In-furnace slag amount estimation device, in-furnace slag amount estimation method, and molten steel production method

Abstract

To provide an in-furnace slag amount estimation device, an in-furnace slag amount estimation method, and a molten steel production method that can estimate with high accuracy an in-furnace slag weight after slag is discharged.SOLUTION: An in-furnace slag amount estimating device (1) includes an input section (11) to which input data is input including in-furnace shape data of a converter, composition and temperature data of molten metal and slag, and in-furnace slag height data of the converter before or during a blowing treatment, a slag bulk density calculation unit (13) that calculates a slag bulk density after tilting the converter using the input data and a slag bulk density estimation model, a slag volume calculation unit (14) that calculates an in-furnace slag volume in the furnace after tilting the converter using slag height data after tilting the converter, the in-furnace shape data, and a slag volume estimation model, and a slag weight calculation unit (15) that calculates an in-furnace slag weight after the converter is tilted to discharge the slag using a calculated slag bulk density and a calculated slag volume.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an in-furnace slag amount estimation device, an in-furnace slag amount estimation method, and a molten steel production method, and more particularly to an in-furnace slag amount estimation device, an in-furnace slag amount estimation method, and a molten steel production method that estimate the amount of in-furnace slag in a refining facility in the steel industry. [Background technology]

[0002] In steelworks, the composition and temperature of molten iron tapped from the blast furnace are adjusted in refining facilities such as pretreatment facilities, converters, and secondary refining facilities. The converter is a process in which impurities in the molten iron are removed and the temperature is raised by blowing oxygen into the furnace, and it plays a very important role in terms of steel quality control and rationalization of refining costs. In recent years, the development of pretreatment methods for molten iron in converters (desiliconization and dephosphorization) has progressed, and as a result, the mainstream method is to tilt the converter after the blowing process to discharge the slag inside the furnace (slag removal), and then turn the converter upright to continue the blowing process. In this method, the amount of auxiliary materials such as lime added is adjusted based on the slag composition at the end of the blowing before slag removal (primary blowing) and the weight of the slag in the furnace after slag removal, so that the slag composition in the blowing after slag removal (secondary blowing) is the desired composition. Conventionally, the amount of slag discharged outside the furnace by slag discharge was estimated by the operator by visual inspection, or the weight of the slag discharged from the ladle that receives the slag discharged outside the furnace by slag discharge was measured by weighing the ladle, and the weight of the slag in the furnace after slag discharge was calculated, and the amount of auxiliary materials to be charged in the secondary blowing was determined. However, the slag during the blowing process is in a foamy state due to CO gas and other gases generated by the reaction in the furnace, and the bulk density varies greatly, so the accuracy of the estimation by visual inspection was low. In addition, it is difficult to prevent the slag from overflowing from the ladle during the slag discharge process. Furthermore, the influence of the metal that flows out during slag discharge and the iron particles in the slag cannot be eliminated, and the accuracy of the slag weight measurement by the weighing machine may not be high. As described above, the low accuracy of the estimation of the weight of the slag in the furnace after slag discharge tends to result in excessive auxiliary materials being charged in the secondary blowing, which causes problems such as increased costs and reduced iron yield.

[0003] Therefore, Patent Document 1 discloses a method of estimating the settling characteristics of the slag in the furnace by measuring the slag height in the furnace multiple times before slag discharge, and estimating the weight of the slag in the furnace after slag discharge based on the settling characteristics and the tilting pattern of the converter during slag discharge. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 129887 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, the weight of the slag in the furnace after slag removal is calculated based on the settling characteristics during slag removal and the slag volume in the furnace calculated geometrically from the tilt angle of the converter. For example, if the shape of the converter throat changes due to wear of the refractory bricks, adhesion of metal, etc., the relationship between the tilt angle of the converter and the slag volume in the furnace changes, so the estimated weight of the slag in the furnace deviates from the actual situation. In addition, the shape near the converter throat may change due to adhesion of metal even during one blowing process. Therefore, it is difficult to obtain accurate shape information at all times. As such, it is difficult to estimate the weight of the slag in the furnace after slag removal with high accuracy by a method of calculating the slag volume in the furnace geometrically from the tilt angle of the converter.

[0006] In consideration of the above circumstances, the object of the present disclosure is to provide an in-furnace slag amount estimation device, an in-furnace slag amount estimation method, and a molten steel manufacturing method that can estimate the in-furnace slag weight after slag removal with high accuracy. [Means for solving the problem]

[0007] An in-furnace slag amount estimation device according to an embodiment of the present disclosure includes: A slag amount estimation device in a converter, which estimates a weight of slag remaining in a converter during a blowing process including a step of tilting the converter to discharge slag from the converter, comprising: an input unit for inputting input data including data on the shape of the converter inside, data on the components and temperatures of the molten metal and slag before or during the blowing process, and data on the height of the slag inside the converter; a slag bulk density calculation unit that calculates a slag bulk density after tilting the converter and discharging the slag using the input data and a slag bulk density estimation model; a slag volume calculation unit that calculates a slag volume in the furnace after the converter is tilted and the slag is discharged, using the slag height data after the converter is tilted and the slag is discharged, the furnace interior shape data, and a slag volume estimation model; and a slag weight calculation unit that calculates the weight of the slag in the converter after the slag is discharged by tilting the converter using the calculated slag bulk density and the calculated slag volume.

[0008] A method for estimating an amount of slag in a furnace according to an embodiment of the present disclosure includes: A method for estimating an amount of slag remaining in a converter, the method being performed by an in-furnace slag amount estimation device that estimates a weight of slag remaining in the converter during a blowing process including a step of tilting the converter to discharge slag from the converter, comprising: an input step of inputting input data including data on the shape of the inside of the converter, data on the components and temperatures of the molten metal and slag before or during the blowing process, and data on the height of the slag inside the converter; a slag bulk density calculation step of calculating a slag bulk density after tilting the converter and discharging the slag using the input data and a slag bulk density estimation model; a slag volume calculation step of calculating a slag volume in the furnace after the converter is tilted and the slag is discharged, using the slag height data after the converter is tilted and the slag is discharged, the furnace interior shape data, and a slag volume estimation model; and a slag weight calculation step of calculating a weight of the slag in the converter after the slag is discharged by tilting the converter using the calculated slag bulk density and the calculated slag volume.

[0009] A method for producing molten steel according to an embodiment of the present disclosure includes: Based on the weight of slag in the furnace calculated by the above-mentioned method for estimating the amount of slag in the furnace, the amount of auxiliary materials to be charged in the secondary blow is determined, and refining operation is performed to produce molten steel. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide an in-furnace slag amount estimation device, an in-furnace slag amount estimation method, and a molten steel manufacturing method that are capable of estimating the in-furnace slag weight after slag removal with high accuracy. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an in-furnace slag amount estimation device according to one embodiment. [Diagram 2] FIG. 2 is a flowchart showing the process of a method for estimating the amount of slag in a furnace according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an apparatus for estimating the amount of slag in a furnace, a method for estimating the amount of slag in a furnace, and a method for producing molten steel according to an embodiment of the present disclosure will be described with reference to the drawings. Here, the amount of slag in a furnace means the weight of slag remaining inside (inside) a converter.

[0013] 1 is a schematic diagram showing a configuration of an in-furnace slag amount estimation device 1 according to an embodiment of the present disclosure. In this embodiment, the in-furnace slag amount estimation device 1 is used as a part of a facility for producing molten steel. The facility for producing molten steel includes a refining facility and a blowing control system including the in-furnace slag amount estimation device 1.

[0014] As shown in FIG. 1, the refining equipment includes a converter 100, a lance 103, an upper hopper 104, and a slag height measuring device 105. The lance 103 is disposed above the molten metal 101 in the converter 100. High-pressure oxygen is ejected from the tip of the lance 103 toward the molten metal 101 below. Impurities in the molten metal 101 are oxidized by this high-pressure oxygen and are taken into the slag 102 (refining process). In addition, auxiliary materials including lime, recarburizer, coolant, etc. are charged into the converter 100 from the upper hopper 104, etc., and are taken into the molten metal 101 and slag 102.

[0015] The slag height measuring device 105 is set on the upper part of the converter 100 and measures the distance from the throat of the converter 100 to the surface of the slag 102 in the converter 100. The slag height measuring device 105 may be, for example, a microwave distance meter. The microwave distance meter may convert the time it takes to emit a microwave and receive a reflected wave from the throat of the converter 100 and the surface of the slag 102 in the converter 100 into a distance, and measure the distance from the throat of the converter 100 to the surface of the slag 102 in the converter 100. The slag height may be measured at any timing or continuously. A signal indicating the measurement result of the slag height measuring device 105 is sent to the control terminal 10.

[0016] Here, in the refining using the converter 100, the steps of "charging", "primary blowing", "slag removal", "secondary blowing", and "tapping" are performed in order in one charge. In the "charging" step, raw materials such as molten pig iron are charged into the converter 100. In the "primary blowing" step, auxiliary raw materials are charged into the converter 100 and blowing is performed, for example, for the purpose of desiliconization or desiliconization and dephosphorization. In the "slag removal" step, a part of the slag 102 with a relatively low basicity (CaO concentration / SiO2 concentration) generated in the primary blowing is discharged outside the furnace by slag removal treatment. In the "secondary blowing" step, auxiliary raw materials are charged into the converter 100 and blowing is performed, for example, for the purpose of at least one of dephosphorization and decarburization. In the "tapping" step, the molten metal 101 is tapped. Usually, multiple charges are performed in the refining, and these steps are repeated. The slag 102 from the secondary blow of the nth charge remaining in the converter 100 may be carried over to the (n+1)th charge.

[0017] Some of the steps will be explained in more detail with reference to the refining facility in Fig. 1. After the first blow, the lance 103 is withdrawn to the top of the converter 100, and the converter 100 is tilted to perform a slag removal process in which the slag 102 in the converter is removed from the converter. The slag removal process ends just before the molten metal 101 is removed, and after the converter 100 is returned to an upright position, the lance 103 is again placed above the molten metal 101 to start the second blow. The blowing conditions, including the amount of auxiliary materials to be charged from the upper hopper 104 in the second blow, are determined based on the results of the first blow and the slag removal process. The in-furnace slag amount estimation device 1 is a device for estimating the weight of the slag 102 in the converter 100 after the slag removal process.

[0018] The blowing control system includes a control terminal 10, a display device 20, and an in-furnace slag amount estimation device 1 as main components. The control terminal 10 may be configured with an information processing device such as a personal computer or a workstation. The control terminal 10 collects performance data on the blowing process and the slag removal process, and controls the blowing conditions including the amount of auxiliary materials charged from an upper hopper 104 or the like so that the temperature and component concentration of the molten metal 101 and the composition of the slag 102 are within desired ranges. The display device 20 may be configured with, for example, a liquid crystal display or a CRT (cathode ray tube) display. The display device 20 may display the calculation results output from the in-furnace slag amount estimation device 1, etc.

[0019] The in-furnace slag amount estimation device 1 is configured with an information processing device such as a personal computer or a workstation. The in-furnace slag amount estimation device 1 includes an input unit 11, a database 12, a slag bulk density calculation unit 13, a slag volume calculation unit 14, a slag weight calculation unit 15, and an output unit 16.

[0020] The input unit 11 is an input interface into which various data related to the refining equipment is input. The input unit 11 may be at least one of a keyboard, a mouse, a pointing device, a data receiving device, and a graphical user interface (GUI). The input unit 11 receives performance data, parameter setting values, and the like from the outside, writes the information to the database 12, and transmits the information to the slag bulk density calculation unit 13 and the slag volume calculation unit 14. Input data is input to the input unit 11 from the control terminal 10. The input data includes furnace shape data, which is a measurement result or a calculation result of the furnace shape of the converter 100. The input data includes data, which is a measurement result or a calculation result of the components and temperatures of the molten metal 101 and the slag 102 before the start of the blowing process or during the process. The input data also includes slag height data, which is a measurement result of the slag height in the converter 100 after the slag removal process. The input unit 11 may also be capable of manual data input (manual input) by, for example, an operator of the refining equipment. The parameter settings of the model equation can be input manually.

[0021] The database 12 stores various measurement results and calculation results in the blowing process and the slag removal process, models and parameters for calculating the amount of slag in the furnace, and the estimation results of the amount of slag in the furnace. The database 12 is composed of a storage device such as a memory and a hard disk drive. The storage device may further store a computer program. Various information input to the input unit 11 and the estimation results of the amount of slag in the furnace calculated by the slag weight calculation unit 15 are transmitted to the database 12. In addition, the models and parameters stored in the database 12 are used by the slag bulk density calculation unit 13 and the slag volume calculation unit 14.

[0022] The slag bulk density calculation unit 13, the slag volume calculation unit 14, and the slag weight calculation unit 15 are each composed of a processor such as a CPU. The slag bulk density calculation unit 13, the slag volume calculation unit 14, and the slag weight calculation unit 15 may be realized, for example, by the processor reading and executing a computer program. Furthermore, the slag bulk density calculation unit 13, the slag volume calculation unit 14, and the slag weight calculation unit 15 may each have a dedicated processor or circuit.

[0023] The slag bulk density calculation unit 13 estimates the bulk density of the slag 102 in the converter 100 after the slag disposal process (after the converter 100 is tilted to discharge at least a part of the slag 102) by calculation using the input data stored in the database 12 and the slag bulk density estimation model. The slag bulk density calculation unit 13 may calculate the bulk density of the slag 102 using data on the primary blowing process and the slag disposal process transmitted from the input unit 11 as input data. The slag bulk density calculation unit 13 transmits the calculated bulk density of the slag 102 after the slag disposal process to the slag weight calculation unit 15.

[0024] The slag volume calculation unit 14 calculates the volume of the slag 102 after the slag removal process by using the measurement results (slag height data) of the height of the slag 102 in the furnace after the slag removal process, the furnace interior shape data, and the slag volume estimation model. The slag volume calculation unit 14 transmits the calculated volume of the slag 102 after the slag removal process to the slag weight calculation unit 15.

[0025] The slag weight calculation unit 15 calculates the weight of the slag in the furnace after the slag removal process using the slag bulk density after the slag removal process calculated by the slag bulk density calculation unit 13 and the slag volume after the slag removal process calculated by the slag volume calculation unit 14. The slag weight calculation unit 15 transmits the calculated amount of slag in the furnace (the weight of the slag 102 remaining in the furnace after the slag removal process) to the output unit 16.

[0026] The output unit 16 transmits the amount of slag in the furnace calculated by the slag weight calculation unit 15 to the control terminal 10 and the database 12. In the secondary blowing, various operation quantities are determined and operation conditions are changed based on the calculation results output from the in-furnace slag amount estimation device 1. The output unit 16 also has a function of transmitting information calculated by the in-furnace slag amount estimation device 1 to the display device 20, and can display the calculation results output from the in-furnace slag amount estimation device 1.

[0027] The in-furnace slag amount estimation device 1 having such a configuration executes the process of the in-furnace slag amount estimation method described below, thereby estimating the weight of the slag 102 after the slag removal process with high accuracy. Hereinafter, the operation of the in-furnace slag amount estimation device 1 when executing the in-furnace slag amount estimation method will be described with reference to the flowchart shown in FIG.

[0028] 2 is a flowchart showing a process of an in-furnace slag amount estimation method according to an embodiment of the present disclosure. The flowchart shown in FIG. 2 starts at the timing when the primary blow is completed. In other words, after the primary blow is completed, the in-furnace slag amount estimation process proceeds to the process of step S1.

[0029] In the process of step S1, the height of the slag 102 in the converter 100 is measured after the slag removal process is completed. The measurement of the height of the slag 102 may be performed after the converter 100 is returned to the upright position in order to facilitate the calculation of the volume described below. The height of the slag 102 in the converter may be obtained based on one measurement value, but it is preferable to obtain a representative value of the height of the slag 102 in an arbitrary period by averaging multiple measurement values ​​that are different in time and space. The measured height of the slag 102 in the converter is transmitted to the input unit 11. This completes the process of step S1, and the process of estimating the amount of slag in the converter proceeds to the process of step S2.

[0030] In the process of step S2, the input unit 11 acquires data of the blowing process and the slag removal process. More specifically, the input unit 11 acquires input data including data on the shape of the converter 100 inside, data on the components and temperatures of the molten metal 101 and the slag 102 before or during the blowing process, and data on the height of the slag inside the converter 100. Step S2 can be called an input step. Here, the data on the shape of the converter 100 inside among the input data may be generated based on measurements of the converter 100 before the "charging" process, that is, before the raw materials are charged, and may be acquired from the control terminal 10 together with other data in step S2. In addition, the input unit 11 transmits the performance data, parameter setting values, and the like to the database 12, the slag bulk density calculation unit 13, and the slag volume calculation unit 14. This completes the process of step S2, and the process of estimating the amount of slag inside the converter proceeds to the process of step S3.

[0031] In the process of step S3, the slag bulk density calculation unit 13 calculates the bulk density of the slag 102 after the slag removal process (slag bulk density D s Step S3 can be referred to as a slag bulk density calculation step. The slag bulk density estimation model can be, for example, a linear combination model as shown in the following formula (1).

[0032]

number

[0033] Here, i is a parameter that specifies the items of explanatory variables obtained from the results of the primary blowing process and the slag treatment process. i are explanatory variables. A iare coefficients corresponding to each explanatory variable. The explanatory variables include at least the tilt angle at which the slag 102 starts to be discharged from the throat when the converter 100 is tilted in the slag discharge process, and the slag discharge process time, which is the time for performing the slag discharge process. The explanatory variables may further include the maximum tilt angle during the slag discharge process, the calculated value of the weight of the slag 102 in the furnace at the end of the first blow, the calculated value of the slag basicity (CaO concentration / SiO2 concentration), the calculated value of the iron concentration in the slag, and the calculated value of the weight of iron flowing in the slag. Here, when the slag starts to flow out due to the tilting of the furnace body, the slag height becomes almost the same as the furnace height. The volume of the slag in the furnace, which is closely related to the bulk density, can be calculated from the tilt angle of the furnace body at which the slag starts to flow out and the furnace shape data. Therefore, it is important that the explanatory variables include at least the tilt angle at which the slag 102 starts to be discharged from the throat. In addition, the slag 102 before the slag discharge treatment contains a large amount of air bubbles and has a relatively low bulk density, and the air bubbles escape during the slag discharge treatment, causing the bulk density to increase. Therefore, it is considered that the bulk density of the slag 102 after the slag discharge treatment tends to be higher as the slag discharge treatment time is longer. Therefore, it is important that the explanatory variables include at least the slag discharge treatment time.

[0034] The model for estimating the bulk density of slag after slag removal is not limited to the above linear combination model, and a machine learning model, etc. can be used.

[0035] Here, the machine learning model can be constructed based on past data stored in the database 12 before operation. The explanatory variables can be obtained from observable measured values, analytical values, calculated values ​​based on these, etc. Also, the slag bulk density can be obtained from the calculation results of the volume of the slag remaining in the furnace and the actual measured value of the amount of slag in the furnace, which will be described later.

[0036] The actual amount of slag in the furnace may be determined from the difference between the amount of slag in the furnace before slag removal, which is calculated based on the amount of auxiliary materials charged during the first blow, and the amount of slag in the furnace after slag removal, which is measured using a weighing scale. The amount of slag in the furnace may also be determined by back-calculating the weight of the removed slag from the slag component analysis value after slag removal and the amount of auxiliary materials charged during the first blow.

[0037] As described above, in addition to the linear regression model, various machine learning models can be constructed using the objective variable and explanatory variables, which are actual values, as training data. A highly accurate model based on any of the methods may be used.

[0038] The slag bulk density calculation unit 13 transmits the calculated bulk density of the slag 102 after the slag removal process to the slag weight calculation unit 15. This completes the process of step S3, and the process of estimating the amount of slag in the furnace proceeds to the process of step S4.

[0039] In the process of step S4, the slag volume calculation unit 14 calculates the volume of the slag 102 after the slag removal process using the slag height data of the slag 102 in the furnace after the slag removal process, the furnace interior shape data, and the slag volume estimation model. Step S4 can be called a slag volume calculation step. In this embodiment, the volume (V s ) is the height of the slag 102 in the furnace (H slag ) and furnace shape data, weight measurement value of molten metal 101 (W metal ), specific gravity of molten metal 101 (ρ metal ) is used to calculate the slag volume estimation model shown in the following equation (2).

[0040]

number

[0041] Here, V(H slag ) is the height of the slag 102 in the furnace (H slag ) and the furnace shape data, V(H slag) may be calculated by integrating the volume of the furnace from the bottom to the height of the slag 102 based on the furnace shape data. Also, V(H slag ) is stored in database 12, and V(H slag ) may be obtained by selecting a calculated value in the database 12 according to the height of the slag 102. Here, the weight measurement value and specific gravity of the molten metal 101 are obtained from the measurement or calculation results of the components of the molten metal 101 before the start of the blowing process or during the process, among the input data. The furnace shape data desirably includes furnace body profile information measured by a laser distance meter or the like. For example, the inside of the furnace before the start of the primary blowing may be measured by a laser distance meter, and the distance from the center line of the furnace body may be obtained as distance data at predetermined intervals in the vertical direction and at predetermined angles around the center line. The obtained distance data is stored in the database 12 as a point cloud in a polar coordinate system, and is used as furnace body profile information for calculating the furnace volume.

[0042] Furthermore, when the furnace body is tilted, the tilt angle may be included as an input, and the height of the slag 102 may be corrected based on the tilt angle before calculating the volume.

[0043] The slag volume estimation model is not limited to the above formula, and a machine learning model, etc. can be used.

[0044] Here, the furnace interior shape data may be updated at an appropriate timing by new measurements to reflect changes in shape, etc. Also, the furnace interior shape data may be corrected using the amount of wear inside the furnace estimated based on the number of times the converter 100 has been used, etc. The slag volume calculation unit 14 transmits the calculated volume of the slag 102 after the slag removal process to the slag weight calculation unit 15. This completes the process of step S4, and the process of estimating the amount of slag in the furnace proceeds to the process of step S5.

[0045] In the process of step S5, the slag weight calculation unit 15 calculates the weight of the slag 102 after the slag removal process by multiplying the estimated bulk density value of the slag 102 after the slag removal process calculated by the slag bulk density calculation unit 13 by the volume of the slag 102 after the slag removal process calculated by the slag volume calculation unit 14. Step S5 can be called a slag weight calculation step.

[0046] The output unit 16 transmits the weight of the slag 102 after the slag removal treatment calculated by the slag weight calculation unit 15 to the database 12. The output unit 16 also transmits the weight of the slag 102 after the slag removal treatment to the control terminal 10. The control terminal 10 may determine the treatment conditions for the secondary blowing based on the result of the slag removal treatment including the obtained weight of the slag 102 and the result of the primary blowing treatment. The output unit 16 also transmits the weight of the slag 102 after the slag removal treatment to the display device 20. The operator can change the treatment conditions for the secondary blowing depending on the weight of the slag 102 after the slag removal treatment displayed on the display device 20. This completes the process of step S5, and the process of estimating the amount of slag in the furnace is also completed.

[0047] Based on the weight of slag remaining inside the converter 100 estimated by the above-mentioned method for estimating the amount of slag in the furnace, an optimal slag design for the secondary blowing can be achieved. In other words, based on the estimated amount of slag in the furnace, the amount of auxiliary materials charged is determined so as to obtain an optimal basicity (CaO concentration / SiO2 concentration), and refining operation (decarburization blowing) is performed to produce good molten steel. In this way, a good molten steel production method can be realized based on the weight of slag in the furnace calculated by the above-mentioned method for estimating the amount of slag in the furnace.

[0048] As described above, the in-furnace slag amount estimation device 1, the in-furnace slag amount estimation method, and the molten steel production method according to the present embodiment can calculate the weight of the slag in the furnace after the slag has been discharged by using the calculated value of the slag bulk density after the slag has been discharged and the in-furnace slag volume calculated from the measurement result of the slag height in the furnace after the slag has been discharged, by using the above-mentioned configuration and process. Therefore, it is possible to eliminate factors of variation such as changes in the shape near the converter throat, and to estimate the weight of the slag in the furnace after the slag has been discharged with high accuracy.

[0049] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications or corrections based on the present disclosure. Therefore, it should be noted that these modifications or corrections are included in the scope of the present disclosure. For example, the functions included in each component or each step can be rearranged so as not to be logically inconsistent, and multiple components or steps can be combined into one or divided. The embodiments of the present disclosure can also be realized as a program executed by a processor included in the device or a storage medium on which a program is recorded. It should be understood that these are also included in the scope of the present disclosure.

[0050] For example, in the present embodiment, a method for estimating the amount of slag in the furnace after the slag removal process without tapping has been described. Here, even in the case where molten metal is tapped after the blowing process and some of the slag in the furnace is carried over to the next blowing process, the amount of slag in the furnace can be estimated by the same method for estimating the amount of slag in the furnace by setting the weight of the molten metal in the furnace to 0. [Explanation of symbols]

[0051] 1. Furnace slag volume estimation device 10 Control Terminal 11 Input section 12 Database 13 Slag bulk density calculation section 14 Slag volume calculation section 15 Slag weight calculation section 16 Output section 20 Display device 100 Converter 101 Molten metal 102 Slug 103 Lance 104 Furnace hopper 105 Slag height measuring device

Claims

1. A slag amount estimation device in a converter, which estimates a weight of slag remaining in a converter during a blowing process including a step of tilting the converter to discharge slag from the converter, comprising: an input unit for inputting input data including data on the shape of the inside of the converter, data on the components and temperatures of the molten metal and slag before or during the blowing process, and data on the height of the slag inside the converter; a slag bulk density calculation unit that calculates a slag bulk density after tilting the converter and discharging the slag using the input data and a slag bulk density estimation model; a slag volume calculation unit that calculates a slag volume in the furnace after the converter is tilted and the slag is discharged, using the slag height data after the converter is tilted and the slag is discharged, the furnace interior shape data, and a slag volume estimation model; and a slag weight calculation unit that uses the calculated slag bulk density and the calculated slag volume to calculate a weight of the slag in the converter after the slag is discharged by tilting the converter.

2. The slag bulk density estimation model inputs explanatory variables including at least the tilt angle at which the slag starts to flow out when the converter is tilted and the slag drainage processing time, and outputs the slag bulk density. The device for estimating the amount of slag in a furnace as described in claim 1.

3. The in-furnace slag amount estimation device according to claim 1 or 2, wherein the slag volume estimation model calculates an in-furnace volume from the hearth to the height of the slag based on the in-furnace shape data and the slag height data obtained by measuring the shape of the furnace before the blowing treatment.

4. The in-furnace slag amount estimation device according to claim 1 , wherein the slag height data is measured by a microwave distance meter.

5. A method for estimating an amount of slag remaining in a converter, the method being performed by an in-furnace slag amount estimation device that estimates a weight of slag remaining in the converter during a blowing process including a step of tilting the converter to discharge slag from the converter, comprising: an input step of inputting input data including data on the shape of the inside of the converter, data on the components and temperatures of the molten metal and slag before or during the blowing process, and data on the height of the slag inside the converter; a slag bulk density calculation step of calculating a slag bulk density after tilting the converter and discharging the slag using the input data and a slag bulk density estimation model; a slag volume calculation step of calculating a slag volume in the furnace after the converter is tilted and the slag is discharged, using the slag height data after the converter is tilted and the slag is discharged, the furnace interior shape data, and a slag volume estimation model; a slag weight calculation step of calculating a weight of the slag in the converter after the slag is discharged by tilting the converter using the calculated slag bulk density and the calculated slag volume.

6. The method for estimating the amount of slag in a furnace according to claim 5, wherein the slag bulk density estimation model inputs explanatory variables including at least the tilt angle at which the slag starts to flow out when the converter is tilted and the slag drainage processing time, and outputs the slag bulk density.

7. The method for estimating the amount of slag in a furnace according to claim 5 or 6, wherein the slag volume estimation model calculates the furnace volume from the hearth to the height of the slag based on the furnace shape data including furnace body profile information obtained by measuring the shape of the furnace before the blowing treatment and the slag height data.

8. The method for estimating the amount of slag in a furnace according to any one of claims 5 to 7, wherein the slag height data is measured by a microwave distance meter.

9. A molten steel producing method for producing molten steel by determining an amount of an auxiliary raw material to be charged for secondary blowing based on a weight of slag in the furnace calculated by the method for estimating the amount of slag in the furnace according to any one of claims 5 to 8, and performing refining operation.

Images