Mineral admixture prepared based on refining slag and production method thereof

Abstract

The invention discloses a mineral admixture prepared based on refining slag. The mineral admixture comprises the following chemical components in percentage by weight: 55-65% of CaO, 16-26% of SiO2, 5-12% of Al2O3, 6-12% of Fe2O3, 6-9% of MgO and the balance of impurities. The method has the advantages that by optimizing a refining LF furnace smelting method, the recycled slag, the slag, the desulfurized gypsum, the water and the waste rock sand are reasonably proportioned, mixed and stirred to prepare the mineral admixture meeting the requirements for compressive strength and breaking strength, and batch supply of products is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a mineral admixture manufactured based on refined slag and a production method thereof. Background Art

[0002] The refined LF furnace in a steel mill is an essential production equipment for steel mills. Among them, LF refined steel slag is a by-product of smelting, accounting for about 10% to 15% of steel production. In recent years, with the rapid development of my country's steel industry, the production of refined LF slag in steel mills has also increased year by year. The refined LF slag in steel mills has good potential hydraulic hardness and can be ground into concrete admixtures. The comprehensive utilization rate of iron slag is about 22%. The main mineral composition is overburned tricalcium silicate and dicalcium silicate, olivine, rhodonite, RO phase, etc. The main uses are road materials, engineering backfill materials, building materials, grinding for cement admixtures and concrete admixtures, etc. The preparation of iron slag powder can also help steel mills solve the environmental pressure of "zero emission" of iron slag.

[0003] At present, refined slag cannot be effectively utilized, which is contrary to the "solid waste does not leave the factory" promoted by the metallurgical industry. Strengthening full-scale utilization and promoting the comprehensive utilization, recycling and "solid waste does not leave the factory" of iron and steel metallurgical solid waste are the general trend of the steel industry. Therefore, it is urgent to design a method that can fully utilize refined slag to produce admixtures. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of low utilization rate of existing refined slag and poor quality of admixtures, and to provide a method for manufacturing mineral admixtures based on refined slag, which can not only improve the utilization rate of refined slag and realize the rational use of slag, but also improve the strength and toughness of the mineral admixture.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A mineral admixture made from refined slag, the chemical composition and percentage of which include: CaO: 55-65%, SiO2: 16-26%, Al2O3: 5-12%, Fe2O3: 6-12%, MgO: 6-9%, and the rest are impurities. The present invention optimizes the smelting method of the refined LF furnace, and mixes the recycled slag with slag, desulfurized gypsum, water, and waste sand in a reasonable proportion to produce a mineral admixture that meets the requirements of compressive strength and flexural strength, thereby achieving batch supply of the product.

[0006] Furthermore, the chemical composition and percentage of the mineral admixture include: CaO: 55-60%, SiO2: 16-20%, Al2O3: 5-10%, Fe2O3: 6-10%, MgO: 6-8%, and the rest are impurities.

[0007] Furthermore, the chemical composition and percentage of the mineral admixture include: CaO: 60-65%, SiO2: 18-26%, Al2O3: 8-12%, Fe2O3: 8-12%, MgO: 7-9%, and the rest are impurities.

[0008] In order to further achieve the purpose of the present invention, a production method for producing mineral admixtures based on refined slag is also provided, and the specific steps are as follows: (1) After smelting in the converter, the molten steel is sent to the LF for refining. The temperature of the molten steel at the station is 1540-1600℃, ensuring smooth bottom stirring argon gas flow; (2) LF uses lime + aluminum for deoxidation and alloying, and the bottom stirring argon gas flow rate is 30-50Nl / min to ensure white slag tapping; (3) After continuous casting of molten steel, the ladle slag is recovered and the recovered refined slag is transported to the slag treatment workshop for slag stewing operation. The slag stewing time is 3 to 10 hours and the slag stewing temperature is 800 to 1200°C; (4) The refined slag after stewing is ground into powder and mixed with gypsum, water and waste sand in a ratio of 4:3:1:7; (5) The stirring temperature is 0-50°C, and cementitious materials are added to prepare mineral admixtures.

[0009] Furthermore, in step (1), the temperature of the molten steel at the station is 1568°C or 1579°C.

[0010] Furthermore, in the step (2), the bottom stirring argon gas flow rate is 35Nl / min or 43Nl / min.

[0011] Furthermore, in the step (3), the slag stewing time is 6 hours or 7 hours, and the corresponding slag stewing temperature is 960°C or 850°C.

[0012] Furthermore, in the step (5), the stirring temperature is 40°C.

[0013] Compared with the prior art, the advantages of the technical solution of the present invention are: (1) The present invention uses lime + aluminum to carry out desulfurization, thereby improving the desulfurization efficiency of the smelting process and the quality of smelting molten steel; (2) The present invention adopts the production method of lime + aluminum, and the CaO content of the obtained refined slag is as high as 60%, and the remaining content is mainly FeO and Al2O3. The refined slag becomes the best raw material for mineral admixture after recycling, and the strength and toughness of the produced mineral admixture are improved; (3) The present invention rationally utilizes the refining slag, effectively reducing the pollution of the smelting slag to the ground and water quality in the factory area, realizing the green and clean production of the steel industry and improving the image of the enterprise; (4) After physical and chemical property testing, the physical and chemical properties of the mineral admixture produced by the present invention have reached the requirements of equivalent cement, and mass production has been achieved. The product is highly practical and the supply performance continues to improve; (5) The present invention pulverizes the slag and mixes it with gypsum, water, and waste sand in a ratio of 4:3:1:7. This is obtained through continuous practice verification, has a unique formula usage right, and the formula can be used by other enterprises, with product versatility. DETAILED DESCRIPTION Example 1

[0014] In order to make the present invention more clear, the following further describes a method for producing a mineral admixture based on refined slag and a production method thereof. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0015] In this embodiment, the components and percentages of the mineral admixture manufactured based on refined slag include: CaO: 57%, SiO2: 19%, Al2O3: 8%, Fe2O3: 7%, MgO: 7%, and the rest are impurities.

[0016] A production method for producing mineral admixtures based on refined slag, characterized in that: S1. After smelting in the converter, the molten steel is sent to LF for refining. The temperature of the molten steel at the station is 1568℃, ensuring smooth flow of bottom stirring argon gas; S2 and LF use lime + aluminum for deoxidation and alloying, and the bottom stirring argon flow rate is 35Nl / min to ensure white slag tapping; S3. After continuous casting of molten steel, the ladle slag is recovered and the recovered refined slag is transported to the slag treatment workshop for slag stewing operation. The slag stewing time is 7 hours and the slag stewing temperature is 960°C. S4, the refined slag after slag stewing is ground and powdered, and mixed with gypsum, water, and waste stone sand in a ratio of 4:3:1:7; S5. The stirring temperature is 40°C, and cementitious materials are added at the same time to prepare mineral admixtures. Example 2

[0017] In this embodiment, a mineral admixture composition and its percentages are manufactured based on refined slag, including: CaO: 56%, SiO2: 17%, Al2O3: 9%, Fe2O3: 7%, MgO: 8%, and the rest are impurities.

[0018] This embodiment also provides a production method for producing mineral admixtures by refining slag, which is characterized by: S1. After smelting in the converter, the molten steel is sent to LF for refining. The temperature of the molten steel at the station is 1579℃, ensuring smooth flow of bottom stirring argon gas; S2 and LF use lime + aluminum for deoxidation and alloying, and the bottom stirring argon flow rate is 43Nl / min to ensure white slag tapping; S3. After continuous casting of molten steel, the ladle slag is recovered and the recovered refined slag is transported to the slag treatment workshop for slag stewing operation. The slag stewing time is 6 hours and the slag stewing temperature is 850°C. S4, the refined slag after slag stewing is ground and powdered, and mixed with gypsum, water, and waste stone sand in a ratio of 4:3:1:7; S5. The stirring temperature is 0-50°C, and cementitious materials are added at the same time to prepare mineral admixtures.

[0019] The performance data of the mineral admixture manufactured according to the above method are as follows:

[0020] It can be seen from the table that the mineral admixture provided by the present invention has performance that meets the strength requirements of cement, can replace the use of cement in product applications, and has been promoted and applied, thereby improving the green recycling of steel enterprises.

[0021] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A method for producing a mineral admixture based on refined slag, characterized in that: The chemical composition and percentage of the mineral admixture include: CaO: 55-65%, SiO2: 16-26%, Al2O3: 5-12%, Fe2O3: 6-12%, MgO: 6-9%, and the rest are impurities.

2. The method for producing mineral admixtures based on refined slag according to claim 1, characterized in that: The chemical composition and percentage of the mineral admixture include: CaO: 55-60%, SiO2: 16-20%, Al2O3: 5-10%, Fe2O3: 6-10%, MgO: 6-8%, and the rest are impurities.

3. The method for producing mineral admixtures based on refined slag according to claim 1, characterized in that: The chemical composition and percentage of the mineral admixture include: CaO: 60-65%, SiO2: 18-26%, Al2O3: 8-12%, Fe2O3: 8-12%, MgO: 7-9%, and the rest are impurities.

4. A production method for producing mineral admixtures based on refined slag as claimed in claim 1, comprising the following specific steps, characterized in that: (1) After smelting in the converter, the molten steel is sent to the LF for refining. The temperature of the molten steel at the station is 1540-1600℃, ensuring smooth flow of bottom stirring argon gas; (2) LF uses lime + aluminum for deoxidation and alloying, and the bottom stirring argon gas flow rate is 30-50Nl / min to ensure white slag tapping; (3) After continuous casting of molten steel, the ladle slag is recovered and the recovered refined slag is transported to the slag treatment workshop for slag stewing operation. The slag stewing time is 3 to 10 hours and the slag stewing temperature is 800 to 1200°C; (4) The refined slag after slag stewing is ground into powder and mixed with gypsum, water and waste sand in a ratio of 4:3:1:7; (5) The stirring temperature is 0-50°C, and cementitious materials are added to prepare mineral admixtures.

5. The method for producing mineral admixtures based on refined slag according to claim 4, characterized in that: In the step (1), the temperature of the molten steel at the station is 1568°C or 1579°C.

6. The method for producing mineral admixtures based on refined slag according to claim 4, characterized in that: In the step (2), the bottom stirring argon gas flow rate is 35Nl / min or 43Nl / min.

7. The method for producing mineral admixtures based on refined slag according to claim 4, characterized in that: In the step (3), the slag stewing time is 6 hours or 7 hours, and the corresponding slag stewing temperature is 960°C or 850°C.

8. The method for producing mineral admixtures based on refined slag according to claim 4, characterized in that: In the step (5), the stirring temperature is 40°C.

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