Converter final slag alkalinity control method and system

Abstract

The invention discloses a converter final slag alkalinity control method, and relates to the technical field of ferrous metallurgy, and the converter final slag alkalinity control method comprises the steps that charging system data are collected in real time, and the charging system data comprise the temperature, the metal charging amount and the slagging auxiliary material adding amount; the converter slag alkalinity is preset based on the charging system data, and the total slag amount, the final slag component content and the converter final slag alkalinity of a converter molten pool are calculated; judging whether the alkalinity of the converter final slag is greater than a first threshold value or not, if so, calculating the adding amount of a first slag modifier, and if not, carrying out the next step; and judging whether the final slag alkalinity of the converter is greater than a second threshold value or not, and if not, calculating the adding amount of a second slag modifier. According to the method, the converter final slag alkalinity is effectively controlled within a proper range in a modification mode, and a reasonable slag adjusting scheme is matched, so that the smelting time is effectively shortened, and the adverse factors of poor dynamic conditions and poor slag deoxidation and inclusion removal performance caused by unreasonable control of the converter slag alkalinity are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy, and in particular to a method and system for controlling the basicity of converter final slag. Background Art

[0002] Slag basicity is one of the important properties of slag. Slags of different basicities will directly affect the quality of converter smelting. When the slag basicity is high, the viscosity of the slag will increase and the fluidity will decrease, affecting the smooth operation of the blast furnace; corroding the converter lining, reducing the service life of the converter, and increasing the smelting cost; reducing the melting point of the slag, thereby affecting the converter smelting efficiency. When the slag basicity is low, although the fluidity is good, the adsorption capacity of inclusions is weak, and at the same time, it will lead to insufficient dephosphorization and desulfurization reactions, which is not conducive to the kinetic conditions of the steel slag reaction and affects the dephosphorization and desulfurization capabilities of the slag.

[0003] At present, converter smelting is in a fast-paced production mode. In order to eliminate the quality problems caused by the poor physical and chemical properties of slag, shorten the smelting time, improve the slag's ability to absorb inclusions, and enhance the slag's dephosphorization and desulfurization capabilities. Domestic and foreign scholars are actively conducting technical research and innovation. Through experimental research on different slag basicities under different process conditions combined with actual factory production experience, it is found that the converter slag basicity is in the range of 2.8-3.2, and the physical and chemical properties are good, which is considered to be the appropriate converter final slag basicity. So how to stably and effectively predict and control the converter slag basicity in production to achieve efficient production is a technical problem that needs to be solved urgently.

[0004] As customers' requirements for steel quality become higher and higher, the converter steelmaking process technology has been challenged. However, there are many types of steel, and the service conditions and quality requirements vary greatly. Therefore, it is very important to select the appropriate slag basicity slag system according to different steel grades and accurately control the appropriate basicity to improve the smelting effect and steel quality. However, in actual operation, the slag basicity is often controlled by manual experience, which will cause fluctuations in the slag basicity, affect the efficiency of dephosphorization and sulfur removal and the removal of inclusions, and thus affect the cleanliness of molten steel and the quality of finished steel. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the disadvantages of the prior art and provide a method and system for controlling the basicity of converter final slag.

[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows: A method for controlling basicity of converter final slag, comprising: Collecting feeding system data in real time, including temperature, metal loading amount, and slag making auxiliary material addition amount; Presetting the basicity of converter slag based on the data of the feeding system, and calculating the total slag amount of the converter molten pool, the content of the final slag components and the basicity of the final converter slag; Determine whether the basicity of the converter final slag is greater than a first threshold value, if so, calculate the amount of the first slag conditioning agent to be added, if not, proceed to the next step; It is determined whether the basicity of the converter final slag is greater than a second threshold value. If not, the amount of the second slag adjusting agent to be added is calculated.

[0007] As a preferred solution of the method for controlling the basicity of the final slag of the converter of the present invention, the calculation of the total slag amount of the converter molten pool includes: The total slag amount in the converter molten pool is calculated by formula 1, which is: ;in, is the total slag volume in the converter molten pool; is the correction coefficient; R' is the preset converter slag basicity; is the silicon content in the metal material; is the silicon content of the slag in the converter molten pool; To adjust the alkalinity of the slag pool, SiO 2 quantity.

[0008] As a preferred solution of the method for controlling the basicity of the final slag of the converter of the present invention, the calculation of the final slag component content includes: The final slag component content is calculated by formula 2 and formula 3, and the formula 2 is: , the formula three is: ; Wherein, f(M) is the content of MgO in converter slag, f(T) is the content of T.Fe in converter slag; f(t) is the tapping temperature of molten steel; f(O 2 ) is the oxygen content in the steel after tapping; is the amount of each slag-making auxiliary material added; is the MgO content in each slag-making auxiliary material; It is the amount of MgO brought into the refractory material on the inner wall of the molten pool.

[0009] As a preferred solution of the method for controlling the basicity of the converter final slag of the present invention, the calculation of the basicity of the converter final slag includes: The basicity of the final slag of the converter is calculated by Formula 4, which is: ; Among them, R is the basicity of converter final slag; M CaO is the mass of CaO in the slag pool; M SiO2 SiO in the slag pool 2 quality; is the correction factor; μ To preset the final slag viscosity; The model is selected for the preset parameters, and when f(M) is less than 8%, μ and f(M) are selected; when f(T) is greater than 15%, μ and f(T) are selected; when the tapping temperature is greater than 1650℃, μ and f(t) are selected.

[0010] As a preferred solution of the method for controlling the basicity of the final slag of the converter of the present invention, the correction coefficient It is 0.5~1.2.

[0011] As a preferred solution of the method for controlling the basicity of the final converter slag of the present invention, the step of judging whether the basicity of the final converter slag is greater than a first threshold value and, if so, calculating the amount of the first slag adjusting agent to be added comprises: It is determined whether the basicity of the final slag of the converter is greater than the first threshold value. If so, the amount of the first slag adjusting agent added is calculated by formula 5, and the formula 5 is: ; in, is the amount of the first slag adjusting agent added; is the average T.Fe content of the slag sample; f(T) is the T.Fe content in the converter final slag; is the total slag volume of the converter molten pool; R is the basicity of the final slag of the converter; R 0 is the first threshold.

[0012] As a preferred solution of the method for controlling the basicity of the final converter slag of the present invention, the step of judging whether the basicity of the final converter slag is greater than the second threshold value, and if not, calculating the amount of the second slag adjusting agent to be added includes: It is determined whether the basicity of the converter final slag is greater than the second threshold value. If not, the amount of the second slag adjusting agent added is calculated by formula 6, and the formula 6 is: ; in, is the amount of the second slag conditioning agent added, is the average T.Fe content of the slag sample, taking 15%; f(T) is the T.Fe content in the converter final slag; is the total slag volume of the converter molten pool; R is the basicity of the final slag of the converter; R 1 is the second threshold.

[0013] As a preferred solution of the method for controlling the basicity of the final slag of the converter of the present invention, the first threshold value R 0 and the second threshold R 1 The range of is 2.5~3.8, wherein the first threshold R 0 is 3.5, the second threshold R 1 is 2.6.

[0014] As a preferred solution of the method for controlling the basicity of the converter final slag of the present invention, the first slag conditioning agent is an iron slag conditioning agent, and the mass fraction of iron oxide therein is not less than 50%, and the particle size is 5 to 20 mm.

[0015] As a preferred solution of the method for controlling the basicity of the converter final slag of the present invention, the second slag conditioning agent is a magnesium slag conditioning agent, and the mass fraction of magnesium oxide therein is not less than 45%, and the particle size is 5 to 15 mm.

[0016] The beneficial effects of the present invention are: (1) The present invention effectively controls the basicity of the converter final slag within a suitable range through a modification method, and combines it with a reasonable slag adjustment scheme to effectively shorten the smelting time and reduce the unfavorable factors such as poor dynamic conditions and poor slag deoxidation and inclusion removal performance caused by unreasonable control of the converter slag basicity.

[0017] (2) The present invention adopts different tempering and modification methods for slag systems with different basicity ranges, and calculates the guiding amount of slag conditioning agent to be added, thereby reducing the blindness and arbitrariness of the tempering and modification, avoiding the interference of human factors, and achieving the effect of automatically and efficiently predicting and controlling the basicity of converter slag. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0019] Figure 1 A schematic diagram of the structure of a flow diagram of a method for controlling the basicity of converter final slag provided in Example 1; Figure 2 A schematic diagram of a control system for converter final slag basicity provided in Example 2; Figure 3 It is a schematic diagram of a calculation processing module in a control system of converter final slag basicity; Figure 4 It is a schematic diagram of the principle of the primary judgment module and the secondary judgment module in the control system of the converter final slag basicity. DETAILED DESCRIPTION

[0020] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific implementation modes and in combination with the accompanying drawings.

[0021] Embodiment 1: Figure 1The following is a flow chart of a method for controlling the basicity of converter final slag provided in this embodiment. The method specifically comprises the following steps: Step S101: collecting feeding system data in real time, the feeding system data including temperature, metal charge amount, and slag-making auxiliary material addition amount.

[0022] Specifically, the data information of the feeding system is collected. It should be noted that the data information of the feeding system collected includes but is not limited to: temperature, metal charge amount and slag-making auxiliary material addition amount.

[0023] Step S102: preset the basicity of the converter slag based on the data of the charging system, and calculate the total slag amount of the converter molten pool, the final slag component content and the basicity of the converter final slag.

[0024] Specifically, first, the operator can roughly estimate the basicity of the converter slag according to the temperature, metal charge amount and slag-making auxiliary material addition amount information collected in step S101. Then, the calculation method of the total slag amount of the converter molten pool, the final slag component content and the basicity of the converter final slag is as follows: The total slag volume of the converter molten pool is calculated by formula 1: ; in, is the total slag amount in the converter molten pool, in kg; is the correction coefficient; R' is the preset converter slag basicity; is the silicon content in the metal material, in wt%; is the silicon content of the slag in the converter molten pool, in wt%; To adjust the alkalinity of the slag pool, SiO 2 Amount, unit is wt%.

[0025] The final slag content is calculated by formula 2 and formula 3. Formula 2 is: , formula three is: ; Wherein, f(M) is the content of MgO in converter slag, in wt%, f(T) is the content of T.Fe in converter slag, in wt%; f(t) is the tapping temperature of molten steel, in °C; f(O 2 ) is the oxygen content in the steel after tapping, in ppm; is the amount of each slag-making auxiliary material added, in kg; is the MgO content in each slag-making auxiliary material, in wt%; It is the amount of MgO brought into the refractory material of the inner wall of the molten pool, in kg.

[0026] The basicity of the final slag of the converter is calculated by formula 4, which is: ; Among them, R is the basicity of converter final slag;M CaO is the mass of CaO in the slag pool slag, in kg; M SiO2 SiO in the slag pool 2 Mass, in kg; is the correction coefficient, specifically 0.5 to 1.2; μ The final slag viscosity is preset in Pa·S. For the preset parameter selection model, when f(M) in the converter final slag is less than 8%, select μ and f(M); 2) When the total iron content of the converter final slag f(T) is greater than 15%, select μ and f(T); 3) When the steelmaking temperature is greater than 1650℃, select μ and f(t).

[0027] Step S103: determine whether the basicity of the converter final slag is greater than the first threshold value. If so, calculate the amount of the first slag conditioning agent to be added. If not, proceed to the next step.

[0028] Specifically, the above step S102 processes the collected feeding system data to obtain the predicted converter final slag basicity. The converter final slag basicity is compared with the first threshold value to determine whether it is greater than the first threshold value. If so, it is necessary to add the first slag adjusting agent, and calculate the addition amount of the first slag adjusting agent. The specific calculation method is as follows: The amount of the first slag conditioning agent added is calculated by formula 5, which is: ; in, is the amount of the first slag conditioning agent added, in kg; is the average T.Fe content of the slag sample, taking 15%; f(T) is the T.Fe content in the converter final slag, in wt%; is the total slag volume of the converter molten pool, in kg; R is the basicity of the final converter slag; R 0 is the first threshold value, and its value range is 2.5~3.8. In this embodiment, the first threshold value R 0 Take 3.5.

[0029] Step S104: determine whether the basicity of the converter final slag is greater than the second threshold value; if not, calculate the amount of the second slag conditioning agent to be added.

[0030] Specifically, after determining that the basicity of the converter final slag is less than or equal to the first threshold, the basicity of the converter final slag is compared with the second threshold to determine whether it is greater than the second threshold. If not, it is necessary to add the second slag adjusting agent, and calculate the addition amount of the second slag adjusting agent. The specific calculation method is as follows: The amount of the second slag conditioning agent added is calculated by formula 6, which is: ; in, is the amount of the second slag conditioning agent added, in kg, is the average T.Fe content of the slag sample, taking 15%; f(T) is the T.Fe content in the converter final slag, in wt%; is the total slag volume of the converter molten pool, in kg; R is the basicity of the converter final slag; R 1 is the second threshold value, and its value range is also 2.5~3.8. In this embodiment, the second threshold value R 1 Take 2.6.

[0031] In this embodiment, the first slag-adjusting agent is an iron slag-adjusting agent, wherein the mass fraction of iron oxide is not less than 50%, and the particle size is 5 to 20 mm. The second slag-adjusting agent is a magnesium slag-adjusting agent, wherein the mass fraction of magnesium oxide is not less than 45%, and the particle size is 5 to 15 mm.

[0032] Example 2: This example provides a control system for converter final slag basicity. Figure 2 The system includes a data acquisition module, a calculation processing module, a judgment module and an output module. The data acquisition module collects data information of the steel mill feeding system in real time and transmits it to the calculation processing module. The calculation processing module processes the information and obtains different output results after classification and processing by the judgment processing module, and outputs different slag basicity schemes through the output module.

[0033] Specifically, the data acquisition module is used to exchange information data with the steel plant's secondary feeding system. The collected information includes temperature, metal charging amount and slag-making auxiliary material addition amount. Different companies may use different auxiliary materials in actual production. The raw and auxiliary materials used by each company can be determined, and each raw and auxiliary material can be sampled to analyze and detect its main chemical composition.

[0034] The calculation and processing module is used to process the data information transmitted from the previous level. Figure 3 The calculation and processing module includes a database module 220, a slag quantity calculation module 210, a final slag composition calculation module 211 and a basicity calculation module 212.

[0035] The database module 220 is used to select the basicity range. The database module 220 is a database model established in advance. Based on a large number of on-site industrial tests and theoretical calculations, the slag basicity database corresponding to different components, different basicity converter slags, and different molten steel tapping temperatures is fitted to guide subsequent production. In this database, the corresponding appropriate final slag basicity can be found as a reference according to the content of MgO and T.Fe in different converter slags, the preset final slag viscosity, and different molten steel tapping temperatures.

[0036] The slag amount calculation module 210 is used to calculate the total slag amount. Specifically, the calculation is performed using the following formula: ; in, is the total slag amount in the converter molten pool, in kg; is the correction coefficient; R' is the preset converter slag basicity; is the silicon content in the metal material, in wt%; is the silicon content of the slag in the converter molten pool, in wt%; To adjust the alkalinity of the slag pool, SiO 2 Amount, unit is wt%.

[0037] The final slag composition calculation module 211 is used to predict the range of the main components of the converter final slag, that is, the content of MgO and T.Fe in the final slag. The calculation is specifically performed by the following formula: ; ; Wherein, f(M) is the content of MgO in converter slag, in wt%, f(T) is the content of T.Fe in converter slag, in wt%; f(t) is the tapping temperature of molten steel, in °C; f(O 2 ) is the oxygen content in the steel after tapping, in ppm; is the amount of each slag-making auxiliary material added, in kg; is the MgO content in each slag-making auxiliary material, in wt%; It is the amount of MgO brought into the refractory material of the inner wall of the molten pool, in kg.

[0038] The basicity calculation module 212 selects in the database module 220 by establishing a mathematical model, thereby obtaining the basicity of the converter final slag. Specifically, the calculation is performed by the following formula: ; Among them, R is the basicity of converter final slag; M CaO is the mass of CaO in the slag pool slag, in kg; M SiO2 SiO in the slag pool 2 Mass, in kg; is the correction coefficient, specifically 0.5 to 1.2; μ The final slag viscosity is preset in Pa·S. The model is selected for the preset parameters, and when f(M) in the converter final slag is less than 8%, μ and f(M) are selected at this time; 2) When the total iron content of the converter final slag f(T) is greater than 15%, μ and f(T) are selected at this time; 3) When the steelmaking temperature is greater than 1650℃, μ and f(t) are selected at this time.

[0039] The judgment processing module 31 is used to judge and classify the data of the previous level and obtain the corresponding output result. It includes a primary judgment module 310 and a secondary judgment module 311, which classify and calculate the data respectively and output the obtained solution in the form of electrical signals. Figure 4 As shown, the first-level judgment procedure and the second-level judgment procedure are: R>R 0 , R>R 1 . R 0 and R 1 The value range is 2.5~3.8. 0 Take 3.5, R 1 Take 2.6.

[0040] Specifically, when the first-level determination module 310 determines that R>R 0 When , the processing function is: ; If R>R 0 , then enter the secondary judgment module (311).

[0041] When the secondary judgment module 311 judges that R>R 1 When , the processing function is: ; in , are the addition amounts of the second slag adjusting agent and the first slag adjusting agent, respectively, in kg; is the average T.Fe content of the slag sample, taking 15%; f(T) is the T.Fe content in the converter final slag, in wt%; is the total slag volume of the converter molten pool, in kg; R is the basicity of the converter final slag; R 0 , R 1 The standard alkalinity range is 2.5~3.8, where R 0 Take 3.5, R 1 Take 2.6.

[0042] It should be noted that the second slag-adjusting agent is a magnesium slag-adjusting agent, wherein the mass fraction of magnesium oxide is not less than 45%, and the particle size is 5 to 15 mm. The first slag-adjusting agent is an iron slag-adjusting agent, wherein the mass fraction of iron oxide is not less than 50%, and the particle size is 5 to 20 mm.

[0043] The output module 41 is used to input the output plan calculated by the upper level into the secondary system of the steel plant after processing to realize automated and efficient production.

[0044] Therefore, the technical solution of the present application effectively controls the basicity of the converter final slag within a suitable range through modification, and combines it with a reasonable slag adjustment scheme to effectively shorten the smelting time and reduce the adverse factors such as poor dynamic conditions and poor slag deoxidation and removal of inclusions caused by unreasonable control of the basicity of the converter slag.

[0045] In addition to the above embodiments, the present invention may also have other implementation modes; any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A method for controlling the basicity of converter final slag, characterized in that: include: Collecting feeding system data in real time, including temperature, metal loading amount, and slag making auxiliary material addition amount; Presetting the basicity of converter slag based on the data of the feeding system, and calculating the total slag amount of the converter molten pool, the content of the final slag components and the basicity of the final converter slag; Determine whether the basicity of the converter final slag is greater than a first threshold value, if so, calculate the amount of the first slag conditioning agent to be added, if not, proceed to the next step; It is determined whether the basicity of the converter final slag is greater than a second threshold value. If not, the amount of the second slag adjusting agent to be added is calculated.

2. The method for controlling the basicity of converter final slag according to claim 1, characterized in that: The calculation of the total slag amount in the converter molten pool comprises: The total slag amount in the converter molten pool is calculated by formula 1, which is: ;in, is the total slag volume in the converter molten pool; is the correction coefficient; R' is the preset converter slag basicity; is the silicon content in the metal material; is the silicon content of the slag in the converter molten pool; The amount of SiO2 introduced by slag-making auxiliary materials to adjust the alkalinity of the slag pool.

3. The method for controlling the basicity of converter final slag according to claim 2, characterized in that: The calculation of the final slag component content includes: The final slag component content is calculated by formula 2 and formula 3, and the formula 2 is: , the formula three is: ; Wherein, f(M) is the content of MgO in the converter slag, f(T) is the content of T.Fe in the converter slag; f(t) is the tapping temperature of the molten steel; f(O2) is the oxygen content in the steel after tapping; is the amount of each slag-making auxiliary material added; is the MgO content in each slag-making auxiliary material; It is the amount of MgO brought into the refractory material on the inner wall of the molten pool.

4. The method for controlling the basicity of converter final slag according to claim 3, characterized in that: The calculation of converter final slag basicity comprises: The basicity of the final slag of the converter is calculated by formula 4, which is: ; Wherein, R is the basicity of the final slag of the converter; M CaO is the mass of CaO in the slag pool; M SiO2 is the mass of SiO2 in the slag pool; is the correction factor; μ To preset the final slag viscosity; The model is selected for the preset parameters, and when f(M) is less than 8%, μ and f(M) are selected; when f(T) is greater than 15%, μ and f(T) are selected; when the tapping temperature is greater than 1650℃, μ and f(t) are selected.

5. The method for controlling the basicity of converter final slag according to claim 4, characterized in that: The correction factor It is 0.5~1.

2.

6. The method for controlling the basicity of converter final slag according to claim 5, characterized in that: The step of judging whether the basicity of the converter final slag is greater than the first threshold value, and if so, calculating the amount of the first slag adjusting agent to be added comprises: It is determined whether the basicity of the final slag of the converter is greater than the first threshold value. If so, the amount of the first slag adjusting agent added is calculated by formula 5, and the formula 5 is: ;in, is the amount of the first slag adjusting agent added; is the average T.Fe content of the slag sample; f(T) is the T.Fe content in the converter final slag; is the total slag amount in the converter molten pool; R is the basicity of the final slag in the converter; R0 is the first threshold value.

7. The method for controlling the basicity of converter final slag according to claim 6, characterized in that: The step of judging whether the basicity of the converter final slag is greater than the second threshold value, and if not, calculating the amount of the second slag adjusting agent to be added includes: It is determined whether the basicity of the converter final slag is greater than the second threshold value. If not, the amount of the second slag adjusting agent added is calculated by formula 6, and the formula 6 is: ;in, is the amount of the second slag conditioning agent added, is the average T.Fe content of the slag sample, taking 15%; f(T) is the T.Fe content in the converter final slag; is the total slag amount in the converter molten pool; R is the basicity of the final slag in the converter; R1 is the second threshold value.

8. The method for controlling the basicity of converter final slag according to claim 7, characterized in that: The first threshold R0 and the second threshold R1 are both in the range of 2.5 to 3.8, wherein the first threshold R0 is 3.5 and the second threshold R1 is 2.

6.

9. The method for controlling the basicity of converter final slag according to claim 1, characterized in that: The first slag conditioning agent is an iron slag conditioning agent, wherein the mass fraction of iron oxide is not less than 50%, and the particle size is 5 to 20 mm.

10. The method for controlling the basicity of converter final slag according to claim 1, characterized in that: The second slag conditioning agent is a magnesium slag conditioning agent, wherein the mass fraction of magnesium oxide is not less than 45%, and the particle size is 5 to 15 mm.

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