~55%, CaO 8%~18%, SiO2 4%~10%, fixed carbon 2%~8%; total alkali metal content ≤3%, which can help activate hydration and improve soil compaction.

[0010] Desulfurized gypsum, core components: calcium sulfate dihydrate ≥80%, free water 10%~15%; particle size concentrated in 20~60μm, average particle size 35μm, no large particles above 100μm, as sulfate activating component to regulate hydration intensity.

[0011] Quicklime, specifications: industrial high activity, CaO≥92%, MgO≤2%, 200 mesh passing rate≥98%, activity≥300mL. Manufacturers: Tangshan Fengrun District Xinsheng Lime Factory, Tangshan Yutian County Hengtong Building Materials Co., Ltd.

[0012] Low-modulus water glass, specifications: modulus 2.0~2.4, Baume degree 38~42°Bé, SiO2≥26%, Na2O≥8.5%, no precipitation, no stratification. Manufacturers: Tangshan Aoding Chemical Co., Ltd., Tangshan Zhongheng Silicon Materials Technology Co., Ltd.

[0013] Optionally, the composite activator is made from the following raw materials in parts by weight: 3-7 parts quicklime, 1-3 parts low-modulus water glass, and 0.5-1.5 parts sodium sulfate.

[0014] Optionally, a steel-based multi-solid waste synergistic consolidation agent comprises the following raw materials in parts by weight: 40 parts steel slag powder, 30 parts blast furnace slag powder, 15 parts steel dust collector ash, 6 parts desulfurization gypsum, and 9 parts composite activator.

[0015] Optionally, the composite activator is made from the following raw materials in parts by weight: 6 parts quicklime, 2 parts water glass, and 1 part sodium sulfate.

[0016] The aforementioned raw materials—steel slag, blast furnace slag, steel dust collector ash, and desulfurization gypsum—all originate from solid waste from steel enterprises in the Tangshan area. The total utilization rate of the solid waste is ≥85wt%, and the 28-day compressive strength is ≥20MPa. These materials are suitable for use in soft soil, roadbeds, backfilling, and stockpile hardening along the Tangshan coast.

[0017] Secondly, the present invention also provides a method for preparing a steel-based multi-solid waste synergistic consolidation agent, comprising:

[0018] Pretreatment: Steel slag, blast furnace slag, and dust collector ash are ground separately to obtain steel slag powder, blast furnace slag powder, and steel dust collector ash;

[0019] Metering and batching: Weigh out steel slag powder, blast furnace slag powder, steel dust collector ash, desulfurization gypsum, and composite activator according to the weight ratio;

[0020] Mixing: Use a zero-gravity mixer or ribbon mixer to mix evenly;

[0021] Finished product: It is ready when packaged in a moisture-proof, airtight container.

[0022] Optionally, steel slag, blast furnace slag, and dust collector ash are all ground to a fineness ≥200 mesh and a specific surface area ≥400 m². 2 / kg.

[0023] Optionally, the stirring time is 3 to 6 minutes.

[0024] Thirdly, the present invention provides the application of the above-mentioned steel-based multi-solid waste synergistic consolidation agent for soft soil foundation solidification, road base construction, mining area backfilling, solid waste dump hardening or dust suppression and soil stabilization projects.

[0025] Optionally, the dosage of the consolidating agent is 8 to 12.5% ​​of the dry mass of the material to be solidified, and can be finely adjusted according to the soil moisture content, soil grade, and engineering strength requirements on site.

[0026] The consolidating agent of this invention can be used in the fields of industrial solid waste resource utilization, soil / soft soil solidification, and road base materials. Specifically, it can be used for soft soil foundation solidification, road base construction, mining area backfilling, solid waste dump hardening, or dust suppression and soil stabilization projects in Tangshan and the coastal areas of North China.

[0027] I. Explanation of the functions and proportions of each raw material in this invention, and the advantages of the low-alkali activator.

[0028] (I) Functions and effects of each component

[0029] Steel slag powder: Provides active calcium and iron oxides, hydrates to form cementing minerals, constructs a solidified framework, and enhances later-stage strength. Blast furnace slag powder: High in glassy active components, rapid hydration reaction, ensuring early-stage consolidation strength. Steel dust: Supplements metal oxides and trace bases, fills pores, and enhances soil density. Desulfurized gypsum: Sulfate activator, regulates hydration rate, inhibits expansion, and optimizes structural stability. The composite activator functions as follows: Quicklime: Rapid hydration generates heat, increases system alkalinity, and activates the potential cementing activity of solid waste; Low-modulus water glass: Hydrolysis produces silicate ions, promoting gel formation and binding loose particles; Sodium sulfate: Sulfate synergistic activation, accelerates mineral crystallization, and shortens solidification time.

[0030] (II) Influence of Composite Activator Ratio

[0031] Only within the reasonable raw material ratio range of this invention can a high-performance steel-based multi-solid waste synergistic consolidation agent be obtained. If the composite activator ratio is too low, the solid waste activity cannot be fully activated, the hydration reaction is weak, and the consolidation strength is insufficient; the particle adhesion is poor, the soil is easily loosened, and the impermeability and compaction resistance are substandard, shortening the service life of the project. If the composite activator ratio is too high, excessive quicklime will cause the system alkalinity to exceed the standard, easily leading to volume expansion and cracking, and deteriorating the stability of the solidified body; excessive water glass will cause the slurry to be too viscous, reducing workability and making it difficult to spread due to excessive solidification; excessive sodium sulfate will cause salt crystallization and alkali return, damaging the internal structure and reducing water resistance and durability.

[0032] (III) The Outstanding Advantages of the Specific Formula of the Invention

[0033] This method employs a range of proportions to adapt to different soil conditions, using a primary and secondary combination of steel slag and blast furnace slag to balance early and late-stage strength. Dust collector ash is used for filling and reinforcement, gypsum is used to control and stabilize deformation, and a composite activator is used to gradually activate the activity of solid waste. Compared with conventional single cementitious materials, the utilization rate of solid waste is significantly improved, the cost is lower, and the overall integrity, load-bearing capacity, and deformation resistance of the solidified layer are all superior to traditional solutions.

[0034] (iv) Unique advantages of low-alkali composite activators

[0035] With mild and controllable alkalinity, it avoids soil alkali corrosion and adverse aggregate reactions caused by high alkali; the multi-component synergistic activation has a much higher activation efficiency than a single activator, resulting in a more complete reaction; it reduces the risk of expansion and cracking, and significantly improves the volume stability of the solidified body; its low-alkali environment is suitable for complex sites such as soft soil and backfill soil, making it applicable to a wider range of situations.

[0036] II. Mechanism by which preparation steps improve product performance

[0037] This invention classifies and grinds steel slag, blast furnace slag, and dust collector ash into powders with a particle size of ≥200 mesh and a specific surface area of ​​≥400 m². 2 The refined particles per kg increase the reaction contact area, breaking the inert crystal lattice of solid waste, releasing internal active components, and significantly improving hydration reaction efficiency and bonding ability. Precise weight proportions ensure a balanced ratio of activation, hydration, and filling of each component, avoiding localized imbalances and ensuring uniform and stable curing performance for each batch. Stirring at a constant speed for 3-6 minutes ensures thorough mixing, allowing the activator to adhere evenly to the surface of the solid waste particles, achieving full coverage of activation, eliminating uneven reaction intensity in certain areas, and resulting in consistent strength after molding.

[0038] III. The deficiencies of the prior art that this invention addresses are as follows:

[0039] To address the issues of low activity and insufficient strength of single solid wastes, this invention employs a complementary combination of various steel-based solid wastes, with synergistic hydration of multiple elements such as calcium, silicon, iron, and aluminum, and deep activation of inert components by a low-alkali composite activator, forming a dense and stable gel structure that significantly improves strength.

[0040] This invention addresses the problems of conventional binders, such as easy expansion and cracking, and poor stability. It utilizes desulfurized gypsum to regulate the hydration process, and a low-alkali activation system to inhibit excessive expansion of free calcium, effectively counteracting the deformation stress of the solidified body and preventing cracking and damage.

[0041] This invention addresses the problems of high cost and low solid waste utilization rate of traditional products. It uses bulk solid waste from steel mills as the main material, replacing high-cost raw materials such as cement, resulting in high solid waste resource utilization rate and lower engineering costs.

[0042] This invention addresses the limitations of conventional solidifying agents, which are suitable for only a limited range of soil types and have poor durability. It employs a multi-stage activation and pore-filling dual-action process, resulting in a solidified body with excellent density, water resistance, freeze-thaw resistance, and compaction resistance. This makes it suitable for various complex engineering scenarios, including soft soil foundations, mining areas, roads, and stockpiles.

[0043] This invention addresses the deficiency of insufficient activation by a single activator. It employs a ternary compound of quicklime, low-modulus water glass, and sodium sulfate, utilizing a multi-mechanism synergy of alkali activation, silica gel formation, and salt crystallization, resulting in an activation effect far superior to that of a single activator material.

[0044] This invention employs an industrial solid waste compounding system, which is green, environmentally friendly, and has a high resource utilization rate; all solid waste powders have a uniform fineness of ≥200 mesh and a specific surface area of ​​≥400 m². 2 / kg; stirring time 3-6 minutes to ensure uniform mixing and stable activation effect; standard dosage 8%-12.5%, suitable for various soil and rock solidification projects, with stable performance and strong applicability. The consolidating agent of this invention is suitable for various soil and rock solidification and solid waste resource utilization projects such as soft soil foundation solidification, road base construction, mining area backfilling, solid waste dump hardening, dust suppression and soil stabilization.

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] This invention utilizes steel slag, blast furnace slag, steel dust collector ash, and desulfurization gypsum from Tangshan area as raw materials, and combines them with quicklime, low-modulus water glass, and sodium sulfate as a ternary composite activator to construct a multi-solid waste synergistic cementing system. Addressing technical challenges such as low activity of individual solid wastes, high cost and strong alkalinity of traditional solidifying agents, easy expansion and efflorescence, and difficulty in adapting to coastal soft soils and high-salt environments, this invention achieves mild alkalinity, sufficient reaction, and volume stability by using steel slag to provide the framework and later-stage strength, blast furnace slag to ensure early strength, dust collector ash for dense filling, and desulfurization gypsum to regulate hydration and inhibit expansion. Combined with a low-alkali composite activator to gradient activate inert components, it achieves a solid waste utilization rate ≥85%, a 28-day compressive strength of 20–28 MPa, and excellent properties such as early strength, water resistance, salt resistance, freeze-thaw resistance, low shrinkage, and no efflorescence. It is suitable for soft soil solidification, road base courses, mining area backfilling, and stockpile hardening. Compared with cement-based solidifying agents, it reduces costs by 30%–50% and carbon emissions by more than 60%, resulting in significant economic and environmental benefits. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a production process flow diagram of the steel-based multi-solid waste synergistic consolidation agent according to an embodiment of the present invention. Detailed Implementation

[0049] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0050] Example 1: High-strength road base layer in Tangshan

[0051] A steel-based multi-solid waste synergistic consolidation agent comprises the following raw materials in parts by weight: 40 parts steel slag powder, 30 parts blast furnace slag powder, 15 parts steel dust collector ash, 6 parts desulfurization gypsum, 6 parts quicklime, 2 parts water glass, and 1 part sodium sulfate.

[0052] A method for preparing a steel-based multi-solid waste synergistic consolidation agent includes:

[0053] Steel slag, blast furnace slag, and steel dust were ground separately to obtain steel slag powder, blast furnace slag powder, and steel dust. The fineness of all three powders was ≥200 mesh, and their specific surface area was ≥400 m². 2 / kg; Preferably, the raw material grinding process involves separately grinding steel slag, blast furnace slag, and dust collector ash to a fineness of 250 mesh and a specific surface area of ​​460 m². 2 / kg;

[0054] Weigh out the steel slag powder, blast furnace slag powder, steel dust collector ash, desulfurization gypsum, and composite activator according to the above weight ratio. The composite activator is composed of 6 parts quicklime, 2 parts water glass, and 1 part sodium sulfate. Put all materials into a ribbon mixer and mix for 4.5 minutes. Then, use a zero-gravity mixer / ribbon mixer to mix for 3 to 6 minutes until uniform and free of lumps. Seal and package in a moisture-proof container to obtain the final product.

[0055] The construction method of the above-mentioned steel-based multi-solid waste synergistic consolidation agent includes:

[0056] Consolidating agent quality: The dry weight of the material to be solidified (such as silty soft soil, iron ore tailings, steel slag tailings solid waste) = 1:10, preferably silty soft soil. The dry weight of the material to be solidified refers to the dry substrate after drying at 105℃ to constant weight and removing large impurities. The particle size of the material is ≤4.75mm, the proportion of coarse particles (particle size >2mm) is ≤15wt%, and the content of fine particles (particle size <0.075mm) is 25-40wt%. After the consolidating agent and the material to be solidified are evenly mixed, water is added and mixed. The moisture content of the mixture after mixing is controlled to be 14.5% (based on the total dry weight of the material). The evenly mixed material is spread, rolled, and naturally cured. Compaction requirements: After spreading, it is rolled in layers with a fixed thickness of 18cm. The compaction degree is ≥95%. Rolling is performed until the surface is flat and there are no obvious wheel marks or loose particles. Natural Curing Standards: 1. Curing Temperature: The ambient temperature should be between 5℃ and 35℃, with an optimal ambient temperature of 20℃. Protective measures are required when the temperature is below 5℃ or above 35℃. For temperatures below 5℃, use insulating blankets; for temperatures above 35℃, cover with shade cloth and replenish water regularly. 2. Curing Method: Immediately after compaction, fully cover with geomembrane for sealing and moisture retention. 3. Curing Duration: 7 days for standard backfilling and site foundation; 14 days for heavy-duty roads and mining backfill projects. 4. During the curing period, vehicle traffic and heavy object compaction are prohibited to prevent surface damage and water loss.

[0057] The properties of the consolidating agent obtained in this embodiment are as follows: 7-day strength: 16MPa, 28-day strength: 28MPa, solid waste utilization rate: 89%, water-resistant, salt-resistant, freeze-thaw resistant, and suitable for Tangshan road base.

[0058] Figure 1 This is a flow chart of the production process of the steel-based multi-solid waste synergistic binder according to an embodiment of the present invention. The specific process flow is as follows: raw material silo (steel slag, blast furnace slag, dust collector ash) → grinding → metering → mixing and stirring → finished product silo → packaging.

[0059] Example 2: Tangshan coastal soft soil consolidation type

[0060] A steel-based multi-solid waste synergistic consolidation agent comprises the following raw materials in parts by weight: 35 parts steel slag powder, 35 parts blast furnace slag powder, 12 parts steel dust collector ash, 7 parts desulfurization gypsum, 5 parts quicklime, 2 parts water glass, and 1 part sodium sulfate.

[0061] A method for preparing a steel-based multi-solid waste synergistic consolidation agent and its application (construction method) are both prepared according to the method described in Example 1.

[0062] The properties of the consolidating agent obtained in this embodiment are as follows: 7-day strength: 12 MPa, 28-day strength: 22 MPa, resistant to seawater erosion, does not effloresce, has low shrinkage, and is suitable for soft soils along the coast such as Caofeidian and Leting.

[0063] Example 3: Low-cost backfilling model for Tangshan mining area

[0064] A steel-based multi-solid waste synergistic consolidation agent comprises the following raw materials in parts by weight: 38 parts steel slag powder, 32 parts blast furnace slag powder, 16 parts steel dust collector ash, 6 parts desulfurization gypsum, 6 parts quicklime, 1.5 parts water glass, and 0.5 parts sodium sulfate.

[0065] A method for preparing a steel-based multi-solid waste synergistic consolidation agent and the application of the consolidation agent are both prepared according to the method described in Example 1.

[0066] The properties of the binder obtained in this embodiment are as follows: 28-day strength: 20 MPa, solid waste utilization rate: 90%, and cost is 40% to 50% lower than that of cement.

[0067] Comparative Example 1

[0068] A consolidating agent comprises the following raw materials in parts by weight: 35 parts blast furnace slag powder, 12 parts steel dust, 7 parts desulfurization gypsum, 5 parts quicklime, 2 parts water glass, and 1 part sodium sulfate. The difference between this comparative example and Example 2 is that steel slag powder was not added.

[0069] The properties of the binder obtained in this comparative example are as follows: 7-day strength 6.3 MPa, 28-day strength 11.8 MPa, loose structure and prone to cracking. Comparative conclusion: Lacking a core skeleton component (steel slag powder), the binder's cementitious system has poor molding, and its strength is far lower than that of the example.

[0070] Comparative Example 2

[0071] A consolidating agent comprises the following raw materials in parts by weight: 20 parts steel slag powder, 20 parts blast furnace slag powder, 30 parts steel dust collector ash, 12 parts desulfurization gypsum, and 18 parts activator; wherein the activator is composed of 12 parts quicklime, 4 parts water glass, and 2 parts sodium sulfate. The raw material ratio in this comparative example deviates significantly from the reasonable range.

[0072] The properties of the binder obtained in this comparative example are as follows: 7-day strength 7.5 MPa, 28-day strength 14.2 MPa, prone to alkali return, and poor water resistance. Comparative conclusion: Imbalance of multiple components disrupts the hydration reaction, resulting in significant deterioration of all properties.

[0073] Comparative Example 3

[0074] A consolidating agent comprises the following raw materials in parts by weight: 35 parts steel slag powder, 35 parts blast furnace slag powder, 12 parts dust collector ash, 7 parts desulfurization gypsum, and 8 parts quicklime. This comparative example uses only quicklime for activation.

[0075] The properties of the consolidating agent obtained in this comparative example are as follows: 7-day strength 8.1 MPa, 28-day strength 15.6 MPa, low density, and weak erosion resistance. In comparison, single-element activation is insufficient, while the ternary compound activation shows significant advantages.

[0076] The preparation methods and applications of the consolidating agents in Comparative Examples 1-3 were all prepared according to the method described in Example 1.

[0077] Each component in the embodiments of the present invention is indispensable, the ratio range is reasonably defined, the compound activation synergistic effect is significantly better than the three control schemes in terms of strength, stability and practicality.

[0078] The test conditions for all embodiments and comparative samples of this invention are completely consistent, and the specific methods are as follows:

[0079] 1. Specimen Preparation: Cylindrical specimens with a diameter of 50 mm × 100 mm were prepared according to method T0804-2024 in the "Test Procedure for Inorganic Binder Stabilized Materials for Highway Engineering" (JTG 3441-2024). The moisture content of the mixture was controlled at 14 ± 1%, and the compaction degree was 95%. The specimens were cured in a standard curing room under the following conditions: temperature 20 ± 2℃ and relative humidity ≥ 95%.

[0080] 2. Unconfined compressive strength test: The test was conducted according to the method T0805-2024 in JTG 3441-2024, with a loading rate of 1 mm / min. The ultimate compressive strength was tested at 7 days and 28 days.

[0081] 3. Water resistance test: Take specimens cured for 28 days and immerse them completely in clean water at 20±2℃ for 7 days. After immersion, remove them and determine their compressive strength according to the aforementioned unconfined compressive strength test method. Strength retention rate = (strength after immersion ÷ strength of the same batch after 28 days of standard curing) × 100%.

[0082] 4. Salt resistance test: The method is the same as the water resistance test, except that the water is replaced with a 5% sodium chloride solution.

[0083] 5. Freeze-thaw resistance test: Specimens cured for 28 days were immersed in clean water at 20±2℃ for 4 days until saturated, and then subjected to 50 freeze-thaw cycles. The parameters for each cycle were: freezing at -20±2℃ for 4 hours, followed by thawing in clean water at 20±2℃ for 4 hours. After the freeze-thaw cycles were completed, the strength retention rate was tested according to the water resistance test method.

[0084] 6. Seawater resistance test: Artificial seawater was prepared according to ASTM D1141-98(2021) standard. The test method is the same as the water resistance test, except that the fresh water is replaced with artificial seawater.

[0085] 7. Efflorescence Resistance and Shrinkage Performance Tests: Efflorescence Resistance Test: Specimens cured for 28 days were placed outdoors in a well-ventilated area (avoiding rain) for 15 days. The proportion of efflorescence area to the total surface area of ​​the specimen was observed and recorded. Judgment Criteria: <1% indicates no efflorescence, 1%–5% indicates minor efflorescence, 5%–15% indicates significant efflorescence, and >15% indicates substantial efflorescence. Volume Shrinkage Rate Test: Immediately after demolding, the initial height and diameter of the specimen were measured using vernier calipers (accuracy 0.02 mm), and the initial volume was calculated. After 28 days of standard curing, the volume was measured and calculated again. Volume shrinkage rate = (initial volume - 28-day volume) ÷ initial volume × 100%. The test results are shown in Table 1.

[0086]

[0087] As shown in Table 1, the embodiments of the present invention have the following advantages: 1. Strength advantage: Compared with the comparative examples lacking core components, having unbalanced proportions, and using a single activator, the rational component ratio and ternary composite activation system of the present invention significantly improve the strength in both early and late stages, resulting in stronger structural load-bearing capacity. 2. Durability advantage: The water resistance, salt resistance, freeze resistance, and seawater erosion resistance retention rates of the embodiments are much higher than those of the comparative examples, with a dense and stable cementitious structure and excellent erosion resistance. 3. Stability advantage: The embodiments of the present invention have extremely low volume shrinkage and virtually no efflorescence; the comparative examples generally have large shrinkage, are prone to efflorescence and cracking, and have poor long-term stability. 4. Necessity of the formulation: The above results prove that steel slag powder is the core skeleton component. The limited proportion range and low-alkali ternary composite activator of this application are the core key to the high performance and high stability of the product, demonstrating significant technological advancement.

[0088] This invention uses local steelmaking solid waste from Tangshan as its core, achieving a solid waste utilization rate of ≥85wt% through the synergistic activation of multiple solid wastes such as steel slag, blast furnace slag, and dust collector ash. It also possesses characteristics such as low cost, early strength, and water and salt resistance, making it suitable for the unique engineering environment of Tangshan. Specifically: 1. All Tangshan solid waste: steel slag, slag, dust collector ash, and desulfurization gypsum, locally sourced with zero long-distance transportation. 2. High solid waste utilization: utilization rate ≥85%, annual utilization of tens of thousands of tons of solid waste. 3. Suitable for Tangshan projects: high salt resistance, water resistance, freeze-thaw resistance → suitable for coastal soft soil; high strength and good stability → suitable for road base courses; low cost → suitable for mine backfilling and stockpile hardening. 4. Low carbon and cement-free: carbon emissions are reduced by at least 60% compared to cement-based methods. 5. Simple process: room temperature mixing, low investment, and quick results. 6. Economic advantages: cost reduction of 30%–50% compared to traditional cement-based solidification.

[0089] This invention provides a Tangshan steel-based multi-solid waste synergistic consolidation agent. The consolidation agent uses steel slag, blast furnace slag, steel dust collector ash, and desulfurization gypsum from the Tangshan area as main raw materials, and is prepared with a low-alkali composite activator. The consolidation agent of this invention has a solid waste utilization rate of ≥85wt%, a 28-day compressive strength of 20-28MPa, and exhibits early strength, water resistance, salt resistance, and freeze-thaw resistance. It is suitable for solidification of soft soil foundations along the Tangshan coast, road base stabilization layers, mine tailings / mining area backfill hardening (8%~12.5%, cured and shaped, high strength, long service life), and hardening and dust suppression of steel solid waste stockpiles (8%~12.5%, cured and shaped, high strength, long service life). This achieves large-scale resource utilization of Tangshan steel solid waste, low carbon and low cost, excellent engineering performance, and significant economic and environmental benefits.

[0090] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the inventive concept of the present invention, can make other changes and modifications to these embodiments, all of which fall within the scope of the present invention.

[0091] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. If such modifications and variations fall within the scope of equivalents of this invention, then this invention also intends to include these modifications and variations.

Claims

1. A steel-based multi-solid waste synergistic consolidation agent, characterized in that, The raw materials include the following parts by weight: 30-45 parts steel slag powder, 25-40 parts blast furnace slag powder, 8-18 parts steel dust collector ash, 4-8 parts desulfurization gypsum, and 5-10 parts composite activator. The composite activator is made from the following raw materials: quicklime, water glass, and sodium sulfate.

2. The steel-based multi-solid waste synergistic consolidation agent according to claim 1, characterized in that, The composite activator is made from the following raw materials in parts by weight: 3-7 parts quicklime, 1-3 parts water glass, and 0.5-1.5 parts sodium sulfate.

3. The steel-based multi-solid waste synergistic consolidation agent according to claim 1, characterized in that, The raw materials include the following parts by weight: 40 parts steel slag powder, 30 parts blast furnace slag powder, 15 parts steel dust collector ash, 6 parts desulfurization gypsum, and 9 parts composite activator.

4. The steel-based multi-solid waste synergistic consolidation agent according to claim 3, characterized in that, The composite activator is made from the following raw materials in parts by weight: 6 parts quicklime, 2 parts water glass, and 1 part sodium sulfate.

5. A method for preparing the steel-based multi-solid waste synergistic consolidation agent according to claim 1, characterized in that, include: Steel slag, blast furnace slag, and dust collector ash are ground separately to obtain steel slag powder, blast furnace slag powder, and iron and steel dust collector ash. Weigh out steel slag powder, blast furnace slag powder, steel dust collector ash, desulfurization gypsum, and composite activator according to the weight ratio, mix them evenly, seal and package them to obtain the final product.

6. The preparation method of the steel-based multi-solid waste synergistic consolidation agent according to claim 5, characterized in that, The fineness of steel slag powder, blast furnace slag powder, and steel dust collector dust is ≥200 mesh, and the specific surface area is ≥400 m². 2 / kg.

7. The preparation method of the steel-based multi-solid waste synergistic consolidation agent according to claim 5, characterized in that, Stir for 3 to 6 minutes.

8. The application of the steel-based multi-solid waste synergistic consolidation agent according to claim 1, characterized in that, It is used for soft soil foundation consolidation, road base construction, mining area backfilling, or dust suppression and soil stabilization projects.

9. The application of the steel-based multi-solid waste synergistic consolidation agent according to claim 8, wherein the dosage of the consolidation agent is 8 to 12.5% ​​of the dry mass of the solidified material.

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