Design and Application Method of an Online Prediction Model for Foaming Slag in Electric Arc Furnace Steelmaking

Abstract

This invention relates to the design and application method of an online prediction model for foamy slag in electric arc furnace steelmaking, belonging to the field of iron and steel metallurgical technology. It solves the technical problem of guiding the electric arc furnace smelting process under different initial charging conditions, automating the foamy slag formation effect, thereby improving smelting quality and reducing production costs. The design method of an online prediction model for foamy slag in electric arc furnace steelmaking includes: Step S1, firstly determining the parameters affecting the initial slag formation time and slag volume; Step S2, during the electric arc furnace smelting process, continuously capturing video using an infrared camera to obtain the slag flow time, slag cross-sectional area, slag flow velocity, slag flow temperature, and number of slag flow cycles, and calculating the slag volume; Step S3, based on the accumulation of data from multiple furnaces, determining the mathematical models between the initial slag formation time and the parameters, and the mathematical models between the slag volume and the parameters. The method of this invention can improve the foamy slag formation efficiency by approximately 2-5%.

Description

Technical Field

[0001] This invention belongs to the field of iron and steel metallurgy technology, and specifically relates to the design and application method of an online prediction model for foamy slag in electric arc furnace steelmaking. Background Technology

[0002] Electric arc furnace steelmaking is a steelmaking process and equipment that uses graphite electrodes to power and heat scrap steel (or molten iron + scrap steel) and slag-forming agents to melt them. At the same time, oxygen is blown and carbon powder is injected into the furnace door and furnace wall to strengthen the smelting process. The smelting process is generally divided into melting period, oxidation period and reduction period. However, with the development of ladle refining technology, the reduction task of electric arc furnace smelting has been gradually moved to the refining process.

[0003] Steel mills have a saying: "Steelmaking is slag making," and "Steelmaking starts with slag making; good slag produces good steel." This is because slag not only interacts with molten steel to remove harmful elements such as phosphorus and sulfur, but also minimizes the loss of iron and other useful elements. This is achieved by protecting the molten steel from excessive oxidation, preventing the absorption of harmful gases, and reducing the burning loss of beneficial elements. Furthermore, slag prevents heat loss, ensuring the smelting temperature, and absorbs inclusions and reaction products floating in the molten steel. Statistics and relevant literature show that in electric arc furnace smelting, good foamed slag can increase the steel-slag reaction interface by hundreds of times, greatly enhancing the physicochemical reactions between steel and slag, thus significantly improving the quality of the molten steel. In addition, foamed slag helps stabilize the electric arc, allowing for submerged arc combustion within the foamed slag. Most of the arc heat is used to heat the molten steel and slag, preventing reflection back into the furnace. Therefore, foamed slag is also beneficial for heating the molten pool and protecting the furnace. Thus, in electric arc furnace smelting, the goal is always to create foamed slag as quickly as possible.

[0004] However, in actual production, the composition, proportion, and temperature of the molten iron and scrap steel added to the electric arc furnace are unstable, and variations in the composition of the slag-forming agent and furnace conditions also contribute to the significant reliance on manual operation in smelting slag formation. Factors such as the ratio and quantity of the slag-forming agent, the amount of carbon injected, the amount of oxygen blown, the voltage selection, and the power supply all introduce considerable uncertainty into the smelting quality. Therefore, how to stably achieve the slag-forming effect of foamy slag while minimizing manual intervention and thus improving smelting quality has always been a key industrial technology that enterprises are concerned about but have yet to fully realize. Summary of the Invention

[0005] To address the above-mentioned technical problems, this invention provides a design and application method for an online prediction model of foamy slag in electric arc furnace steelmaking. This model aims to guide the electric arc furnace smelting process under different initial conditions and charging states, automatically achieve the slag-forming effect of foamy slag, thereby improving smelting quality and reducing production costs.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] On the one hand, the present invention provides a design method for an online prediction model of foamy slag in electric arc furnace steelmaking, comprising the following steps:

[0008] Step S1: First, determine the relevant technical parameters that affect the initial slag formation time and slag volume of foam slag;

[0009] Step S2: During the process of smelting a batch of steel in an electric arc furnace, the slag flow time, cross-sectional area, speed, temperature, and number of slag flows are obtained by continuously capturing video with an infrared camera, and the amount of slag flow is calculated.

[0010] Step S3: Based on the accumulation of data from multiple furnaces, determine the mathematical model between the initial slag formation time and relevant technical parameters, as well as the mathematical model between the slag volume and relevant technical parameters.

[0011] Furthermore, in step S1, the relevant technical parameters affecting the initial slag formation time of the foamy slag include: the initial temperature of the furnace, the quality, composition and temperature of the steel material fed into the furnace, the quality and temperature of the slag-forming agent fed into the furnace in the early stage, the power supply, oxygen blowing, and carbon injection in the early stage, and the erosion of the furnace lining in the early stage; the "early stage" in the slag-forming agent fed into the furnace in the early stage, the power supply, the oxygen blowing, the carbon injection, and the erosion of the furnace lining in the early stage refers to the time interval from charging the furnace to the formation of the initial slag.

[0012] Furthermore, in step S1, the relevant technical parameters affecting the amount of foamy slag flow include: the initial temperature of the furnace, the quality, composition, and temperature of the steel charge entering the furnace, the quality and temperature of the slag-forming agent entering the furnace throughout the entire cycle, the power supply, oxygen blowing, and carbon injection throughout the entire cycle, and the erosion of the furnace lining throughout the entire cycle; the "entire cycle" in the slag-forming agent entering the furnace throughout the entire cycle, the power supply, the oxygen blowing, and the carbon injection, and the erosion of the furnace lining throughout the entire cycle refers to the time interval from charging the furnace to tapping out and smelting one batch of steel.

[0013] Furthermore, in step S2, the formula for calculating the amount of slag is:

[0014]

[0015] In the formula S 流渣量 S represents the amount of slag, expressed in kilograms. i流渣量 The amount of slag removed in the i-th slag removal is expressed in kilograms; n is the number of slag removal cycles; ρ is the density of the foamed slag, expressed in kilograms per cubic meter; A i流渣 V represents the cross-sectional area of ​​the slag flow in the i-th slag flow, in square meters; i流渣 Δt represents the velocity of the i-th slag flow, in meters per second. i The duration of the i-th slag flow is expressed in seconds.

[0016] Furthermore, in step S3, the mathematical model relating the initial slag formation time to relevant technical parameters is as follows:

[0017]

[0018] In the formula, S 炉内渣量 Δt represents the amount of slag remaining in the furnace, in kilograms; t0 represents the electrode energizing time at the start of smelting, t0 = 0; Δt 0-1 The initial slag formation time is calculated from t0 = 0, in minutes; M 钢铁料 The total mass of steel material, in kilograms; [e i [e] represents the equivalent concentration of component i in the steel material, expressed as the mass percentage of each component in the steel material, in %. The equivalent concentration of carbon in the steel material is [e]. 碳 This includes the amount of carbon injected, calculated by adding the carbon content in the steel material to the amount of carbon injected previously, and then dividing by the total mass M of the steel material. 钢铁料 percentage, x i Q is the equivalent reaction order number of the oxidation reaction of component i; 前期氧 To determine the equivalent oxygen concentration during the initial oxygen blowing, the ratio of oxygen content to iron mass percentage is used, i.e., the oxygen blowing rate and the total mass M of the steel material. 钢铁料 Percentage, in %. i K represents the equivalent reaction order number of the oxidation reaction between element O and each component i in the steel material; i M represents the equivalent reaction rate coefficient of the oxidation reaction of each component i in the steel feedstock, which varies with temperature T, where T is the temperature of the material in the furnace in °C, and of represents other factors affecting the equivalent reaction rate coefficient; 前期造渣剂 The mass of the slagging agent initially fed into the furnace is expressed in kilograms; M 前期炉衬侵蚀 This represents the initial erosion amount of the furnace lining, expressed in kilograms.

[0019] Furthermore, in step S3, the mathematical model between the slag flow rate and relevant technical parameters is as follows:

[0020]

[0021] In the formula, S 流渣量 The total slag volume over the entire cycle is expressed in kilograms; M 钢铁料 t represents the total mass of the steel material, in kilograms; t0 represents the electrode energizing time at the start of smelting, which is taken as t0 = 0 here; t n-1 The final slag removal time is calculated from t0 = 0, in minutes; [e] i [The value] represents the equivalent concentration of each component i in the steel material, expressed as a percentage by mass of each component in the steel material, in %. The equivalent concentration of carbon in the steel material includes the amount of carbon injected. This is calculated by adding the carbon content in the steel material and the total amount of carbon injected over the entire cycle, and then dividing by the total mass M of the steel material.钢铁料 percentage, x i Q is the equivalent reaction order number of the oxidation reaction of component i; 全周期氧 The equivalent oxygen concentration for the entire oxygen blowing cycle is determined by the percentage of iron mass, i.e., the oxygen blowing rate and the total mass M of the steel material. 钢铁料 Percentage, in %. i K represents the equivalent reaction order number of the oxidation reaction between element O and each component i in the steel material; i M represents the equivalent reaction rate coefficient of the oxidation reaction of each component i in the steel feedstock, which varies with temperature T, where T is the temperature of the material in the furnace in °C, and of represents other factors affecting the equivalent reaction rate coefficient; 全周期造渣剂 The mass of slagging agent fed into the furnace throughout the entire cycle is expressed in kilograms; M 全周期炉衬侵蚀 S represents the total erosion of the furnace lining over its entire lifespan, expressed in kilograms. 炉内渣量 The amount of slag remaining in the furnace is expressed in kilograms.

[0022] Furthermore, the amount of slag S stored in the furnace 炉内渣量 for:

[0023]

[0024] In the formula, S 炉内渣量 The amount of slag stored in the furnace is in kilograms; π is the mathematical constant pi; α is the inclination angle of the furnace body, positive when the furnace body is tilted forward and negative when the furnace body is tilted backward, in degrees; R is the radius of the furnace body cavity at the lower edge of the furnace door, in meters; H is the distance between the lower edge of the furnace door and the surface of the molten steel when the furnace body is vertical, i.e., when α = 0°, in meters; ρ is the density of the foamy slag, in kilograms per cubic meter.

[0025] On the other hand, the present invention also provides a method for using an online prediction model for foamy slag in electric arc furnace steelmaking, comprising the following steps:

[0026] Step 1: Establish evaluation criteria for the initial slag formation time, slag flow rate, and slag volume based on production practice;

[0027] Step 2: Collect process data from traditional smelting operations, and gradually determine the equivalent reaction rate coefficient K for slag formation in the mathematical model according to the established evaluation criteria. i and equivalent reaction fraction u i x i ;

[0028] Step 3: Apply the mathematical model with determined parameters to gradually guide production practice, ultimately achieving automated production; the parameter is the equivalent reaction rate coefficient K. i and equivalent reaction fraction u i x i .

[0029] Furthermore, the evaluation criteria in step 1 include: the evaluation criteria for the initial slag formation time are: for a top-charged open-top electric arc furnace, the steel material is molten iron + scrap steel, the furnace body inclination angle α = 0°, when Δt 0-1 ≤8min, rated as excellent; when 8min<Δt 0-1 ≤12min, rated as good; when Δt 0-1 >12min, rated as poor; for a horizontal continuous feeding electric arc furnace, the steel material is all scrap steel, when Δt 0-1 ≤2min, rated as excellent; when 2min<Δt 0-1 ≤4min, rated as good; when Δt 0-1 >4 minutes, rated as poor;

[0030] The evaluation criterion for slag flow velocity is: when the furnace body inclination angle α = 0°, V i流渣 When the velocity is ≥1 m / s, the slag formation is considered excellent, and the metallurgical effect is very good; when the velocity is 0.2 m / s < V, the slag formation is considered excellent, and the metallurgical effect is very good. i流渣 When V < 1, the slag formation is considered moderate, and the metallurgical effect is good; i流渣 When the speed is ≤0.2m / s, the slag formation is considered poor and the metallurgical effect is poor.

[0031] Convection slag volume S 流渣量 The evaluation criteria are: when the furnace body tilt angle α = 0°, S 流渣量 ≤0.00025M 造渣剂 +0.005M 钢铁料 The slag volume is small, rated as excellent; 0.00025M 造渣剂 +0.005M 钢铁料 <S 流渣量 ≤0.00035M 造渣剂 +0.008M 钢铁料 To maintain a moderate slag flow rate and sustain process operation; S 流渣量 >0.00035M 造渣剂 +0.008M 钢铁料 The excessive amount of slag requires improvement of the process operation.

[0032] Furthermore, in step 2, the equivalent reaction fraction u i x i Optimize it into a function of time t.

[0033] Compared with the prior art, the present invention can achieve at least one of the following technical effects:

[0034] (1) This invention uses an infrared camera to continuously capture video to observe the slag flow phenomenon, realizes online real-time prediction and monitoring of the foam slag status during electric arc furnace smelting, and accumulates data by establishing a mathematical model to guide the optimization of power supply and feeding schemes, which can improve the foam slag production efficiency by about 2% to 5%.

[0035] (2) The foam slag flow quantity statistical method of the present invention can monitor and quantify the flow quantity and total flow quantity of each slag flow in the electric arc furnace smelting process, solve the practical technical problem that the flow slag in electric arc furnace steelmaking cannot be quickly measured, realize the quantitative monitoring of electric arc furnace foam slag flow, and the data error rate is ≤10%.

[0036] (3) The foam slag prediction model design method of the present invention simulates foam slag as a reaction product, selects the most easily observed flowing slag as a partial reaction product, and establishes a chemical reaction rate equation as a mathematical model based on the basic theory of metallurgical physicochemistry, providing a new idea for the automatic control of electric arc furnace steelmaking process.

[0037] (4) This invention introduces the furnace body tilt angle as an influencing factor into the slag flow index, providing a measurable reference standard for the flexible control of electric arc furnace steelmaking.

[0038] (5) The foam slag evaluation method of the present invention includes data collection, analysis and evaluation comparison of indicators such as initial slag formation time, slag flow rate and slag flow amount, and has the function of quantitative evaluation and process guidance. Detailed Implementation

[0039] The following detailed description, in conjunction with specific embodiments, provides a method for designing and using an online prediction model for foamy slag in electric arc furnace steelmaking. These embodiments are for comparative and illustrative purposes only, and the present invention is not limited to these embodiments.

[0040] Key physicochemical properties of slag include basicity, viscosity, melting temperature, oxidizing and reducing properties. These properties play a decisive role in the smooth progress of the smelting process and ensuring the quality of molten steel. There's a saying in steel mills: "Early slag formation, good slag formation." Therefore, early slag formation and the creation of high-quality foamed slag effectively improve steelmaking efficiency and reduce time and material costs. Furthermore, the quantity of slag is also a crucial factor affecting smelting. To ensure that the composition, temperature, and gas content of the steel meet product requirements, especially regarding harmful elements such as residual oxygen and phosphorus, a certain thickness of slag must be maintained on the surface of the molten steel. A larger slag volume can also appropriately improve deoxidation and dephosphorization efficiency. However, excessive slag volume increases slag consumption, easily causes splashing, increases heat loss and iron loss, and exacerbates erosion of the furnace lining, reducing furnace life.

[0041] Based on the analysis of the impact of the properties of foamy slag on smelting, and while maintaining a low overall cost, this invention proposes a design method for an online prediction model of foamy slag in electric arc furnace steelmaking, focusing on the initial slag formation time, slag flow rate, and slag volume. It should be noted that in electric arc furnace smelting, foamy slag has high reactivity and is beneficial for accelerating chemical reactions within the furnace. Foamy slag during the oxidation period is very beneficial for dephosphorization and decarburization. Due to the intense reaction and vigorous boiling of the steel slag, foamy slag will intermittently and automatically flow out of the furnace door, or, when the slag volume is large, some foamy slag will automatically flow out of the furnace door when the furnace body is tilted. Therefore, automatic slag flow from the furnace door is a normal phenomenon in the electric arc furnace smelting process. Furthermore, the smelting conditions within the furnace can be determined by observing the initial slag formation time, slag flow rate, and slag volume, thereby adjusting the next step of the operating process. In other words, the online prediction of foamy slag in this invention refers to the prediction of the initial slag formation time, slag flow rate, and slag volume during the smelting of a heat of steel in an electric arc furnace. The initial slag formation time, slag flow rate, and slag volume are referred to as slag flow indicators. This invention uses an infrared camera to continuously capture video to observe the slag flow phenomenon.

[0042] Specifically, the design method of the online prediction model for foamy slag in electric arc furnace steelmaking of the present invention includes the following steps:

[0043] Step S1: First, determine the relevant technical parameters that affect the initial slag formation time and slag volume of foam slag;

[0044] Step S2: During the process of smelting a batch of steel in an electric arc furnace, the slag flow time, cross-sectional area, speed, temperature, and number of slag flows are obtained by continuously capturing video with an infrared camera, and the amount of slag flow is calculated.

[0045] Step S3: Based on the accumulation of data from multiple furnaces, determine the mathematical model between the initial slag formation time and relevant technical parameters, as well as the mathematical model between the slag volume and relevant technical parameters.

[0046] Steelmaking slag refers to the general term for the products formed when oxides generated by the oxidation of impurities in the steelmaking feedstock (molten iron and / or scrap steel, etc.) by oxidants react with slag-forming agents and furnace linings in a physicochemical reaction. It is evident that slag formation consists of two main steps: first, the elements in the steel feedstock are oxidized; second, the oxidized products react with the slag and furnace lining in a physicochemical reaction. Therefore, the substances and energy involved in these two steps are factors affecting foamy slag. As a manifestation of foamy slag, flowing slag is also influenced by the substances and energy involved in these two steps.

[0047] Specifically, in step S1, the initial slag formation time Δt affects the formation time of the foam slag. 0-1The relevant technical parameters include: the initial temperature of the furnace, the quality, composition, and temperature of the steel charge, the quality and temperature of the slagging agent initially introduced into the furnace, the initial power supply, initial oxygen blowing rate, initial carbon injection rate, and the initial erosion rate of the furnace lining. The "initial period" in the initial slagging agent, initial power supply, initial oxygen blowing rate, initial carbon injection rate, and initial erosion rate of the furnace lining refers to the time interval from charging the furnace to the formation of the initial slag flow.

[0048] Similarly, throughout the entire smelting cycle, the relevant technical parameters affecting the amount of foamy slag flow include: the initial temperature of the furnace, the quality, composition, and temperature of the steel charge, the quality and temperature of the slagging agent fed into the furnace throughout the cycle, the power supply, oxygen blowing, and carbon injection throughout the cycle, and the erosion of the furnace lining throughout the cycle. The "entire cycle" in these parameters refers to the time interval from charging the furnace to tapping and smelting one heat of steel.

[0049] Specifically, in step S2, each slag removal time includes the start time and end time of each slag removal, such as the initial slag removal start time t. 1-0 Initial slag removal end time t 1-1 The initial slag flow duration Δt1=t 1-1 -t 1-0 The second slag flow start time t 2-0 The second slag removal end time t 2-1 The duration of the second slag flow is Δt2=t 2-1 -t 2-0 ...; The start time of the nth slag flow is t n-0 The end time t of the nth slag removal n-1 The duration of the nth slag flow is Δt n =t n-1 -t n- 0.

[0050] It should be noted that the starting point for each slag flow is determined by the outflow of high-temperature slag from the furnace door, and the infrared camera image shows dynamic outflow of high-temperature fluid at 1000-1400℃ from the furnace door; the ending point for the slag flow is determined by the absence of high-temperature slag from the furnace door, and the infrared camera image shows the absence of dynamic outflow of high-temperature fluid at 1000-1400℃ from the furnace door.

[0051] The cross-sectional area of ​​the slag flow refers to the area of ​​the slag cross-section perpendicular to the slag flow direction at the furnace door. In a new or cleaned electric arc furnace door, the door size is approximately a regular rectangle, and the slag flow cross-section is also approximately a regular rectangle. When the lower left and right sides of the electric arc furnace door are slightly blocked by condensed slag, the slag flow cross-section is approximately a rectangle at the top and a trapezoid at the bottom, or a trapezoid. When the lower left and right sides of the electric arc furnace door are severely blocked by condensed slag, with the blockages connecting left and right, the slag flow cross-section is approximately a rectangle at the top and a triangle at the bottom, or a triangle. In summary, because the shape of the slag flow cross-section is unstable and irregular during each slag flow, this invention records dynamic infrared images of each slag flow exiting the furnace door and extracts the edge lines of the slag flow in the images at certain time intervals, such as every second. Then, auxiliary software is used to calculate the area enclosed by the edge lines, thus obtaining the real-time slag flow cross-sectional area.

[0052] The slag flow velocity is measured using infrared optical velocity sensing technology. The measurement principle of infrared optical velocity sensing is to use an infrared light source and a photosensitive detector to calculate the flow velocity by measuring the changes in infrared light signals in the fluid. Specifically, video of slag flow at the electric arc furnace door, or at least two photographs, are captured and the displacement distances of 5 to 20 random points over a certain period of time are compared to determine the slag flow velocity for each instance.

[0053] The slag temperature is measured using an infrared camera at each slag flow point at the furnace door. Specifically, the average value is obtained by averaging the temperatures at 5 to 20 points between 1000 and 1400°C. It should be noted that when the temperature is below 1000°C, the slag has poor fluidity and is difficult to flow; when the temperature is above 1400°C, this point should be molten steel, and the value at that point is discarded.

[0054] The number of slag flows, n, is the cumulative number of each slag flow, which is automatically obtained by recording the time of each slag flow. The number of slag flows, n, does not include the last slag dumping after tapping.

[0055] The slag volume is the total mass of slag from n slag flows during the smelting of one heat of steel, excluding the slag discarded after tapping. The slag volume is calculated using the following formula:

[0056]

[0057] In equation (1), S 流渣量 S represents the amount of slag, expressed in kilograms. i流渣量 The amount of slag removed in the i-th slag removal is expressed in kilograms; n is the number of slag removal cycles; ρ is the density of the foamed slag, expressed in kilograms per cubic meter; A i流渣 V represents the cross-sectional area of ​​the slag flow in the i-th slag flow, in square meters; i流渣 Δt represents the velocity of the i-th slag flow, in meters per second. iThe duration of the i-th slag flow is expressed in seconds.

[0058] Specifically, in step S3, the initial slag formation time Δt is determined. 0-1 The mathematical model, or mathematical function relationship, between the relevant technical parameters is as follows:

[0059]

[0060] In equation (2): S 炉内渣量 Δt represents the amount of slag remaining in the furnace, in kilograms; t0 represents the electrode energizing time at the start of smelting, which is taken as t0 = 0 here; Δt 0-1 The initial slag formation time is calculated from t0 = 0, in minutes; M 钢铁料 The total mass of steel material, in kilograms; [e i [e] represents the equivalent concentration of component i in the steel material, expressed as the mass percentage of each component in the steel material, in %. The equivalent concentration of carbon in the steel material is [e]. 碳 This includes the amount of carbon injected, which is the sum of the carbon content in the steel material and the amount of carbon injected in the previous stage, divided by the total mass M of the steel material. 钢铁料 percentage, x i Q is the equivalent reaction order number of the oxidation reaction of component i; 前期氧 To determine the equivalent oxygen concentration during the initial oxygen blowing, the ratio of oxygen content to iron mass percentage is used, i.e., the oxygen blowing rate and the total mass M of the steel material. 钢铁料 Percentage, in %. i K represents the equivalent reaction order number of the oxidation reaction between element O and each component i in the steel material; i M represents the equivalent reaction rate coefficient for the oxidation reaction of each component i in the steel feedstock, varying with temperature T, where T is the temperature of the material in the furnace (in °C), and of represents other factors affecting the equivalent reaction rate coefficient, such as catalyst and solid surface properties; 前期造渣剂 The mass of the slagging agent initially fed into the furnace is expressed in kilograms; M 前期炉衬侵蚀 This represents the initial erosion amount of the furnace lining, expressed in kilograms.

[0061] It should be noted that T and Q 前期氧 、[e iThe smelting temperature T is a function of time t, where t is in minutes, and varies depending on the specific smelting or smelting operation. The smelting temperature T varies with heat inputs during the initial smelting operation, including the initial power supply, the exothermic oxidation reaction of the initial oxygen blowing, and the exothermic slag formation reaction, as well as heat outputs such as furnace dust, flue gas, and electrical losses. The initial smelting temperature depends on the quality and temperature of the steel charge, the quality and temperature of the slagging agent, and the initial temperature of the electric arc furnace. Specific calculation methods refer to the national standard GB / T37428-2019 "Test and Calculation Method for Heat Balance of Electric Arc Furnaces," and can also be collected in real-time during the smelting process. During the initial smelting operations, oxygen blowing and carbon injection may be performed intermittently, so the Q in the steel charge... 前期氧 and [e 碳 The concentration of [e] can vary significantly at certain specific time points during the smelting process; the composition of steel materials [e] i These values ​​change as the reaction proceeds and can be sampled in real time during the smelting process; therefore, they are functions of time.

[0062] The amount of slag in the furnace, S 炉内渣量 The value represents the amount of slag in the furnace at the critical slag flow point, that is, the amount of foamy slag stored in the furnace body below the furnace door and above the molten steel. The inequality in equation (2) indicates that when the amount of slag produced in the early stage of smelting exceeds the amount of slag stored in the furnace, S... 炉内渣量 When slag flow occurs naturally, the earliest point at which slag flow occurs, i.e., the moment when the amount of slag produced in the early stage of smelting just exceeds the amount of slag remaining in the furnace, is taken as the initial slag flow formation time Δt. 0-1 .

[0063] The mathematical model, i.e., the mathematical function relationship, between the slag flow rate and relevant technical parameters throughout the smelting cycle is as follows:

[0064]

[0065] In equation (3): S 流渣量 For the total slag flow rate over the entire cycle, S is calculated according to equation (1). 流渣量 The result is obtained through calculation, with the unit being kilograms; M 钢铁料 t represents the total mass of the steel material, in kilograms; t0 represents the electrode energizing time at the start of smelting, which is taken as t0 = 0 here; t n-1 This is the end time of the final slag removal, calculated from t0 = 0, in minutes. i [The value] represents the equivalent concentration of each component i in the steel material, expressed as a percentage by mass of each component in the steel material, in %. The equivalent concentration of carbon in the steel material includes the amount of carbon injected, which is calculated by adding the carbon content in the steel material and the total amount of carbon injected over the entire cycle, and then dividing by the total mass M of the steel material. 钢铁料 percentage, x i Q is the equivalent reaction order number of the oxidation reaction of component i; 全周期氧The equivalent oxygen concentration for the entire oxygen blowing cycle is determined by the percentage of iron mass, i.e., the oxygen blowing rate and the total mass M of the steel material. 钢铁料 Percentage, in %. i K represents the equivalent reaction order number of the oxidation reaction between element O and each component i in the steel material; i M represents the equivalent reaction rate coefficient for the oxidation reaction of each component i in the steel feedstock, varying with temperature T, where T is the temperature of the material in the furnace (in °C), and of represents other factors affecting the equivalent reaction rate coefficient, such as catalyst and solid surface properties; 全周期造渣剂 The mass of slagging agent fed into the furnace throughout the entire cycle is expressed in kilograms; M 全周期炉衬侵蚀 S represents the total erosion of the furnace lining over its entire lifespan, expressed in kilograms. 炉内渣量 The amount of slag remaining in the furnace is expressed in kilograms.

[0066] It should be noted that T and Q 全周期氧 、[e i The smelting temperature T is a function of time t, where t is in minutes, and varies depending on the specific smelting or smelting operation. The smelting temperature T varies with the heat input during the entire smelting operation, including the total power supply, the exothermic oxidation reaction of oxygen blowing, and the exothermic slag formation reaction, as well as the heat output from furnace dust, flue gas, and electrical losses. The initial smelting temperature depends on the quality and temperature of the steel charge, the quality and temperature of the slagging agent, and the initial temperature of the electric arc furnace. Specific calculation methods refer to the national standard GB / T37428-2019 "Test and Calculation Method for Heat Balance of Electric Arc Furnaces," and can also be obtained through real-time temperature measurement during the smelting process. During the entire smelting operation, oxygen blowing and carbon injection operations are performed intermittently, so the Q in the steel charge... 全周期氧 and [e 碳 The concentration of [e] can vary significantly at certain specific time points during the smelting process; the composition of steel materials [e] i These values ​​change as the reaction proceeds and can be sampled in real time during the smelting process; therefore, they are functions of time.

[0067] Specifically, in the slag-forming reactions during the reduction and oxidation phases of the electric arc furnace, the oxidizing elements participating in slag formation in the steel feedstock mainly include Fe, C, Si, Mn, and P. Their chemical reaction equations with oxygen are as follows:

[0068] [Fe]+1 / 2O2=(FeO) (4)

[0069] [C] + 1 / 2O2 = CO (5)

[0070] [Si] + O2 = SiO2 (6)

[0071] [Mn]+ 1 / 2O2=MnO (7)

[0072] 2[P] + 5 / 2O2 = P2O5 (8)

[0073] It should be noted that due to the differences in the steel grades being smelted and the composition of the steel feedstock, the requirements for dephosphorization and decarburization during the smelting process are different. For example, in the smelting of all-scrap steel, the phosphorus and carbon content of the steel feedstock is inherently low. The requirements for the final phosphorus content are different for smelting ordinary steel and stainless steel. Therefore, different standards are adopted for the slag flow index in actual operation. For example, when the dephosphorization task is heavy, the slag flow volume is large; when the dephosphorization task is light, the slag flow volume is small, which can maintain a low material and energy consumption. The furnace body inclination angle is a means of controlling the slag flow volume.

[0074] Therefore, for smelting purposes, electric arc furnaces sometimes maintain a certain tilt angle during smelting. For example, when the furnace body tilts forward (positive tilt angle), the amount of slag stored inside the furnace will be less than when the furnace body is vertical (0° tilt angle); conversely, when the furnace body tilts backward (negative tilt angle), the amount of slag stored inside the furnace will be more than when the furnace body is vertical (0° tilt angle). Based on the assumption that the furnace cavity below the furnace door is an inverted truncated cone with a taper of 2, the amount of slag stored inside the furnace, S... 炉内渣量 for:

[0075]

[0076] In equation (9), S 炉内渣量 The amount of slag stored in the furnace is in kilograms; π is the mathematical constant pi; α is the inclination angle of the furnace body, positive when the furnace body is tilted forward and negative when the furnace body is tilted backward, in degrees; R is the radius of the furnace body cavity at the lower edge of the furnace door, in meters; H is the distance between the lower edge of the furnace door and the surface of the molten steel when the furnace body is vertical, i.e., when α = 0°, in meters; ρ is the density of the foamy slag, in kilograms per cubic meter.

[0077] Iron and steel metallurgical reactions are complex physicochemical reactions involving high temperatures and multiple phases, including series reactions, parallel reactions, and opposing reactions. They are characterized by numerous variables, complex processes, complex uncertainties, and severe process coupling. In actual complex production processes, on the one hand, the widespread application of automatic control systems has preserved a large amount of actual production data. On the other hand, engineers have acquired much empirical knowledge of the production process through long-term contact with it. Therefore, complex processes contain a large amount of quantitative, semi-quantitative, and qualitative information, making it difficult to establish accurate mathematical models.

[0078] This invention simulates the physicochemical process of slag formation as two steps: the oxidation reaction of various components in the steel charge and the carbon injection, and the physicochemical combination of various oxidation products with slag-forming agents and furnace lining erosion products. Foam slag is simulated as a product of these two steps, while flowing slag, the most easily observed component, is selected as a partial product. The oxidation reactions of various components in the steel charge are identified as the limiting steps in the slag formation process. A reaction rate equation is established through simulation, and the mass of each oxidation product is obtained by integrating over time. In this mathematical model, the equivalent reaction rate coefficient K for each oxidation reaction is... i The simulation is a function of the furnace material temperature, as well as the properties of the catalyst and solid surface. Under normal circumstances, it is only a function of temperature, and temperature changes are related to power supply and oxygen blowing rate. However, in some special cases, such as changes in the process (e.g., the addition of fluxing and slagging agents, changes in the particle size of the injected carbon), K will also be affected. i It should be noted that the oxidation reactions of the various components in the steel material in this mathematical model do not fully reflect the actual reaction conditions during the smelting process. Instead, the mathematical model is established by simulating the oxidation reaction products as part of the slag. Chemical reactions that actually occur but whose reaction products do not enter the slag are not reflected in the model.

[0079] Regarding the above-mentioned online prediction model for foamy slag in electric arc furnace steelmaking, this invention proposes a method for using the online prediction model for foamy slag in electric arc furnace steelmaking, comprising the following steps:

[0080] Step 1: Establish evaluation criteria for the initial slag formation time, slag flow rate, and slag volume based on production practice;

[0081] Step 2: Collect process data from traditional smelting operations, and gradually determine the equivalent reaction rate coefficient K for slag formation in the mathematical model according to the established evaluation criteria. i and equivalent reaction fraction u i x i ;

[0082] Step 3: Apply the mathematical model with determined parameters to guide production practice step by step, and finally realize automated production.

[0083] It should be noted that due to the diversity of electric arc furnace types, as well as the diversity of steelmaking materials and scrap ratios, the same slag flow index evaluation standard is adopted for the same type of electric arc furnace, the same steel grade, the same scrap ratio, similar molten iron composition, and the same furnace body inclination angle.

[0084] Specifically, in step 1, the shorter the initial slag formation time and the larger the slag volume per unit time calculated from the start of electrode energization in smelting, the faster the foam slag forms and the better the smelting. For example, the evaluation principle for the initial slag formation time is: for a top-charged open-top electric arc furnace, the steel material is molten iron + scrap steel, the furnace body inclination angle α = 0°, when Δt... 0-1 ≤8min, rated as excellent; when 8min<Δt 0-1 ≤12min, rated as good; when Δt 0-1 >12min, rated as poor. For a horizontally continuously fed electric arc furnace, the steel feed is all scrap steel, when Δt 0-1 ≤2min, rated as excellent; when 2min<Δt 0-1 ≤4min, rated as good; when Δt 0-1 >4min, rated as poor.

[0085] In this model, infrared light-sensing velocity technology is used to calculate the flow rate and corresponding evaluation criteria are established, such as when the furnace body tilt angle α = 0°, and V... i流渣 When the velocity is ≥1 m / s, the slag formation is considered excellent, and the metallurgical effect is very good; when 0.2 m / s < V i流渣 When V < 1, the slag formation is considered moderate, and the metallurgical effect is good; when V i流渣 When the speed is ≤0.2m / s, the slag formation is considered poor and the metallurgical effect is poor.

[0086] Slag flow rate S during electric arc furnace smelting process 流渣量 It is not only causally related to various operating parameters in the smelting process, but also directly related to the total mass M of the slag-forming agent added. 造渣剂 The total mass of added steel material M 钢铁料 There is a relationship, so the amount of slag flow S is... 流渣量 and M 造渣剂 M 钢铁料 Related to the determination of slag flow rate S 流渣量 Evaluation criteria, such as furnace body tilt angle α = 0°, S 流渣量 ≤0.00025M 造渣剂 +0.005M 钢铁料 The slag volume is small, rated as excellent; 0.00025M 造渣剂 +0.005M 钢铁料 <S 流渣量 ≤0.00035M 造渣剂 +0.008M 钢铁料 To ensure a moderate amount of slag flow, which can maintain process operation; S 流渣量 >0.00035M 造渣剂 +0.008M 钢铁料 The excessive amount of slag requires improvement of the process operation.

[0087] It should be noted that in step 2, the determination of mathematical model parameters first addresses the case of the same electric arc furnace type, smelting the same steel grade, using the same scrap ratio, and having similar molten iron composition. Building upon this, the process further addresses the case of the same electric arc furnace type, smelting the same steel grade, using different scrap ratios, and having similar molten iron composition. This process is then repeated for the case of the same electric arc furnace type, smelting the same steel grade, using different scrap ratios, and having dissimilar molten iron composition. This process continues until finally addressing the case of different electric arc furnace types, smelting different steel grades, using different scrap ratios, and having dissimilar molten iron composition. In short, the parameter determination follows a gradual and steady approach, finding the greatest common divisor under varying smelting conditions.

[0088] Specifically, based on the actual conditions of electric arc furnace smelting, the model can be further optimized, such as by increasing the equivalent reaction stage number u. i x i It is related to the state of matter and reaction stages within the furnace, and thus can be set as a function of time t; the model can also be further simplified, such as simulating oxidation reactions as elementary reactions to determine the equivalent reaction order number u. i x i The components in the steel material [e i [t] The simulated constant value at the time of furnace entry, the equivalent concentrations of oxygen blowing and carbon injection are simulated as the ratio of the total amount during the smelting period to the total mass of steel material, and the equivalent reaction rate coefficient K is also included. i The simulation is treated as a constant value.

[0089] In step 3, the model with determined parameters is applied to gradually reduce manual intervention and gradually increase the frequency of automated production, progressively transitioning to fully automated production. The parameter is the equivalent reaction rate coefficient K. i and equivalent reaction fraction u i x i ;

[0090] Application examples

[0091] The nominal capacity 120-ton top-charged open-top electric arc furnace is fed in 1 to 3 stages to complete the steel material. All slag-forming auxiliary materials are added at the same time as the last steel material. The steel material is molten iron + scrap steel. One carbon-oxygen lance is used at the furnace door, three lances are used on the furnace wall to blow oxygen, and one carbon injection lance is used on the furnace wall.

[0092] Step 1: Establish evaluation criteria for the initial slag formation time, slag flow rate, and slag volume based on production practice;

[0093] Furnace body inclination angle α=0°, initial slag formation time Δt 0-1 ≤8min, rated as excellent; when 8min < initial slag formation time Δt 0-1≤12min, rated as good; initial slag formation time Δt 0-1 >12min, rated as poor. When V i流渣 When the velocity is ≥1 m / s, the slag formation is considered excellent, and the metallurgical effect is very good; when 0.2 m / s < V i流渣 When V < 1, the slag formation is considered moderate, and the metallurgical effect is good; when V i流渣 When the speed is ≤0.2m / s, slag formation is considered poor, resulting in poor metallurgical performance. 流渣量 ≤0.00025M 造渣剂 +0.005M 钢铁料 The slag volume is small, rated as excellent; 0.00025M 造渣剂 +0.005M 钢铁料 <S 流渣量 ≤0.00035M 造渣剂 +0.008M 钢铁料 To ensure a moderate amount of slag flow, which can maintain process operation; S 流渣量 >0.00035M 造渣剂 +0.008M 钢铁料 The excessive amount of slag requires improvement of the process operation.

[0094] Step 2: Collect process data from traditional smelting operations, and gradually determine the equivalent reaction rate coefficient K for slag formation in the mathematical model according to the established evaluation criteria. i and equivalent reaction fraction u i x i ;

[0095] The oxidizing elements involved in slag formation in steelmaking materials mainly include Fe, C, Si, Mn, and P. Their chemical reaction equations with oxygen are as follows:

[0096] [Fe] + 1 / 2O₂ = (FeO)

[0097] [C] + 1 / 2O₂ = CO

[0098] [Si] + O2 = SiO2

[0099] [Mn]+1 / 2O2=MnO

[0100] 2[P] + 5 / 2O2 = P2O5

[0101] Following a simplified approach, the equivalent reaction order numbers of the elementary reactions were determined by simulating them separately. Process data from the early stages of conventional smelting operations were also collected and processed to obtain the average equivalent reaction rate coefficient K for each element in the early stages. i Specifically, x 铁 =1, u 铁 =0.5, K 铁 =933.84; x 碳=1, u 碳 =0.5, K 碳 =11413.58; x 硅 =1, u 硅 =1,K 硅 =1.638889×10 6 ;x 锰 =1, u 锰 =0.5, K 锰 =60045.83; x 磷 =2, u 磷 =2.5, K 磷 =2.04478×10 12 ;

[0102] The elementary reactions were simulated separately to determine their equivalent reaction order numbers. Process data from the entire cycle of conventional smelting were collected and processed to obtain the average equivalent reaction rate coefficient K of each element over the entire cycle. i Specifically, x 铁 =1, u 铁 =0.5, K 铁 =106; x 碳 =1, u 碳 =0.5, K 碳 =726;x 硅 =1, u 硅 =1,K 硅 =120599; x 锰 =1, u 锰 =0.5, K 锰 =12990.36; x 磷 =2, u 磷 =2.5, K 磷 =1.364×10 10 .

[0103] Step 3: Apply the mathematical model with determined parameters to guide production practice step by step.

[0104] The nominal capacity 120-ton top-charged open-top electric arc furnace is used to add steel materials in 1 to 3 stages. All slag-forming auxiliary materials are added at the same time as the last steel material. The steel material is molten iron + scrap steel. One carbon-oxygen lance is used at the furnace door, three lances are used on the furnace wall to blow oxygen, and one carbon injection lance is used on the furnace wall to smelt Q345 steel.

[0105] 86 tons of scrap steel, temperature 20℃, composition (by mass percentage): C: 0.20%, Si: 0.35%, Mn: 1.2%, P: 0.03%, S: 0.03%; 42 tons of molten iron, temperature 1350℃, composition (by mass percentage): C: 4.1%, Si: 0.5%, Mn: 0.55%, P: 0.16%, S: 0.03%; furnace temperature before charging: 1380℃; 3750 kg of slag-forming auxiliary materials added initially, temperature 20℃; furnace material temperature after charging: 480℃; initial power supply: 9450 kWh; initial oxygen supply: 1030 Nm³. 3 The oxygen mass is 1500 kg, the initial carbon injection is 180 kg, and the initial furnace lining erosion is M. 前期炉衬侵蚀 =100kg.

[0106] According to the simplified treatment, as can be seen from the above, the total mass M of the steel material is... 钢铁料 =128000 kg, the mass percentage composition of the initial steel material is: C: 1.62%, Si: 0.4%, Mn: 0.987%, P: 0.068%, S: 0.03%, Q 前期氧 1.17%.

[0107] When the furnace body inclination angle α = 0°, the density of the foamy slag ρ = 2200 kg / m³ 3 The furnace can store slag amount S 炉内渣量 It weighs 6.6 tons.

[0108] Referring to the national standard GB / T37428-2019 "Test and Calculation Method for Heat Balance of Electric Arc Furnace", the furnace material temperature during the initial slag flow is calculated to be 1500℃. Using the preliminary data obtained in step 2, the initial slag formation time Δt can be calculated according to formula (2). 0-1 =10min.

[0109] In actual smelting, the measured furnace material temperature during the initial slag flow was 1480℃, and the initial slag formation time was 11 min, with a deviation rate of 9.1%. 8 min < the initial slag formation time Δt 0-1 ≤12min, good.

[0110] The total amount of slag-forming auxiliary materials added throughout the entire cycle is 3750 kg, the total power supply throughout the entire cycle is 27000 kWh, and the total oxygen supply throughout the entire cycle is 5000 Nm³. 3 The oxygen mass was 7272.73 kg, the total carbon injection volume for the entire cycle was 1800 kg, and the total furnace lining erosion volume for the entire cycle was M. 全周期炉衬侵蚀 =150kg.

[0111] According to the simplified treatment, as can be seen from the above, the total mass M of the steel material is... 钢铁料=128000 kg, the mass percentage composition of the steel material throughout the entire cycle is: C: 2.89%, Si: 0.4%, Mn: 0.987%, P: 0.068%, S: 0.03%, Q 全周期氧 5.68%.

[0112] When the furnace body inclination angle α = 0°, the density of the foamy slag ρ = 2200 kg / m³ 3 The furnace can store slag amount S 炉内渣量 It weighs 6.6 tons.

[0113] Using the full-cycle data obtained in step 2, the full-cycle slag flow rate S can be calculated according to formula (9). 流渣量 It weighs 1016 kilograms.

[0114] In actual smelting, infrared cameras are used to capture video of the furnace door during the electric arc furnace smelting process. During the initial slag flow, the infrared system measures v. 1流渣 The flow rate is 0.3 m / s, indicating moderate slag formation and good metallurgical effect. However, the flow velocity is close to the lower limit of the judgment standard. The initial carbon injection amount can be appropriately increased, and oxygen blowing can be used to enhance the control of foamed slag fluidity. The total slag flow rate S for the entire cycle is obtained by statistically analyzing and accumulating the slag flow rate per cycle. 流渣量 The value is 1000 kg, and the deviation rate from the calculated value is 1.6%, which is within the range of 641 kg = 0.00025 M. 造渣剂 +0.005M 钢铁料 <S 流渣量 ≤0.00035M 造渣剂 +0.008M 钢铁料 =Within the range of 1025kg, although it is within the moderate range of slag volume, it is close to the lower limit of excessive slag volume, and attention needs to be paid to adjusting the process operation. The tapping temperature is 1590℃.

[0115] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A design method for an online prediction model of foamy slag in electric arc furnace steelmaking, characterized in that, Includes the following steps: Step S1: First, determine the relevant technical parameters that affect the initial slag formation time and slag volume of foam slag; Step S2: During the process of smelting a batch of steel in an electric arc furnace, the slag flow time, cross-sectional area, speed, temperature, and number of slag flows are obtained by continuously capturing video with an infrared camera, and the amount of slag flow is calculated. Step S3: Based on the accumulation of data from multiple furnaces, determine the mathematical model between the initial slag formation time and relevant technical parameters, as well as the mathematical model between the slag volume and relevant technical parameters; In step S3, the mathematical model between the initial slag formation time and relevant technical parameters is as follows: In the formula, S 炉内渣量 The amount of slag remaining in the furnace is expressed in kilograms; t0 is the electrode energization time at the start of smelting, t0=0; t 0-1 The initial slag formation time is calculated starting from t0=0, in minutes; M 钢铁料 The total mass of steel material, in kilograms; [e i [e] represents the equivalent concentration of component i in the steel material, expressed as the mass percentage of each component in the steel material, in % units. The equivalent concentration of carbon in the steel material is [e]. 碳 This includes the amount of carbon injected, calculated by adding the carbon content in the steel material to the amount of carbon injected previously, and then dividing by the total mass M of the steel material. 钢铁料 The percentage is calculated as [e] 碳 ], x i Q is the equivalent reaction order number of the oxidation reaction of component i; 前期氧 The equivalent oxygen concentration for the initial oxygen blowing is determined by the percentage of iron mass, i.e., the oxygen blowing amount divided by the total mass M of the steel material. 钢铁料 Percentage, in %. i K represents the equivalent reaction order number of the oxidation reaction between element O and each component i in the steel material; i (T(t),of) represents the equivalent reaction rate coefficient of each component i in the steel material during oxidation, which varies with temperature T, where T is the temperature of the material in the furnace in °C, and of represents other factors affecting the equivalent reaction rate coefficient; M 前期造渣剂 The mass of the slagging agent initially fed into the furnace is expressed in kilograms; M 前期炉衬侵蚀 This represents the initial erosion amount of the furnace lining, expressed in kilograms. In step S3, the mathematical model between the slag volume and the relevant technical parameters is as follows: In the formula, S 流渣量 The total slag volume over the entire cycle is expressed in kilograms; M 钢铁料 t represents the total mass of the steel material, in kilograms; t0 represents the electrode energizing time at the start of smelting, which is taken as t0=0 here; t n-1 The final slag removal time is calculated from t0=0, in minutes; [e] i [e] represents the equivalent concentration of each component i in the steel material, expressed as the mass percentage of each component in the steel material, in % (%). The equivalent concentration of carbon in the steel material is [e]. 碳 This includes the amount of carbon injected, calculated by adding the carbon content in the steel material and the total amount of carbon injected throughout the cycle, and dividing by the total mass M of the steel material. 钢铁料 The percentage is calculated as [e] 碳 ], x i Q is the equivalent reaction order number of the oxidation reaction of component i; 全周期氧 The equivalent oxygen concentration for the entire oxygen blowing cycle is calculated as a percentage of iron mass, i.e., the oxygen blowing rate divided by the total mass M of the steel material. 钢铁料 Percentage, in %. i K represents the equivalent reaction order number of the oxidation reaction between element O and each component i in the steel material; i (T(t),of) represents the equivalent reaction rate coefficient of each component i in the steel material during oxidation, which varies with temperature T, where T is the temperature of the material in the furnace in °C, and of represents other factors affecting the equivalent reaction rate coefficient; M 全周期造渣剂 The mass of slagging agent fed into the furnace throughout the entire cycle is expressed in kilograms; M 全周期炉衬侵蚀 S represents the total erosion of the furnace lining over its entire lifespan, expressed in kilograms. 炉内渣量 The amount of slag remaining in the furnace is expressed in kilograms.

2. The method according to claim 1, characterized in that, In step S1, the relevant technical parameters affecting the initial slag formation time of the foamy slag include: the initial temperature of the furnace, the quality, composition and temperature of the steel material fed into the furnace, the quality and temperature of the slag-forming agent fed into the furnace in the early stage, the power supply, oxygen blowing, and carbon injection in the early stage, and the erosion of the furnace lining in the early stage; the "early stage" in the slag-forming agent fed into the furnace in the early stage, the power supply, the oxygen blowing, the carbon injection, and the erosion of the furnace lining refers to the time interval from charging the furnace to the formation of the initial slag.

3. The method according to claim 1, characterized in that, In step S1, the relevant technical parameters affecting the amount of foamy slag flow include: the initial temperature of the furnace, the quality, composition and temperature of the steel charge, the quality and temperature of the slag-forming agent charged into the furnace throughout the entire cycle, the power supply, oxygen blowing, and carbon injection throughout the entire cycle, and the erosion of the furnace lining throughout the entire cycle. The "entire cycle" in the slag-forming agent charged into the furnace throughout the entire cycle, the power supply, the oxygen blowing, and the carbon injection, and the erosion of the furnace lining throughout the entire cycle refers to the time interval from charging the furnace to tapping out and smelting one batch of steel.

4. The method according to claim 1, characterized in that, In step S2, the formula for calculating the amount of slag is: , In the formula S 流渣量 S represents the amount of slag, expressed in kilograms. i流渣量 The amount of slag removed in the i-th slag removal is expressed in kilograms; n is the number of slag removal cycles; ρ is the density of the foamed slag, expressed in kilograms per cubic meter; A i流渣 V represents the cross-sectional area of ​​the slag flow in the i-th slag flow, in square meters; i流渣 Let be the velocity of the i-th slag flow, in meters per second; t i The duration of the i-th slag flow is expressed in seconds.

5. The method according to claim 1, characterized in that, The amount of slag S stored in the furnace 炉内渣量 for: In the formula, S 炉内渣量 The amount of slag stored in the furnace is in kilograms; π is the mathematical constant pi; α is the inclination angle of the furnace body, positive when the furnace body is tilted forward and negative when the furnace body is tilted backward, in degrees; R is the radius of the furnace body cavity at the lower edge of the furnace door, in meters; H is the vertical distance between the lower edge of the furnace door and the surface of the molten steel when the furnace body is vertical, i.e., when α=0°, in meters; ρ is the density of foamy slag, in kilograms per cubic meter.

6. A method for using an online prediction model for foamy slag in electric arc furnace steelmaking designed based on the design method described in any one of claims 1 to 5, characterized in that, The method of use includes the following steps: Step 1: Establish evaluation criteria for the initial slag formation time, slag flow rate, and slag volume based on production practice; Step 2: Collect process data from traditional smelting operations, and gradually determine the equivalent reaction rate coefficient K for slag formation in the mathematical model according to the established evaluation criteria. i (T(t),of) and equivalent reaction fraction u i x i ; Step 3: Apply the mathematical model with determined parameters to gradually guide production practice, ultimately achieving automated production; the parameter is the equivalent reaction rate coefficient K. i (T(t),of) and equivalent reaction fraction u i x i .

7. The method of use according to claim 6, characterized in that, The evaluation criteria in step 1 include: the evaluation criteria for the initial slag formation time are: for a top-charged open-top electric arc furnace, the steel material is molten iron + scrap steel, and the furnace body tilt angle α = 0°, when... t 0-1 ≤8min, rated as excellent; when 8min < t 0-1 ≤12min, rated as good; when t 0-1 >12min, rated as poor; for horizontal continuous feeding electric arc furnaces, the steel feed is all scrap steel, when t 0-1 ≤2min, rated as excellent; when 2min < t 0-1 ≤4min, rated as good; when t 0-1 >4 minutes, rated as poor; The evaluation criterion for slag flow velocity is: when the furnace body inclination angle α = 0°, V i流渣 When the velocity is ≥1 m / s, the slag formation is considered excellent, and the metallurgical effect is very good; when the velocity is 0.2 m / s < V, the slag formation is considered excellent, and the metallurgical effect is very good. i流渣 When V < 1, the slag formation is considered moderate, and the metallurgical effect is good; i流渣 When the speed is ≤0.2m / s, the slag formation is considered poor and the metallurgical effect is poor. Convection slag volume S 流渣量 The evaluation criteria are: when the furnace body tilt angle α = 0°, S 流渣量 ≤0.00025M 造渣剂 +0.005M 钢铁料 The slag volume is small, rated as excellent; 0.00025 M 造渣剂 +0.005M 钢铁料 <S 流渣量 ≤0.00035 M 造渣剂 +0.008M 钢铁料 To maintain a moderate slag flow rate and sustain process operation; S 流渣量 >0.00035 M 造渣剂 +0.008 M 钢铁料 The excessive amount of slag requires improvement of the process operation.

8. The method of use according to claim 6, characterized in that, In step 2, the equivalent reaction fraction number u i x i Optimize it into a function of time t.

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