Guidance method, intermediate slag removal method, molten iron refining method, molten steel manufacturing method, guidance system, refining system, and model generation method

Abstract

To provide a guidance method and a guidance system for outputting information for realizing stable intermediate slag discharge while considering changes in operation conditions, an intermediate slag discharge method for executing intermediate slag discharge by selecting a tilting pattern of a furnace, a method for refining molten iron, a refining system, a method for producing molten steel, and a model generation method for generating a model used in the guidance method.SOLUTION: A guidance method outputs information for selecting a tilting pattern of a furnace 40 in a process of discharging slag 2 from the furnace 40 for treating molten iron 3. The guidance method includes a step of inputting information on the forming and sedation of the slag 2 based on at least one of the mass, viscosity or solid fraction of the slag 2, or a gas flow rate generated in the furnace 40 to a model, and a step of outputting a loss cost based on at least one of an amount of lime to be charged or a flow rate of molten iron 3 when the furnace 40 is tilted using each of a plurality of tilting patterns from the model.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a guidance method for generating guide information used to select a furnace tilting pattern for discharging foamed slag containing carbon monoxide gas from a converter furnace after blowing treatments such as desiliconization and dephosphorization, a model generation method for generating a model that outputs guide information, and a method for producing molten steel, the method including a procedure for tilting a furnace to discharge slag. [Background technology]

[0002] In recent years, advances in molten iron pretreatment technology have led to the development of various molten iron pretreatment methods using converter-type refining furnaces. A typical example is a method in which the next charge of molten iron is charged into a converter without removing the desiliconization slag from the previous charge, and desiliconization and dephosphorization are performed. After partially discharging the slag from the furnace, dephosphorization and decarburization are subsequently performed. The process of removing the slag during the desiliconization, dephosphorization, and decarburization processes is also called the intermediate slag removal process.

[0003] As described above, in a refining method that performs an intermediate slag removal process, it is important to stably remove as much slag as possible from the furnace while suppressing the amount of molten iron that flows out in order to reduce costs. When refining is continued after the intermediate slag removal process, the smaller the mass of slag remaining in the furnace, the smaller the amount of auxiliary materials that are newly added for desiliconization, dephosphorization, and decarburization treatments.

[0004] On the other hand, in the intermediate slag draining process, it may be difficult to stably discharge a large amount of slag out of the furnace depending on the operating conditions of the refining furnace. For example, if the volume of slag formed in the furnace decreases or the apparent viscosity of the slag increases significantly under certain operating conditions, the slag draining speed decreases significantly, making it difficult to stably discharge a large amount of slag out of the furnace.

[0005] To solve these problems, methods have been proposed for stabilizing the amount of slag discharged by avoiding certain operating conditions. For example, in the configuration described in Patent Document 1, a method is proposed in which the basicity or temperature of the slag is adjusted to prevent a decrease in slag discharge performance due to an increase in the solid fraction or viscosity of the slag. Also, in the configuration described in Patent Document 2, a method is proposed in which the blowing is performed so that the foam height of the slag before discharge is constant in all charges in order to stabilize the slag discharge rate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-262576 [Patent Document 2] Japanese Patent Publication No. 2022-105886 Summary of the Invention [Problem to be solved by the invention]

[0007] Increasing the amount of slag discharged outside the furnace during the intermediate slag discharge process is important in order to reduce the amount of lime input in the next process. The methods for improving and stabilizing slag discharge performance by controlling the operating conditions described in Patent Document 1 or controlling the slag height described in Patent Document 2 focus on controlling the operating conditions. However, with these methods, it is difficult to maintain stable slag discharge even when the operating conditions change.

[0008] Therefore, the present disclosure aims to provide a guidance method and guidance system that outputs information for achieving stable intermediate slag removal while taking into account changes in operating conditions, an intermediate slag removal method that selects a furnace tilting pattern to perform intermediate slag removal, a molten iron refining method, a refining system and a molten steel manufacturing method, and a model generation method that generates a model to be used in the guidance method. [Means for solving the problem]

[0009] (1) A guidance method according to one embodiment of the present disclosure is a guidance method for outputting information for selecting a tilting pattern for a furnace that processes molten pig iron in a process of removing slag from the furnace, the guidance method including the steps of: inputting information related to slag foaming and settling based on at least one of the mass of the slag, the viscosity of the slag, the solid fraction of the slag, or the gas flow rate generated in the furnace into a model; and outputting from the model a loss cost based on at least one of the amount of lime added or the amount of molten pig iron outflow when tilting the furnace using each of a plurality of tilting patterns.

[0010] (2) An intermediate slag removal method according to one embodiment of the present disclosure includes the steps of: selecting one tilting pattern from the plurality of tilting patterns based on the loss cost output by executing the guidance method described in (1) above; and removing the slag by controlling the furnace using the selected tilting pattern.

[0011] (3) A method for refining molten iron according to one embodiment of the present disclosure includes a step of performing blowing in a furnace to which auxiliary materials are added, and a step of performing the intermediate slag removal method described in (2) above.

[0012] (4) A method for producing molten steel according to an embodiment of the present disclosure includes a step of pouring molten iron treated by carrying out the method for refining molten iron described in (3) above from a furnace.

[0013] (5) A guidance system according to an embodiment of the present disclosure outputs information for selecting a tilting pattern for a furnace that processes molten pig iron in a process of removing slag from the furnace. The guidance system includes a model and a calculation device. The model receives as input information regarding slag foaming and settling based on at least one of the mass of the slag, the viscosity of the slag, the solid fraction of the slag, or the gas flow rate generated in the furnace, and outputs a loss cost based on at least one of the amount of lime to be added or the amount of molten pig iron that flows out when tilting the furnace using each of a plurality of tilting patterns. The calculation device executes a process of inputting information regarding slag foaming and settling into the model and a process of outputting information for selecting the tilting pattern, including the loss cost output from the model.

[0014] (6) A refining system according to one embodiment of the present disclosure includes a refining apparatus that performs intermediate slag removal by blowing in a furnace to which auxiliary materials are added, and the guidance system described in (5) above. The guidance system outputs information for selecting the tilting pattern of the furnace when removing slag from the furnace to process molten iron. The refining apparatus controls the furnace using the tilting pattern of the furnace selected based on the information output by the guidance system.

[0015] (7) A model generation method according to an embodiment of the present disclosure is a model generation method for generating a model in which information on slag foaming and settling is input in the guidance method described in (1) above, the model generation method comprising the steps of: calculating the volume and apparent viscosity of slag foamed in the furnace based on information on the foaming and settling of the slag based on at least one of the mass of the slag, the viscosity of the slag, the solid fraction of the slag, and the gas flow rate generated in the furnace; and setting a plurality of tilting patterns as patterns for tilting the furnace, and performing fluid analysis of the molten iron and slag in the furnace when tilting the furnace using each of the plurality of tilting patterns, thereby generating a model for the plurality of tilting patterns. the amount of molten iron to be introduced into the furnace in the next blowing operation based on the amount of slag discharged from the furnace; the cost of introducing lime into the furnace by estimating the amount of lime to be introduced into the furnace in the next blowing operation based on the amount of slag discharged from the furnace when the amount of slag discharged is calculated; the cost of introducing molten iron from the furnace based on the amount of molten iron discharged when the amount of molten iron discharged is calculated; and the process of generating a model that outputs at least one of the lime introduction cost and the molten iron discharge cost as a loss cost for each of the plurality of tilting patterns when information on slag foaming and settling is input. [Effects of the Invention]

[0016] According to the present disclosure, there are provided a guidance method and guidance system that output information for realizing stable intermediate slag removal while taking into account changes in operating conditions, an intermediate slag removal method that selects a furnace tilting pattern to perform intermediate slag removal, a molten iron refining method, a refining system and a molten steel manufacturing method, and a model generation method that generates a model to be used in the guidance method. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a block diagram illustrating an example configuration of a refining system according to the present disclosure. [Figure 2]FIG. 1 is a cross-sectional view showing an example of a process for foaming slag in a refining furnace. [Figure 3] FIG. 1 is a cross-sectional view showing an example of a process for discharging slag by tilting a refining furnace. [Figure 4] 1 is a flowchart illustrating an example procedure of a guidance method according to the present disclosure. [Figure 5] 1 is a graph showing an example of a tilting pattern of a refining furnace. [Figure 6] 10 is a graph showing an example of loss costs when tilting a refining furnace according to each tilting pattern. [Figure 7] 1 is a flowchart illustrating an example of a procedure for a model generation method according to the present disclosure. [Figure 8] FIG. 2 is a cross-sectional view showing an example of the shape of a furnace body of a refining furnace. [Figure 9] FIG. 2 is a plan view showing an example of the shape of the throat of a refining furnace. [Figure 10] 10 is a cross-sectional view taken along the line AA in FIG. 9. [Figure 11] 10 is a flowchart illustrating an example of the procedure of a guidance method based on the shape of a furnace. [Figure 12] 10 is a flowchart illustrating an example of the procedure of a model generation method based on the shape of a furnace. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of a refining system 100 (see FIG. 1, etc.) and a calculation device 50 (see FIG. 1, etc.), as well as a guidance method and an intermediate slag removal method according to the present disclosure, will be described with reference to the drawings. Each drawing is a schematic and may differ from the actual product. Furthermore, the following embodiments exemplify devices or methods for embodying the technical ideas of the present disclosure, and are not intended to limit the configuration to those described below. In other words, the technical ideas of the present disclosure can be modified in various ways within the technical scope described in the claims.

[0019] According to the refining system 100 and calculation device 50, as well as the model generation method, guidance method, and intermediate slag removal method of the present disclosure, a furnace tilting pattern is selected to achieve stable intermediate slag removal while taking into account changes in operating conditions. The furnace tilting pattern will be described later. By achieving stable intermediate slag removal, the amount of impurities remaining in the furnace after intermediate slag removal is reduced. The reduction in the amount of impurities reduces the amount of lime input in the next process. As a result, the operating costs of refining are reduced.

[0020] The model generation method according to the present disclosure includes a step of modeling the loss costs for various conditions of forming and settling of slag 2 (see FIG. 2, etc.) when the furnace is tilted using each of a plurality of candidate tilting patterns. The model generation method may create a database of the loss costs for each candidate furnace tilting pattern for various operating conditions.

[0021] The guidance method according to the present disclosure includes a step of deriving information on the foaming and settling of slag 2 based on furnace operation information or measurement values, and inputting the information into a model to output the loss cost when tilting the furnace for each of a plurality of candidate tilting patterns. The intermediate slag removal method according to the present disclosure includes a step of selecting one tilting pattern from a plurality of candidate tilting patterns, tilting the furnace, and removing the slag 2.

[0022] (Configuration example of refining system 100) As shown in FIG. 1, a refining system 100 according to one embodiment includes a calculation device 50, a refining device 40, and a database 30.

[0023] <Refining Device 40> As illustrated in FIG. 2, the refining apparatus 40 includes a refining furnace 1 and a top-blowing lance 42. In this embodiment, the refining furnace 1 is of a converter type. The refining furnace 1 is not limited to a converter type and may be of various other types. The refining furnace 1 is also simply referred to as a furnace. The refining apparatus 40 according to this embodiment is configured to perform desiliconization treatment on the molten pig iron 3 contained in the refining furnace 1. The refining apparatus 40 is not limited to desiliconization treatment, and may be configured to perform various other treatments such as dephosphorization treatment.

[0024] In a refining apparatus 40, a desiliconization treatment is performed on the molten pig iron 3 in a refining furnace 1. In the desiliconization treatment, an oxygen-containing gas is supplied to the molten pig iron 3 from a top-blowing lance 42. The oxygen-containing gas supplied from the top-blowing lance 42 reacts with silicon (Si) in the molten pig iron 3 to produce slag 2. The slag 2 is also called desiliconization slag. Because the density of the slag 2 is lower than the density of the molten pig iron 3, the slag 2 floats above the molten pig iron 3.

[0025] The oxygen-containing gas supplied from the top lance 42 reacts with the carbon in the molten pig iron 3 to generate carbon monoxide (CO) gas. The slag 2 becomes foamy due to the inclusion of CO gas bubbles. The apparent volume of the slag 2 increases by several times or more due to the inclusion of CO gas bubbles. This state is also called a foaming state.

[0026] As illustrated in FIG. 3 , the refining apparatus 40 controls the tilt angle of the refining furnace 1, represented by θ, to tilt the furnace, thereby discharging at least a portion of the slag 2 from the furnace without allowing the molten iron 3 to flow out of the furnace. The process of discharging the slag 2 is also referred to as a slag removal process. The tilt angle (θ) of the refining furnace 1 is the angle between the vertical axis, represented by the dashed line, and the axis of the refining furnace 1, represented by the dashed line. The refining apparatus 40 tilts the furnace 1 by controlling the tilt angle of the furnace 1 based on a predetermined tilting pattern. The tilting pattern is a pattern of time-dependent changes in the tilt angle of the furnace 1. The tilting pattern may specify the amount of change in the tilt angle of the furnace 1 per unit time. The amount of change in the tilt angle of the furnace 1 per unit time is also referred to as the tilting rate. The tilting pattern may specify the tilt angle of the furnace 1 when the tilting rate is changed. The tilting pattern may specify a maximum tilt angle of the refining furnace 1. The maximum tilt angle of the refining furnace 1 may be set so that the molten iron 3 does not flow out of the refining furnace 1 or so that the amount of the molten iron 3 flowing out of the refining furnace 1 is reduced.

[0027] The refining apparatus 40 may further include an input device that inputs auxiliary materials into the refining furnace 1. The auxiliary materials may include, for example, lime. The input device may be configured to control the type or amount of the auxiliary materials input into the refining furnace 1.

[0028] The refining apparatus 40 may include a process computer that controls the flow rate of gas supplied from the top-blowing lance 42, the type or amount of additives introduced into the refining furnace 1, the tilting angle of the refining furnace 1, etc. The process computer may include, for example, a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The process computer may include, for example, a storage device such as a semiconductor memory or an electromagnetic recording medium. The process computer may include a communication interface for communicating with other devices such as a calculation device 50.

[0029] The refining apparatus 40 may be equipped with a measuring device for measuring the shape of the refining furnace 1. The shape of the refining furnace 1 may include the shape of the inner wall 6 of the refining furnace 1, i.e., the furnace body shape. The shape of the refining furnace 1 may include the shape of the throat 5 of the refining furnace 1, i.e., the throat shape. The measuring device may be configured to measure the three-dimensional shape of the refining furnace 1. The measuring device may include a distance measuring sensor such as a laser rangefinder that measures the distance to each part of the refining furnace 1. The measuring device may include a camera that photographs the refining furnace 1. The measuring device may be configured to acquire point cloud data of the refining furnace 1. The measuring device may be an external device that is not included in the refining system 100.

[0030] The measuring device may measure the shape of the refining furnace 1 in a state where the molten pig iron 3 and the slag 2 are discharged from the refining furnace 1. If the measuring device is a camera, the camera may photograph the refining furnace 1 in a state where the molten pig iron 3 and the slag 2 are discharged from the refining furnace 1, or may photograph the refining furnace 1 in a state where the refining furnace 1 is filled with the molten pig iron 3 or the slag 2.

[0031] <Calculation device 50> The calculation device 50 generates and outputs information for selecting a tilting pattern of the refining furnace 1 in the process of discharging slag 2 from the refining furnace 1 based on information about the foaming and settling of slag 2 in the refining furnace 1. The information about the foaming and settling of slag 2 is calculated based on operation information of the refining furnace 1 or measurement values ​​in the refining furnace 1. The information for selecting the tilting pattern of the refining furnace 1 includes the loss cost when the refining furnace 1 is tilted using each of multiple tilting pattern candidates. The loss cost includes at least one of the cost of adding lime in the process after discharging slag 2 or the cost of spilling molten iron when discharging slag 2. The information about the foaming and settling of slag 2 in the refining furnace 1 includes at least one of the mass of slag 2 in the refining furnace 1, the viscosity of slag 2, the solid fraction of slag 2, or the flow rate of gases such as CO gas generated in the refining furnace 1. The calculation device 50 may calculate information regarding the foaming and settling of the slag 2 in the refining furnace 1 based on operation information of the refining furnace 1 or measurement values ​​in the refining furnace 1.

[0032] The computing device 50 includes a processor 52 , a memory unit 54 , and an interface 56 .

[0033] The processor 52 may be configured to include, for example, a CPU or a GPU in order to control and manage various functions of the computing device 50. The processor 52 may realize the functions of the computing device 50 by reading and executing a program stored in the storage unit 54.

[0034] The storage unit 54 stores various types of information or data used by the calculation device 50. The storage unit 54 may store, for example, a program executed by the processor 52, or data or processing results used in processing executed by the processor 52. The storage unit 54 may function as a work memory for the processor 52. The storage unit 54 may be configured to include, for example, a semiconductor memory, but is not limited to this. The storage unit 54 may be configured as, for example, an internal memory of the processor 52, or may be configured as an electromagnetic recording medium such as a hard disk drive (HDD) accessible from the processor 52. The storage unit 54 may be configured as a non-transitory readable medium. The storage unit 54 may be configured integrally with the processor 52 or may be configured separately from the processor 52.

[0035] The interface 56 may include a communication interface for communicating with other devices, such as the refining apparatus 40 or the database 30, via a wired or wireless connection. The communication interface may be configured to communicate with other devices via a network. The interface 56 may include an input / output port for inputting and outputting data to and from other devices. The interface 56 transmits and receives necessary data and signals to and from a process computer or a higher-level system. The interface 56 may communicate based on a wired communication standard or a wireless communication standard. For example, the wireless communication standard may include cellular phone communication standards such as 3G, 4G, and 5G. Furthermore, for example, the wireless communication standard may include IEEE 802.11, Bluetooth (registered trademark), and the like. The interface 56 may support one or more of these communication standards. The interface 56 is not limited to these examples and may communicate with other devices or input and output data based on various standards.

[0036] The interface 56 may be configured to output information acquired from the processor 52. The interface 56 may notify the user of information by outputting visual information such as text, graphics, or images, directly or via an external device. The interface 56 may include a display device or may be connected to a display device via a wired or wireless connection. The display device may include various displays such as a liquid crystal display. The interface 56 may notify the user of information by outputting auditory information such as sound, directly or via an external device. The interface 56 may include an audio output device such as a speaker or may be connected to an audio output device via a wired or wireless connection. The interface 56 may include a vibration device. The interface 56 may notify the user of information by outputting not only visual information, auditory information, or tactile information, but also information that the user can perceive with other senses, directly or via an external device.

[0037] The interface 56 may include an input device that accepts input from a user. The input device may include, for example, a keyboard or physical keys, a touch panel or touch sensor, or a pointing device such as a mouse. The input device is not limited to these examples and may include various other devices.

[0038] <Database 30> The database 30 stores information associating loss costs with information on the foaming and settling of the slag 2, which is used by the calculation device 50 to generate information for selecting a tilting pattern for the refining furnace 1. The loss costs include at least one of the lime injection cost or the molten iron outflow cost when the refining furnace 1 is tilted according to each of a plurality of candidate tilting patterns.

[0039] The database 30 may be configured as a part of the storage unit 54 of the computing device 50. The database 30 may be configured as a storage device separate from the computing device 50. The database 30 may be configured as a cloud service.

[0040] (Example of the operation to remove slag 2) In the refining system 100 according to this embodiment, the calculation device 50 generates information for selecting a tilting pattern for the refining furnace 1. The refining device 40 tilts the refining furnace 1 according to the selected tilting pattern to remove the slag 2. An example of the operation of the refining system 100 based on the procedure of the flowchart illustrated in FIG. 4 will be described below.

[0041] <Example of guidance procedure> The processor 52 of the calculation device 50 calculates information related to the foaming and settling of the slag 2 (step S1). The processor 52 may calculate the information related to the foaming and settling of the slag 2 based on operational information or measurement values ​​of the refining apparatus 40. The operational information or measurement values ​​may include, for example, the amount of molten iron, the amount of scrap, the amount of auxiliary raw material charged, the flow rate or composition of exhaust gas, or the bottom-blown gas flow rate. The information related to the foaming and settling of the slag 2 may include at least one of the mass of the slag 2, the viscosity of the slag 2, the solid fraction of the slag 2, or the transition of the gas flow rate generated in the refining furnace 1.

[0042] The processor 52 may calculate information regarding the foaming and settling of the slag 2 based on operational information or measurements of the refining apparatus 40, for example, as described below.

[0043] The processor 52 derives the composition of slag 2 other than FeO and the mass of slag 2 based on the amounts of lime and impurities contained in the amount of molten iron, the amount of scrap, and the amount of charged auxiliary materials. The processor 52 also estimates the mass of FeO and the temperature of slag 2 immediately after blowing by calculating the heat of reaction and sensible heat using the composition of slag 2 other than FeO, the mass of slag 2, and the flow rate or components of the exhaust gas. The processor 52 may estimate the mass of FeO and the temperature of slag 2 using, for example, the method described in JP 2018-150589 A.

[0044] The processor 52 calculates the mass of slag 2 by adding the mass of FeO and the mass of components other than FeO in slag 2. The processor 52 also calculates the viscosity and solid fraction of slag 2 by performing physical property calculations based on a phase diagram using the composition, mass, and temperature of slag 2.

[0045] The processor 52 calculates the change in the gas flow rate generated in the refining furnace 1 by adding together the amount of CO gas generated at the end of blowing, which is estimated based on the exhaust gas flow rate and components, and the amount of CO gas estimated based on the bottom-blown gas flow rate during intermediate slag removal of the slag 2.

[0046] The processor 52 executes a process of inputting information about the foaming and settling of the slag 2 into the model (step S2). The model calculates the loss cost corresponding to the input information about the foaming and settling of the slag 2 for each candidate tilting pattern of the refining furnace 1.

[0047] The tilting pattern of the refining furnace 1 is specified as the change in the tilt angle of the refining furnace 1 over time, as illustrated by the graph in Figure 5, for example. In the graph in Figure 5, the horizontal axis represents time, and the vertical axis represents the tilt angle of the refining furnace 1. Five tilting patterns, Cases 1 to 5, are illustrated. In each tilting pattern, the tilt angle of the refining furnace 1 increases at the same tilting speed up to a predetermined angle. After the tilt angle of the refining furnace 1 reaches the predetermined angle, the tilting speed slows down. In each tilting pattern, the slowed tilting speed is assumed to be the same. The tilt angle of the refining furnace 1 continues to increase at the slowed tilting speed until it reaches the maximum tilt angle.

[0048] In the tilting pattern of Case 1, the predetermined angle is represented by θ1. θ1 is the same as the maximum tilt angle of the refining furnace 1. Therefore, in the tilting pattern of Case 1, the tilt angle of the refining furnace 1 reaches the maximum tilt angle while the tilting speed remains unchanged. In the tilting patterns of Cases 2 to 5, the predetermined angles are represented by θ2 to θ5.

[0049] In the tilting pattern of Case 5, the period until the tilt angle of the refining furnace 1 reaches a predetermined angle (θ5) is represented as P1. The period until the tilt angle of the refining furnace 1 reaches the maximum tilt angle is represented as P2. The tilting speed slows down during the period represented by P2. The period after the tilt angle of the refining furnace 1 reaches the maximum tilt angle is represented as P3. In other words, the period before the period represented by P2 is represented as P1. The period after the period represented by P2 is represented as P3. In Case 1, there is no period represented by P2. The lengths of the period represented by P2 differ from one another in Cases 2 to 5. The smaller the predetermined angle in each tilting pattern, the longer the period represented by P2 in that tilting pattern. In other words, the smaller the predetermined angle, the slower the refining furnace 1 is tilted.

[0050] The tilt pattern is not limited to the pattern exemplified in Fig. 5. A pattern in which the tilt speed is varied during the period represented by P1 may be set as a candidate. A pattern in which the tilt speed is varied during the period represented by P2 may be set as a candidate. A pattern in which the maximum tilt angle is varied may be set as a candidate. The graph representing the tilt pattern is not limited to a combination of straight lines, and may include curved lines.

[0051] A model may be generated for each of a plurality of candidate tilting patterns of the refining furnace 1. When a model is generated for each candidate tilting pattern, the processor 52 inputs information about the foaming and settling of the slag 2 into the model corresponding to each candidate tilting pattern, and causes the model to calculate the loss cost corresponding to each candidate tilting pattern. When a model corresponding to each candidate tilting pattern is generated, each model can operate in parallel. As a result, the loss cost corresponding to each candidate tilting pattern can be calculated in parallel.

[0052] The model may be configured to receive, as input, information identifying candidate tilt patterns. When the model receives, as input, information identifying candidate tilt patterns, the processor 52 inputs, into the model, information related to the forming and settling of the slag 2 and information identifying each candidate tilt pattern for which loss costs are to be calculated, and causes the model to calculate loss costs corresponding to each candidate tilt pattern. When models that receive, as input, information identifying candidate tilt patterns, are generated, the models are consolidated into one. As a result, the models can be easily managed.

[0053] The model may be configured as a database-type model, which is the database 30 itself, associating information on the forming and settling of the slug 2 with loss costs for each candidate tilting pattern. The model may be configured in the form of a regression analysis model of the relationship between information on the forming and settling of the slug 2 and loss costs. The model may be prepared in advance. The model may be generated by the calculation device 50 or another device. The model may be stored in the database 30, regardless of whether it is in database format. An example of a procedure for the calculation device 50 or another device to generate the model will be described later.

[0054] Returning to the flowchart of Figure 4, the processor 52 outputs the loss cost when tilting the refining furnace 1 for each candidate tilting pattern from the model to which information on the foaming and settling of the slag 2 has been input (step S3). When a model has been generated for each candidate tilting pattern of the refining furnace 1, the processor 52 inputs information on the foaming and settling of the slag 2 into the model of each candidate tilting pattern, and outputs the loss cost when tilting the refining furnace 1 for each candidate from the model of each candidate. When the model is configured to receive information identifying a candidate tilting pattern as input, the processor 52 inputs information on the foaming and settling of the slag 2 and information identifying each candidate tilting pattern, and outputs the loss cost when tilting the refining furnace 1 for each candidate from the model.

[0055] Figure 6 shows an example of the loss cost calculated for each candidate tilting pattern as a bar graph. The loss cost may be output as a separate cost: lime injection cost, represented by a diagonal line that slopes upward to the right, and molten iron outflow cost, represented by a diagonal line that slopes downward to the right. In the graph of Figure 6, the horizontal axis corresponds to the tilting pattern. The vertical axis corresponds to the value obtained by normalizing the loss cost so that the sum of the lime injection cost and the molten iron outflow cost when the tilting pattern is Case 2 is 1. In the example of Figure 6, the loss cost is smallest when the tilting pattern is Case 2.

[0056] The loss costs of each candidate tilting pattern obtained by the procedure from steps S1 to S3 described above are referenced to select a tilting pattern to be used for controlling the tilting of the refining furnace 1 when performing slag removal of the slag 2. Therefore, the loss costs of each candidate tilting pattern are used as guidance information for selecting a tilting pattern. A user who operates or manages the refining system 100 may refer to the loss costs of each candidate tilting pattern as guidance information and select a tilting pattern to be used for controlling the refining furnace 1. In other words, the processor 52 can provide guidance to help the user select a tilting pattern. In other words, the processor 52 executes a process to output information for selecting a tilting pattern, including the loss costs output from the model.

[0057] The procedures from steps S1 to S3 described above may be executed as a guidance method. The guidance method may be realized as a guidance program executed by the processor 52. The guidance program may be stored in a non-transitory computer-readable medium. When the calculation device 50 executes the guidance method or the guidance program, it is also referred to as a guidance device. A configuration including the calculation device 50 and the database 30 that stores the model is also referred to as a guidance system. In other words, the guidance system may include the calculation device 50 and the model. The guidance system may include a model stored in the database 30, or may include a model that is not stored in the database 30. The refining system 100 may include a refining device 40 and a guidance system.

[0058] <Example of intermediate slag removal procedure> Returning to the flowchart of FIG. 4, a tilting pattern to be used by the refining apparatus 40 to control the tilting of the refining furnace 1 is selected based on the loss cost of each candidate tilting pattern output from the model in step S3 (step S4). As described above, a user who operates, controls, or manages the refining system 100 or the refining apparatus 40 may select a tilting pattern based on the loss cost and control the refining apparatus 40 to tilt the refining furnace 1 using the selected tilting pattern. The user may select one tilting pattern that minimizes the loss cost. The user may also narrow down the candidate tilting patterns by taking into account the state of the refining apparatus 40 and select one tilting pattern from the narrowed down candidates that minimizes the loss cost. The user may select one tilting pattern based on the loss cost of each candidate tilting pattern and the state of the refining apparatus 40. The user may also consider the operable range of the crane equipment that tilts the refining furnace 1 as the state of the refining apparatus 40. The user may consider the number of operations or the operating time of the refining apparatus 40 after maintenance as the state of the refining apparatus 40. The user may consider the period until scheduled maintenance of the refining apparatus 40 as the state of the refining apparatus 40.

[0059] The processor 52 of the calculation device 50 may select a tilting pattern and output the selected tilting pattern to the refining device 40. The processor 52 may narrow down candidate tilting patterns based on the state of the refining device 40, and select one tilting pattern that minimizes the loss cost from the narrowed down candidates.

[0060] The slag 2 is discharged using the tilting pattern selected in step S4 (step S5). The user who operates, controls, or manages the refining system 100 or the refining apparatus 40 may operate the refining apparatus 40 to tilt the refining furnace 1 based on the tilting pattern selected by the user himself / herself, thereby discharging the slag 2. The refining apparatus 40 may tilt the refining furnace 1 based on the tilting pattern selected by the processor 52, thereby discharging the slag 2.

[0061] After the procedure of step S5 is performed, the execution of the procedure of the flowchart in Fig. 4 is terminated. The procedures of steps S4 and S5 described above may be performed as an intermediate slag removal method. As described above, the intermediate slag removal method may be performed by a user or by the processor 52. When the processor 52 performs the intermediate slag removal method, the intermediate slag removal method may be realized as a slag removal program executed by the processor 52. The slag removal program may be stored in a non-transitory computer-readable medium.

[0062] <Summary> As described above, in the refining system 100 according to this embodiment, the calculation device 50 calculates information about the foaming and settling of the slag 2 based on the operating conditions of the refining apparatus 40. The calculation device 50 calculates the loss cost of each candidate tilting pattern of the refining furnace 1 as guidance information for selecting a tilting pattern of the refining furnace 1 based on the information about the foaming and settling of the slag 2. The user or the calculation device 50 can select a tilting pattern of the refining furnace 1 taking the loss cost into consideration and perform slag removal of the slag 2. As a result, stable intermediate slag removal is achieved while taking into consideration changes in operating conditions.

[0063] (Example of model generation) As described above, the calculation device 50 inputs information about the foaming and settling of the slag 2 into the model to calculate the loss cost of each candidate tilting pattern of the refining furnace 1. The model may be generated by the calculation device 50 or another device. An example of the operation of the calculation device 50 to generate a database-type model will be described below.

[0064] The processor 52 of the computing device 50 may execute a model generation method including the steps of the flowchart illustrated in Fig. 7. The model generation method may be implemented as a model generation program executed by the processor 52. The model generation program may be stored in a non-transitory computer-readable medium.

[0065] The processor 52 calculates the volume of the slag 2 and the apparent viscosity of the slag 2 based on the information on the foaming and settling of the slag 2 (step S11). In other words, the processor 52 may calculate the volume of the slag 2 and the apparent viscosity of the slag 2 based on the information on the foaming and settling of the slag 2. Specifically, the processor 52 executes a formulation of the settling behavior of the foamed slag 2 and the apparent viscosity of the foamed slag 2, which affect the slag removal performance of the slag 2. The settling behavior of the foamed slag 2 is expressed as a change in the volume of the slag 2 over time.

[0066] The change in the volume of slag 2 over time, which represents the settling behavior of slag 2, is calculated by the following equation (1): where V(t) [m 3 ] represents the change in the volume of slag 2 over time. m s [kg] represents the mass of slug 2. μ [Pa·s] represents the viscosity of slug 2. φ s [%] represents the solid fraction of slag 2. Q(t)[m 3 / s] represents the time change in the CO gas flow rate generated in the refining furnace 1. In other words, the settling behavior of slag 2 is expressed as a function of the mass, viscosity, and solid fraction of slag 2, as well as the CO gas flow rate generated.

number

[0067] The apparent viscosity of the slag 2 is calculated by the following formula (2): s [Pa·s] represents the apparent viscosity of slag 2. μ [Pa·s] represents the viscosity of slag 2. φ g [%] represents the gas phase ratio, which is the proportion of gas phase contained in the foamed slag 2. s [%] represents the solid fraction of slag 2.

number

[0068] φ represents the gas phase ratio g [%] is also expressed as a function of the mass, density, and volume of slug 2. Therefore, the above formula (2) can be transformed into the following formula (3): where μ [Pa·s] represents the viscosity of slug 2. m s [kg] represents the mass of slug 2. s [kg / m 3 ] represents the density of slag 2. V(t)[m 3 ] represents the volume of slag 2. φ s [%] represents the solid fraction of slag 2.

number

[0069] Processor 52 may calculate the volume of slug 2 and the apparent viscosity of slug 2 using equations (1) and (3) described above.

[0070] The processor 52 sets multiple candidates for the tilting pattern of the refining furnace 1 and calculates the amount of discharged slag or the amount of flowing molten iron when the refining furnace 1 is tilted according to each candidate tilting pattern (step S12). The amount of discharged slag is the amount of slag 2 discharged from the refining furnace 1 when the refining furnace 1 is tilted according to the tilting pattern. The amount of flowing molten iron is the amount of molten iron 3 that flows out from the refining furnace 1 when the refining furnace 1 is tilted according to the tilting pattern.

[0071] Specifically, the processor 52 performs a fluid analysis of the behavior of the formed slag 2 and the molten iron 3 when the refining furnace 1 is tilted according to each of the tilting pattern candidates. The fluid analysis may be performed by numerical calculation. As a result of the fluid analysis, the processor 52 calculates the mass [kg] of the discarded slag and the amount [kg] of the outflowing molten iron for each of the tilting pattern candidates.

[0072] The processor 52 estimates the amount of lime to be added in the next blowing based on the amount of discharged slag, and calculates the lime addition cost based on the estimated amount of lime (step S13). The lime addition cost includes the value of the lime itself and the value of the energy required to add the lime. The processor 52 may calculate the lime addition cost on a monetary basis.

[0073] Specifically, the processor 52 can calculate the mass of lime to be added in the next blow based on the balance of the amount of phosphorus in the refining furnace 1 throughout the entire refining process. In other words, the mass of lime is calculated based on the mass of discharged slag, the initial amount of phosphorus in the refining furnace 1, and the amount of phosphorus at the target end point in the refining furnace 1. The processor 52 may calculate the mass of lime to be added in the next blow using the following equation (4): where m l [kg] represents the mass of lime. s [kg] represents the mass of the discharged slag calculated in step S12. m P [kg] represents the initial amount of phosphorus in the refining furnace 1. m' P [kg] represents the amount of phosphorus at the target end point in the refining furnace 1.

number

[0074] The processor 52 may calculate the lime input cost on a monetary basis based on the mass of lime to be input in the next blow. The processor 52 may also calculate the lime input cost as an increase in the lime cost based on an excess amount of lime among the amount of lime to be input in the next blow. The processor 52 may calculate the lime input cost based on the cost of lime per unit mass.

[0075] The processor 52 calculates the molten iron spilling cost based on the amount of spilled molten iron (step S14). The molten iron spilling cost includes the value of the spilled molten iron 3 itself. The processor 52 may calculate the molten iron spilling cost on a monetary basis. The processor 52 may calculate the loss based on the reduction in yield due to the spill of the molten iron 3 as the molten iron spilling cost. The processor 52 may calculate the molten iron spilling cost based on the cost of the molten iron 3 per unit mass.

[0076] The processor 52 generates a database-type model based on at least one of the lime injection cost and the hot metal outflow cost (step S15). The processor 52 calculates either the lime injection cost or the hot metal outflow cost, or the sum of the lime injection cost and the hot metal outflow cost, as the loss cost. The processor 52 associates information about the foaming and settling of the slag 2 with the loss cost and stores them in the database 30.

[0077] For example, the processor 52 may calculate the combined cost of lime input cost and hot metal spill cost using the following equation (5): where L represents the loss cost. m represents the hot metal spill cost. L l represents the cost of lime input. ΔL m represents the cost of molten iron3 per unit mass. m' m represents the mass of the poured hot metal 3. ΔL l represents the cost of lime per unit mass. m l represents the mass of lime to be added in the next blowing.

number

[0078] The processor 52 associates the information on the forming and settling of the slag 2 used to calculate the loss cost with the loss cost calculated based on that information and stores them in the database 30. As described above, the processor 52 can generate a database-type model.

[0079] The processor 52 may generate a regression analysis model. When generating a regression analysis model, the processor 52 may perform regression analysis by acquiring information on the foaming and settling of the slag 2 in the actual refining process and the amount of slag 2 discharged or the amount of molten iron 3 that flows out in the actual refining process. The processor 52 can generate a regression equation based on the results of the regression analysis and generate a model based on the regression equation.

[0080] The processor 52 may perform machine learning using, as learning data, information on the foaming and settling of the slag 2 in the actual refining process and the amount of slag 2 discharged or the amount of molten iron 3 that flows out in the actual refining process. By performing machine learning, the processor 52 may generate a trained model that outputs a loss cost when information on the foaming and settling of the slag 2 is input.

[0081] When the information on the foaming and settling of the slag 2 in the actual refining process and the amount of discharged slag 2 or the amount of outflow of molten iron 3 in the actual refining process are acquired as discrete data, the processor 52 may generate intermediate data by interpolating the data. The information on the foaming and settling of the slag 2 used for the regression analysis or machine learning may be acquired as experimental data in a beaker, for example.

[0082] <Example of operation based on the shape of refining furnace 1> As described above, the calculation device 50 generates information for selecting a tilting pattern of the refining furnace 1 so as to reduce the loss cost, based on information on the foaming and settling of the slag 2. Here, the amount of slag 2 discharged or the amount of molten iron 3 that flows out, which affects the loss cost in the refining process, is determined according to the shape of the refining furnace 1.

[0083] The shape of the refining furnace 1 may be deformed by performing refining in the refining furnace 1. For example, as shown in Figure 8, the wear of the inner wall 6 of the refining furnace 1 may cause the furnace body shape of the refining furnace 1 to be deformed. Figure 8(a) shows the cross-sectional shape of the refining furnace 1 in an unused state. Figure 8(b) shows the cross-sectional shape of the refining furnace 1 in a state where the inner wall 6 has worn down due to refining and has thinned from the position of the inner wall 6 in an unused state, indicated by the dashed line, to the position of inner wall 6b. Figure 8(c) shows the cross-sectional shape of the refining furnace 1 in a state where the number of refining operations has been increased compared to Figure 8(b), and the inner wall 6 has worn down further and thinned down to the position of inner wall 6c. It can be seen that the wear of the inner wall 6 of the refining furnace 1 increases as the number of refining operations in the refining furnace 1 increases.

[0084] The greater the wear on the inner wall 6 of the refining furnace 1, the larger the internal volume of the refining furnace 1. As the internal volume of the refining furnace 1 increases, the level of the molten pig iron 3 in the refining furnace 1 becomes lower. When the level of the molten pig iron 3 becomes lower, it becomes difficult to remove the slag 2 even if the refining furnace 1 operates with the same tilting pattern. In other words, the degree of wear on the inner wall 6 of the refining furnace 1 affects the information for selecting a tilting pattern that reduces loss costs. As a result, loss costs can be reduced by selecting a tilting pattern for the refining furnace 1 taking into account the shape of the furnace body.

[0085] Furthermore, as illustrated in Figures 9 and 10, the shape of the refining furnace 1 may be deformed due to the adhesion of ingots 4 to the throat 5 of the refining furnace 1. Figure 10 is a cross-sectional view taken along the line AA in Figure 9. If the throat 5 of the refining furnace 1 becomes narrower, it becomes more difficult to remove the slag 2, even if the refining furnace 1 operates with the same tilting pattern. In other words, the throat shape of the refining furnace 1 affects the information used to select a tilting pattern that reduces loss costs. As a result, loss costs can be reduced by selecting a tilting pattern for the refining furnace 1 taking into account the throat shape of the refining furnace 1.

[0086] The calculation device 50 may generate information for selecting a tilting pattern for the refining furnace 1 based on information about the shape of the refining furnace 1. The information about the shape of the refining furnace 1 may include information about at least one of the shape of the furnace body or the shape of the throat of the refining furnace 1. An example of the operation in which the refining system 100 executes the steps of the flowchart illustrated in Fig. 11 will be described below.

[0087] The processor 52 of the calculation device 50 calculates information relating to the forming and settling of the slag 2 (step S21). The processor 52 may execute the procedure of step S21 in the same manner as step S1 in FIG.

[0088] The processor 52 acquires information about the shape of the refining furnace 1 (step S22). The processor 52 may acquire the information about the shape of the refining furnace 1 from a measuring device provided in the refining apparatus 40 or an external measuring device. The processor 52 may acquire measurement results of the distance to each part of the refining furnace 1 from a laser rangefinder as the information about the shape of the refining furnace 1, and calculate the body shape, throat shape, or three-dimensional shape of the refining furnace 1 by reconstructing space based on the distance measurement results. The processor 52 may acquire an image of the refining furnace 1 from a camera as the information about the shape of the refining furnace 1, and calculate the body shape, throat shape, or three-dimensional shape of the refining furnace 1 based on the image of the refining furnace 1. The measuring device may generate and output measurement data of the body shape, throat shape, or three-dimensional shape of the refining furnace 1. The processor 52 may acquire measurement data of the body shape, throat shape, or three-dimensional shape of the refining furnace 1 from the measuring device as the information about the shape of the refining furnace 1.

[0089] The processor 52 executes a process of inputting information on the foaming and settling of the slag 2 and information on the shape of the refining furnace 1 into the model (step S23). The processor 52 may execute the process of inputting information on the foaming and settling of the slag 2 into the model in the same manner as step S2 of FIG.

[0090] The processor 52 may input measurement data of the furnace body shape or furnace throat shape or three-dimensional shape of the refining furnace 1 into the model as information about the shape of the refining furnace 1.

[0091] The processor 52 may extract, as information about the shape of the refining furnace 1, the values ​​of parameters representing characteristic features from measurement data on the furnace body shape or furnace throat shape or three-dimensional shape of the refining furnace 1, and input them into the model.

[0092] The processor 52 may calculate, for example, the internal volume of the refining furnace 1 as a parameter representing the furnace body shape of the refining furnace 1. The larger the internal volume of the refining furnace 1, the lower the liquid level of the molten pig iron 3 in the refining furnace 1. The lower the liquid level of the molten pig iron 3, the more difficult it is to remove the slag 2 above the molten pig iron 3. As a result, the internal volume of the refining furnace 1 affects the loss cost.

[0093] The processor 52 may calculate, for example, the amount of wear of the inner wall 6 of the refining furnace 1 as a parameter representing the furnace body shape of the refining furnace 1. The processor 52 may calculate the amount of wear of the inner wall 6 of the refining furnace 1 at the side of the refining furnace 1, or may calculate the amount of wear of the bottom of the refining furnace 1. The processor 52 may calculate the thickness of the wall of the furnace body of the refining furnace 1 as a parameter representing the furnace body shape of the refining furnace 1.

[0094] The greater the wear amount of the inner wall 6 of the refining furnace 1, the larger the internal volume of the refining furnace 1. Furthermore, the thinner the wall thickness of the furnace body of the refining furnace 1, the larger the internal volume of the refining furnace 1. The larger the internal volume of the refining furnace 1, the lower the level of the molten pig iron 3 in the refining furnace 1. The lower the level of the molten pig iron 3, the more difficult it is to remove the slag 2 above the molten pig iron 3. As a result, the wear amount of the inner wall 6 of the refining furnace 1 or the wall thickness of the refining furnace 1 affects the loss cost.

[0095] The processor 52 may calculate, for example, the aperture ratio of the throat 5 of the refining furnace 1 as a parameter representing the throat shape of the refining furnace 1. The aperture ratio of the throat 5 may be calculated as the value obtained by dividing the area of ​​the opening narrowed by the adhesion of the metal 4 when the throat 5 is viewed from above by the area of ​​the opening of the throat 5 when no metal 4 is attached. The smaller the aperture ratio of the throat 5 of the refining furnace 1, the more difficult it is for the slag 2 to be discharged. As a result, the aperture ratio of the throat 5 affects the loss cost.

[0096] The slag 2 is discharged from the semicircle of the throat 5 of the refining furnace 1 that becomes lower when the refining furnace 1 is tilted. In other words, the loss cost is significantly affected by the shape of the semicircle of the throat 5 of the refining furnace 1 that becomes lower when the refining furnace 1 is tilted. Therefore, the processor 52 may calculate the opening ratio of the semicircle of the outer edge of the throat 5 that becomes lower when the refining furnace 1 is tilted as a parameter representing the throat shape of the refining furnace 1, so as to improve the calculation accuracy of the loss cost.

[0097] The processor 52 may calculate radius data of the throat 5 as a parameter representing the throat shape of the refining furnace 1. The radius data of the throat 5 is expressed as the distance from the center of the throat 5 to each part of the outer edge of the throat 5. If no ingot 4 is attached to the throat 5, the radius data of the throat 5 is calculated as a uniform radius in all directions. If the shape of the throat 5 is asymmetric due to the attachment of ingot 4, the radius data of the throat 5 is calculated as the relationship between, for example, the distance from the center to the outer edge of the throat 5 in the measurement direction of the radius of the throat 5 and the angle of the measurement direction with respect to a reference direction. The reference direction may be the direction in which the outer edge of the throat 5 is lowest when the refining furnace 1 is tilted.

[0098] The smaller the radius in the direction in which the outer edge of the throat 5 lowers when the refining furnace 1 is tilted, the more difficult it is to discharge the slag 2. In other words, the greater the amount of ingot 4 attached in the direction in which the outer edge of the throat 5 lowers when the refining furnace 1 is tilted, the more difficult it is to discharge the slag 2. As a result, the radius data of the throat 5 affects the loss cost.

[0099] The processor 52 may calculate the average value of the radius of the entire circumference of the throat 5 as a parameter representing the throat shape of the refining furnace 1, or may calculate the average value of the radius of the semicircle of the throat 5 that is lower when the refining furnace 1 is tilted. The smaller the average value of the radius of the throat 5, the more difficult it is for the slag 2 to be discharged. As a result, the average value of the radius of the throat 5 affects the loss cost.

[0100] The model calculates the loss cost corresponding to the input information for each candidate tilting pattern of the refining furnace 1. The processor 52 outputs the loss cost when the refining furnace 1 is tilted for each candidate tilting pattern from the model to which information on the foaming and settling of the slag 2 and information on the shape of the refining furnace 1 have been input (step S24). The processor 52 may execute the procedure of step S24 in the same manner as step S3 in FIG.

[0101] Based on the loss cost of each candidate tilting pattern output from the model in step S24, a tilting pattern to be used by the refining apparatus 40 to control the tilting of the refining furnace 1 is selected (step S25). As in step S4 of Figure 4, a user who operates, controls, or manages the refining system 100 or the refining apparatus 40 may select a tilting pattern based on the loss cost and control the refining apparatus 40 with the selected tilting pattern to tilt the refining furnace 1. The processor 52 may select the tilting pattern and output the selected tilting pattern to the refining apparatus 40.

[0102] The slag 2 is removed using the tilting pattern selected in step S25 (step S26). The procedure of step S26 may be performed in the same manner as the procedure of step S5 in Fig. 4. After the procedure of step S26 is performed, the execution of the procedure of the flowchart in Fig. 11 is terminated.

[0103] As described above, the calculation device 50 inputs information about the foaming and settling of the slag 2 and information about the shape of the refining furnace 1 into the model in order to calculate the loss cost of each candidate tilting pattern of the refining furnace 1. Therefore, the model needs to be generated so that information about the shape of the refining furnace 1 can be input in addition to information about the foaming and settling of the slag 2. Below, an example of the operation of the processor 52 of the calculation device 50 to generate a model to which information about the shape of the refining furnace 1 can be input will be described.

[0104] The processor 52 may execute a model generation method including the steps of the flowchart illustrated in Fig. 12. The model generation method may be realized as a model generation program executed by the processor 52. The model generation program may be stored in a non-transitory computer-readable medium.

[0105] The processor 52 calculates the volume of the slag 2 and the apparent viscosity of the slag 2 based on the information on the foaming and settling of the slag 2 (step S31). The processor 52 may execute the procedure of step S31 in the same manner as step S11 in FIG.

[0106] The processor 52 calculates shape data of the refining furnace 1 (step S32). As in step S22 of Fig. 11, the processor 52 may calculate data on the furnace body shape or furnace throat shape, or three-dimensional shape of the refining furnace 1 as the shape data of the refining furnace 1. The processor 52 may also acquire data on the furnace body shape or furnace throat shape, or three-dimensional shape of the refining furnace 1 from a measuring device as the shape data of the refining furnace 1.

[0107] The processor 52 sets a plurality of candidates for the tilting pattern of the refining furnace 1, and calculates the amount of discarded slag or the amount of flown molten iron when the refining furnace 1 is tilted according to each candidate for the tilting pattern (step S33). The processor 52 may execute the procedure of step S31 in the same manner as step S12 in FIG.

[0108] The processor 52 estimates the amount of lime to be added in the next blow based on the amount of discarded slag, and calculates the lime addition cost based on the estimated amount of lime (step S34). The processor 52 calculates the molten iron outflow cost based on the amount of outflowed molten iron (step S35). The processor 52 may execute steps S34 and S35 in the same manner as steps S13 and S14 in FIG. 7.

[0109] The processor 52 generates a model based on at least one of the lime input cost or the molten iron outflow cost (step S36). The processor 52 may associate information about the foaming and settling of the slag 2 and information about the shape of the refining furnace 1 with loss costs and store the information in the database 30 to generate a database-type model. The processor 52 may perform the procedure of step S36 in the same manner as step S15 in Fig. 7 to associate information about the foaming and settling of the slag 2 with loss costs.

[0110] When generating a database-format model, the processor 52 may calculate parameter values ​​that represent characteristic features of the measurement data of the furnace body shape or throat shape or three-dimensional shape of the refining furnace 1 as information about the shape of the refining furnace 1, and associate the calculated values ​​with loss costs. By representing the information about the shape of the refining furnace 1 with parameter values, the amount of data required to generate a database-format model can be reduced.

[0111] When generating a regression analysis model as a model, the processor 52 may perform regression analysis using information on the foaming and settling of the slag 2 in the actual refining process, information on the shape of the actual refining furnace 1, and the amount of slag 2 discharged or the amount of molten iron 3 flowing out in the actual refining process. The processor 52 may use measurement data of the furnace body shape or throat shape or three-dimensional shape of the refining furnace 1 as information on the shape of the refining furnace 1 for the regression analysis. The processor 52 can generate a regression equation based on the results of the regression analysis and generate a model based on the regression equation.

[0112] The processor 52 may perform machine learning using, as learning data, information on the foaming and settling of the slag 2 in the actual refining process, information on the shape of the actual refining furnace 1, and the amount of slag 2 discharged or the amount of molten iron 3 that flows out in the actual refining process. By performing machine learning, the processor 52 may generate a trained model that outputs a loss cost when the information on the foaming and settling of the slag 2 and the information on the shape of the refining furnace 1 are input.

[0113] When the processor 52 acquires information about the actual shape of the refining furnace 1 as discrete data, it may generate intermediate data by interpolating the data.

[0114] After executing the procedure of step S36, processor 52 ends the execution of the procedure of the flowchart in FIG.

[0115] (Other embodiments) By executing the above-described guidance method and intermediate slag removal method, slag 2 is removed from the refining furnace 1. The process computer of the refining apparatus 40 may remove the slag 2 from the refining furnace 1 by tilting the refining furnace 1 in a tilting pattern selected based on the loss cost generated by the above-described guidance method. After removing the slag 2, the process computer of the refining apparatus 40 may add auxiliary materials to the refining furnace 1 and perform the next blow. The process computer of the refining system 100 or the refining apparatus 40 may execute a method for refining molten iron 3, including a step of performing blowing in the furnace to which auxiliary materials have been added, and a step of executing the above-described intermediate slag removal method.

[0116] The process computer of the refining apparatus 40 may produce molten steel by pouring the molten pig iron 3 treated by executing the above-described refining method from the refining furnace 1. The process computer of the refining system 100 or the refining apparatus 40 may execute a method for producing molten steel, which includes a step of pouring the molten pig iron 3 refined by executing the above-described refining method.

[0117] 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 could make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present disclosure. For example, the functions included in each component or step can be rearranged so as not to cause logical inconsistencies, and multiple components or steps can be combined or divided into one. The embodiments of the present disclosure can also be realized as a program executed by a processor included in an apparatus or a storage medium on which a program is recorded. It should be understood that these are also included within the scope of the present disclosure. [Explanation of symbols]

[0118] 100 Refining System 30 Database (Example of a model) 40 Refining equipment (1: refining furnace, 2: slag, 3: molten iron, 4: ingot, 5: furnace throat, 6: inner wall, 6b, 6c: worn inner wall, 42: top blowing lance) 50 Calculation device (52: Processor, 54: Memory unit, 56: Interface)

Claims

1. 1. A guidance method for outputting information for selecting a tilting pattern of a furnace in a process of removing slag from a furnace treating molten iron, comprising: inputting information into a model regarding the foaming and settling of the slag based on at least one of the mass of the slag, the viscosity of the slag, the solid fraction of the slag, or the gas flow rate generated in the furnace; outputting from the model a loss cost based on at least one of the amount of lime added or the amount of molten iron outflow when tilting the furnace using each of the plurality of tilting patterns; A guidance method, including:

2. selecting one tilt pattern from the plurality of tilt patterns based on a loss cost output by executing the guidance method according to claim 1; controlling the furnace using a selected tilting pattern to desludge the slag; An intermediate slag removal method, comprising:

3. A method for refining molten iron, comprising the steps of: performing blowing in a furnace to which auxiliary materials have been added; and performing the intermediate slag removal method according to claim 2.

4. A method for producing molten steel, comprising the step of pouring from a furnace molten iron that has been treated by carrying out the method for refining molten iron according to claim 3.

5. 1. A guidance system that outputs information for selecting a tilting pattern of a furnace in a process of removing slag from a furnace that processes molten iron, comprising: a model and a calculation device, The model is Accepting as input information regarding foaming and settling of the slag based on at least one of a mass of the slag, a viscosity of the slag, a solid fraction of the slag, or a gas flow rate generated in the furnace; outputting a loss cost based on at least one of the amount of lime to be added or the amount of molten iron that flows out when the furnace is tilted using each of the plurality of tilting patterns; The calculation device executes a process of inputting information regarding the slag forming and settling into the model, and a process of outputting information for selecting the tilting pattern, including the loss cost output from the model.

6. a refining device that performs intermediate slag removal by blowing in a furnace to which auxiliary materials are added; and the guidance system according to claim 5, the guidance system outputs information for selecting the tilting pattern of the furnace when deslag is removed from the furnace to treat molten iron; the refining apparatus controls the furnace using the tilting pattern of the furnace selected based on the information output by the guidance system. Refining system.

7. 2. A model generation method for generating a model for inputting information about slag forming and settling in the guidance method according to claim 1, comprising: Calculating the volume and apparent viscosity of the foamed slag in the furnace based on information about foaming and settling of the slag based on at least one of the mass of the slag, the viscosity of the slag, the solid fraction of the slag, and the gas flow rate generated in the furnace; a step of setting a plurality of tilting patterns as patterns for tilting the furnace, and performing a fluid analysis of the molten iron and slag in the furnace when the furnace is tilted using each of the plurality of tilting patterns, thereby calculating at least one of the amount of slag discharged from the furnace and the amount of molten iron flowing out from the furnace when the furnace is tilted using each of the plurality of tilting patterns; calculating a cost of adding lime to the furnace by estimating an amount of lime to be added to the furnace in the next blowing operation based on the amount of slag removed when the amount of slag removed is calculated; a step of calculating a cost of molten iron outflow from the furnace based on the amount of molten iron outflowed when the amount of molten iron outflowed is calculated; generating a model that outputs at least one of the lime injection cost and the hot metal outflow cost as a loss cost for each of the plurality of tilting patterns when information on the slag foaming and settling is input; A model generation method comprising:

8. 8. The model generating method according to claim 7, wherein in the step of generating the model, a database is generated as the model, in which information on the slag foaming and settling and at least one of the lime input cost and the molten iron outflow cost are associated with each of the plurality of tilting patterns.

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