Steel slag modified cementing material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of solid waste resource utilization, and discloses a steel slag modified cementing material, a preparation method and application, and the preparation method comprises the following steps: S1, collecting high-temperature steel slag; s2, regulating and controlling components of the molten steel slag under heat preservation; s3, phase modification and reconstruction in the heat preservation stage; s4, reconstructing a first-stage cooling phase of the modified steel slag; s5, carrying out second-stage cooling phase reconstruction on the modified steel slag; and S6, cooling post-treatment is carried out. According to the invention, through synchronous improvement of a formula and a preparation process, direct treatment of molten steel slag, and a method of combining thermal insulation and two-stage cooling phase reconstruction and modification, the content of each component in the steel slag, crystal grains and other phases are controlled, so that the steel slag meets new national standard requirements at the same time; the treated modified material can be used as clinker to be applied to manufacturing of ordinary Portland cement, and the consumption amount is increased. According to the method, energy and resources are utilized at the same time, the resource utilization value and the total consumption amount of the steel slag are increased, and the method has high application value in industry.

Description

Technical Field

[0001] The invention belongs to the field of solid waste resource utilization and metallurgical technology, and specifically relates to a steel slag modified gelling material, a preparation method and an application thereof. Background Art

[0002] Steel slag is an industrial waste and one of the bulk solid wastes that is difficult to process and utilize in the metallurgical industry. In recent years, with the continuous increase in steel production, the output of steel slag, as a by-product of the steelmaking process, has also increased dramatically. At present, most steel companies only use steel slag for initial crushing and magnetic separation to recover the iron in it, while most of the steel slag tailings are directly piled up and stored, which not only pollutes the environment, but also occupies a large amount of land resources, and is also a waste of resources for steel slag.

[0003] Steel slag contains the gelling minerals tricalcium silicate (3CaO·SiO2) and dicalcium silicate (2CaO·SiO2), so steel slag is also often used in cement, concrete, etc. However, due to the small number of silicate minerals in steel slag, large grains, and poor gelling activity, the activity of steel slag is much lower than that of cement clinker. However, with the promulgation and implementation of the new national standard GB 175-2023, steel slag can no longer be directly used in cement admixtures, reducing the utilization of steel slag. In addition, the current application methods of steel slag are to naturally cool the steel slag to room temperature before using it, and the discharge temperature of steel slag is as high as 1600°C, and a large amount of heat energy is not effectively utilized.

[0004] Among the existing patent technologies, the Chinese invention document CN108658483A discloses a method for preparing auxiliary cementitious materials by reducing and recovering iron from steel slag and secondary slag, which comprises mixing converter steel slag (reduced to room temperature), a reducing agent and a component adjustment material evenly, heating and calcining them separately, remelting them under a high temperature reducing atmosphere, and then cooling them by water quenching. After separating the metallic iron, the secondary slag is dried and ground to obtain an auxiliary cementitious material. This technical solution requires additional energy for remelting (the remelting and calcining temperature is 1455-1495°C), but cannot utilize the waste heat of the molten steel slag itself, and has high energy consumption; the crystal development particle size of the components in the steel slag cannot be controlled by directly water quenching, so only auxiliary cementitious materials can be obtained, and cement clinker cannot be directly replaced.

[0005] Chinese invention document CN115745449A discloses a method for preparing micro powder by smelting and tempering steel slag. The method comprises the following steps: fully stirring and mixing steel slag and acidic oxide, adding a reducing agent and stirring and mixing to obtain a steel slag mixture, then adding the steel slag mixture into a smelting furnace and smelting the steel slag mixture until the steel slag mixture becomes liquid, and then rapidly freezing the tempered slag solution at 1500°C and cooling it to below 50°C within 10 to 15 seconds. The cooling rate is 96 to 145°C / s. The purpose of the cooling is to shorten the waiting time for the natural cooling of the tempered slag and quickly obtain the low-temperature tempered slag for further processing into micro powder and emptying the container for processing the next batch of steel slag, rather than to adjust the grain size of the internal components of the tempered slag.

[0006] In other documents, the existing patent technology CN104016600A discloses a method of removing iron by magnetic separation after high-temperature reconstruction and modification of steel slag with silicon-rich materials. The volume stability and gelling activity of the steel slag are improved by adding silicon-rich materials for high-temperature reconstruction and modification. The iron minerals are then separated by magnetic separation, and those with high iron content can be used as raw materials for ironmaking. However, this method fails to make full use of the heat of steel slag, and still achieves the purpose of steel slag modification through secondary heating and calcination, and the properties of its product cannot directly replace cement clinker; another invention patent CN111996314A discloses a method for extracting iron by carbon thermal reduction of hot converter slag, which ensures that the temperature of converter steel is above 1600°C, and after steel is tapped, coke powder and hot converter slag are mixed in batches in a slag tank, followed by nitrogen blowing and stirring, and river sand is added in batches to modify the converter slag, which can achieve more than 80% of the iron-containing oxides in the converter slag to be reduced to metallic iron; although this method utilizes the heat of converter slag, the degree of iron reduction is not complete and the recovery rate is low, and the method proposes that the modified converter slag can be used in slag cement (not ordinary silicate cement) to replace part of the cement clinker, and the application field is relatively limited. The third invention patent, CN106348626A, discloses a method for recycling converter molten slag to produce concrete admixtures, which achieves the purpose of improving the cementitious activity of slag and recycling slag by adding ferrosilicon, a reducing agent, to the molten slag. The ferrosilicon, a reducing agent used in this method, is relatively expensive and can only be used as a concrete admixture with low value. The fourth invention patent, CN102796833A, discloses a modification process for molten slag iron reduction and component reconstruction, which modifies the slag by adding coke and silica to the molten slag. However, this method still requires the mixed slag to be heated again, and the microcrystalline glass particles prepared by this method are not proposed. Although the application range is large, the actual total amount is far less than that of cement, which limits the industrial consumption capacity of large amounts of slag.

[0007] In summary, with the promulgation and implementation of the new national standard GB 175-2023, existing technologies can no longer absorb and recycle solid waste steel slag in large quantities; moreover, existing technologies cannot simultaneously maximize the value of the "heat" of newly molten steel slag, the "iron" in the steel slag, and the "slag" resources after iron removal, while meeting the industry's demand for low-cost, high-value resource utilization of steel slag and expanding the total absorption capacity. Summary of the invention

[0008] The object of the present invention is to overcome the above technical deficiencies, provide a method for preparing a steel slag modified cementitious material and its application, by simultaneously improving the formula and the preparation process, directly transporting and treating the molten steel slag in an intermediate slag tank, and combining the insulation with the two-stage cooling phase reconstruction modification method, controlling the development of the steel slag phase grains in the modified cementitious material, making the composition and particle size of each component similar to cement clinker, and controlling the content of each component within the range required by the new national standard GB / T21372-2024 silicate cement clinker (including the free calcium oxide content, etc.), so that the modified material can be supplied to cement plants as cement clinker and the consumption amount can be increased; more than 97wt% of the iron-containing oxides in the molten steel slag are reduced to metallic iron, and other components are modified into cementitious materials, thereby realizing the high-value, resource-based, and large-consumption synchronous comprehensive utilization of the "heat", "iron" and "slag" resources in the molten steel slag, so as to solve the problems of energy waste, low utilization rate of solid waste steel slag, land occupation and environmental pollution in the metallurgical industry.

[0009] In order to achieve the above technical purpose, the technical solution provided by the present invention is as follows: A method for preparing a steel slag modified gelling material, characterized in that it comprises the following steps: S1. Collect high temperature slag Use an insulated intermediate slag pot to collect the high-temperature molten slag (about 1700℃) discharged from the steelmaking converter and transfer it to the modification workshop; S2. Control of molten slag composition under heat preservation Keep the temperature of the slag in the slag pot at 1500~1600℃ in a molten state, add the pre-prepared modified powder to the molten slag, mix and stir. During the stirring process, the Ca 2+ Ions diffuse and react with silicate ions and 2CaO·SiO2 to reconstruct the phase and form 3CaO·SiO2, the main phase of silicate cement. At the same time, the iron-containing phase in the molten slag reacts with the reducing agent in the modified powder to generate elemental iron. The modified powder is a mixed powder composed of a reducing agent, a calcium material and a silicon material in a set ratio and a particle diameter of 5-50 mm, wherein the mass ratio of each component is reducing agent: calcium material: silicon material: molten steel slag = (0.08-0.18): (0.12-0.23): (0.018-0.055): 1; S3, phase modification and reconstruction during heat preservation stage Stop stirring and continue to keep the temperature of the steel slag in the slag pot at a molten state of 1500-1600°C for 30-60 minutes to make the composition of the molten steel slag uniform. In this process, the reduced molten iron naturally settles to the bottom of the slag pot, and the molten modified steel slag after the adjustment naturally floats on the upper part of the slag pot; the molten modified steel slag naturally floating on the upper part of the slag pot is transferred to another slag pot with insulation for modification to separate the slag and iron; S4, Phase reconstruction of the first stage of cooling of modified steel slag The molten modified steel slag with a temperature of 1500-1600℃ after transfer is slowly cooled to 1250-1300℃ at a rate of 10-30℃ / min to carry out the first stage of cooling phase reconstruction. In this process, the main phases of cement clinker, 3CaO·SiO2 and 2CaO·SiO2, are precipitated from the molten modified steel slag, and small crystals gradually develop and grow. S5, Phase reconstruction of the second stage of cooling of modified steel slag The modified steel slag is rapidly cooled from 1250-1300℃ to room temperature at a cooling rate of 40-70℃ / s. This process stops the generated 3CaO·SiO2 grains from growing further, makes the 3CaO·SiO2 grains moderate, inhibits the decomposition of the 3CaO·SiO2 phase, and prevents the 2CaO·SiO2 crystal form from transforming into the γ type. The various components of the molten modified steel slag interact with each other and gradually form the main phases 3CaO·SiO2 and 2CaO·SiO2 contained in the cement clinker. S6. Post-cooling treatment The step S5 is cooled to room temperature to obtain a blocky slag-modified cementitious material which has undergone heat preservation and two-stage cooling phase reconstruction, which is first crushed and then ground to a specific surface area SSA of 300m² / kg≤SSA≤400m² / kg to prepare a silicate cement clinker mainly composed of 3CaO·SiO2, 2CaO·SiO2 and other phases.

[0010] A steel slag modified cementitious material is prepared by the method, wherein the content of each component and the grain size and other physical phases in the steel slag modified cementitious material are controlled within the range required by the new national standard GB / T 21372-2024 silicate cement clinker (including free calcium oxide content, etc.).

[0011] The application of the steel slag modified cementitious material as clinker in the preparation of ordinary Portland cement can directly replace the ordinary Portland cement clinker under the national standard GB / T 21372-2024, and can be directly used as cement after being ground with auxiliary materials such as gypsum.

[0012] Compared with the prior art, the beneficial effects of the present invention include: 1. The steel slag modified cementitious material, preparation method and application provided by the present invention, through the simultaneous improvement of the formula and the preparation process, adopts the direct treatment of molten steel slag, and controls the content of each component in the steel slag, the grain and other phases through the method of heat preservation and two-stage cooling phase reconstruction combined with modification, so that the molten steel slag and the components of the modified powder interact with each other and gradually form the main phases 3CaO·SiO2 and 2CaO·SiO2 contained in the cement clinker, so that the phase composition such as the steel slag component and the grain size of the modified cementitious material is similar to the cement clinker phase, and the content of each component in the powdered steel slag modified cementitious material can be controlled to meet the requirements of the national standard GB 175-2023 general silicate cement on the fineness of silicate cement, so that the treated modified material can be used as clinker, applied to the manufacture of ordinary silicate cement, and the consumption is improved.

[0013] 2. The steel slag modified cementitious material, preparation method and application provided by the present invention adopt two slag pots to transport and modify the molten steel slag respectively, without the need for secondary heating and calcination. The waste heat of the steel slag can be used to reduce more than 97wt% of the iron-containing oxides in the molten steel slag into metallic iron, and the other part is prepared as a modified cementitious material, thereby realizing the high-value, resource-based and large-volume comprehensive utilization of "heat", "iron" and "slag", and can simultaneously solve the problems of energy waste, low utilization rate of solid waste steel slag, land occupation and environmental pollution in the metallurgical industry.

[0014] 3. The present invention can efficiently utilize the waste heat and various minerals of molten steel slag at the same time through the coordinated coordination of components, formulas and processes. Modified powder is added in the high-temperature modification stage to adjust the physical phase of the steel slag, and then the physical phase modification is carried out in three stages of heat preservation, slow cooling and rapid cooling. The cementitious material in the upper part of the slag pot after separation can be applied to the cement field, and the molten iron resources recovered in the lower part of the slag pot can be re-invested in steel plant production, thereby effectively reducing energy waste, and also reducing the waste of land resources and environmental pollution caused by steel slag stacking. On the one hand, it comprehensively utilizes energy and resources, is conducive to industrialization, and large-volume steel slag solid waste treatment, and can also achieve carbon emission reduction in the high-energy consumption steel metallurgical industry.

[0015] 4. The modification treatment method of the molten steel slag of the present invention is simple and has a scientific process. The slag pot used is an existing device. The reducing agent, calcium material and silicon material are mixed and stirred with the molten steel slag to make the components uniform, and then the waste heat of the molten steel slag is used to perform a carbon thermal reduction reaction to obtain the molten steel slag after upper modification in the slag pot. The reduced molten iron completely settles to the bottom of the slag pot due to its high density, and the slag and iron can be automatically separated in the insulation stage. The present invention mixes and stirs the calcium material, silicon material and steel slag in the slag pot to make them fully react with the silicon dioxide and other components in the steel slag, so that the content of gelling minerals in the steel slag is increased to form a phase-modified steel slag, and by controlling the reduction speed, 3CaO·SiO2 and 2CaO·SiO2 are mainly generated therein, and the content of each component can be controlled within the new national standard GB / T 21372-2024 Portland cement clinker requirements (including free calcium oxide content, etc.), so it can be supplied to cement plants as ordinary Portland cement clinker, which can replace Portland cement clinker and greatly increase the total consumption and application value of steel slag.

[0016] 5. The present invention reduces the iron phase in the steel slag by adding reducing agents such as coke particles, activated carbon, carbon pitch, and graphite product recycling materials to the molten steel slag; reduces the viscosity by adding calcium oxide, a calcium material, and increases the amount of liquid phase to promote the generation of 3CaO·SiO2. At the same time, the calcium material consumes silicon dioxide in the steel slag to generate 3CaO·SiO2, thereby increasing the gelling property of the modified steel slag; adds a small amount of silicon materials such as quartz sand, silica fume, and quartz waste to adjust the mineral components, which can react with the excess calcium material that has not reacted with the steel slag to generate 3CaO·SiO2. During the cooling process of the upper modified steel slag, part of the 3CaO·SiO2 will decompose to generate 2CaO·SiO2 and free calcium oxide. Therefore, the degree of decomposition is controlled by controlling the cooling rate, and the gelling material is directly obtained after cooling. The reduced molten iron settles to the bottom of the slag pot due to its high density, and can be efficiently recycled.

[0017] 6. The present invention combines the resource utilization of solid waste with metallurgical technology to provide a low-cost, high-value, large-capacity high-temperature phase reconstruction and modification method and high-value material for molten steel slag; by pouring the molten steel slag into a slag pot, adding modified powder into the slag pot, mixing and stirring, and then keeping warm and performing high-temperature melting modification, the reduced iron is completely settled to the bottom of the slag pot to obtain the upper modified molten steel slag; the modified molten steel slag is poured into a slag pot (or other insulation container), the insulation time and the cooling rate are controlled to perform three-stage continuous phase modification, and after cooling to room temperature, a blocky cementitious material with component content and grain size meeting the requirements can be directly obtained; in this process, the iron settled at the bottom of the slag pot can be first recovered and used in steel production. The invention recovers almost all the iron elements in the steel slag, reduces more than 97wt% of the iron-containing oxides in the steel slag into metallic iron, and simultaneously adjusts the physical phase composition and grain size of the steel slag, so that the physical phase composition of the modified steel slag is close to that of the cement clinker, thereby obtaining a low-cost, high-performance cementitious material that can replace the national standard GB / T 21372-2024 silicate cement clinker, and has a high utilization value in industry.

[0018] 7. The preparation method provided by the present invention can realize the three-stage phase reconstruction of molten steel slag, so that the phase composition of the modified steel slag gel material is close to the cement clinker phase, and the prepared cement product meets the various requirements for general Portland cement in the GB 175-2023 standard, and can reduce more than 97wt% of the iron-containing oxides in the molten steel slag to metallic iron; less equipment is used, the process steps are simple, easy to control, stable quality, easy to industrialize, large consumption capacity and efficient use of energy and resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of XRD test of steel slag raw material in the embodiment of the present invention, original steel slag used in embodiments 1 to 5, and steel slag modified gelling material obtained; Figure 2 This is a schematic diagram of the BSE test of the steel slag modified cementitious material prepared in Example 3 of the present invention; Figure 3 This is a schematic diagram of XRD test of the steel slag modified gelling material prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with the accompanying drawings and a number of specific embodiments, so that those skilled in the art can implement the invention with reference to the description.

[0021] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0022] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0023] Basic Example The method for preparing the slag modified gelling material provided in this embodiment comprises the following steps: S1. Collect high temperature slag Use an insulated intermediate slag pot to collect the high-temperature molten slag (about 1700℃) discharged from the steelmaking converter and transfer it to the modification workshop; The steel slag is ordinary converter molten steel slag, and its total iron content is 20-40wt%; S2. Control of molten slag composition under heat preservation Keep the temperature of the steel slag in the slag pot at a molten state of 1500~1600℃, add the pre-prepared modified powder to the molten steel slag, mix and stir, the stirring speed is 10~50 r / min, and the stirring time is 10~60 min; during the stirring process, the Ca in the molten state 2+ Ions diffuse and react with silicate ions and 2CaO·SiO2 to reconstruct the phase and form 3CaO·SiO2, the main phase of silicate cement. At the same time, the iron-containing phase in the molten slag reacts with the reducing agent in the modified powder to generate elemental iron. The modified powder is a mixed powder composed of a reducing agent, a calcium material and a silicon material in a set ratio and a particle diameter of 5-50 mm, wherein the mass ratio of each component is reducing agent: calcium material: silicon material: molten steel slag = (0.08-0.18): (0.12-0.23): (0.018-0.055): 1; The reducing agent is one or more of coke particles, activated carbon, carbon asphalt, and graphite product recycling materials, and the carbon content is ≥85wt%.

[0024] The calcium material in the modified powder contains calcium oxide, and the content of calcium oxide is 90-100wt%.

[0025] The siliceous material in the modified powder is one or more of quartz sand, silica ash, and quartz waste, wherein the content of silicon dioxide is 90-100wt%.

[0026] S3, phase modification and reconstruction during heat preservation stage Stop stirring and continue to keep the temperature of the steel slag in the slag pot at a molten state of 1500-1600°C for 30-60 minutes to make the composition of the molten steel slag uniform. In this process, the reduced molten iron naturally settles to the bottom of the slag pot, and the molten modified steel slag after the adjustment naturally floats on the upper part of the slag pot; the molten modified steel slag naturally floating on the upper part of the slag pot is transferred to another slag pot with insulation for modification to separate the slag and iron; after the insulation is completed and the slag and iron are separated, the molten iron naturally settled at the bottom of the slag pot is recovered and reused in steel production; In the high-temperature melt phase modification and reconstruction process of this step, the calcium material and silicon material in the modified powder are continuously dissolved and diffused by heat, and the modified powder and steel slag are mixed and stirred to make the modified powder and steel slag more uniform. 2+ Ions diffuse and react with silicate ions and 2CaO·SiO2 to form 3CaO·SiO2, the main phase of silicate cement. At the same time, the addition of calcium material reduces the viscosity of the system and increases the diffusion rate of particles in the liquid phase, which is beneficial to the formation of 3CaO·SiO2 and the reaction of the iron-containing phase in the molten steel slag with the reducing agent in the modified material to form elemental iron. This process regulates the chemical composition of the molten steel slag through the modified powder, so that the iron element sinks to the bottom of the slag tank in the form of elemental iron, and the remaining chemical composition is close to the chemical composition of cement clinker. S4, Phase reconstruction of the first stage of cooling of modified steel slag The molten modified steel slag with a temperature of 1500-1600℃ after transfer is cooled slowly to 1250-1300℃ at a rate of 10-30℃ / min by air cooling (natural cooling) to carry out the first stage of cooling phase reconstruction. In this process, the main phases of cement clinker, 3CaO·SiO2 and 2CaO·SiO2, are precipitated from the molten modified steel slag, and small crystals gradually develop and grow. S5, Phase reconstruction of the second stage of cooling of modified steel slag The modified steel slag is rapidly cooled from 1250~1300℃ to room temperature by air cooling (blowing cold air into the slag pot) at a cooling rate of 40~70℃ / s. This process stops the generated 3CaO·SiO2 grains from growing further, making the 3CaO·SiO2 grains moderate, inhibiting the decomposition of the 3CaO·SiO2 phase and preventing the 2CaO·SiO2 crystal form from transforming into the γ type, so that the various components of the molten modified steel slag interact with each other and gradually form the main phases 3CaO·SiO2 and 2CaO·SiO2 contained in the cement clinker; S6. Post-cooling treatment The step S5 is cooled to room temperature to obtain a blocky slag-modified cementitious material which has undergone heat preservation and two-stage cooling phase reconstruction, which is first crushed and then ground to a specific surface area SSA of 300m² / kg≤SSA≤400m² / kg to prepare a silicate cement clinker mainly composed of 3CaO·SiO2, 2CaO·SiO2 and other phases.

[0027] During the phase modification and reconstruction process of the cooling process of steps S4-S5, in the controlled cooling process, the main phases of cement clinker such as 3CaO·SiO2 and 2CaO·SiO2 are precipitated from the molten steel slag, and the 3CaO·SiO2 grains are made moderate by controlling the cooling rate, inhibiting the decomposition of the 3CaO·SiO2 phase, and preventing the 2CaO·SiO2 crystal from transforming into the γ type; this process enables the molten modified steel slag to gradually form the main phases such as 3CaO·SiO2, 2CaO·SiO2, etc., with components, content ratios and grain sizes that meet the requirements of cement clinker, so as to improve the strength of cement.

[0028] A steel slag modified cementitious material is prepared by the above method, and the content of each component and the grain size and other physical phases in the steel slag modified cementitious material are controlled within the range required by the new national standard GB / T 21372-2024 silicate cement clinker (including free calcium oxide content, etc.).

[0029] The application of the steel slag modified cementitious material as clinker in the preparation of ordinary Portland cement can directly replace the ordinary Portland cement clinker specified in the national standard GB / T 21372-2024; after grinding with auxiliary materials such as gypsum, ordinary Portland cement can be prepared and used directly as cement. Specifically, auxiliary materials such as gypsum can be added to the blocky steel slag modified cementitious material prepared after cooling in step S6, and the mixture is ground together until the fineness of the Portland cement meets the requirements of the national standard GB 175-2023 general Portland cement, and the finished ordinary Portland cement can be directly obtained.

[0030] In order to more clearly understand the purpose, technical solutions and advantages of the present invention, the present invention is further described in detail below in combination with multiple specific embodiments based on the above basic embodiments. The specific data involved in the specific examples described here are only used to explain the present invention and are not used to limit the present invention.

[0031] The converter slag used in the following embodiments is all taken from steel enterprises (such as Baosteel and Masteel). According to the standard test of YB / T 148-2015 "Determination of total iron content in steel slag", its total iron content is 20~40wt%; each component in the modified powder is a commercially available product; and the slag pot adopts an existing conventional slag pot.

[0032] Example 1 The slag-modified cementitious material, preparation method and application thereof provided in this embodiment are specific applications based on the aforementioned basic embodiments; the converter slag used in this embodiment is taken from Baosteel Group, and its total iron content is about 25wt% on average.

[0033] The preparation method of the steel slag modified gelling material provided in this embodiment is substantially the same as that in the basic embodiment, and specifically further comprises the following steps: Prepare modified powder in advance, the components and mass ratio of the modified powder are reducing agent: calcium material: silicon material: molten steel slag = 0.10: 0.12: 0.018: 1, and the particle diameter of each component is greater than 5mm and not greater than 50mm (D 50 =45mm); The reducing agent is a mixture of coke particles with a carbon content of ≥85wt% and recycled graphite products in a mass ratio of 1:1; the coke particles are produced by Gongyi Xinjiayuan Water Purification Materials Co., Ltd., and the recycled graphite products are recycled graphite crucibles produced by Baofeng Graphite Products. The calcium material is produced by Fuchen Tianjin Chemical Reagent Co., Ltd., and the calcium oxide content is 90wt% of calcium oxide. In other embodiments, other compounds or mixtures containing 90wt% of calcium oxide as a main component may also be used.

[0034] The silicon material is quartz sand produced by Tianjin Zhonglian Chemical Reagent Co., Ltd., in which the silicon dioxide content is 90wt%.

[0035] S1. Collect high temperature slag Use a conventional insulated intermediate slag pot (with a volume of 16 cubic meters) to collect the high-temperature molten slag of about 1700°C discharged from the steelmaking converter, guide the molten slag from the converter into the slag pot, and then transfer it to the modification treatment workshop; S2. Control of molten slag composition under heat preservation Keep the temperature of the steel slag in the slag pot in a molten state of 1500~1600℃, add the pre-prepared modified powder into the molten steel slag, mix and stir, the stirring speed is 30 r / min, and the stirring time is 40 min; S3, phase modification and reconstruction during heat preservation stage After reaching the set stirring time, stop stirring and continue to keep the temperature of the slag in the slag pot at a molten state of 1500~1600℃ for 60 minutes to make the composition of the molten slag uniform; after the insulation is completed and the slag and iron are separated, the molten iron that naturally settles at the bottom of the slag pot is recovered and reused in steel production, and the molten modified slag that naturally floats on the top of the slag pot is transferred to another slag pot with insulation for modification; S4, Phase reconstruction of the first stage of cooling of modified steel slag The molten modified steel slag with a temperature of 1500-1600℃ after transfer is cooled slowly to 1250-1300℃ at a rate of 10-30℃ / min by air cooling (natural cooling) to carry out the first stage of cooling phase reconstruction. In this process, the main phases of cement clinker, 3CaO·SiO2 and 2CaO·SiO2, are precipitated from the molten modified steel slag, and small crystals gradually develop and grow. S5, Phase reconstruction of the second stage of cooling of modified steel slag After the modified steel slag is slowly cooled to 1250~1300℃, the air cooling method (blow cold air into the slag pot) is used to control the modified steel slag to be rapidly cooled from 1250~1300℃ to room temperature at a cooling rate of 50℃ / s. This process stops the generated 3CaO·SiO2 grains from growing further, makes the 3CaO·SiO2 grains moderate, inhibits the decomposition of the 3CaO·SiO2 phase and prevents the 2CaO·SiO2 crystal form from transforming into the γ type, so that the various components of the molten modified steel slag interact with each other and gradually form the main phases 3CaO·SiO2 and 2CaO·SiO2 contained in the cement clinker; S6. Post-cooling treatment The blocky slag modified cementitious material obtained in step S5 is cooled to room temperature and reconstructed by heat preservation and two-stage cooling, and is first crushed and then ground to a specific surface area SSA of 300m² / kg≤SSA≤400m² / kg, thereby preparing a silicate cement clinker mainly composed of 3CaO·SiO2, 2CaO·SiO2 and other phases. Gypsum and other auxiliary materials can also be added to the blocky slag modified cementitious material, and then ground together to meet the requirements of the national standard GB 175-2023 general silicate cement on the fineness of silicate cement, so as to prepare a silicate cement product.

[0036] The above embodiments of the present invention focus on the phase reconstruction modification of the molten steel slag by heat preservation and two-stage cooling, so that the prepared cementitious material can replace the national standard GB / T 21372-2024 silicate cement clinker. When the amount of modified powder added is gradually increased, the calcium oxide content in the system increases, the alkalinity increases, the viscosity decreases, the liquid phase volume increases, the molecular fluidity is high, and the ion diffusion capacity is strong. At the same time, in the preparation process of the present invention, the mixing and stirring step also makes the components more uniform, promotes the reaction of 2CaO·SiO2 in the modified slag with calcium oxide to generate 3CaO·SiO2, and gradually increases the content of 3CaO·SiO2. In addition, the present invention controls the cooling rate and reduces the decomposition of 3CaO·SiO2 into 2CaO·SiO2, so that the RO phase solid solution in the slag is decomposed and reacted, and the decomposition produces MgO and iron oxide (FeOx); the FeOx decomposed from the RO phase solid solution and the Ca2Fe2O5 in the slag are reduced by the reducing agent in the modified powder to elemental molten iron, which naturally settles to the bottom of the slag pot under the action of gravity and is separated from the slag for easy recycling; and due to the increase in the calcium oxide content, a small amount of aluminum-containing components in the slag also generate a certain amount of 3CaO·Al2O3 with calcium oxide.

[0037] The properties of the steel slag used in this embodiment and the steel slag modified cementitious material prepared are shown in the attached Figure 1 The chemical composition of the prepared steel slag modified cementitious material is shown in Table 2, and the results of iron reduction rate and free calcium oxide content are shown in Table 1.

[0038] Example 2 The steel slag modified gelling material, preparation method and application thereof provided in this embodiment are also specific applications based on the aforementioned basic embodiment, and are basically the same as those in Example 1. The difference between the preparation steps S1-S6 and those in Example 1 is that: Prepare modified powder in advance, the mass ratio of each component in the modified powder is reducing agent: calcium material: silicon material: molten steel slag = 0.10: 0.17: 0.037: 1, wherein the particle diameter of each component is not more than 50mm (D50 = 40mm); The reducing agent is a mixture of commercially available coke particles (Gongyi Xinjiayuan Water Purification Material Co., Ltd.) with a total carbon content of ≥87.5wt% and recycled graphite products (produced by Baofeng Graphite Products) in a mass ratio of 2:1; The calcium material is commercially available calcium oxide with a calcium oxide content of 95 wt %; The silicon material is silica fume with a silicon dioxide content of 95 wt%, specifically 92 ordinary silica fume produced by Beijing Zhengyuan Yixinxin Material Technology Co., Ltd.; In the preparation method of this embodiment, the difference is: S2. Control of molten slag composition under heat preservation Keep the temperature of the steel slag in the slag pot in a molten state of 1500~1600℃, add the pre-prepared modified powder into the molten steel slag, mix and stir, the stirring speed is 20 r / min, and the stirring time is 50 min; S3, phase modification and reconstruction during heat preservation stage After reaching the set stirring time, stop stirring and continue to keep the temperature of the steel slag in the slag pot at a molten state of 1500~1600℃ for 55 minutes to make the composition of the molten steel slag uniform; after the insulation is completed and the slag and iron are separated, the molten iron that naturally settles at the bottom of the slag pot is recovered and reused in steel production, and the molten modified steel slag that naturally floats on the upper part of the slag pot is transferred to another insulation slag pot for modification; S4, Phase reconstruction of the first stage of cooling of modified steel slag The molten modified steel slag with a temperature of 1500-1600℃ after transfer is cooled slowly to 1250-1300℃ at a rate of 10-30℃ / min by air cooling (natural cooling) to carry out the first stage of cooling phase reconstruction. In this process, the main phases of cement clinker, 3CaO·SiO2 and 2CaO·SiO2, are precipitated from the molten modified steel slag, and small crystals gradually develop and grow. S5, Phase reconstruction of the second stage of cooling of modified steel slag After the modified steel slag is slowly cooled to 1250~1300℃, the air cooling method is used to control the modified steel slag to be rapidly cooled from 1250~1300℃ to room temperature at a cooling rate of 60℃ / s.

[0039] The preparation method, materials and other application contents of this embodiment are the same as those of embodiment 1. The steel slag used and the properties of the steel slag modified cementitious material prepared are shown in the attached Figure 1 The chemical composition of the prepared steel slag modified cementitious material is shown in Table 2, and the results of iron reduction rate and free calcium oxide content are shown in Table 1.

[0040] Example 3 The steel slag modified gelling material, preparation method and application thereof provided in this embodiment are also specific applications based on the aforementioned basic embodiment, and are basically the same as those in Example 1. The difference between the preparation steps S1-S6 and those in Example 1 is that: Prepare modified powder in advance, the components and mass ratio of the modified powder are reducing agent: calcium material: silicon material: molten steel slag = 0.10: 0.23: 0.055: 1, and the particle diameter of each component is not more than 45mm (D 50 =35mm); The reducing agent is a mixture of activated carbon with a carbon content of ≥89.5wt% and carbon pitch in a mass ratio of 1:1; The calcium material is produced by Shanghai Huake Experimental Equipment Co., Ltd., and the calcium oxide content is 99.95wt%; The silicon material is quartz sand produced by Xi'an Yizhichen Biotechnology Co., Ltd., in which the silicon dioxide content is 99.7wt%.

[0041] In the preparation method of this embodiment, the difference is: S2. Control of molten slag composition under heat preservation Keep the temperature of the slag in the slag pot in a molten state of 1500~1600℃, add the pre-prepared modified powder into the molten slag, mix and stir, the stirring speed is 30 r / min, and the stirring time is 45 min; S3, phase modification and reconstruction during heat preservation stage After reaching the set stirring time, stop stirring and continue to keep the temperature of the slag in the slag pot at a molten state of 1500~1600℃ for 60 minutes to make the composition of the molten slag uniform; after the insulation is completed and the slag and iron are separated, the molten iron that naturally settles at the bottom of the slag pot is recovered and reused in steel production, and the molten modified slag that naturally floats on the top of the slag pot is transferred to another slag pot with insulation for modification; S4, Phase reconstruction of the first stage of cooling of modified steel slag The molten modified steel slag with a temperature of 1500-1600℃ after transfer is cooled slowly to 1250-1300℃ at a rate of 10-30℃ / min by air cooling (natural cooling) to carry out the first stage of cooling phase reconstruction. In this process, the main phases of cement clinker, 3CaO·SiO2 and 2CaO·SiO2, are precipitated from the molten modified steel slag, and small crystals gradually develop and grow. S5, Phase reconstruction of the second stage of cooling of modified steel slag After the modified steel slag is slowly cooled to 1250~1300℃, the air cooling method is used to control the modified steel slag to be rapidly cooled from 1250~1300℃ to room temperature at a cooling rate of 55℃ / s.

[0042] The preparation method, materials and other application contents of this embodiment are the same as those of embodiment 1. The steel slag used and the properties of the steel slag modified cementitious material prepared are shown in the attached Figure 1 The chemical composition of the prepared steel slag modified cementitious material is shown in Table 2, and the results of iron reduction rate and free calcium oxide content are shown in Table 1.

[0043] Example 4 The steel slag modified gelling material, preparation method and application thereof provided in this embodiment are also specific applications based on the aforementioned basic embodiments. The basic contents of the preparation method, materials and application of this embodiment are the same as those of embodiment 1, except that: The modified powder added to the slag pot has the following components and mass ratios: reducing agent: calcium material: silicon material: molten steel slag = 0.08: 0.23: 0.055: 1; the particle diameter of each component is not more than 40 mm (D50 = 35 mm); The reducing agent is a mixture of activated carbon with a carbon content ≥89.5wt% and solid carbon asphalt prepared in a mass ratio of 1:1; the activated carbon is produced by Fuchen Tianjin Chemical Reagent Co., Ltd., and the carbon asphalt is solid carbon asphalt produced by Hebei Deri New Materials Technology.

[0044] The calcium raw material is calcium oxide, the content of calcium oxide is 99.95wt%, and it is produced by Shanghai Huake Experimental Equipment Co., Ltd.

[0045] The siliceous material is quartz sand, in which the content of silicon dioxide is 99.7wt%, and it is produced by Xi'an Yizhichen Biotechnology Co., Ltd.

[0046] In the preparation method of this embodiment, the difference is: S2. Control of molten slag composition under heat preservation Keep the temperature of the slag in the slag pot in a molten state of 1500~1600℃, add the pre-prepared modified powder into the molten slag, mix and stir, the stirring speed is 10 r / min, and the stirring time is 60 min; S3, phase modification and reconstruction during heat preservation stage After reaching the set stirring time, stop stirring and continue to keep the slag temperature in the slag pot at a molten state of 1500~1600℃ for 30 minutes to make the molten slag composition uniform; after the insulation is completed and the slag and iron are separated, the molten iron that naturally settles at the bottom of the slag pot is recovered and reused in steel production, and the molten modified slag that naturally floats on the top of the slag pot is transferred to another slag pot for modification; S4, Phase reconstruction of the first stage of cooling of modified steel slag The molten modified steel slag with a temperature of 1500-1600℃ after transfer is cooled slowly to 1250-1300℃ at a rate of 10-30℃ / min by air cooling (natural cooling) to carry out the first stage of cooling phase reconstruction. In this process, the main phases of cement clinker, 3CaO·SiO2 and 2CaO·SiO2, are precipitated from the molten modified steel slag, and small crystals gradually develop and grow. S5, Phase reconstruction of the second stage of cooling of modified steel slag After the modified steel slag is slowly cooled to 1250~1300℃, the air cooling method is used to control the modified steel slag to be rapidly cooled from 1250~1300℃ to room temperature at a cooling rate of 70℃ / s.

[0047] The preparation method, materials and other application contents of this embodiment are the same as those of embodiment 1. The steel slag used and the properties of the steel slag modified cementitious material prepared are shown in the attached Figure 1 The chemical composition of the prepared steel slag modified cementitious material is shown in Table 2, and the results of iron reduction rate and free calcium oxide content are shown in Table 1.

[0048] Example 5 The steel slag modified gelling material, preparation method and application thereof provided in this embodiment are also specific applications based on the aforementioned basic embodiments. The basic contents of the preparation method, materials and application of this embodiment are the same as those of embodiment 1, except that: The components and mass ratio of the modified powder added to the slag pot are reducing agent: calcium material: silicon material: molten steel slag = 0.18: 0.23: 0.055: 1; the particle diameter of each component is not more than 40mm (D50 = 30mm); The reducing agent is a mixture of activated carbon with a carbon content ≥89.5wt% and solid carbon asphalt prepared in a mass ratio of 1:1; the activated carbon is produced by Fuchen Tianjin Chemical Reagent Co., Ltd., and the carbon asphalt is solid carbon asphalt produced by Hebei Deri New Materials Technology.

[0049] The calcium raw material is calcium oxide, the content of calcium oxide is 99.95wt%, and it is produced by Shanghai Huake Experimental Equipment Co., Ltd.

[0050] The siliceous material is quartz waste with a silicon dioxide content of 99.5wt%, which is the waste discarded from the production of beakers by Shuniu Glass Instrument Co., Ltd.

[0051] In the preparation method of this embodiment, the difference is: S2. Control of molten slag composition under heat preservation Keep the temperature of the steel slag in the slag pot at a molten state of 1500~1600℃, add the pre-prepared modified powder into the molten steel slag, mix and stir, the stirring speed is 50 r / min, and the stirring time is 10 min; S3, phase modification and reconstruction during heat preservation stage After reaching the set stirring time, stop stirring and continue to keep the temperature of the slag in the slag pot at a molten state of 1500~1600℃ for 50 minutes to make the composition of the molten slag uniform; after the insulation is completed and the slag and iron are separated, the molten iron that naturally settles at the bottom of the slag pot is recovered and reused in steel production, and the molten modified slag that naturally floats on the top of the slag pot is transferred to another slag pot for modification; S4, Phase reconstruction of the first stage of cooling of modified steel slag The molten modified steel slag with a temperature of 1500-1600℃ after transfer is cooled slowly to 1250-1300℃ at a rate of 10-30℃ / min by air cooling (natural cooling) to carry out the first stage of cooling phase reconstruction. In this process, the main phases of cement clinker, 3CaO·SiO2 and 2CaO·SiO2, are precipitated from the molten modified steel slag, and small crystals gradually develop and grow. S5, Phase reconstruction of the second stage of cooling of modified steel slag After the modified steel slag is slowly cooled to 1250~1300℃, the air cooling method is used to control the modified steel slag to be rapidly cooled from 1250~1300℃ to room temperature at a cooling rate of 70℃ / s.

[0052] The preparation method, materials and other application contents of this embodiment are the same as those of embodiment 1. The steel slag used and the properties of the steel slag modified cementitious material prepared are shown in the attached Figure 1 The chemical composition of the prepared steel slag modified cementitious material is shown in Table 2, and the results of iron reduction rate and free calcium oxide content are shown in Table 1.

[0053] In the above embodiments, the reduction rate of iron is R Fe It can be obtained from formula 1: Formula 1 in C 0 is the total iron content of molten slag and modified powder, C 1 is the total iron content of the modified molten steel slag.

[0054] The free calcium oxide content of modified steel slag was determined according to the national standard method GB / T176-2017 cement chemical analysis method.

[0055] The iron reduction rate and free calcium oxide content obtained by modifying the steel slag in Examples 1 to 5 are shown in Table 1, and the chemical composition of the prepared steel slag modified cementitious material is shown in Table 2.

[0056] Table 1

[0057] It can be seen from Table 1 that the iron reduction rate in all embodiments of the present invention is greater than 97%, which basically achieves complete iron removal, and the free calcium oxide content is less than ≤1.5% required in the national standard GB / T 21372-2024 silicate cement clinker. It can be seen that the component contents in all embodiments meet the national standards.

[0058] Table 2

[0059] As can be seen from Table 2, the iron content in the steel slag modified cementitious material is significantly reduced, and is basically reduced to elemental iron. The composition of each component and the crystal particle size and other phases all meet the requirements of the national standard GB / T 21372-2024 "Portland Cement Clinker", especially the requirements for magnesium oxide content, sulfur trioxide content, calcium-silicon ratio and silicate mineral content, so that it can be directly used as cement clinker and applied to cement manufacturing.

[0060] XRD tests were performed on the original steel slag material and the steel slag modified gelled materials prepared in Examples 1 to 5. The results are as follows: Figure 1 As shown. Figure 1 It can be seen that the main phases in the original steel slag are dicalcium silicate (2CaO·SiO2, i.e. C2S), dicalcium ferrite (Ca2Fe2O5, i.e. C2F) and RO phase solid solution. During the modification process, the molten steel slag reacts with the modified powder, and after two phase reconstructions, a steel slag modified cementitious material is obtained. At this time, its phase composition is tricalcium silicate (3CaO·SiO2, i.e. C3S), dicalcium silicate (2CaO·SiO2) and tricalcium aluminate (3CaO·Al2O3, i.e. C3A) and magnesium oxide, which is basically the same as cement clinker. The steel slag modified cementitious material prepared in Example 3 was tested for backscattering, and the results are as follows: Figure 2 As shown in the figure, ring-shaped or polygonal 3CaO·SiO2, elliptical and irregular 2CaO·SiO2, and 3CaO·Al2O3 are formed in the steel slag modified cementitious material, which are similar to the microscopic morphology of cement clinker. Among them, 3CaO·SiO2 and 2CaO·SiO2, which are the main minerals of Portland cement clinker, are well developed, with moderate crystal size and clear interface.

[0061] Comparative Example 1 The method for preparing silicate cement clinker provided in this comparative example adopts the same components (steel slag, modified powder), proportions and main preparation process as those of the aforementioned Example 3, except that it omits step S4 of the first stage cooling phase reconstruction of the modified steel slag, and directly proceeds to step S5, in which the modified steel slag at 1600°C is directly rapidly cooled to room temperature at a cooling rate of 55°C / s (air cooling method) to obtain a blocky steel slag modified cementitious material, which is then ground into powder for testing.

[0062] The XRD test diagram of the steel slag modified cementitious material powder prepared in this comparative example is shown in the attached Figure 3 .Depend on Figure 3 It can be seen that in the modified material that was directly cooled from the molten state at 1500~1600℃ to room temperature, a large amount of 3CaO·SiO2 was not generated, but only 2CaO·SiO2 was generated. Its composition, proportion and crystal particle size do not meet the standard requirements and cannot be used as Portland cement clinker.

[0063] In summary, the above embodiments of the present invention provide a steel slag modified cementitious material, a preparation method and an application thereof. By improving the formula and the preparation process simultaneously, a slag pot is used to directly transport and modify the molten steel slag. Through a method of heat preservation and two-stage cooling phase reconstruction combined with modification, the content of each component in the steel slag, the grain growth and other phases are controlled, so that the molten steel slag and the components of the modified powder interact with each other and gradually form the main phases 3CaO·SiO2 and 2CaO·SiO2 contained in the cement clinker, so that the phase composition of the steel slag component and the grain size of the cementitious material finally obtained after the modification is similar to the cement clinker phase, and the content of each component in the powdered steel slag modified cementitious material is controlled to be within the range required by the new national standard GB / T 21372-2024 silicate cement clinker (including the free calcium oxide content, etc.), so that the treated modified cementitious material can replace cement clinker, thereby obtaining a high-value and large-absorption cementitious material, and the manufactured cement product complies with GB The various requirements for general-purpose Portland cement in Standard 175-2023 increase the resource utilization value and total consumption of steel slag, and have high utilization value in industry.

[0064] Within the scope of the above-mentioned components, proportions and processes recorded in the specification of the present invention, the steel slag modified cementitious materials, preparation methods and applications obtained by making other specific selections can all achieve the technical effects recorded in the present invention, so they will not be listed one by one.

[0065] The above embodiments illustrate the present invention, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of application of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a steel slag modified gelling material, characterized in that: It includes the following steps: S1. Collect high temperature slag Use an insulated intermediate slag pot to collect the high-temperature molten slag discharged from the steelmaking converter and transfer it to the modification workshop; S2. Control of molten slag composition under heat preservation Keep the temperature of the slag in the slag pot at 1500~1600℃ in a molten state, add the pre-prepared modified powder to the molten slag, mix and stir. During the stirring process, the Ca 2+ Ions diffuse and react with silicate ions and 2CaO·SiO2 to reconstruct the phase and form 3CaO·SiO2, the main phase of silicate cement. At the same time, the iron-containing phase in the molten slag reacts with the reducing agent in the modified powder to generate elemental iron. The modified powder is a mixed powder composed of a reducing agent, a calcium material and a silicon material in a set ratio and a particle diameter of 5-50 mm, wherein the mass ratio of each component is reducing agent: calcium material: silicon material: molten steel slag = (0.08-0.18): (0.12-0.23): (0.018-0.055): 1; S3, phase modification and reconstruction during the heat preservation stage Stop stirring and continue to keep the temperature of the steel slag in the slag pot at a molten state of 1500-1600°C for 30-60 minutes to make the composition of the molten steel slag uniform. In this process, the reduced molten iron naturally settles to the bottom of the slag pot, and the molten modified steel slag after the adjustment naturally floats on the upper part of the slag pot; the molten modified steel slag naturally floating on the upper part of the slag pot is transferred to another slag pot with insulation for modification to separate the slag and iron; S4, Phase reconstruction of the first stage of cooling of modified steel slag The molten modified steel slag with a temperature of 1500-1600℃ after transfer is slowly cooled to 1250-1300℃ at a rate of 10-30℃ / min to carry out the first stage of cooling phase reconstruction. In this process, the main phases of cement clinker, 3CaO·SiO2 and 2CaO·SiO2, are precipitated from the molten modified steel slag, and small crystals gradually develop and grow. S5, Phase reconstruction of the second stage of cooling of modified steel slag The modified steel slag is rapidly cooled from 1250-1300℃ to room temperature at a cooling rate of 40-70℃ / s. This process stops the generated 3CaO·SiO2 grains from growing further, makes the 3CaO·SiO2 grains moderate, inhibits the decomposition of the 3CaO·SiO2 phase, and prevents the 2CaO·SiO2 crystal form from transforming into the γ type. The various components of the molten modified steel slag interact with each other and gradually form the main phases 3CaO·SiO2 and 2CaO·SiO2 contained in the cement clinker. S6. Post-cooling treatment The step S5 is cooled to room temperature to obtain a blocky slag-modified cementitious material which has undergone heat preservation and two-stage cooling phase reconstruction, which is first crushed and then ground to a specific surface area SSA of 300m² / kg≤SSA≤400m² / kg to prepare a silicate cement clinker mainly composed of 3CaO·SiO2 and 2CaO·SiO2 phases.

2. The method for preparing the steel slag modified gelling material according to claim 1, characterized in that: Step S3 also includes the following steps: S3-1, recovering the molten iron that naturally settles at the bottom of the slag pot in step S3 and reusing it in steel production.

3. The method for preparing the steel slag modified gelling material according to claim 1, characterized in that: In the step S2, the modified powder is added to the slag tank and stirred during mixing, with a stirring speed of 10-50 r / min and a stirring time of 10-60 min.

4. The method for preparing the steel slag modified gelling material according to claim 1, characterized in that: The steel slag is ordinary converter molten steel slag, and its total iron content is 20-40wt%.

5. The method for preparing the steel slag modified gelling material according to claim 1, characterized in that: In step S4, the slow cooling of the first stage of cooling and phase reconstruction of the modified steel slag is performed by air cooling; and in step S5, the rapid cooling of the second stage of cooling and phase reconstruction of the modified steel slag is performed by wind cooling.

6. The method for preparing the steel slag modified gelling material according to claim 1, characterized in that: The reducing agent is one or more of coke particles, activated carbon, carbon asphalt, and graphite product recycling materials, and the carbon content is ≥85wt%.

7. The method for preparing the steel slag modified gelling material according to claim 1, characterized in that: The calcium material in the modified powder contains calcium oxide, and the content of calcium oxide is 90-100wt%.

8. The method for preparing the steel slag modified gelling material according to claim 1, characterized in that: The siliceous material in the modified powder is one or more of quartz sand, silica ash, and quartz waste, wherein the content of silicon dioxide is 90-100wt%.

9. A steel slag modified gelling material, characterized in that: The invention is prepared by the method according to any one of claims 1 to 8.

10. Use of the steel slag modified cementitious material according to claim 9 as clinker in the preparation of ordinary Portland cement.

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