KR20180052749A - Preliminary treatment method for molten iron and preliminary treatment control device for molten iron - Google Patents

Abstract

And estimating the carbon concentration in the molten iron after the removal treatment with high accuracy. A data acquiring step of acquiring exhaust gas data relating to molten iron before the denitrification process and an exhaust gas component including an exhaust gas component and an exhaust gas flow rate discharged from the converter at the time of the denitration process in a molten iron preliminary process using a converter, The amount of decarburization during the untreating process calculated on the basis of the exhaust gas data is corrected using the correction value calculated on the basis of the operating factor in the untreating process, And a carbon concentration estimation step of estimating the carbon concentration.

Description

Preliminary treatment method for molten iron and preliminary treatment control device for molten iron

The present invention relates to a molten iron preliminary treatment method and a molten iron preliminary treatment control device for estimating a carbon concentration in molten iron after a denitrification treatment in a molten iron preliminary treatment using a converter.

In the transferring operation in the steelmaking process, in order to set the molten steel component concentration (for example, carbon concentration and the like) and the molten steel temperature at the time of blowout (at the end of the decarburization process) to the target value, And a damping control in which dynamic control is combined is performed. In the static control, before the start of the culling, the molten steel component concentration at the time of blowout and the molten steel temperature are set to a target value The amount of oxygen to be injected and the amount of the various raw materials to be injected are determined and the crying is carried out in accordance with this. On the other hand, in the dynamic control, during the brewing, the molten steel component concentration and the molten steel temperature are actually measured using the sub-lance, and based on the measured values, The blowing-in oxygen amount and the input amount of the various sub-materials are updated, and the renewed values are used to perform the blowing.

2. Description of the Related Art In recent years, development of a technique called MURC (Multi Refining Converter) capable of performing preliminary ironing and decarburization processing in the same way in the converter winding is progressing. In the MURC, the dephosphorization treatment, which is one of the preliminary treatment for molten iron in the refining, and the decarburization treatment in the refining, can be continuously performed. As a result, the heat loss that can be caused by transferring the charcoal to the other converter in the steelmaking process is reduced. Therefore, since a large amount of scrap can be used for blowing, the production efficiency in the steelmaking process can be remarkably improved.

In the case where scrap is charged in a large amount into the converter, the scrap may remain in the charcoal after it has been subjected to the de-phosphorus treatment. When such unheated scrap exists, it becomes difficult to perform the above-described sub-lance measurement on the charcoal in the converter. This is because the sub-lance collides with the unhealthy scrap and the sub-lance is damaged, which can cause serious accidents. Therefore, in the case of starting decarburization treatment after demineralization, it is difficult to measure the carbon concentration in the molten metal at the start of the decarburization treatment by using the sub-lance. Therefore, when the denitrification treatment and the decarburization treatment are continuously performed by the same converter, the amount of oxygen taken in by the static control and the amount of the various auxiliary materials It is required to determine the amount of input.

However, depending on the progress of the removal process, there is a case where the carbon concentration in the charcoal does not decrease or decrease much more than the original assumption. In this case, there is a possibility that the carbon concentration in the molten steel after the decarburization treatment largely deviates from the target carbon concentration. Therefore, in order to reliably obtain the molten steel having the target carbon concentration, it is necessary to perform the static control based on the carbon concentration in the molten iron after the denitration treatment, not before the denitration treatment. Since it is difficult to directly measure the carbon concentration in the molten iron after the denitrification treatment, a technique for theoretically estimating the carbon concentration in molten iron after the denitration treatment is required.

Various techniques have been developed so far as techniques for estimating the carbon concentration in the transferring operation. For example, Patent Document 1 discloses a method of calculating a parameter relating to decarburized oxygen efficiency using exhaust gas data discharged from a converter in decarburization treatment, estimating a carbon concentration in molten steel subjected to decarburization treatment using the parameter And the like. In this technique, in the decarburization treatment, in the stage of the deceleration peaking stage in which the injected oxygen reacts with the carbon in the molten steel at a ratio of almost one to one (here, the ratio of one-to-one refers to one to one in molar ratio) A model combining a behavior in which the oxygen efficiency becomes constant and a behavior in which the decarbonization efficiency is lowered at the stage where the carbon concentration in the molten steel is lower than the threshold value is used. This makes it possible to estimate the carbon concentration reflecting the change of the decarburization treatment, thereby improving the estimation accuracy of the carbon concentration and the molten steel temperature in the molten steel.

Japanese Patent Application Laid-Open No. 11709090

However, the carbon concentration in the molten steel estimated by the technique described in Patent Document 1 is to estimate the carbon concentration in the molten iron in the decarburization treatment. In the denitrification treatment, the oxygen flow rate injected into the electric furnace differs from the decarbonization treatment. Specifically, in the decarburization treatment, oxygen is blown at high speed from the uptake lance for decarburization of molten steel, but oxygen is blown at a low rate in order to efficiently produce iron oxide slag for promoting denitration in the denitration treatment. When the oxygen flow rate injected into the converter differs, the mechanism of the oxidation reaction occurring in the converter also differs. Therefore, even when the technique relating to estimation of carbon concentration disclosed in Patent Document 1 is directly applied to the estimation of the carbon concentration in the molten iron in the denitration treatment, it is difficult to estimate the carbon concentration in the molten iron after the denitration treatment with high accuracy.

It is therefore an object of the present invention to provide a new and improved molten iron pretreatment method and a molten iron pretreatment method capable of accurately estimating the carbon concentration in molten iron after the denitrification treatment, And to provide a control device.

In order to solve the above problems, according to one aspect of the present invention, in a molten iron preliminary treatment using a converter, molten iron data relating to molten iron before the denitration treatment, and exhaust gas components discharged from the converter during the denitration treatment, And correcting the amount of decarburization at the time of the removal processing calculated on the basis of the exhaust gas data by using a correction value calculated on the basis of the operating factor at the time of the removal processing And a carbon concentration estimating step of estimating a carbon concentration after the denitration processing on the basis of the corrected decarbonization amount and the above-mentioned hot-water data.

In the carbon concentration estimating step, the correction value may be calculated by a regression formula using the operating factor as an explanatory variable.

The operating factor at the time of the dephosphorization treatment may include a factor indicating the state of the product of slag at the time of the dephosphorization treatment.

The operational factor indicating the status of the product of the slag may include operational factors related to the acoustic information in the converter.

The target carbon concentration after the removal process and the oxygen intake amount into the converter in the decarburization process performed after the removal process are further acquired in the data acquisition step, And an oxygen amount correcting step of correcting the intake oxygen amount based on the comparison result of the carbon concentration and the target carbon concentration after the de-phosphorus treatment.

According to another aspect of the present invention, there is provided a hot water preliminary process control device for controlling a hot water preliminary process using a converter, the hot water preliminary process control device comprising: And a control unit for controlling the amount of decarbonization at the time of the removal process calculated based on the exhaust gas data based on the operating factors at the time of the removal process And a carbon concentration estimating section for estimating a carbon concentration after the denitration processing based on the corrected decarbonization amount and the chartered line data.

The charter preliminary processing method is characterized in that the amount of decarburization obtained by using the exhaust gas data is corrected by using a corrected decarburization amount corrected by a correction value expressed by a regression equation having explanatory variables as factors for explaining the operation factor at the time of denitration processing, Estimate the carbon concentration in the charcoal. This makes it possible to estimate the carbon concentration in the molten iron after the denitrification process with high accuracy without performing the sub-lance measurement after the denitration process. Therefore, it becomes possible to more reliably obtain molten steel having the carbon concentration of the target value after the decarburization treatment.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to estimate the carbon concentration in the molten iron after the denitration treatment with high accuracy.

Fig. 1 is a diagram showing a configuration example of a molten iron preliminary processing system according to an embodiment of the present invention.
Fig. 2 is a flowchart showing a method of preliminary processing of a molten iron by the iron wire preliminary processing system according to the embodiment. Fig.
3 is a graph showing an estimation error of decarburization amount? C _offgas based on exhaust gas data in the comparative example.
Fig. 4 is a _graph showing the relationship between the decarbonization amount [ _Delta] C _offgas + Correction term? C _correct .
5 is a _graph showing the relationship between the decarbonization amount [ _Delta] C _offgas + Correction term? C _correct .
6 is a graph showing an estimation error of the carbon concentration C _deP in Example 1. FIG.
7 is a graph showing an estimation error of carbon concentration C _deP in Example 2. Fig.

Best Modes for Carrying Out the Invention Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description will be omitted.

In the decarburization process, pig iron or steel may exist depending on the carbon concentration, but in the following description, the molten iron or molten steel in the converter is referred to as molten steel for convenience in order to avoid complication . In addition, the word "chartered line" is used for the denial process. In the present specification, " after removal processing " is used to mean " at the end of the removal processing (at the end of the removal processing) " That is, the "after the dehulling process" does not include the time after the start of the decarburization process.

It is also assumed that the carbon preliminary treatment method according to the embodiment of the present invention estimates the carbon concentration in the molten iron after the deodorizing treatment by MURC, but the present invention is not limited to this example. For example, it is possible to estimate the carbon concentration in the molten iron after the dephosphorization process using another transferring method such as SRP (Simple Refining Process), etc., in the molten iron preliminary processing method according to one embodiment of the present invention. That is, the preliminary ironing method according to one embodiment of the present invention can estimate the carbon concentration in the molten iron after the deindustrial treatment, irrespective of the transferring method used in the preliminary ironing process (particularly the deinducing process).

<1. System Configuration>

Fig. 1 is a diagram showing a configuration example of a molten iron preliminary processing system 1 according to an embodiment of the present invention. Referring to Fig. 1, a molten iron preliminary treatment system 1 according to the present embodiment includes a transfer finishing facility 10, a molten iron preliminary processing control device 20, and a metering control device 30. As shown in Fig.

(Converter conversion equipment)

The converter assembly 10 includes a converter 11, a flue 12, an outlet lance 13, an exhaust gas component analyzer 101, and an exhaust gas flow meter 102. In addition, the converter assembly facility 10 may further include a sound meter 111 and a sound collection microphone 112. On the basis of the control signal output from the measurement control device 30, for example, the converter 10 receives the start and stop of the supply of oxygen to the molten iron by the jacket lance 13, the input of the coolant, (11) performs disposal of molten iron and slag. Although not shown in the figure, the converter installation apparatus 10 is provided with a sub-lance for measuring the component concentration of the molten iron and the molten iron temperature, a transmission device for supplying oxygen to the upright lance 13, Various devices used for blowing by a common converter such as a cold material feeding device having a driving system for feeding a cold material and a sub-material feeding device having a driving system for feeding a sub material to the converter 11 can be installed.

An outlet lance 13 used for blowing is inserted from the furnace of the converter 11 and the oxygen 14 sent from the transmission device is supplied to the lean line in the furnace through the outlet lance 13. [ In order to stir the molten iron, an inert gas such as nitrogen gas or argon gas or the like can be introduced from the bottom of the converter 11 as the off gas 15. In the converter (11), a molten iron wire from a blast furnace, a small amount of iron scrap, a coolant for adjusting the molten iron temperature, and a subsidiary raw material for slag formation such as burnt lime are charged / introduced. When the auxiliary raw material is powder, it may be supplied into the converter 11 together with the oxygen 14 through the extender lance 13.

In the denitrification treatment, the phosphorus contained in the molten iron is chemically reacted with the minor ingredient including the iron oxide and the calcium oxide-containing substance contained in the slag in the converter, as represented by the following formula (1) . That is, by increasing the concentration of the iron oxide of the slag by blowing, the de-phosphorus reaction can be promoted. In the formula (1), &quot; [substance X] &quot; represents substance X in molten iron, and &quot; (substance Y) &quot; represents substance Y in slag.

Further, the carbon in the molten iron is oxidized and reacted with oxygen supplied from the extruding lance 13 (decarburization reaction). Thereby, CO or CO ₂ exhaust gas is generated. These exhaust gases are discharged from the converter 11 to the flue 12.

As described above, in the transferring blowing, the blown oxygen reacts with carbon, phosphorus, or silicon in the molten iron to generate oxides. The resulting oxide is discharged as exhaust gas or stabilized as slag. Carbon is removed by the oxidation reaction in the blowing, and phosphorus and the like are introduced into the slag and removed, thereby producing a low carbon and low-impurity steel.

Further, from the furnace of the converter 11, in addition to the outboard lances 13, a sub-lance (not shown) can also be inserted into the furnace. The tip of the sub-lance is immersed in molten steel (or molten iron) at a predetermined timing, whereby the component concentration and the molten steel temperature in the molten steel including the carbon concentration are measured. The measurement of the component concentration and / or the molten steel temperature by the sub-lance is referred to as a sub-lance measurement. The results of the sublance measurement are transmitted to the wire preliminary process control device 20 through the measurement control device 30. [ In the present embodiment, the sublength measurement is not performed because there is an unheated scrap in the converter 11 in the dephasing process, but the sublance measurement can be performed at a predetermined timing during the decarburization process.

The exhaust gas generated by the blowing flows into the flue 12 provided outside the converter 11. [ In the flue 12, an exhaust gas component analyzer 101 and an exhaust gas flow meter 102 are installed. The exhaust gas component analyzer 101 analyzes the components contained in the exhaust gas. The exhaust gas component analyzer 101 analyzes the concentration of CO and CO ₂ contained in the exhaust gas, for example. The exhaust gas flow meter 102 measures the flow rate of the exhaust gas. The exhaust gas component analyzer 101 and the exhaust gas flow meter 102 sequentially analyze and measure the exhaust gas at a predetermined sampling period (for example, 5 to 10 (sec) cycle). The data on the exhaust gas component analyzed by the exhaust gas component analyzer 101 and the data on the exhaust gas flow rate measured by the exhaust gas flow meter 102 (hereinafter, these data are referred to as "exhaust gas data") , And outputted to the wire preliminary process control device 20 through the measurement control device 30 as time series data. The emission gas data may be sequentially output to the wire preliminary process control device 20 or may be collectively output to the wire preliminary process control device 20 when the removal process is completed.

In addition, the converter assembly facility 10 may include a sound meter 111 and a sound collection microphone 112. The sound collector microphone 112 acquires a sound generated from the inside of the converter 11 and outputs a signal relating to the sound to the sound meter 111. The sound meter 111 performs signal processing on the acquired signal, and generates a processing result as sound information. The acoustic information generated here is outputted to the wire preliminary process control device 20 through the measurement control device 30. [ This acoustic information is information reflecting the status of the slag in the converter 11 during the removal process and can be used as a parameter of the operating factor in the removal process. Further, the operating factors in the removal process will be described in detail later.

In addition to the sound meter 111 and the sound collecting microphone 112, a device for acquiring the parameter of the operating factor indicative of the status of the slag in the converter 11 during the detoxification process is installed . For example, by measuring the slag level of the converter 11 by irradiating microwaves into the converter 11, it is possible to grasp the status of the product of the slag. In the case of acquiring the slag level as a parameter of the operating factor, in the transfer finishing facility 10, for example, a microwave irradiating device for irradiating a microwave into the converter 11, an antenna for receiving microwaves reflected on the bath surface, A slag level measuring device for analyzing the slag level based on the microwave received by the antenna may be provided.

(Charging line preliminary process control device)

The chartered preliminary process control device 20 includes a data acquisition unit 201, a carbon concentration estimation unit 202, a correction amount calculation unit 203, a charter preparatory process database 21 and an input / output unit 22. The wire preliminary process control device 20 has a hardware configuration such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a storage and a communication device, The functions of the acquisition unit 201, the carbon concentration estimation unit 202, the correction amount calculation unit 203, and the preliminary ironing database 21 are realized. The input / output unit 22 is realized by an input device such as a keyboard, a mouse, or a touch panel, an output device such as a display or a printer, and a communication device.

In Fig. 1, only functions characteristic of the present invention are mainly shown among the functions of the preliminary ironing processing control device 20. In addition to the functions shown in the drawings, the preliminary ironing control device 20 has a general function that is required in performing control relating to preliminary processing for preliminary ironing.

For example, the wire preliminary processing control device 20 has a function of controlling the entire process relating to the preliminary processing of the wire such as the blowing of oxygen into the converter 11 and the introduction of the cold material and the auxiliary raw material. Further, for example, the preliminary ironing control device 20 calculates the amount of oxygen input to the converter 11, the amount of cold material (hereinafter, referred to as &quot; cold material amount &quot; And a function of determining the amount of the sub-material to be charged and the like. Further, for example, the wire preliminary process control device 20 has a function of controlling the measurement target and the measurement timing, etc., with respect to the sublance measurement performed in general dynamic control.

(For example, the above-mentioned control method of the cold material and the sub-raw material introduction, the method of determining the amount of oxygen to be blown, the amount of various kinds of cold material and the sub-raw material before the start of the culling in the static control, and the like) As a control method of the sub-lance measurement, various known methods can be applied, and detailed description is omitted here.

The charterer preliminary processing control device 20 estimates the carbon concentration in the charcoal after the dephosphorization process, using the various data and the exhaust gas data stored in the charter preprocessing database 21 as input values. Then, based on the carbon concentration in the estimated molten iron, the molten iron preliminary processing control device 20 corrects the indicated oxygen amount and the indicated coldness amount determined by the static control before the denitration processing. The chartered preliminary process control device 20 also outputs to the input / output unit 22 the carbon concentration in the estimated charcoal, the corrected intake oxygen amount, and the indicated value of the coolant amount. Each of the instruction values output to the input / output unit 22 is output to the measurement control device 30 that controls the operation of the converter assembly facility 10. [ The measurement control device 30 performs control relating to the transmission to the converter 11 and the insertion of the coolant into the converter 11 in accordance with the respective instruction values acquired from the wire preliminary process control device 20. [

Specific functions of each functional unit of the preliminary process control apparatus 20 will be described later.

The charter preliminary process database 21 is a database for storing various data used in the charterer preliminary process control device 20 and is realized by a storage device such as a storage device. The charterer preliminary processing database 21 stores chartered line data 211, parameters 212, target data 213 and the like, for example, as shown in Fig. These data may be added, updated, changed, or deleted through an input device or a communication device (not shown). The various data stored in the charter preparation database 21 is called by the data acquisition unit 201. [ The charterer preliminary processing database 21 also stores the result of the estimation by the carbon concentration estimating unit 202 (for example, the carbon concentration in the molten iron after the denitration process) or the correction result by the correction amount calculating unit 203 For example, an indication value after correction of the oxygen amount of intake). 1, the storage device having the hot-wire preliminary process database 21 according to the present embodiment is constituted integrally with the hot-spare process control device 20 as shown in Fig. 1. In another embodiment, The storage device having the preliminary process database 21 may be configured separately from the preliminary process control device 20.

The charter data 211 is various data related to charcoal in the converter 11. [ For example, the charter data 211 includes information on charter (initial charter weight per charge, concentration of charcoal components (carbon, phosphorus, iron, manganese, etc.), charcoal temperature, do. The charter data 211 also includes various kinds of information (for example, information about the input of the sub materials and the cold material (information about the sub materials and the amount of cold material) and the information Information about the measurement of the lance (information on the object to be measured, measurement timing, etc.), information on the amount of oxygen to be taken, and the like). The parameter 212 is various parameters used by the carbon concentration estimating unit 202 and the correction amount calculating unit 203. For example, the parameter 212 includes a parameter in a regression equation with the operating factor as an explanatory variable and a parameter for calculating the correction amount. The target data 213 includes data such as the target component concentration in the molten iron (in the molten steel), the target temperature, and the like at the time of the post-removal treatment, the decarburization treatment, and the measurement of the sub-lance.

The input / output unit 22 acquires the result of the estimation of the carbon concentration by the carbon concentration estimation unit 202 or the correction result of the correction value of the intake oxygen amount by the correction amount calculation unit 203, And outputting it to the apparatus. For example, the input / output unit 22 may output an indication value after correction of the oxygen amount of intake acquired from the correction amount calculation unit 203 to the transfer apparatus 10. As a result, the blowing is performed reflecting the instruction value after the correction of the blowing oxygen amount. Further, the input / output unit 22 may display the carbon concentration in the estimated molten iron, or the indication value after the correction of the oxygen intake amount, to the operator. In this case, the input / output unit 22 may also output to the converter 10 the information regarding the instructions such as the transmission or the cold feed input, which is input by the operation of the operator who viewed the displayed information. Further, the input / output unit 22 may output the estimation result or the like stored in the charter preparation database 21.

(Measurement control device)

The measurement control device 30 has a hardware configuration such as a CPU, a ROM, a RAM, a storage, and a communication device. The measurement control device 30 has a function of communicating with each device provided in the converter assembly facility 10 and controlling the overall operation of the converter assembly facility 10. [ For example, the measurement control device 30 controls the supply of cold materials and auxiliary raw materials to the converter 11 in accordance with an instruction from the preliminary processing control device 20. The measurement control device 30 acquires data obtained from the respective devices of the transfer apparatus 10 such as the exhaust gas component analyzer 101 and the discharge gas flow meter 102 and supplies them to the pre- .

<2. Processing by the wire preliminary processing control device>

Hereinafter, respective functions of the wire preliminary process control device 20 shown in Fig. 1 will be described in order. In the following description, unless otherwise stated, the unit (mass%) of the concentration of each component is expressed as (%).

(Data acquisition unit)

The data acquiring unit 201 acquires the charter data 211, the parameters 212 and the target data 213 stored in the charter preparation database 21 and the exhaust gas component analyzer 101 and the exhaust gas flow meter 102 As shown in Fig. The data acquisition unit 201 may sequentially acquire data sequentially measured by the exhaust gas component analyzer 101 and the exhaust gas flow meter 102 during the detoxification process or collectively after the detoxification process. The data acquisition unit 201 outputs the acquired data to the carbon concentration estimation unit 202. [

(Carbon concentration estimating unit)

The carbon concentration estimating unit 202 estimates the carbon concentration in the molten iron after the denitration processing based on the various data acquired by the data acquiring unit 201. [ Hereinafter, a method of estimating the carbon concentration by the carbon concentration estimating unit 202 will be described.

The carbon concentration in the molten iron after the denitrification treatment can be estimated by the mass balance of carbon in the molten iron before and after the denitrification treatment. That is, it is considered that the difference in the mass of carbon contained in the molten iron before and after the denitration process coincides with the mass of carbon contained in the exhaust gas generated by the denitration process (that is, the mass balance is balanced). The inventors of the present invention examined the carbon concentration in the molten iron after the denitrification treatment by using the material resin model related to carbon.

First, the mass (carbon decarbonization amount) of carbon contained in the exhaust gas generated by the denitration process is calculated based on the exhaust gas data. The decarbonization amount? C _offgas (ton) based on the exhaust gas data is expressed by the following equation (2).

Here, the decarbonization amount wc [i] (g / sec) per unit time obtained from the exhaust gas data is calculated by the following equation (3).

Here, CO [i + N] (%) represents the CO concentration in the exhaust gas, CO ₂ [i + N] (%) represents the CO ₂ concentration in the exhaust gas, V _offgas [i] (Nm ³ / Is the total exhaust gas flow rate. CO [i] (%) and CO ₂ [i] (%) can be obtained by the exhaust gas component analyzer 101. In _{addition, V offgas [i] (Nm} 3 / hr (NTP)) , can be obtained by the exhaust gas flowmeter (102). The i in each parenthesis [] indicates the sampling period by the exhaust gas component analyzer 101 and the exhaust gas flow meter 102. [ The N in the brackets [] corresponds to the analysis delay (time delay until the exhaust gas reaches the installation position of the exhaust gas component analyzer 101) by the exhaust gas component analyzer 101. The specific value of the analysis delay N may be appropriately determined in accordance with the installation position of the exhaust gas component analyzer 101 in the flue 12 and the like. Also, "NTP" means Normal Temperature Pressure. The value obtained by multiplying V _offgas [i] by 1000 is divided by 3600 in order to convert the unit to (L / sec). Also, dividing by 22.4 (L / mol) is for converting into the number of moles. Further, 12 is the atomic weight of carbon.

On the other hand, the decarbonization amount (decarbonization amount based on the component change) ΔC _c (ton) based on the result of the measurement of the composition of the carbon concentration in the molten iron before and after the denitration treatment is expressed by the following formula (4).

C _HM (%) represents the carbon concentration in the molten iron before the denitration treatment, W _HM (ton) represents the weight of the molten iron before the denitration treatment, C _SC (%) represents the carbon concentration in the scrap charged into the converter 11 before the denitrification, W _SC (ton) is the weight of the scrap charged in the converter 11 before dephosphorization treatment, C _CM (%) is by weight of carbon concentration, W _CM (ton) of naengseon before dephosphorization process is cold-line before the dephosphorization process, C _{sub, j} represents the carbon concentration in the sub raw material j charged into the converter 11 before the denitrification process and W _{sub j} represents the weight of the sub raw material j charged in the converter 11 before the denitrification process. The performance amount of these is included in the charter data 211.

C _deP (%) is the carbon concentration in the molten iron after the _{de-phosphorus} treatment.

When the carbonaceous material resin before and after the denitration treatment is balanced, the decarbonization amount? C _offgas based on the exhaust gas data and the decarbonization amount? _{C C} based on the component change can be made equal. That is, the relationship between the decarbonization amount? _{C offgas} based on the exhaust gas data and the decarbonization amount? _{C C} based on the component change is expressed by the following equation (5).

From the above, the carbon concentration C _deP in the molten iron after the _{de-phosphorus treatment} can be expressed by the following formula (6) by applying the above formulas (2) to (4) to the above formula (5). Thereby, it is possible to theoretically calculate the carbon concentration C _deP in the molten iron after the removal treatment.

However, the carbon concentration C _deP in the molten iron after the _{de-phosphorus} treatment based on the exhaust gas data obtained by the equation (6) is significantly different from the _actual value C _{deP, a} of the carbon concentration obtained from the sampled molten iron after the _de- The present inventors have found out. This is because there is a large error in the decarbonization amount? C _offgas based on the exhaust gas data calculated in the above equations (2) and (3).

It is considered that the above-mentioned error is caused mainly by the measurement error by the discharge gas flow meter 102. When the exhaust gas flows into the pipe of the exhaust gas flow meter 102, dust such as soot generated from the converter 11 may enter the pipe. Such dust adheres to the pipe (for example, orifice or the like), so that the passage of the exhaust gas in the pipe becomes unstable and the measurement error by the exhaust gas flow meter 102 becomes large. It is difficult to suppress the measurement error itself caused by the exhaust gas flow meter 102 because the state of the inside of the pipe of the exhaust gas flow meter 102 is varied.

As a result of intensive studies, the inventors of the present invention have found that by _{adding the} correction term ΔC _correct (ton), which is a correction value for correcting the decarburization amount ΔC _offgas based on the exhaust gas data, to the above equation (5) To improve the estimation accuracy of the carbon concentration C _{deP in} the molten iron after the _removal treatment. The above equation (5) is expressed by the following equation (7) by adding the correction term? C _correct .

The estimation model of this correction term? C _correct is constructed by various statistical methods. For example, the correction term? C _correct according to the present embodiment is an objective variable calculated by a regression equation obtained by a well-known multiple regression analysis method with various operational factors X as explanatory variables. Specifically, the correction term? C _correct is expressed by the following equation (8).

Here, α _k is a regression coefficient corresponding to the k-th operation factor X _k , and α ₀ is a constant. Specific examples of the operating factor X include those shown in Table 1 below. However, the operating factors shown in Table 1 are only examples, and all the operating factors X may be considered in the estimation of the correction term? C _correct . In the estimation of the correction term? C _correct , all or some of the operating factors included in the following Table 1 may be used.

The present inventors have found out that the estimation accuracy of the carbon concentration C _{deP in} the molten iron after the removal treatment is improved by including the correction term? C _correct having the above-described operation factor X _j as the explanatory variable in the material resin model.

As a result of intensive studies, the present inventors have found that, as a result, the operating factors (the dose, the molten iron content, the molten iron temperature, the molten iron content, the amount of oxygen injected, the amount of auxiliary raw materials, in addition to corresponding to N-2), by reflecting the operation factors that reflect the good condition of the slag in the electric furnace (11) at the time of the dephosphorization process in the correction term ΔC _correct, the estimation accuracy of the carbon concentration C _deP of dephosphorization hot metal after the treatment The present inventors have found out that further improvement is possible.

The _{reason why} the operating factor reflecting the situation of the slag goods can further improve the estimation accuracy of the carbon concentration C _{deP in} the molten iron after the _{denitrification} treatment is that the product status of the slag is the _de- This is because it reflects efficiency. The decarbonization efficiency is an index showing the efficiency of reaction between oxygen taken in the converter 11 and carbon in the molten iron. When the blown oxygen comes into contact with the molten iron exposed on the bath surface, decarburization reaction occurs. However, in the denitration treatment, phosphorus is preferentially introduced into the slag. Therefore, a large amount of slag is present on the surface of the molten iron. Here, depending on the situation of the slag, it is difficult for the decontamination reaction to occur because the injected oxygen is less likely to come into contact with the molten iron, or even if the injected oxygen is less likely to contact the molten iron, And thus a decarburization reaction may occur. Therefore, it is difficult to predict whether the decarburization reaction will be suppressed or promoted depending on the situation of the slag goods. However, it is presumed that the situation of the slag goods may have something to do with the decarburization reaction. That is, it is considered that the condition of the slag in the converter 11 affects the ease of occurrence of decarburization reaction, that is, the efficiency of decarburization oxygen. Therefore, the estimating, by reflecting the operation factors that reflect the good condition of the slag in the correction term ΔC _correct, by considering the influence of decarburization variation in oxygen efficiency of the converter 11 of the dephosphorization process dephosphorization carbon concentration C _deP in the hot metal after the treatment can do. Thus, the inventors of the present invention _{paid attention to} the _{fact that} the estimation accuracy of the carbon concentration C _{deP in} the molten iron after the _denitration treatment was improved.

As shown in Table 1, for example, a sound meter value (db) and a measured value (m) of the slag height by microwave are included in operating factors reflecting the situation of the slag goods during the removal process.

The sound meter value is a value output by the sound meter 111. The sound meter 111 acquires the sound in the converter 11 as an acoustic signal through the sound collecting microphone 112 and outputs it as a sound meter value. The sound meter value varies depending on the situation of the slag goods in the converter 11. [ By using this sound meter value as a factor of operation, it is possible to reflect the situation of the slag goods to the correction term? C _correct .

The slag level is a value output from a slag level measuring device (not shown). The slag level measuring device obtains, for example, a microwave irradiated in the converter 11 through an antenna, and analyzes the slag level from the microwave. This slag level varies depending on the situation of the slag in the converter 11. By using the slag level as a fishing factor in the same manner as the sound meter value, it is possible to reflect the good condition of the slag to the correction term? C _correct .

If it is possible to grasp the status of the slag by another physical measurement method, the measurement result obtained by these measurement methods may be used as the operating factor. As a result of intensive study by the present inventors, it has been found out that it is preferable to use the sound meter value as a factor of operation reflecting the goods situation of the slag.

In the present embodiment, the estimated model of the correction term? C _correct is constructed by multiple regression analysis, but the estimated model may be constructed by other statistical methods. Other statistical methods may be, for example, a statistical method using a machine learning algorithm such as a neural network or a random forest.

The estimation method of the correction term? C _correct has been described above. The carbon concentration C _deP in the molten iron after the _{denitrification treatment} is represented by the following equation (9) by applying the equations (2) to (4) and the equation (8) to the equation (7).

The carbon concentration estimating unit 202 estimates the carbon concentration C _deP in the molten iron after the _denitration processing by substituting the various data acquired by the data acquiring unit 201 into the above equation (9). The carbon concentration estimating unit 202 outputs the estimated carbon concentration C _deP to the _correction amount calculating unit 203. [ Further, the carbon concentration estimating unit 202 may output the estimated carbon concentration C _deP to the input / output unit 22.

(Correction amount calculation unit)

Based on the comparison result of the carbon concentration C _deP estimated by the carbon concentration estimating unit 202 and the target carbon concentration C _aim after the removal processing included in the target data 213, The amount of oxygen taken in the decarburization treatment included in the reformer 213 is corrected. The target carbon concentration C _aim after the de-phosphorus treatment and the oxygen intake amount O _{2, aim} in the decarburization treatment are the amounts determined by the static control before the de-phosphorus treatment. The correction amount calculation unit 203 calculates the correction amount? O2 _{, correct} of the intake oxygen amount by using the above-described estimation result or the like. Then, the correction amount calculation unit 203 updates the initially-fetched oxygen amount O2 _{, aim} using the correction amount? O2 _{, correct} of the fetched oxygen amount, and acquires the fetched oxygen amount O2 _{, corrected} after the update.

The correction amount of the oxygen amount can be calculated by the following equation (10).

Here,? Is a parameter. In this parameter, for example, a theoretical value corresponding to the chemical equivalent of oxygen reacting with carbon may be substituted. Thereby, the oxygen amount corresponding to the _difference between the estimated carbon concentration C _deP and the target carbon concentration C _aim is calculated.

The correction amount calculation unit 203 outputs information on _corrected oxygen amount O _{2, corrected} , to the input / output unit 22.

Further, the correction amount calculation unit 203 may not only correct the initially- _fetched oxygen amount O _{2, aim} , but also modify the original amount of _coldness . For example, when the corrected oxygen amount O _{2, corrected} is less than the initially determined oxygen amount O _{2, aim} , the molten iron temperature of the converter 11 in the decarburization treatment may be lowered. Therefore, even if the correction amount calculating section 203 corrects the amount of cold material to be supplied to the converter 11 to be small based on, for example _{, the corrected} intake oxygen amount O _{2, corrected} and the molten iron temperature (molten steel temperature) do. Thereby, even when the amount of oxygen injected in the decarburization treatment is reduced to a small extent after the denitrification treatment, it is possible to reach the target molten steel temperature that was initially determined. The correction amount calculation unit 203 outputs information on the amount of coldness after the correction to the input / output unit 22.

As described above, the configuration example of the wire preliminary processing system 1 according to the present embodiment has been described with reference to Fig.

<3. Flow of preliminary processing of molten iron>

Fig. 2 is a flowchart showing a method of preliminary processing of a molten iron by the molten iron preliminary processing system 1 according to the present embodiment. Referring to Fig. 2, the flow of the preliminary ironing method by the preliminary ironing system 1 according to the present embodiment will be described. Each process shown in Fig. 2 corresponds to each process executed by the preliminary process control device 20 shown in Fig. Therefore, the details of each process shown in Fig. 2 are omitted, and the outline of each process is explained.

In the hot wire preliminary processing method according to the present embodiment, first, the data acquisition unit 201 acquires the hot wire data and the exhaust gas data (step S101). Specifically, the data acquiring unit 201 acquires the charac- terized data 211, the parameters 212 and the target data 213 shown in Fig. 1, and the exhaust gas component analyzer 101 and the exhaust gas flow meter 102 The measured emission gas data is acquired.

Next, the carbon concentration estimating unit 202 estimates the carbon concentration in the molten iron after the denitration processing based on the obtained various data (step S103). Specifically, the carbon concentration estimating unit 202 estimates the carbon concentration in the molten iron after the denitrification process by substituting various data contained in the charcoal data and the exhaust gas data into the above equation (9). Further, in the estimation of the correction term? C _correct in the equation (9), various operational factors can be selected. For example, in order to further improve the carbon concentration in the molten iron after the denitrification treatment, it is preferable that a factor of operation reflecting the goods situation of the slag is selected in the estimation of? C _correct .

Next, the amount-of-correction calculating section 203 calculates the amount of oxygen taken in the converter 11 in the decarburization treatment, based on the comparison result of the carbon concentration in the molten iron after the estimated de-phosphorus treatment and the target carbon concentration in the molten iron after the de- (Step S105). Further, in addition to the correction of the amount of oxygen to be blown, it is preferable that the amount of cold material at the time of decarburization is adjusted so as to match the molten iron temperature with the target molten iron temperature after the denitration treatment. Further, the input / output unit 22 gives an instruction to the transfer finishing facility 10 to blow the oxygen based on the corrected oxygen amount and the amount of cold material and to insert the coolant. The converter assembly 10 performs processing relating to the transfer to the converter 11 and the insertion of the coolant in accordance with the instruction.

The processing procedure of the hot wire preliminary processing method according to the present embodiment has been described above with reference to Fig. In the embodiment described above, the amount of oxygen taken in the converter 11 and the amount of cold charged are all corrected on the basis of the carbon concentration in the molten iron after the estimated de-phosphorus treatment, but this embodiment is not limited to this example Do not. For example, in the molten iron preliminary processing method according to the present embodiment, only the amount of intake oxygen whose carbon concentration in the molten steel satisfies the target value may be modified. In this case, in step S105, based on the estimated carbon concentration in the molten iron after the de-phosphorus treatment, only the amount of oxygen taken in which the carbon concentration in the molten steel satisfies the target value may be calculated.

<4. Theorem>

As described above, according to the present embodiment, by using the corrected decarburization amount corrected by the correction value expressed by the regression formula using the operating factor at the time of the denitration processing as the explanatory variable as the decarburization amount obtained by using the exhaust gas data , The carbon concentration in the molten iron after the denitrification treatment is estimated. This makes it possible to estimate the carbon concentration in the molten iron after the denitrification process with high accuracy without performing the sub-lance measurement after the denitration process.

In the estimation of the correction value according to the present embodiment, a deceleration factor in the converter 11 is reflected in the above-mentioned correction term by using the operating factor reflecting the situation of the slag in the converter 11 as the operating factor . This makes it possible to estimate the carbon concentration in the molten iron after the dephosphorization treatment with higher accuracy.

Further, according to the present embodiment, the intake oxygen amount injected in the decarburization treatment is corrected using the estimation result of the carbon concentration. By performing the decarburization treatment based on the modified oxygen amount, it is possible to more reliably obtain molten steel that satisfies the target carbon concentration after the decarburization treatment. Further, it is possible to more reliably obtain molten steel satisfying the target molten steel temperature after the decarburization treatment by modifying the amount of cold material charged into the converter 11 according to the correction of the amount of oxygen to be blown.

The configuration shown in Fig. 1 is merely an example of the preliminary ironing processing system 1 according to the present embodiment, and the specific configuration of the preliminary ironing processing system 1 is not limited to this example. The charterer preliminary processing system 1 may be configured so as to be capable of realizing the above-described functions, and can take all the configurations that can be generally assumed.

For example, each of the functions of the preliminary ironing processing control device 20 may not be executed entirely in one device, or may be executed by cooperation of a plurality of devices. For example, one apparatus having only one or a plurality of functions of the data acquisition unit 201, the carbon concentration estimation unit 202, and the correction amount calculation unit 203 can communicate with another apparatus having other functions So that the same function as that of the illustrated wire preliminary process controlling apparatus 20 may be realized.

It is also possible to produce a computer program for realizing the respective functions of the preliminary ironing processing control apparatus 20 according to the present embodiment shown in Fig. 1, and mount the processing in a processing apparatus such as a PC. In addition, a computer-readable recording medium storing such a computer program can also be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. The computer program described above may be distributed via a network, for example, without using a recording medium.

Example

Next, an embodiment of the present invention will be described. In order to confirm the effect of the present invention, in this embodiment, the validity of the correction term obtained by the iron preliminary processing method according to the present embodiment, the estimation accuracy of the carbon concentration by the iron preliminary processing method according to the present embodiment, The application of the preliminary treatment method of molten iron to the actual operation was verified. The following examples are merely for the purpose of verifying the effects of the present invention, and the present invention is not limited to the following examples.

(Validity of correction term and estimation accuracy of carbon concentration)

First, the validity of the correction term? C _correct obtained by the hot _wire preliminary processing method according to the present embodiment and the estimation accuracy of the carbon concentration C _deP in the hot _wire after the _{de-phosphorus} processing by the hot _wire preliminary processing method according to the present embodiment were verified.

In the first embodiment, the off-gas data, by using the molten iron data and operating factors, the decarburized amount ΔC _offgas and the correction term based on the decarburized amount ΔC _correct to ΔC _c, the exhaust gas based on the component data change was calculated. The decarbonization amount? C _offgas based on the exhaust gas data is calculated using the above-described equations (2) and (3), and the correction term? C _correct is calculated using the above equation (8). In addition, the decarburization amount ΔC _c based on the change component, was calculated using the formula (4). Here, was that there is a relationship of the formula (7) between the decarburized amount ΔC _c, decarburized amount ΔC _offgas and the correction term ΔC _correct based on exhaust gas data based on composition changes.

On the other hand, in the comparative example, by using the off-gas data, and the molten iron data, the decarburized amount ΔC _offgas based on a decarburized amount ΔC _c and emission data based on the change component was calculated. Decarburized amount ΔC _c method of calculating based on the decarburized amount ΔC _offgas and the component changes based on exhaust gas data is the same as the embodiment. Here, the correction term ΔC _correct is not used, the decarburized amount ΔC between the _offgas based on a decarburized amount ΔC _c and emission data based on the change component has been that there is a relationship of formula (5).

In the examples and the comparative examples, the _actual value of the carbon concentration in the molten iron sampled from the converter after the _{denitrification} process is substituted into the C _deP in the equation (4) for the verification of the validity of the correcting term? C _correct . That is, in this embodiment, the decarbonization amount? Cc based on the component change is a value obtained based on the actual value.

Further, the example did not use the operation factor that reflects the good condition of the slag in the estimate of the correction term ΔC _correct as in Example 1 and subjected to an example of using the estimate of the anti-correcting the operation factor that reflects the good condition of the slag ΔC _correct Example 2. Table 2 shows a list of data and operating factors used for estimating the carbon concentration in the molten iron after the denitration treatment in Examples 1, 2 and Comparative Examples. Further, in this embodiment, a sound meter value is used as a factor of operation reflecting the situation of the slag goods.

As an index showing the validity of the correction term? C _correct , the decarbonization amount? C _offgas (corrected decarbonization amount obtained by adding the correction term? C _correct ) based on the exhaust gas data calculated in the first, second, calculating the error (estimation error) from the decarburized amount ΔC of _c based on the change, respectively, followed by the standard deviation σ of that estimation error. It can be said that the smaller the standard deviation? Is, the smaller the estimation error is, i.e., the more effective the correction term? C _correct is.

As an index showing the estimation precision of the carbon concentration, the carbon concentration C _deP estimated using the equation (9) in Examples 1 and 2 and the carbon concentration in the charcoal sampled from the converter after the _de- And the standard deviation? Of the estimation error was obtained. It can be said that the smaller the standard deviation?, The smaller the estimation error, that is, the higher the estimation accuracy.

The results are shown in Figs. Fig. 3 is a diagram showing an estimation error of the decarbonization amount? C _offgas based on the exhaust gas data in the comparative example. 4 is a _graph showing the relationship between the decarbonization amount [ _Delta] C _offgas + Correction term? C _correct . 5 is a _graph showing the relationship between the decarbonization amount [ _Delta] C _offgas + Correction term? C _correct . In each figure, the x-axis represents the amount of decarburization based on the actual value by analyzing the composition of the carbon concentration, and the y-axis represents the decarburization amount based on the exhaust gas data (including the correction term [Delta] C _correct ).

3 to 5, the standard deviation sigma of the estimation error in Comparative Example 1 was 0.80, while the standard deviation sigma of the estimation error in Example 1 was 0.51, and the estimation The standard deviation of the error was 0.40. From this result, it can be confirmed that the error of the decarburization amount with respect to the actual data is reduced by the correction by the correction term? C _correct . Further, it is more effective to include, in the correction term? C _correct , a factor of operation that reflects the status of the product of slag, in that the standard deviation? In Example 2 is smaller than the standard error? In Example 1 appear.

Next, the results of estimating the carbon concentration after the denitration treatment are shown in Figs. 6 and 7. Fig. 6 is a graph showing an estimation error of the carbon concentration C _deP in Example 1. FIG. 7 is a graph showing an estimation error of the carbon concentration C _{deP in} the second embodiment. In each figure, the x-axis represents the actual value obtained by analyzing the composition of the carbon concentration, and the y-axis represents the estimated value of the carbon concentration estimated using the iron preliminary treatment method according to the present embodiment.

6 and 7, the standard deviation sigma of the estimation error in the first embodiment is 0.15, and the standard deviation sigma of the estimation error in the second embodiment is 0.11. Since any standard deviation sigma shows a low level, the estimation accuracy of the carbon concentration C _deP is high. The estimation accuracy of the carbon concentration C _deP was calculated by using the operating factor reflecting the product status of the slag in that the standard deviation? In Example 2 was smaller than the standard error? In Example 1 It was confirmed that it can be increased further.

As described above, in this embodiment, it is found that the carbon concentration C _deP can be estimated with high accuracy by introducing the correction term? C _correct , as compared with the comparative example. In particular, as shown in Example 2, it was found that the estimation accuracy of the carbon concentration C _deP can be further improved by using the operating factor reflecting the product status of the slag for the estimation of the correction term? C _correct .

(Application to Operation)

Next, using the past performance data, it is verified whether or not the application of the preliminary ironing method according to the present embodiment to the operation is possible. Specifically, with respect to past operating performance data, the estimation result of the carbon concentration in the molten iron after the dehooking treatment obtained by the iron preliminary treatment method according to the embodiment, and the result of correction of the amount of oxygen taken in and the amount of cold water in the decarburization treatment Respectively.

Table 3 is a table showing application examples of the estimation result of the carbon concentration to the operation performance data and the correction result of the oxygen amount and the like. Table 3 shows the history of the planned value, the actual value and the estimated value or the corrected indication value for each of the carbon concentration, the molten iron temperature, the intake oxygen amount, and the cold storage amount in the charcoal. The predetermined value is a value previously estimated by the static control before the removal processing. The performance value is the value measured or set in the past operation. The estimated value and the corrected indication value are the estimated values of the carbon concentration obtained by the preliminary ironing method of the present embodiment, and the indicated values of the amount of oxygen absorbed and the amount of cold stored. Here, the indication value of the correction amount of the intake oxygen amount corresponds to _, for example, correction _corrected intake oxygen amount O _{2, corrected} based on the formula (10).

Referring to Table 3, when the carbon concentration in the molten iron at the end of the denitrification treatment is 4.0%, the carbon concentration in the molten steel is 0.5% at the time of measuring the sub-lance during the decarburization treatment, It is assumed that the carbon concentration (target carbon concentration) in the molten steel is 0.1%. According to this, the amount of oxygen is blown, by a static control before the dephosphorization process, the decarburization process is initiated when 7.0Nm ³ / ton, when the sub-lance measurement during decarburization treatment 25.0Nm /ton(7.0+18.0 ^3), the end of the decarburization treatment It is determined to be 30.0 Nm ^{3 /} ton (7.0 + 18.0 + 5.0). The value of the cold stock amount is 2.0 ton during degumming and 5.0 ton from the start of the decarburization treatment to the time of measuring the sub-lance.

However, the carbon concentration in the molten steel at the time of measuring the sub-lance of the actual operation was 0.10%. On the other hand, the molten iron temperature at the time of measuring the sub-lance remained at a predetermined value of 1600 占 폚. As a result, at the end of the decarburization treatment, the carbon concentration in the molten steel was 0.04% which is lower than the initial target carbon concentration. This is considered to be because the carbon concentration in the molten iron at the termination of the denitrification treatment was lower than the initially determined 4.0%.

On the other hand, according to the iron wire pretreatment method of the present embodiment, the carbon concentration in the molten iron at the end of the dephosphorization treatment is estimated to be 3.5%. Further, in accordance with this estimation result, the oxygen amount at the time of starting the decarburization treatment and at the time of measuring the sub-lance is modified from 18.0 to 13.0 Nm ³ / ton. Further, according to the result of estimation of the carbon concentration and the result of correction of the oxygen amount, the amount of cold water was modified to 2.5 tons. On the basis of this modification, the carbon concentration in the sub-lance measurement satisfies 0.5%, which is previously assumed, if the operation is performed, so that the carbon concentration in the molten steel at the end of the decarburization treatment is not lowered further, Is possible from the results shown in Table 3. &lt; tb &gt;&lt; TABLE &gt; In other words, by applying the iron preliminary treatment method according to the present embodiment to an actual operation, it becomes possible to more surely achieve the target carbon concentration in the molten steel.

While the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to these examples. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It is understood to belong to the technical scope.

1: Charter preparation system
10: Converter installation
11: Converter
12: Year
13:
20: Charter preliminary process control device
21: Charter preliminary processing database
22: Input / output unit
30: Measurement control device
101: Exhaust gas component analyzer
102: Exhaust gas flow meter
111: Sound meter
112: Acoustic microphone
201: Data acquisition unit
202: carbon concentration estimating unit
203: Fixed amount calculation unit

Claims (6)

In the iron wire preliminary processing using the converter,
A data acquiring step of acquiring exhaust gas data including charter data relating to charcoal before the denitrification process and an exhaust gas component and an exhaust gas flow rate discharged from the converter during the denitration process;
The amount of decarburization at the time of the untreating process calculated based on the exhaust gas data is corrected using the correction value calculated based on the operating factor at the time of the removal process, The carbon concentration estimation step for estimating the carbon concentration after the
And the preliminary treatment method. The method according to claim 1,
In the carbon concentration estimating step, the correction value is calculated by a regression formula using the operating factor as an explanatory variable. 3. The method according to claim 1 or 2,
The operating factor at the time of the dephosphorization treatment includes a factor of operation indicating the condition of the slag at the time of the dephosphorization treatment. The method of claim 3,
Wherein the operating factor indicating the availability of the slag includes operational factors relating to the acoustic information in the converter. 5. The method according to any one of claims 1 to 4,
The target carbon concentration after the removal process and the oxygen intake amount into the converter in the decarburization process performed after the removal process are further acquired in the data acquisition step,
Further comprising an oxygen amount correcting step of correcting the oxygen intake amount based on a result of comparison between the estimated carbon concentration after the de-phosphorus treatment and the target carbon concentration after the de-phosphorus treatment. A wire preliminary process control device for controlling a wire preliminary process using a converter,
A data acquiring section that acquires exhaust gas data including molten metal data relating to molten metal before the denitrification process and an exhaust gas component and an exhaust gas flow rate discharged from the converter during the denitration process;
The amount of decarburization at the time of the untreating process calculated based on the exhaust gas data is corrected using the correction value calculated based on the operating factor at the time of the removal process, The carbon concentration estimating unit for estimating the carbon concentration after the
The preliminary process control device.

Images