Steel ladle drainage agent with high self-opening rate and production method thereof

Abstract

The invention discloses a steel ladle drainage agent with a high self-opening rate and a production method of the steel ladle drainage agent, and belongs to the field of steel smelting, and the steel ladle drainage agent comprises the following raw materials in parts by mass: 9-12 parts of MgO, 22-26 parts of Fe2O3, 34-37 parts of Gr2O3, 26-30 parts of SiO2 and 0.1-0.3 part of C. Compared with a traditional chromium drainage agent, the steel ladle drainage agent provided by the invention has the advantages that the compression strength is obviously reduced and the thickness of a sintered layer is reduced by about 30% at the high temperature of 1550 DEG C; by introducing a magnesium material, the adding amount of aluminum oxide is reduced, and the molten steel flocculation problem is solved; the steel ladle drainage agent provided by the invention improves the pouring rate of the steel ladle, and reduces the influence of oxygen burning and open pouring on the quality of molten steel.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steel smelting, and particularly relates to a high self-opening rate ladle drainage agent and a production method thereof. BACKGROUND

[0002] Before the ladle is loaded with molten steel, in order to avoid the direct contact of the molten steel with the upper nozzle, which leads to the solidification of the molten steel due to the temperature reduction, a certain amount of drainage agent is generally put into the upper nozzle, the purpose is that the molten steel can flow out with the drainage agent when the nozzle slide plate is opened, but due to the long transportation distance of some steel plants, the ladle is loaded with molten steel for a long time from the converter tapping to the continuous casting opening, which leads to the sintering of the drainage agent being too heavy, so that the molten steel cannot be automatically opened, and the molten steel needs to be burned with oxygen to open, which increases the risk and reduces the quality of the billet.

[0003] Therefore, it is an urgent problem for those skilled in the art to provide a high self-opening rate ladle drainage agent and a production method thereof. SUMMARY

[0004] In order to solve the above problems, the present application provides a high self-opening rate ladle drainage agent and a production method thereof.

[0005] In order to achieve the above purpose, the present application adopts the following technical solutions: A high self-opening rate ladle drainage agent, comprising the following mass parts of raw materials: MgO 9-12 parts, Fe2O3 22-26 parts, Gr2O3 34-37 parts, SiO2 26-30 parts and C 0.1-0.3 parts Preferably, the following mass parts of raw materials are included: MgO 11 parts, Fe2O3 24 parts, Gr2O3 36.8 parts, SiO2 28 parts and C 0.2 parts.

[0006] Preferably, the particle size mass parts of the raw materials are as follows: >20 mesh 9-12 parts, 20-40 mesh 35-38 parts, 40-70 mesh 49.7-55.9 parts, and <70 mesh 0.1-0.3 parts.

[0007] Preferably, the particle size of the MgO is 20-30 mesh; The particle size of the Fe2O3 and Gr2O3 is 20-70 mesh; The particle size of the SiO2 is 20-60 mesh; The particle size of the C is -100-120 mesh.

[0008] Preferably, the following raw materials are selected for the drainage agent: calcined sand, chromium concentrate, sintering inhibitor and carbon.

[0009] The application uses high-temperature calcined sand, chromium concentrate, refractory agent and carbon as raw materials, the refractory agent has the characteristics of MgO content ≥95%, liquid phase temperature ≥2650℃, and good sphericity, the high-temperature calcined sand has SiO2 content ≥98%, liquid phase temperature ≥1730℃, and after being uniformly mixed with the chromium concentrate, the sintering strength of the chromium concentrate is reduced to a certain extent, the sintering layer thickness is reduced, and the lubricity of the flow agent is effectively improved by using the carbon in cooperation with the good sphericity, and the opening rate of the flow agent is significantly improved.

[0010] Preferably, the calcined sand is 15-18 parts by weight, the refractory agent is 5-6 parts by weight, the chromium concentrate is 75-82 parts by weight, and the carbon is 0.2-0.3 parts by weight.

[0011] Preferably, the calcined sand is 15 parts by weight, the refractory agent is 5 parts by weight, the chromium concentrate is 79.8 parts by weight, and the carbon is 0.2 parts by weight.

[0012] Preferably, the calcined sand is high-temperature calcined sand, and SiO2 ≥98%; Fe2O3 in the chromium concentrate is ≤30%, and Gr2O3 ≥46%; MgO in the refractory agent is ≥95%; The carbon is flaky graphite.

[0013] The production method of the high-opening-rate ladle flow agent comprises the following steps: (1) The raw materials are weighed according to the mass fraction; (2) Half of the total mass of the calcined sand, the chromium concentrate and the refractory agent and the carbon are uniformly mixed for the first time, and then the remaining calcined sand, chromium concentrate and refractory agent are uniformly mixed for the second time.

[0014] Preferably, the carbon in step (2) is added by blowing.

[0015] Preferably, the first-time mixing time in step (2) is 10-12 min, and the rotating speed is 4-5 r / min; The second-time mixing time is 40-45 min, and the rotating speed is 4-5 r / min.

[0016] Compared with the prior art, the application has the following beneficial effects: (1) The ladle flow agent provided by the application has a significantly reduced compression strength and a sintering layer thickness reduced by about 30% compared with the traditional chromium flow agent under the condition of 1550℃ high temperature; (2) The ladle flow agent of the application reduces the amount of added alumina by introducing magnesium materials, thereby reducing the problem of molten steel flocculation; (3) The ladle drainage agent provided by the application improves the ladle tapping rate and reduces the influence of oxygen burning and open tapping on the quality of molten steel. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, below the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0018] Figure 1 Sintering layer schematic diagram of the application and traditional drainage agent for application example. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] Embodiment 1 The present application provides a production method of high self-opening rate ladle drainage agent, comprising the following specific steps: (1) The raw materials are weighed, including the following weight parts: high-temperature calcined baked sand 15 parts, burn inhibitor 5 parts, chromium concentrate 79.8 parts and carbon 0.2 parts; wherein, the high-temperature calcined baked sand SiO2≥98%, the particle size requirement is 20-60 mesh, the chromium concentrate Fe2O3≤30%, Gr2O3≥46%, the particle size is 20-70 mesh, the burn inhibitor MgO≥95%, the particle size is 40-60 mesh, and the carbon is selected from -195 scale graphite; the final product parameters are obtained as follows: MgO 11 parts, Fe2O3 24 parts, Gr2O3 36.8 parts, SiO2 28 parts, C 0.2 parts, the particle size is: >20 mesh 15 parts, 20-40 mesh 33 parts, 40-70 mesh 42 parts, and <70 mesh 10 parts; (2) The prepared high-temperature calcined baked sand, chromium concentrate and burn inhibitor are first put into 50% of the double-shaft spiral stirrer, the carbon is directly blown into the stirrer through the air feeding device, and after net mixing for 10 min at 4-5 r / min, the remaining 50% is put in, and after net mixing for 40 min at 4-5 r / min, the discharge is transferred to the finished product bin through the material cup. Under the high-temperature reduction condition of 1550℃ for 0.5h, the pressure resistance value is compared and detected after cooling, and the pressure resistance value is 16MPa.

[0021] Embodiment 2 (1) The raw materials are weighed, including the following weight parts: high-temperature calcined roasted sand 17 parts, burning inhibitor 5 parts, chromium concentrate 77.8 parts and carbon 0.2 parts; wherein, the high-temperature calcined roasted sand SiO2≥98%, the particle size requirement is 20-60 mesh, the chromium concentrate Fe2O3≤30%, Gr2O3≥46%, the particle size is 20-70 mesh, the burning inhibitor MgO≥95%, the particle size is 40-60 mesh, and the carbon is selected from -195 flaky graphite; the final product parameters are obtained as follows: MgO 12 parts, Fe2O3 23.5 parts, Gr2O3 36.3 parts, SiO2 28 parts, C 0.2 parts, and the particle size is: >20 mesh 15.5 parts, 20-40 mesh 33.5 parts, 40-70 mesh 43 parts, and <70 mesh 8 parts; (2) The prepared high-temperature calcined roasted sand, chromium concentrate and burning inhibitor are first put into 50% of the double-shaft spiral mixer, the carbon is directly blown into the mixer through the air feeding device, and after mixing for 12 min at 4-5 r / min, the remaining 50% is put in, and after mixing for 45 min at 4-5 r / min, the material is discharged through the material cup and transferred to the finished product bin. After cooling, the pressure resistance value is compared and detected under the reduction high-temperature condition of 1550℃ for 0.5 h, and the pressure resistance value is 16.1 MPa.

[0022] Example 3 (1) The raw materials are weighed, including the following weight parts: high-temperature calcined roasted sand 17 parts, burning inhibitor 5 parts, chromium concentrate 77.8 parts and carbon 0.2 parts; wherein, the high-temperature calcined roasted sand SiO2≥98%, the particle size requirement is 20-60 mesh, the chromium concentrate Fe2O3≤30%, Gr2O3≥46%, the particle size is 20-70 mesh, the burning inhibitor MgO≥95%, the particle size is 40-60 mesh, and the carbon is selected from -195 flaky graphite; the final product parameters are obtained as follows: MgO 12 parts, Fe2O3 23.5 parts, Gr2O3 36.3 parts, SiO2 28 parts, C 0.2 parts, and the particle size is: >20 mesh 15.5 parts, 20-40 mesh 33.5 parts, 40-70 mesh 43 parts, and <70 mesh 8 parts; (2) The prepared high-temperature calcined roasted sand, chromium concentrate and burning inhibitor are first put into 50% of the double-shaft spiral mixer, the carbon is directly blown into the mixer through the air feeding device, and after mixing for 12 min at 4-5 r / min, the remaining 50% is put in, and after mixing for 45 min at 4-5 r / min, the material is discharged through the material cup and transferred to the finished product bin. After cooling, the pressure resistance value is compared and detected under the reduction high-temperature condition of 1550℃ for 0.5 h, and the pressure resistance value is 16.3 MPa.

[0023] Comparative Example Comparative experiments were conducted by adjusting the amount of sintering inhibitor added in Example 1. The sintering inhibitor was set to 2%, 3%, 4%, 5% (the ratio in Example 1), 6%, 7%, and 8% respectively, increasing sequentially, while the chromium concentrate was reduced accordingly. The results were compared under the high-temperature reduction conditions of 1550℃ for 0.5h. After cooling, the pressure resistance values ​​were compared and tested. The pressure resistance values ​​were 23.4MPa, 22MPa, 19MPa, 16MPa, 18.3MPa, 19.6MPa, 22.5MPa, and 30.4MPa, respectively. Through experimental comparison, the pressure resistance was the lowest when the amount of sintering inhibitor added was 5%, indicating the lowest sintering performance. Therefore, the 5% addition amount was selected as the production scheme.

[0024] Application examples Taking a 210t RH furnace in a large steel plant in Northeast China as an example, this branch plant has been in operation for over 10 years. Operating conditions include: steel-bearing time ranging from 90 to 180 minutes, tapping temperature of 1650-1710℃, primarily producing silicon steel and ultra-low carbon steel. Using traditional aluminum-chromium flow guides (25 parts Al2O3, 17 parts Fe2O3, 28 parts Gr2O3, 20 parts SiO2, and 0.2 parts C), the initial casting rate consistently remained between 99.1% and 99.3%. By adopting the flow guide of this invention (product of Example 1), the initial casting rate was increased to 99.6%-99.8%. Figure 1 The diagram shows the sintered layers of the flow-guiding agent of this invention and the conventional flow-guiding agent. It can be seen that the sintered layer of the flow-guiding agent of this invention is significantly thinner than that of the conventional flow-guiding agent. This demonstrates that the solution of this invention has positive practical performance for industrial production, can bring certain economic benefits to enterprises, and more importantly, improves the safe, continuous, and stable production capacity of the user unit.

[0025] The various embodiments are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between the various embodiments can be referred to each other.

[0026] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. 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 the invention. Therefore, the invention 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 disclosed herein.

Claims

1. A high spout rate ladle flux characterized by, The raw materials include the following quality parts: MgO 9-12 parts, Fe2O3 22-26 parts, Gr2O3 34-37 parts, SiO2 26-30 parts and C 0.1-0.3 parts.

2. The high opening rate ladle flux according to claim 1, characterized in that, The particle size of the raw materials is as follows: >20 mesh 9-12 parts, 20-40 mesh 35-38 parts, 40-70 mesh 49.7-55.9 parts, <70 mesh 0.1-0.3 parts.

3. The high openability ladle flux according to claim 1, characterized by, The particle size of the MgO is 20-30 mesh; The particle size of the Fe2O3 and Gr2O3 is 20-70 mesh; The particle size of the SiO2 is 20-60 mesh; The particle size of the C is -100-120 mesh.

4. The high opening rate ladle flux according to claim 1, characterized in that, The drainage agent is selected from the following raw materials: Roasted sand, chromium concentrate, burning inhibitor and carbon.

5. The high openability ladle flux according to claim 4, wherein The roasted sand is 15-18 parts by weight, the burning inhibitor is 5-6 parts by weight, the chromium concentrate is 75-82 parts by weight and the carbon is 0.2-0.3 parts by weight.

6. The high openability ladle flux according to claim 4, wherein The roasted sand is high-temperature calcined roasted sand, SiO2≥98%; The Fe2O3 in the chromium concentrate is ≤30%, and the Gr2O3 is ≥46%; The MgO in the burning inhibitor is ≥95%; The carbon is flaky graphite.

7. The method for producing a high self-opening rate ladle flux according to any one of claims 1 to 6, characterized in that, The method specifically includes the following steps: (1) The raw materials are weighed according to the quality parts; (2) Half of the total mass of the roasted sand, the chromium concentrate and the burning inhibitor and the carbon are first mixed uniformly, and then the remaining roasted sand, chromium concentrate and burning inhibitor are added for second mixing.

8. The method of producing a high-opening-ratio ladle flux according to claim 7, characterized by, The carbon in step (2) is added by blowing.

9. The method of producing a high-opening-ratio ladle flux according to claim 7, characterized by, The first mixing in step (2) is performed for 10-12 min at a speed of 4-5 r / min; The second mixing is performed for 40-45 min at a speed of 4-5 r / min.

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