JP2000160213A - Method for managing stock of molten iron - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the calculating quantity for grasping a stock, to improve the accuracy for grasping the stock, to prevent the sudden blasting reduction caused by excess molten iron or the production loss caused by too little stock from happening and to reduce the time and the cost required for the stock management and the correction of operation based on the stock management. SOLUTION: In a tapped molten iron quantity grasping arithmetic part 12, necessary molten iron quantity grasping arithmetic part 14 and molten iron stocked quantity grasping arithmetic part 16, firstly, the tapped molten iron quantity, necessary molten iron quantity and present molten iron stocked quantity, are obtd. In these arithmetic parts, the calculation is executed with a simple and little calculating quantity. After executing such a calculation, in a molten iron stocked quantity estimating arithmetic part 20, the molten iron stocked quantity just after a prescribed term, is estimated. The estimation in the molten iron stocked quantity estimating arithmetic part 20 is executed in the simple calculation, such as addition and subtraction, and the calculating quantity is little.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing hot metal from a plurality of blast furnaces in a specific range when the hot metal is used in a plurality of steel plants in a specific range. In relation to the method of managing hot metal inventory to grasp the amount of hot metal, in particular, it not only reduces the amount of calculation in grasping the stock, but also improves the stock grasp accuracy, and suddenly reduces wind in the blast furnace due to excess hot metal, or The present invention relates to a hot metal inventory management method capable of preventing a production loss due to an understock, and reducing labor and cost required for the inventory management and the operation correction based on the inventory management. In addition, the above-mentioned specific range includes an integrated steel mill that uses hot metal from a plurality of blast furnaces in a plurality of steelmaking factories and casting iron factories.

[0002]

2. Description of the Related Art Hot metal that has a plurality of blast furnace groups and a plurality of steelmaking plants, and from which the hot metal is produced from the blast furnace groups in the plant, is the amount of hot metal in stock in an integrated steelworks used in the steelmaking plant in the plant. It is necessary to grasp correctly. When the stock runs out, the operation of the post-process below the steelmaking plant will be delayed. On the other hand, if the stock overflows, the worst case is to shut down the blast furnace.

[0003] With regard to the logistics and energy management method by a computer in a conventional integrated steelworks, for example, Japanese Patent Publication No. Sho 44-3158 and Japanese Patent Publication No. Sho 52-18416 are mentioned. These are operation management methods in which a predetermined operation pattern is input to a computer, and when an unexpected situation occurs, a necessary action is taken and a human makes a correction. However, the actual logistics of the integrated steelworks are constantly changing, and unforeseen situations often occur, requiring constant human correction.

[0004] On the other hand, from the viewpoint of "unified management of multiple processes" in an integrated steelworks, Japanese Patent Laid-Open No. 61-22711 is disclosed.
0. According to the present invention, the unit of calculation is divided into blocks having the following four functions in order to centrally manage the process from the blast furnace to the steelmaking plant.

A1. Calculation of the required amount of hot metal for each process: The required amount of hot metal in the steelmaking factory during a predetermined period T from a preset time Ti to Tj is calculated from the number of tapping charges, the hot metal ratio, and the topped inventory in the predetermined period T. I do.

A2. Prediction of hot metal output and hot metal components: Various blast furnace component data such as hot metal output during the predetermined period T, for example, past weighing results, variation in coke staying in the hearth and iron ore charging pitch, etc. In consideration of the above, the amount of hot metal from the blast furnace during the predetermined period T is predicted by the autoregressive model. Further, the tapping component and the temperature are also predicted from the furnace top gas component, the furnace body radiated heat, the past components, the actual temperature, and the like by the autoregressive model.

A3. Judgment of hot metal supply availability: Is it possible to supply hot metal, such as the required components and temperature, to each factory, taking into account target amounts and component values such as the required hot metal amount and hot metal hot metal amount obtained in A1 and A2 above? Predict whether or not. Only when it is determined that the supply is not possible, the out-of-furnace component adjustment in the blast furnace is performed. If it is still not possible, the supply to other factories or the inventory adjustment of the topeed is performed, and the optimum operation pattern is selected each time.

A4. Implementation of operation corresponding to time: A3
Before the time Ti, the tope is prepared under the inclined gutter using the optimum pattern determined by
At the same time, tapping starts and ends at time Tj.

On the other hand, a technique for similarly performing detailed scheduling in each step is disclosed in Japanese Patent Application Laid-Open No. 09-24990.
3 are mentioned. This is because the hot metal inventory, tapping, and tapping schedule from the blast furnace to the steelmaking factory are managed collectively, and the hot metal at the time of tapping the blast furnace and the order received are linked one-to-one, Temporal control of the intermediate process is implemented.

[0010]

Although such a detailed management method seems to be detailed and advantageous at first glance, it has the following disadvantages.

B1. Although it is possible to predict the required amount of hot metal in a steel mill within a given period, the variation in tapping speed, especially the difference between the start and end of tapping, is large. Even in consideration of the charging results, the predicted values and the actual values often deviate greatly. For this reason, it is difficult to make the hot metal consumption in the blast furnace and the steelmaking one-to-one coincide with each other in the unit of torpedo or the unit of the blowing charge.

B2. When the required amount of hot metal in steelmaking matches the predicted tapping schedule in the blast furnace, mutual information is advantageous in performing hot metal inventory management. However, in addition to the deviation of the tapping amount shown in B1, there is a factory having a plurality of component adjustment functions between the blast furnace and the steelmaking plant, so that there are variations in the composition of the hot metal and various "transportation" by the plant. In the actual operation, it is impossible to make the hot metal consumption between the blast furnace and the steel mill one-to-one in the actual operation due to the time lag.

B3. When the quantitative and temporal “shift” shown in B1 and B2 above occurs, the tapping is not performed until the tapping time (Ti) estimated from the use time of the hot metal in steelmaking,
It is meaningless to have a detailed operation management in which blowing and tapping are performed on a one-to-one basis, such as starting tapping for the first time at time Ti, but rather because blast furnace tapping is subject to time constraints. Loss increases and the turnover rate of the topped car decreases. When the rotation rate decreases, the thermal loss of the hot metal increases without recovery, and therefore, the operation is disadvantageous in total cost as compared with the method in which the time constraint of the blast furnace is not implemented.
Regarding the relationship between such a decrease in rotation rate and heat loss,
One example is described in JP-A-4-280908.

[0014] The operation between the blast furnace and the steelmaking plant is collectively managed as shown in the invention of JP-A-61-227110,
In addition, when each step from the blast furnace to the steelmaking operation is performed in a one-to-one manner, there is also a problem regarding the load of calculation.

In the calculation, since the amount of information to be handled is enormous, the required capacity of the process computer is large, and it is difficult to store and process information on other hot metal management, for example, information on hot metal components, on the same computer, or In some cases, it becomes impossible. For this reason, it is necessary to prepare a computer having a very large calculation capability or to separately prepare an independent computer for performing the hot metal inventory calculation. This not only increases the cost for inventory management, but also makes it impossible for the latter to take in other information necessary for schedule management online, thereby deteriorating the calculation efficiency.

[0016] Further, in the case where a one-to-one correspondence is made between steelmaking and a blast furnace as in the related art, there is a problem regarding the accuracy of calculation.

That is, in this calculation, not only the calculation load is large, but also the schedule is greatly shifted due to the fluctuation of the transport time between the factories, so that the stock calculation accuracy is deteriorated. Therefore, there have been problems such as sudden wind erosion due to excess hot metal inventory caused by a decrease in calculation accuracy or insufficient production due to insufficient hot metal inventory.

The present invention has been made to solve the above-mentioned conventional problems, and not only reduces the amount of calculation for grasping inventory, but also improves the accuracy of inventory grasp, and reduces the sudden occurrence of blast furnace due to excess hot metal. It is an object of the present invention to provide a hot metal inventory management method capable of preventing a production loss due to wind or understock, and reducing the labor and cost required for the inventory management and operation correction based on the inventory management. .

[0019]

SUMMARY OF THE INVENTION According to the present invention, when hot metal from a plurality of blast furnaces in a specific range is used in a plurality of steel mills in a specific range, the hot metal is stocked in the range of the blast furnace and the steel mill. In the hot metal inventory management method for grasping the amount of hot metal that is present, based on the current production situation, a step of grasping the hot metal quantity to be tapped from the blast furnace group in a predetermined period in the future, based on the production schedule Grasping the required amount of hot metal to be used in the steelmaking plant group during the predetermined period, and grasping the current amount of hot metal inventory in the specific range; and Estimating the amount of hot metal inventory for the predetermined period based on the current amount of hot metal inventory, so as to grasp the hot metal inventory in the specific range, thereby solving the above problem.

Further, in the above-described method for managing hot metal inventory, when tope is used when transporting hot metal from the blast furnace to the steelmaking plant, the amount of hot metal to be tapped is determined by the speed at which hot metal is supplied from the blast furnace to the tope. And the required amount of hot metal is determined according to the elapsed time of the supply, and the required amount of hot metal is determined according to the speed at which the hot metal is discharged from the topeed to the foundry and / or the steelmaking plant and the elapsed time of the discharge. By doing so, while the hot metal is being supplied from the blast furnace to the topied and loaded, or when the required amount is loaded, or while the hot metal is being discharged from the topied to the foundry and / or the steelmaking plant, Hot metal inventory at the time of completion can also be accurately grasped.

Hereinafter, the operation of the present invention will be briefly described.

According to the present invention, when hot metal from a plurality of blast furnaces in a specific range is used in a plurality of steel mills in a specific range, the amount of hot metal in stock in the blast furnace and the steel mills is determined. The premise is a hot metal inventory management method for grasping. As a specific range for grasping the stock amount in this way, for example, there is an integrated steel mill. Alternatively, it may include several blast furnaces, steel mills, and cast iron mills in a range where hot metal can be transported, including such an integrated steel mill.

Prior to computerization, conventionally, humans grasped hot metal inventory based on manual calculation and experience, and operated in an integrated steel mill. In the case where this is to be computerized, conventionally complicated calculations have been performed.
However, even when such a computer is used, the present invention has been made by noting that not only the calculation results by humans do not match, but also a problem due to inadequate inventory management occurs.

In the present invention, the basic concept of a simple calculation method and judgment by a human being is investigated, arranged, and adjusted, and this is utilized to summarize a hot metal inventory management method. The hot metal inventory management method of the present invention can be introduced into a calculation system, and a simplified and easy-to-use system can be constructed as compared with a conventional computerized system.

The present invention focuses on the fact that the hot metal inventory immediately after the predetermined period can be estimated based on the amount of hot metal, the required amount of hot metal, and the current amount of hot metal invented. We focus on the estimation method. Further, these amounts are determined as simply as possible.

That is, according to the present invention, the amount of hot metal discharged from the blast furnace group in a predetermined period in the future is determined based on the current production situation. Further, based on the production schedule, the required amount of hot metal used in the steelmaking factory group in the predetermined period is grasped. Further, the current hot metal inventory in the specific range is grasped. In this way, the tapping hot metal amount, the required hot metal amount, and the current hot metal stock amount are first obtained by a simple and small calculation method. After that, the hot metal stock amount in the predetermined period is estimated based on the hot metal hot tap amount, the required hot metal amount, and the current hot metal stock amount. Such estimation is a simple operation such as addition or subtraction.

As described above, according to the present invention, not only the amount of calculation for grasping the stock is reduced, but also the stock grasping accuracy is improved, and the blast furnace sudden wind reduction due to excessive hot metal or the production loss due to the insufficient stock is reduced. It is possible to reduce the trouble and cost required for the inventory management and the operation correction based on the inventory management, as well as to prevent the problem beforehand.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

First, FIG. 1 is a block diagram showing a configuration of a calculation unit which realizes a hot metal inventory management method according to an embodiment to which the present invention is applied.

In this figure, the present embodiment comprises a tapping hot metal amount grasping operation unit 12, a required hot metal amount grasping operation unit 14, a hot metal stock amount grasping operation unit 16, and a hot metal stock amount estimation calculating unit 20.
And is realized by. These are realized by a program of a process control computer.

The tapping hot metal amount grasping calculation unit 12 grasps the hot metal tapping from the blast furnace group in a predetermined period in the future based on the current production situation. The predetermined period is a unit of a period when the method of managing hot metal inventory according to the present invention is performed, and is hereinafter simply referred to as a predetermined period. Further, the required hot metal amount grasping calculation unit 14 grasps a required hot metal amount used in the steelmaking factory group in the predetermined period based on the production schedule. Next, the hot metal inventory amount calculation unit 16 further obtains the current hot metal inventory amount in the specific range. in this way,
In the tapping hot metal amount grasping calculation unit 12, the required hot metal amount grasping calculation unit 14, and the hot metal stock amount grasping calculation unit 16, first, the tapping hot metal amount, the required hot metal amount, And the current hot metal inventory. These amounts of hot metal are in the hot metal inventory management method to which the present invention is applied, and are hereinafter referred to by their names.

Thereafter, the hot metal inventory estimation unit 20 estimates the hot metal inventory immediately after the predetermined period on the basis of the hot metal tapping amount, the required hot metal amount, and the current hot metal inventory amount. . The stock amount is hereinafter referred to as an estimated hot metal stock amount. The estimation in the hot metal inventory estimation operation unit 20 is a simple operation such as addition or subtraction, and the amount of calculation is small.

The calculation in the present embodiment will be described below.

In this embodiment, the calculation of the hot metal inventory is simplified to reduce the calculation load. The simplification of the calculation of the hot metal inventory is specifically as follows.

C1. Simplification of hot metal supply in the blast furnace: For the prediction of tapping from the blast furnace, simulation calculations as in the past were not performed, and the past iron ore charging results and past tapping speed results were not calculated. 2 Estimate based on information.
As these performance data, performance data within the past 24 hours is preferably used. Further, the tapping amount at each time is estimated by providing a constant value during the normal operation in which the blowing amount is not changed and providing several patterns for the decreasing and increasing wind operations.

C2. Simple calculation of hot metal use speed in steelmaking:
The amount of hot metal used in steelmaking is calculated from the amount of hot metal used per operating unit and the hot metal charging interval based on the operation schedule for a predetermined period from now. This predetermined period is preferably 24 hours. In order to reduce the calculation load, a hot metal charging pitch (charging to charging interval) is not calculated online, but a reference table for each steel type is created based on past data and used. The hot metal charging pitch is an interval between charging of hot metal and charging of the next hot metal.

C3. Independence and simplified calculation of schedule management between blast furnace and steelmaking: When grasping hot metal inventory using the information of C1 and C2, the time of blast furnace tapping and the time of use in steelmaking, which have been conventionally implemented, are set to 1 The so-called “tied” operation, which is performed on a one-to-one basis, is not performed in the present embodiment. The tied operation is an operation in which at the start of tapping, the torpedo decides on which charge and when to use it in a steelmaking plant. In the present embodiment, the future hot metal stock amount after a predetermined period, that is, the estimated hot metal stock amount is estimated by a simple calculation such as the following equation (1). As described above, in the present embodiment, the “tied” operation of the steelmaking use time and tapping use time for each torpedo is eliminated in consideration of only the balance between supply and demand after a predetermined period.

Estimated hot metal inventory = current hot metal inventory + hot metal output-required hot metal quantity (1)

Next, in the present embodiment, the correction of the hot metal stock is performed during the receiving of iron from the topeed and the dispensing from the toeded as described below to improve the calculation accuracy.

When grasping the hot metal inventory, if the hot metal is conventionally supplied into the tope or discharged into another container, the process is completely completed (when the tope is full,
Until it becomes empty), the inventory does not fluctuate, and the fluctuation at the time of completion of receiving iron and at the time of discharging is large, which hinders the management of the inventory amount to an appropriate value. For example, when hot metal is supplied from a plurality of blast furnaces to a plurality of torpedo cars (200 to 400 t / unit), when the supply of the hot metal ends at the same time, the stock increases by 400 to 800 t at a stretch, and the actual stock fluctuations It is feared that a wrong judgment may be made in adjusting the hot metal inventory. In order to avoid such inventory fluctuations, the present embodiment has devised the following method.

D1. Regarding the topido during pig iron receiving, when the elapsed time from the start of pig iron receiving to the topied is x,
A fictitious inventory amount is predicted from the start of the pig iron to the completion of the pig iron by the following equation (2), and the inventory amount until the completion of the pig iron is managed as a continuous value.

[0042] Inventory amount of topido during receiving iron (t / unit) = tapping speed (t / h) x x (min) / 60) (2)

D2. In the process of discharging hot metal from a torpedo to another container (for example, the process of discharging to a pig iron machine in a foundry, or the process of directly discharging to a hot metal charging pot or a smelting furnace in a steelmaking plant), Similarly, when the elapsed time from the discharge of hot metal to x is x, the discharge amount is continuously corrected and reflected in the hot metal inventory.

Required amount of hot metal from discharging topido (t / unit) = discharging speed (t / h) × x (min) ÷ 60) (3)

Here, FIG. 2 is a graph showing the supply of hot metal to the tope and the discharge from the tope to another container.

In this graph, the time Ts is the start time of the supply of hot metal from the blast furnace to the tope or the start time of the discharge from the tope to another container. The time Te is
This is the end time of the supply of hot metal to the tope or the end time of discharge from the tope to another container. In addition, hot metal amount Wt
Is the loading capacity at the time when the supply from the blast furnace to the topeed is completed, or the loading capacity immediately before discharging from the topedo to another container.

Conventionally, at the time Te, the hot metal amount Wt is simply grasped at one time as being loaded on the tope. Alternatively, simply at time Te, the hot metal amount Wt was grasped as being discharged to another container at one time in a lump. On the other hand, in the present embodiment, the hot metal tapping amount W supplied from the blast furnace to the topido is determined by the speed at which the hot metal is supplied from the blast furnace to the topido and the elapsed time of the supply, as indicated by a dashed line in this graph. Ask. At the same time, the amount of hot metal remaining when the hot metal is discharged from the topied to another container is determined in accordance with the speed at which the hot metal is discharged from the topied to the different container and the elapsed time of the discharging.

When the amount of hot metal remaining when discharged from the topido into another container is taken as a stock amount, it is represented as a two-dot chain line in FIG.

As described above, the amount of hot metal to be supplied from the blast furnace to the topedo is determined in accordance with the speed at which the hot metal is supplied from the blast furnace to the topedo and the elapsed time of the supply, or the hot metal is discharged from the torpedo to another container. When determining the required amount of hot metal to be performed in accordance with the speed at which the hot metal is discharged from the torpedo to the separate container, and the elapsed time of the discharge, the amount of hot metal and the required amount of hot metal are carefully measured in accordance with the elapsed time. It is not necessary to continuously determine. Such a thing is also included in the present invention.

That is, from the time Ts to the time Te, the tapping hot metal amount and the remaining hot metal amount may be obtained at appropriate time intervals. Alternatively, from the time Ts to the time Te, the tapping hot metal amount and the remaining hot metal amount may be obtained at intervals of about 2 to 4 divisions. By doing so, the frequency of obtaining these can be reduced, so that the amount of calculation and the amount of calculation can be reduced as compared with the case of obtaining them closely and continuously. Also in this case, the amount of hot metal stock can be grasped with higher accuracy than in the past.

As described above, the present invention is implemented using a computer, for example, but a preferred configuration of an operation screen for facilitating the processing will be described.

The operation screen is composed of a screen for displaying a predicted value of the hot metal inventory in the future (here, called an actual operation screen) and a screen for inputting operation data and the like (here, called an input screen). preferable.

In the above-mentioned actual operation screen, by displaying the predicted value from the present time to 24 hours later in the center of the screen, the predicted future stock value can be quickly and online grasped. If the predicted inventory value exceeds a certain management range, a warning bell is automatically notified to that effect, adjustment of tapping amount, adjustment of steelmaking operation,
Alternatively, the molten iron inventory is corrected to be within an appropriate range by adjusting the casting iron operation.

The above-described data input screen is used for predicting hot metal inventory. On this screen, information such as tapping speed, future casting iron schedule, hot metal supply stop time, etc. is input and automatically calculated. The result of the automatic calculation is reflected in the inventory calculation on the actual operation screen described above. The steelmaking schedule and the amount of hot metal to be used for each operation unit are automatically calculated, and can be grasped on a steelmaking schedule screen different from these two screens.

The effect of the present embodiment will be described.

FIG. 3 is a graph showing the transition of the actual hot metal inventory of the present embodiment (that is, the case where the hot metal inventory management is performed by an operator's manual calculation), and FIG. 4 is the present embodiment. or,
FIG. 5 is a graph showing, as a comparative example, the transition of the actual hot metal inventory when the above-described so-called tying management is performed. According to the comparative example, the one-to-one relationship breaks down due to the temporal and quantitative deviations at the steelmaking plant. Nevertheless, if one-on-one operation is continued, hot metal inventory fluctuations will increase and the actual calculation function will be lost.

In the present embodiment, fluctuations in the hot metal inventory at the time of tapping the blast furnace and discharging the hot metal to another container are continuously processed. In FIGS. 3 to 5, the horizontal axis represents time, which is expressed from 0:00 to 23:00 in one day. The vertical axis indicates the hot metal inventory.

As is clear from comparison of these graphs,
By applying the present invention, the hot metal inventory fluctuation is reduced from 700 t to 350 t per hour at the maximum, and a more true hot metal inventory management can be performed in real time.

FIG. 6 is a graph showing the distribution of the difference between the estimated stock amount obtained by manual calculation and the actual stock amount according to the present embodiment.

In this embodiment, processing is performed by a computer. Further, in this graph, the estimation is made eight hours later, that is, the above-mentioned predetermined period is eight hours. From this figure, the difference between the case where the detailed hand calculation is performed and the case where the computer calculation according to the present invention is performed is only 40 t.
This indicates that the hot metal inventory can be accurately predicted in the present embodiment. As a result,
It has become possible to reduce the number of personnel who have been performing inventory calculations in the office by one person. In addition, by automatically performing and displaying inventory forecasts up to 24 hours later by automatic calculation, it has become possible to reduce sudden wind reduction due to excess hot metal inventory from 4 times / year to 0 times / year.

As described above, by applying the present invention, not only the calculation load on the computer can be remarkably reduced, but also the operation from the blast furnace to the steel making can be reduced in time and quantity by one.
The calculation accuracy is improved as compared with the calculation result of one-to-one correspondence, and it is possible to prevent a sudden blast furnace wind reduction due to excess hot metal or a production loss due to an insufficient inventory. Furthermore, in the past, one dedicated operator was required in order to improve the accuracy, but with the improvement and simplification of the calculation accuracy, it becomes possible to perform unmanned hot metal inventory management.

[0062]

According to the present invention, not only the amount of calculation for grasping inventory is reduced, but also the accuracy of grasping inventory is improved.
It is possible to prevent a sudden blast furnace wind reduction due to excess hot metal or a production loss due to an insufficient inventory, and to reduce the labor and cost required for the inventory management and the modification of the operation based on the inventory management.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a calculation unit that implements a hot metal inventory management method according to an embodiment of the present invention;

FIG. 2 is a graph showing the supply of hot metal to a topid and the discharge from the topid to another container.

FIG. 3 is a graph showing the transition of actual hot metal inventory by a conventional hot metal inventory management method.

FIG. 4 is a graph showing the transition of actual hot metal inventory by the hot metal inventory management method of the embodiment.

FIG. 5 is a graph showing the transition of actual hot metal inventory by the hot metal inventory management method of the comparative example.

FIG. 6 is a graph showing a distribution of a difference between the estimated stock amount and the actual stock amount by the embodiment and the manual calculation.

[Explanation of symbols]

 Reference numeral 12: Hot metal content grasping calculation part 14: Required hot metal quantity calculation part 16 ... Hot metal stock quantity calculation part 20: Hot metal stock quantity estimation calculation part

Continued on the front page F term (reference) 4K012 BB00 4K014 AD01 AE00 5B049 AA06 BB07 CC27 CC31 EE01 EE12 FF03 FF04 5H215 AA04 AA06 BB01 BB20 CC09 CX01 GG01 JJ14 9A001 JJ49 JJ52 KK54 LL09

Claims (2)

[Claims] 1. When hot metal from a plurality of blast furnaces in a specific range is used in a plurality of steel mills in a specific range, the amount of hot metal in stock in the range of the blast furnace and the steel factory is grasped. In the hot metal inventory management method for the present invention, based on the current production situation, grasp the amount of hot metal tapping from the blast furnace group in a predetermined period in the future, based on the production schedule, the steelmaking in the predetermined period The step of grasping the required amount of hot metal used in the factory group, and the step of grasping the current amount of hot metal inventory in the specific range, based on the tapping hot metal amount and the required hot metal amount and the current hot metal inventory amount, Estimating the amount of hot metal inventories for the predetermined period, wherein the hot metal inventory in the specific range is grasped. 2. The hot metal inventory management method according to claim 1, wherein when the hot metal is transported from the blast furnace to the steelmaking plant, the hot metal is transferred from the blast furnace to the torpedo. And the required amount of hot metal is determined according to the speed of discharging hot metal from the topied to the foundry and / or the steelmaking plant, and the elapsed time of the discharge. A method for managing hot metal inventory, characterized in that it is determined by: