Method for preparing artificial fish reef by using steel slag cementitious material

Abstract

This application relates to a method for preparing artificial reefs using steel slag cementitious materials. The method includes: obtaining a mixture; the mixture being a mixture of steel slag and desulfurized gypsum, or a mixture of blast furnace slag, steel slag, and desulfurized gypsum; wherein the steel slag content in the mixture is ≤50wt%; wherein the steel slag is converter steel slag, and the metallic iron content of the steel slag is ≤2wt%; and the mixture is subjected to iron removal and grinding sequentially to obtain a specific surface area ≥420m². 2 / kg of steel slag cementitious material; the steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain a concrete mixture; the concrete mixture is sequentially molded, left to stand, and demolded to obtain a cured blank; the cured blank is then cured to obtain an artificial reef. This utilizes the alkaline substances in steel slag to react with carbon dioxide in seawater to fix carbon, achieving cross-industry collaborative development.

Description

Technical Field

[0001] This application relates to the fields of solid waste resource utilization and building component technology, and in particular to a method for preparing artificial reefs from steel slag cementitious materials. Background Technology

[0002] Artificial reefs are key facilities in the construction of marine ranches. Their function is to create suitable habitats, breeding grounds, and foraging grounds for various marine organisms, thereby enhancing marine biodiversity and maintaining the stability and balance of marine ecosystems. With its long coastline, my country's demand for artificial reefs for marine ecological restoration and fisheries resource conservation continues to grow, making their role in marine ecological construction increasingly prominent.

[0003] Currently, cement is commonly used as the main binding material in the construction of artificial reefs. The high cost of cement raw materials and the energy-intensive production process keep the production cost of traditional artificial reefs high, thus limiting their large-scale application. Meanwhile, the large amounts of solid waste generated by the steel industry, such as steel slag and blast furnace slag, face the practical problems of limited resource utilization and difficulties in large-scale disposal. Summary of the Invention

[0004] This application provides a method for preparing artificial reefs using steel slag cementitious materials, in order to solve the following technical problem: how to reduce the raw material cost of artificial reefs and improve the utilization rate of steel slag. This application provides a method for preparing artificial reefs using steel slag cementitious materials, the method comprising: A mixture is obtained; the mixture is composed of steel slag and desulfurization gypsum, or a mixture composed of blast furnace slag, steel slag and desulfurization gypsum; in the mixture, the content of steel slag is ≤50wt%; wherein the steel slag is converter steel slag, and the metallic iron content of the steel slag is ≤2wt%; The mixture was subjected to iron removal and grinding in sequence to obtain a specific surface area ≥420m². 2 / kg of steel slag cementitious materials; The steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain a concrete mixture; The concrete mixture is sequentially molded, left to stand, and demolded to obtain a cured green body. The molded body is cured to obtain an artificial reef.

[0005] Optionally, the moisture content of the mixture is ≤15%.

[0006] Optionally, before the grinding, the maximum particle size of the mixture is ≤20mm; wherein, 95% of the mixture has a particle size ≤10mm.

[0007] Optionally, the grinding is performed using a vertical mill, and the rotor speed of the vertical mill is 105 r / min to 130 r / min.

[0008] Optionally, the mass ratio of the steel slag cementitious material to the fly ash is 3:1 to 4:1; the mass ratio of the steel slag cementitious material to the water is 2.0:1 to 4.0:1.

[0009] Optionally, the settling time is 3 to 5 hours.

[0010] Optionally, the curing process involves wrapping the curing blank with geotextile, film, and burlap sacks.

[0011] Optionally, when the curing temperature is ≥5℃, the wrapped curing blank is sprayed with water every day to keep the surface moist, and the number of days for watering and moisturizing is ≥7 days; the total curing time is ≥14 days.

[0012] Optionally, when the mixture is a mixture of blast furnace slag, steel slag and desulfurized gypsum, and the steel slag content is 30wt%, the strength index of the obtained steel slag cementitious material reaches the PO 42.5 cement strength standard.

[0013] Optionally, the artificial reef has a strength grade ≥ C25.

[0014] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a method for preparing artificial reefs using steel slag cementitious materials. The method includes: obtaining a mixture; the mixture is a mixture of steel slag and desulfurization gypsum, or a mixture of blast furnace slag, steel slag, and desulfurization gypsum; in the mixture, the content of steel slag is ≤50wt%; wherein the steel slag is converter steel slag, and the metallic iron content of the steel slag is ≤2wt%; the mixture is subjected to iron removal and grinding sequentially to obtain a specific surface area ≥420m². 2 / kg of steel slag cementitious material; the steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain a concrete mixture; the concrete mixture is then molded, left to stand, and demolded to obtain a cured blank; the cured blank is then cured to obtain an artificial reef. At the raw material level, converter steel slag, blast furnace slag, desulfurization gypsum, and other bulk solid wastes from the steel industry are creatively selected as the main base material for the cementitious material. These materials are byproducts of the production process, and their acquisition cost is significantly lower than that of traditional cement. Firstly, the raw materials were strictly defined and combined, limiting the metallic iron content of the steel slag and various feasible material proportioning modes, aiming to control the chemical and physical properties of the raw materials from the source, laying the foundation for the preparation of high-performance cementitious materials. At the process level, a pre-process iron removal step removes metallic impurities that interfere with grinding, followed by deep grinding in a vertical mill to a specific specific surface area, greatly increasing the reactive surface area of ​​the mixture. The highly reactive steel slag cementitious material is mixed with aggregates and water in a certain proportion and then molded. A specific temperature and humidity controlled curing regime is then applied, which effectively promotes the hydration reaction of the highly reactive steel slag cementitious material, ultimately forming artificial reef concrete products with a stable microstructure and sufficient mechanical strength. This process transforms low-value solid waste into structural materials that meet the requirements of marine engineering.

[0015] In summary, this technical solution constitutes a complete and efficient closed-loop technology, from low-cost solid waste screening and proportioning design at the raw material end to targeted physical activation and precise process control at the processing end. The essence of this technical solution lies in the organic combination of materials science and process engineering to achieve the resource-based and high-value utilization of industrial solid waste such as steel slag, while ensuring that the final artificial reef product meets the specified performance standards. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0018] Figure 1 This is a flowchart illustrating a method for preparing artificial reefs using steel slag cementitious materials, as provided in an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1~6" cover all sub-ranges between 1 and 6 (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6). Unless otherwise specified, the terms "including" and "contains" used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship. "And / or" indicates that multiple situations can exist individually or simultaneously. Expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0021] Figure 1 This is a flowchart illustrating a method for preparing artificial reefs using steel slag cementitious materials, as provided in an embodiment of this application.

[0022] Please see Figure 1 This application provides a method for preparing artificial reefs using steel slag cementitious materials, the method comprising: S1. Obtain a mixture; the mixture is a mixture of steel slag and desulfurization gypsum, or a mixture of blast furnace slag, steel slag and desulfurization gypsum; in the mixture, the content of steel slag is ≤50wt%; wherein the steel slag is converter steel slag, and the metallic iron content of the steel slag is ≤2wt%; S2. The mixture is subjected to iron removal and grinding in sequence to obtain a specific surface area ≥420m². 2 / kg of steel slag cementitious materials; S3. Mix the steel slag cementitious material, fly ash, aggregate, water and water-reducing agent to obtain a concrete mixture; S4. The concrete mixture is sequentially molded, left to stand, and demolded to obtain a cured blank. S5. The curing blank is cured to obtain an artificial reef.

[0023] In the above technical solution, solid waste from the steel industry is transformed into high-performance cementitious materials through specific raw material formulation and pretreatment processes, thereby preparing artificial reefs suitable for marine environments. The core of this solution lies in selecting raw materials such as converter steel slag with specific compositions and particle sizes, purifying them through iron removal and deep grinding and activation to obtain active cementitious materials with high specific surface area. Subsequently, this active cementitious material is mixed with aggregates in a specific ratio, and a temperature- and humidity-controlled curing system is used to form a stable and dense microstructure in the mixture. The resulting artificial reef product possesses the required mechanical strength, durability, and environmental protection characteristics, thus achieving the synergistic goal of solid waste resource utilization and low-cost marine engineering materials.

[0024] In some embodiments, the content of steel slag in the mixture is ≤50wt%.

[0025] By leveraging the synergistic effect of the active components of steel slag with blast furnace slag and desulfurization gypsum, the final steel slag cementitious material possesses sufficient mechanical properties and durability, thus enabling it to replace traditional cement in the preparation of artificial reefs. By optimizing the proportion of steel slag, the material maximizes the utilization of solid waste from the steel industry while ensuring the artificial reefs achieve the required engineering strength, effectively reducing raw material costs. For example, the steel slag content in the mixture can be 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, etc.

[0026] In some embodiments, the steel slag is converter steel slag, and the metallic iron content of the steel slag is ≤2wt%.

[0027] The steel slag used is converter steel slag with a metallic iron content of ≤2wt%. Using relatively stable converter steel slag and strictly controlling its metallic iron content ensures the fundamental stability and performance of the steel slag cementitious material from the raw material stage. This also reduces wear on equipment during grinding and avoids the negative impact of metallic iron on the cementitious hydration reaction, thus guaranteeing that the final steel slag cementitious material has high and stable activity. For example, the metallic iron content of the steel slag can be 1wt%, 2wt%, etc.

[0028] In some embodiments, the moisture content of the mixture is ≤15%.

[0029] The wet basis moisture content of the mixture can be determined by drying and then calculated using the following formula: In the formula, m is the mass of the mixture before drying (in grams); m1 is the mass of the mixture after drying (in grams); and W is the wet basis moisture percentage of the mixture (in %). During the industrial production assessment, the moisture content of the mixture entering the mill during the 72-hour assessment period is taken as the arithmetic mean of multiple test results. The moisture content of the mixture should be ≤15% primarily to prevent adhesion and clumping due to excessive moisture, thus avoiding impact on grinding efficiency and even equipment blockage. This ensures the mixture maintains a loose and uniform physical state, guaranteeing a stable and efficient grinding process, ultimately resulting in a stable and highly active steel slag cementitious material. For example, the moisture content of the mixture can be 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0030] In some embodiments, the maximum particle size of the mixture is ≤20 mm before the grinding is performed; wherein, 95% of the mixture has a particle size ≤10 mm.

[0031] The particle size determination method involves dry sieving the dried mixture using a 10mm square-hole sieve to directly obtain the percentage of material passing through the sieve, thus confirming that the particle size distribution meets the control requirements. Before grinding, the maximum particle size of the mixture is ≤20mm; among which, 95% of the mixture has a particle size ≤10mm. Controlling the particle size of the mixture within this range reduces the grinding load on the vertical mill, minimizing equipment wear and energy consumption, while ensuring that all mixture particles are fully and uniformly activated and ground. This results in the stable preparation of highly active steel slag cementitious materials, laying a reliable foundation for the final preparation of qualified artificial reefs. For example, the maximum particle size of the mixture can be 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, etc.; among which, 95% of the mixture has a particle size of 2mm, 4mm, 6mm, 8mm, 10mm, etc.

[0032] In some embodiments, the grinding is performed using a vertical mill with a rotor speed of 105 r / min to 130 r / min.

[0033] When using a vertical mill for grinding, the particle size of the finished steel slag cementitious material can be controlled by adjusting the rotor speed. The fineness of the output material varies with the rotor speed: increasing the rotor speed results in a finer output material, while decreasing the rotor speed coarser particles. This flexibly adjustable grinding method allows for precise adjustment of the grinding degree based on the actual state of the feed mixture, consistently obtaining highly active steel slag cementitious material that meets the fineness requirements. This method ensures both grinding production efficiency and guarantees that the final steel slag cementitious material meets the activity requirements for preparing high-strength artificial reefs. For example, the rotor speed of the vertical mill can be 105 r / min, 110 r / min, 115 r / min, 120 r / min, 125 r / min, 130 r / min, etc.

[0034] In some embodiments, the specific surface area of ​​the steel slag cementitious material is ≥420 m². 2 / kg.

[0035] The specific surface area is determined by taking representative samples hourly from the finished product elevator chute and the storage silo discharge port, with each sample weighing no less than 200g. The test is conducted according to GB / T 8074-2008 "Determination of Specific Surface Area of ​​Cement (Bradley Method)" to accurately obtain the specific surface area value of the cementitious material. The specific surface area of ​​steel slag cementitious materials is ≥520m². 2 The specific surface area of ​​this material (approximately 420 m² / kg) increases the contact area for the hydration reaction of the cementitious particles, effectively stimulating the cementitious activity of the steel slag. During subsequent concrete mixing, the high specific surface area ensures the full hydration reaction of the steel slag cementitious material, thereby enabling the final artificial reef concrete to stably reach the required structural strength level and meet the mechanical performance requirements of marine engineering for artificial reefs. This provides a reliable guarantee for using steel slag to replace traditional cement in the preparation of artificial reefs. For example, the specific surface area of ​​the steel slag cementitious material can be 420 m² / kg. 2 / kg, 430m 2 / kg, 440m 2 / kg, 450m 2 / kg, etc.

[0036] In some embodiments, the mass ratio of the steel slag cementitious material to the fly ash is 3:1 to 4:1; the mass ratio of the steel slag cementitious material to the water is 2.0:1 to 4.0:1.

[0037] The mass ratio of steel slag cementitious material to fly ash is 3:1 to 4:1; the mass ratio of steel slag cementitious material to water is 2.0:1 to 4.0:1. Controlling the proportion of fly ash can fully utilize its micro-aggregate effect. Fly ash effectively fills the particle gaps between aggregates, optimizing the particle size distribution and microstructure of concrete, thereby improving the density of the concrete mixture. Simultaneously, strictly controlling the mass ratio of water to cementitious material aims to precisely meet the water requirements for the hydration reaction of the cementitious material, avoiding the formation of pores after excessive water evaporation. For example, the mass ratio of steel slag cementitious material to fly ash can be 3:1, 4:1, etc.; the mass ratio of steel slag cementitious material to water can be 2.0:1, 3.0:1, 4.0:1, etc.

[0038] In some implementations, the settling time is 3 to 5 hours.

[0039] The settling time is between 3 and 5 hours. This settling time allows sufficient time for the mixture to naturally expel internal air bubbles and for the material to settle evenly, resulting in a stable and uniform initial dense structure in the green body. This settling time ensures that the green body completes its initial solidification and shaping, preventing deformation, cracking, or collapse during demolding due to structural instability, thus ensuring the integrity and uniformity of the green body's shape. At the same time, it avoids delaying the production rhythm due to excessively long settling time, thereby balancing the quality of green body forming and production efficiency, providing a reliable foundation for subsequent curing to obtain qualified artificial reefs. For example, the settling time can be 3 hours, 4 hours, or 5 hours.

[0040] In some embodiments, the curing process involves wrapping the curing blank with geotextile, film, and burlap sacks.

[0041] During the curing process, geotextiles, films, and burlap sacks are used to wrap the curing blanks, creating a composite moisture-retaining protective layer on the outside. This protective layer effectively reduces excessive evaporation of moisture from the curing blanks, providing stable humidity conditions for the continuous hydration reaction of the steel slag cementitious material and preventing surface shrinkage and cracking due to rapid moisture loss. Simultaneously, it buffers the interference of external temperature fluctuations on the hydration of the curing blanks and prevents damage from external impacts, ensuring uniform and thorough hydration of the curing blanks.

[0042] In some embodiments, when the curing temperature is ≥5℃, the wrapped curing blank is sprayed with water every day to keep the surface moist, and the number of days for watering and moisturizing is ≥7 days; the total curing time is ≥14 days.

[0043] When the curing temperature is ≥5℃, the wrapped curing blank should be sprayed with water daily to keep the surface moist for ≥7 days. This watering and moisturizing measure can continuously maintain a moist environment inside the curing blank, meeting the continuous water requirements of the early hydration process of the steel slag cementitious material, avoiding excessive water loss leading to incomplete hydration reaction, and preventing cracking of the curing blank surface due to water loss and shrinkage. This ensures the stable and balanced development of the early strength of the curing blank, laying the foundation for the final performance of the artificial reef. For example, when the curing temperature is ≥5℃, the wrapped curing blank should be sprayed with water daily to keep the surface moist for 7, 8, 9, or 10 days, etc.

[0044] The total curing time is ≥14 days. This curing duration is adapted to the hydration development rate characteristics of the active components in steel slag-based cementitious materials, ensuring that the active components within the cementitious system continuously and fully complete the hydration reaction, and promoting the stable growth of concrete strength to meet design requirements. For example, the total curing time can be 14 days, 15 days, 16 days, etc.

[0045] In some embodiments, when the mixture is a mixture of blast furnace slag, steel slag and desulfurized gypsum, and the steel slag content is 30 wt%, the highest strength index of the obtained steel slag cementitious material reaches the PO 42.5 cement strength standard.

[0046] The steel slag cementitious material prepared under this dosage ratio can reach the strength standard of traditional cement, verifying the rationality of the raw material compounding design of this invention. It proves that the steel slag cementitious material prepared with industrial solid waste as the main raw material can fully meet the strength requirements of cementitious materials for artificial reef preparation. It not only realizes the large-scale and high-value utilization of steel slag, but also completely replaces traditional cement as the cementitious component of artificial reef concrete, effectively reducing the raw material production cost of artificial reefs, while ensuring that the structural strength of the final artificial reef can meet the requirements of marine engineering.

[0047] In some embodiments, the artificial reef has a strength grade ≥ C25.

[0048] Artificial reefs should have a strength grade of ≥C25, which meets the performance requirements for long-term service in marine environments. After deployment, artificial reefs need to withstand long-term water flow impacts, loads, and marine environmental erosion; sufficient structural strength is a core prerequisite for ensuring the integrity of their shape and the stability of their function. For example, the strength grade of artificial reefs can be C25, C30, C35, C40, etc.

[0049] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards / industry standards / the disclosure herein; if there are no corresponding national standards / industry standards / the disclosure herein, they are performed according to generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer.

[0050] Example 1 Steel slag and desulfurization gypsum were mixed to obtain a mixture; wherein the steel slag content was 50 wt%, the metallic iron content of the steel slag was 1.8 wt%, and the moisture content of the mixture was 6.2%. The mixture was subjected to iron removal to remove internal metallic impurities. Before grinding, the maximum particle size of the mixture was 10 mm, and 95% of the mixture had a particle size of 8 mm. The mixture was then ground using a vertical mill with a rotor speed of 125 r / min, resulting in a specific surface area of ​​422 m². 2 / kg of steel slag cementitious materials; Steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain concrete mixture; wherein the mass ratio of steel slag cementitious material to fly ash is 3:1; and the mass ratio of steel slag cementitious material to water is 2.4:1. The concrete mixture is sequentially molded, left to stand, and then demolded to obtain a cured blank; the standing time is 4 hours. The prefabricated body is cured by wrapping it with geotextile, film and burlap sacks; the curing temperature is 30℃, and the wrapped prefabricated body is kept moist by sprinkling water for 7 days; the total curing time is 28 days, and the artificial reef is obtained.

[0051] Example 2 Blast furnace slag, steel slag, and desulfurization gypsum were mixed to obtain a mixture; wherein the steel slag content was 50 wt%, the metallic iron content of the steel slag was 1.8 wt%, and the moisture content of the mixture was 5.3%. The mixture was subjected to iron removal to remove internal metallic impurities. Before grinding, the maximum particle size of the mixture was 15 mm. The mixture was then ground using a vertical mill with a rotor speed of 120 r / min, resulting in a specific surface area of ​​423 m². 2 / kg of steel slag cementitious materials; Steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain concrete mixture; wherein the mass ratio of steel slag cementitious material to fly ash is 3:1; the mass ratio of steel slag cementitious material to water is 2.2:1. The concrete mixture is sequentially molded, left to stand, and then demolded to obtain a cured blank; the standing time is 4 hours. The prefabricated body is cured by wrapping it with geotextile, film and burlap sacks; the curing temperature is 30℃, and the wrapped prefabricated body is kept moist by sprinkling water for 7 days; the total curing time is 28 days, and the artificial reef is obtained.

[0052] Example 3 Blast furnace slag, steel slag, and desulfurization gypsum were mixed to obtain a mixture; wherein the steel slag content was 40 wt%, the metallic iron content of the steel slag was 1.7 wt%, and the moisture content of the mixture was 6.5%. The mixture was subjected to iron removal to remove internal metallic impurities. Before grinding, the maximum particle size of the mixture was 15 mm. The mixture was then ground using a vertical mill with a rotor speed of 120 r / min, resulting in a specific surface area of ​​435 m². 2 / kg of steel slag cementitious materials; Steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain concrete mixture; wherein, the mass ratio of steel slag cementitious material to fly ash is 4:1; the mass ratio of steel slag cementitious material to water is 2.4:1. The concrete mixture is sequentially molded, left to stand, and then demolded to obtain a cured blank; the standing time is 4 hours. The prefabricated body is cured by wrapping it with geotextile, film and burlap sacks; the curing temperature is 20℃, and the wrapped prefabricated body is kept moist by sprinkling water for 7 days; the total curing time is 28 days, and the artificial reef is obtained.

[0053] Example 4 Blast furnace slag, steel slag, and desulfurization gypsum were mixed to obtain a mixture; wherein the steel slag content was 30 wt%, the metallic iron content of the steel slag was 1.7 wt%, and the moisture content of the mixture was 5%. The mixture was subjected to iron removal to remove internal metallic impurities. Before grinding, the maximum particle size of the mixture was 16 mm. The mixture was then ground using a vertical mill with a rotor speed of 130 r / min, resulting in a specific surface area of ​​503 m². 2 / kg of steel slag cementitious materials; Steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain concrete mixture; wherein the mass ratio of steel slag cementitious material to fly ash is 4:1; and the mass ratio of steel slag cementitious material to water is 2.5:1. The concrete mixture is sequentially molded, left to stand, and then demolded to obtain a cured blank; the standing time is 4 hours. The prefabricated body is cured by wrapping it with geotextile, film and burlap sacks; the curing temperature is 30℃, and the wrapped prefabricated body is kept moist by sprinkling water for 7 days; the total curing time is 28 days, and the artificial reef is obtained.

[0054] Example 5 Blast furnace slag, steel slag, and desulfurization gypsum were mixed to obtain a mixture; wherein the steel slag content was 20 wt%, the metallic iron content of the steel slag was 1.8 wt%, and the moisture content of the mixture was 7%. The mixture was subjected to iron removal to remove internal metallic impurities. Before grinding, the maximum particle size of the mixture was 16 mm, and 95% of the mixture had a particle size of 8 mm. The mixture was then ground using a vertical mill with a rotor speed of 120 r / min, resulting in a specific surface area of ​​482 m². 2 / kg of steel slag cementitious materials; Steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain concrete mixture; wherein, the mass ratio of steel slag cementitious material to fly ash is 4:1; the mass ratio of steel slag cementitious material to water is 2.4:1. The concrete mixture is sequentially molded, left to stand, and then demolded to obtain a cured blank; the standing time is 4 hours. The prefabricated body is cured by wrapping it with geotextile, film and burlap sacks; the curing temperature is 25℃, and the wrapped prefabricated body is kept moist by sprinkling water for 7 days; the total curing time is 28 days, and the artificial reef is obtained.

[0055] Comparative Example 1 C30 concrete The material ratio is 300 kg of cement and 50 kg of fly ash, and the mass ratio of cementitious material to water is 1.79:1. The concrete mixture is sequentially molded, left to stand, and then demolded to obtain a cured blank; the standing time is 4 hours. The prefabricated body is cured by wrapping it with geotextile, film and burlap sacks; the curing temperature is 20℃, and the wrapped prefabricated body is kept moist by sprinkling water for 7 days; the total curing time is 28 days, and the artificial reef is obtained.

[0056] Comparative Example 2 C40 concrete The material ratio is 370 kg of cement and 50 kg of fly ash, with a cementitious material to water mass ratio of 2.5:1; The concrete mixture is sequentially molded, left to stand, and then demolded to obtain a cured blank; the standing time is 4 hours. The prefabricated body is cured by wrapping it with geotextile, film and burlap sacks; the curing temperature is 20℃, and the wrapped prefabricated body is kept moist by sprinkling water for 7 days; the total curing time is 28 days, and the artificial reef is obtained.

[0057] Effect data: The effect data of Examples 1 to 5 and Comparative Examples 1 to 2 are shown in Table 1.

[0058] Table 1

[0059] The above effect data table provides a clear comparison of the differences between various embodiments and comparative examples. The following conclusions can be drawn: As can be seen from Examples 1-5 and Comparative Examples 1-2, Examples 1-5 not only achieve similar or even higher early strength, but also exhibit significantly better resistance to sulfate attack and long-term seawater immersion. After immersion in seawater for 60 days, the compressive strength of Examples 3 and 4 can still be maintained at a high level of 45.8 MPa and 49.6 MPa, respectively, which is much higher than the 29.4 MPa and 34.6 MPa of Comparative Examples 1-2. This fully demonstrates that the steel slag cementitious material prepared in this application is beneficial to the artificial reef in maintaining structural stability and durability in harsh marine environments for a long time.

[0060] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A method for preparing artificial reefs using steel slag cementitious materials, characterized in that, The method includes: A mixture is obtained; the mixture is composed of steel slag and desulfurization gypsum, or a mixture composed of blast furnace slag, steel slag and desulfurization gypsum; in the mixture, the content of steel slag is ≤50wt%; wherein the steel slag is converter steel slag, and the metallic iron content of the steel slag is ≤2wt%; The mixture was subjected to iron removal and grinding in sequence to obtain a specific surface area ≥420m². 2 / kg of steel slag cementitious materials; The steel slag cementitious material, fly ash, aggregate, water and water-reducing agent are mixed to obtain a concrete mixture; The concrete mixture is sequentially molded, left to stand, and demolded to obtain a cured green body. The molded body is cured to obtain an artificial reef.

2. The method according to claim 1, characterized in that, The moisture content of the mixture is ≤15%.

3. The method according to claim 1, characterized in that, Before the grinding is performed, the maximum particle size of the mixture is ≤20mm; wherein, 95% of the mixture has a particle size ≤10mm.

4. The method according to claim 1, characterized in that, The grinding is carried out using a vertical mill, and the rotor speed of the vertical mill is 105 r / min to 130 r / min.

5. The method according to claim 1, characterized in that, The mass ratio of the steel slag cementitious material to the fly ash is 3:1 to 4:1; the mass ratio of the steel slag cementitious material to the water is 2.0:1 to 4.0:

1.

6. The method according to claim 1, characterized in that, The settling time is 3 to 5 hours.

7. The method according to claim 1, characterized in that, The curing process involves wrapping the curing blank with geotextile, film, and burlap sacks.

8. The method according to claim 1 or 7, characterized in that, When the curing temperature is ≥5℃, the wrapped curing blank is sprayed with water every day to keep the surface moist, and the number of days for watering and moisturizing is ≥7 days; the total curing time is ≥14 days.

9. The method according to claim 1, characterized in that, When the mixture is a mixture of blast furnace slag, steel slag and desulfurized gypsum, and the steel slag content is 30wt%, the strength index of the obtained steel slag cementitious material reaches the strength standard of PO 42.5 cement.

10. The method according to claim 1, characterized in that, The artificial reef has a strength grade ≥ C25.

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