JP6520255B2 - Operation method of converter - Google Patents

Description

  The present invention relates to an operation method of a converter for performing smelting treatment such as removal of P, removal of C and the like of hot metal, and to an operation method of a converter for discharging slag by using two waste ladles.

  Hot metal produced in blast furnaces contains C, P, S, etc. as main impurities. Therefore, at the same time as removing C by blowing oxygen into hot metal in a converter, a CaO source such as quicklime is added and a converter hot metal pretreatment process is performed to remove impurities such as P as slag.

  For converter hot metal pre-treatment, converter hot metal pre-treatment of single charge type of hot metal in which molten metal is charged once into the converter and dephosphorization (de-P) and de-carbonization (de-C) processing are continuously performed. Method, for example, a method called MURC (Multi-Refining Converter) method, and after removing P, the hot metal is once taken out of the converter, and when removing C, the hot metal is charged again into the converter twice. There is a type of converter hot metal pretreatment, for example, a method called LD-ORP (LD converter-Optimized Refining Process) method.

  In the converter hot metal pre-treatment, the slag is discharged to a waste pan introduced under the converter. In recent years, in order to meet the demand for the quality of steel materials and to improve production efficiency, in the same converter, the treatment is interrupted once after de-Ping, and an intermediate discharge step (a step of discharging slag out of the furnace) is performed. After that, the refining method (that is, the above-mentioned MURC method) in which the de-C treatment is continuously performed is actively adopted.

  Heretofore, as shown in Patent Document 1, in the operation of the converter, one waste ladle is carried into the furnace with respect to one converter and the waste treatment is performed. In this case, in consideration of the capacity of the waste ladle and the amount of slag discharged, replacement of the waste ladle has been performed, for example, at the stage where the discharge treatment has been performed about twice. Moreover, as a technique which performs the drainage processing using a drainage pan stably and efficiently, the technology of use of a sedation material like patent document 2 and the enlargement of a drainage pan, for example has been devised.

JP 2000-328127 A JP, 2009-287050, A

However, in the case of the converter hot metal pretreatment method (MURC method) of the single charge type of molten iron, the interval of the waste is short, and in the waste processing method as shown in Patent Document 1, the replacement of the waste pan is too late Processing delays may occur.
Further, the use of a sedative agent as shown in Patent Document 2 and the enlargement of a waste pan require a large investment, and there is a concern that the efficiency is low and the productivity is lowered.

  In view of the above circumstances, it is an object of the present invention to make the waste treatment in the converter hot metal pretreatment more efficient than before, and to realize the improvement of productivity without increasing the cost. To provide.

In order to achieve the above object, according to the present invention, there is provided a method of operating a converter for dephosphorizing treatment, decarburizing treatment and exhaust treatment for hot metal in the same converter, wherein the waste treatment is The decarburization slag generated in the decarburizing treatment is accommodated in a first decanter pot, and the decarburization slags produced in the decarburizing treatment are carried out using two deductor pots integrally connected and movable on the same rail. Loading and unloading process for storing dephosphorization slag generated in phosphorus treatment in the second waste pan and carrying out the two waste pans outside the converter and carrying in two new waste pans A method of operating a converter is provided, which is performed in the time required for the decarburizing treatment and tapping of molten steel .

  In the method of operating the converter, the hot metal is subjected to dephosphorization treatment, discharge treatment of the dephosphorization slag, decarburization treatment, discharge treatment of the decarburized slag in order to the molten metal, and the discharge treatment of the decarburized slag is performed as described above The first waste pan may be disposed below the converter, and the dephosphorization slag may be disposed by placing the second waste pan below the converter.

  In the method of operating the converter, the method has a carrying-in / out process for carrying out the two waste ladles out of the converter and carrying in two new waste ladles and removing phosphorus and dephosphorizing slag. When the series of processes is repeated multiple times with the series of processes including waste disposal, decarburization, and decarburization of decarburized slag, at least one of the two waste ladles is fully loaded and unloaded. It may be carried out at the stage when the amount stage or both of the two discharge pans become full.

  The capacity of one waste ladle may be set to a capacity that can accommodate at least twice the slag generated in one decarburization treatment or the dephosphorization treatment.

  According to the present invention, it is possible to make the waste treatment in the converter hot metal pretreatment more efficient than in the conventional case, and to realize the improvement of productivity without increasing the cost.

It is a schematic sectional drawing of a converter. It is explanatory drawing about converter hot metal pre-processing which performs de-P process, an intermediate | middle discharge process, and de-C treatment continuously in the same converter. It is a schematic explanatory drawing about the conventional displacement process. It is explanatory drawing which shows an example of the conventional operation schedule at the time of operating a converter using MURC method. It is a schematic explanatory drawing about the operation method of the converter which concerns on this Embodiment. It is a schematic explanatory drawing about the displacement process which concerns on this Embodiment. It is explanatory drawing which shows the operation schedule in case four converter hot metal pre-processings from 1st MURC to 4th MURC are implemented continuously.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, components having substantially the same functional configuration will be assigned the same reference numerals and redundant description will be omitted.

  First, the configuration of the converter used when applying the method of operating the converter according to the embodiment of the present invention will be briefly described. FIG. 1 is a schematic cross-sectional view of a converter 2. As shown in FIG. 1, the converter 2 has a structure in which a refractory lining 4 made of refractory brick or the like is attached to the inner surface of a steel converter container 3. Further, the upper end of the converter 2 is an opening 5 through which the molten metal, scraps, auxiliary materials and the like are put into the converter 2, and the slag 5 from the inside of the converter 2 through the opening 5 Are discharged. In the side surface of the converter 2, a steel extraction hole 6 located below the opening 5 is formed. The molten metal (molten metal or refined molten steel) is discharged from the inside of the converter 2 through the steel outlet holes 6.

  Next, converter hot metal pre-treatment in the method of operating a converter according to the present embodiment will be described with reference to the drawings. FIG. 2 is an explanatory view of a refining method (that is, MURC method) in which de-P treatment, intermediate displacement step and de-C treatment are continuously performed in the same converter, and in FIG. 2 (a) to (f) The steps are described in order. In addition, in FIG. 2, the refractory lining 4 stuck on the inner surface of the converter 2 is abbreviate | omitted, and it illustrates and demonstrates for convenience of explanation. Moreover, the application range of this invention is not limited to what is called MURC method, For example, it is applicable also to converter hot metal pre-treatments, such as LD-ORP method.

First, as shown in FIG. 2A, the scrap 9 and the hot metal 10 are inserted into the converter 2. Then, as shown in FIG. 2 (b), the acid feeding mechanism 12 feeds the acid into the converter 2. Moreover, although not shown in figure, injection | pouring of an auxiliary raw material is performed in the converter 2 immediately after the start of acid supply. De-P-slag 15a (hereinafter, also simply referred to as slag 15a) is generated in the upper layer of the hot metal 10 stored in the bottom of the converter 2 by the feeding of the acid and the auxiliary material. That is, in the step shown in FIG. 2 (b), de-P treatment is carried out by oxidizing and removing Si (silicon) and P (phosphorus) contained in the hot metal 10, and accompanying this, the generated oxide and CaO etc. Slag 15a is produced. The auxiliary materials to be added in this de-P treatment are, for example, quick lime as a CaO source and ingot cake as an Al ₂ O ₃ source. In addition, the basicity (CaO / SiO ₂ ) of the slag at the time of this de-P treatment is about 1.1. Here, although it is supposed that the ingot cake as an Al ₂ O ₃ source is introduced immediately after the start of the acid feeding, it may be introduced during the de-P treatment. In de-P treatment, iron ore may be added for temperature control.

  Next, as shown in FIG. 2 (c), after finishing the de-P treatment, that is, after interrupting the acid feeding, the converter 2 is inclined in a state where the steel delivery hole 6 is up to make the slag 5a An intermediate discharge process is performed to discharge part of the converter 2. The reason that the amount of slag discharged in this intermediate waste process is a part of the amount of slag generated in the de-P treatment is that a part of the slag 15a generated in the de-p treatment prevents discharge of molten iron in the furnace It is because it remains inside. In addition, it is preferable that the amount of slag discharged | emitted here is about 50% of the amount of slag produced | generated in the said P removal process.

Then, after completion of the intermediate displacement process, as shown in FIG. 2 (d), the acid feeding mechanism 12 starts the feeding of the acid again into the converter 2. Moreover, although not shown in figure, injection | pouring of an auxiliary raw material is performed in the converter 2 immediately after the start of acid supply. C (carbon) inside the hot metal 10 is oxidized by the feeding of the acid and the auxiliary materials, and a de-C slag 15 b (hereinafter, also simply described as the slag 15 b) made of an oxide, CaO or the like is generated. This process is a de-C treatment. The auxiliary materials introduced in this de-C treatment are, for example, quick lime as a CaO source and dolomite as a MgO source for protecting the refractory (refractory lining 4 shown in FIG. 1). Note that this de-C treatment is performed in a state where a part of the slag 15a generated in the above-described de-P treatment in the converter 2 also remains. That is, the slag 15b also contains the above-mentioned slag 15a. In addition, the basicity (CaO / SiO ₂ ) of the slag at the time of this de-C treatment is about 3.5.

  Next, after completion of the decarburization treatment, as shown in FIG. 2 (e), the converter 2 is inclined in a state where the steel delivery hole 6 is down, and the molten steel 10 '(refined hot metal 10) from the steel delivery hole 6 So-called tapping is performed. And as shown in FIG.2 (f), the slag 15b which remains in the converter 2 after taking out molten steel 10 'is an opening part by inclining the converter 2 in the state which made the steel-making hole 6 up. It is discharged from 5. This is referred to as a complete discharge process because the contents of the converter 2 are completely discharged.

  The converter hot metal pre-treatment in the method of operating the converter according to the present embodiment has been described above with reference to FIG. 2, but in this method, the intermediate discharge process shown in FIG. The complete displacement step shown in 2 (f) is carried out as a slag displacement step (discharge treatment). In these waste processes, rails (rails) are installed under the converter 2, and a pot for slag recovery called a waste pan is moved along the rails to arrange the waste pan under the converter 2. Be done.

  In the operation method of the conventional converter, one waste ladle was carried into the furnace with respect to one converter, and the said waste process was implemented. FIG. 3 is a schematic explanatory view of a conventional displacement process. In addition, FIG. 3 shows the mode at the time of implementation of the said complete displacement process.

  As shown in FIG. 3, a track 20 is installed below the converter 2, and a discharge pan 30 is provided along the track 20 so as to be movable. The discharge pan 30 includes a pan portion 30a having an opening at the upper portion, and a pedestal portion 30b supporting the pan portion 30a and having a configuration (for example, a wheel or the like) movable on the rail 20. Here, the capacity of the waste ladle 30 is such that the slag discharged in the intermediate discharging process or the complete discharging process can accommodate twice the amount of slag discharged in each discharging process. It has become.

  In the conventional converter operation method, when the converter hot metal pre-treatment is repeatedly performed by the MURC method, slag discharged in the intermediate discharge process (also referred to as slag by de-P treatment, de-P slag 15 a) The slag discharged in the complete drainage process (slag from de-C treatment, also referred to as de-carbonized slag 15b) is recovered in one reject pan 30 and the recovered drainage pan 30 is removed from the track 20 In the next intermediate discharge process, a new discharge pan was carried in to carry out the discharge process. Here, since only one route 20 is provided for one converter and the loading and unloading of the waste ladle takes a predetermined time, the waste disposal process in the MURC method that is repeatedly performed is waste It may have been done waiting for the loading and unloading of the pan 30.

  FIG. 4 is an explanatory drawing showing an example of a conventional operation schedule when the converter is operated using the MURC method. In addition, what is described as "MURC" in FIG. 4 shows the de-P treatment and de-C treatment using the MURC method, and what is described as "de-P removal" is an intermediate discharge process of the de-P slag. The one described as "de-C-exhaust" indicates the complete de-excitation process of the de-C slag. Further, the horizontal direction in FIG. 4 indicates the length of time (elapsed time), and the operation time progresses in the right direction in the drawing. The converter hot metal pre-treatment by the MURC method in actual operation is repeated several times, but here, the case where the converter hot metal pre-treatment by the MURC method is carried out twice in a row, the first MURC and the second MURC is illustrated There is.

As shown in FIG. 4, in the MURC method, an intermediate displacement step (de-P-elimination) and a complete displacement step (de-C-elimination) are performed at predetermined intervals, and converter converter hot metal spare by MURC method is continuously carried out. When performing processing, one set of drainage pans 30 is used through each pretreatment. Here, in the processing by each MURC method, the de-P treatment is completed when the predetermined time t1 has elapsed after the start, and the intermediate displacement step is performed after the intermediate displacement step, and the de-C treatment is terminated when the predetermined time t2 elapses after the intermediate displacement step Complete elimination process is performed. Since the capacity of the waste pan 30 is two times of the slag discharge amount discharged in the discharge step (intermediate displacement step, complete displacement step), it is empty at the start of the intermediate displacement step in the first MURC The waste ladle 30 carried under the converter in the state of (1) becomes full with the slag discharged by the intermediate displacement process and the complete displacement process in the first MURC.
Therefore, after the completion of the first MURC complete displacement process, the full capacity discharge pan 30 is carried out of the furnace, and the empty new exhaust pan 30 is subjected to the intermediate displacement process and complete displacement in the second MURC. It is carried into the furnace for the process. And in 2nd MURC, the slag in a middle displacement process and a complete displacement process will be discharged by the said new discharge pan 30 similarly to 1st MURC.

  Here, in the converter hot metal pretreatment by the MURC method, it is known that the de-C treatment requires more time than the de-P treatment. One cycle of converter hot metal pretreatment by the MURC method is, for example, about 35 minutes, and the required time t1 from the start to the end of the intermediate displacement step (that is, the de-P treatment) is about 10 minutes, after the intermediate displacement step It takes about 25 minutes to complete the complete displacement (ie, de-C treatment). That is, when the converter hot metal pre-treatment by the MURC method is continuously performed using the same converter 2 with the operation schedule as shown in FIG. 4, the second MURC after the completion of the complete displacement process in the first MURC It takes only a short time (for example, about 10 minutes) to start the intermediate displacement process at the end of the 1st MURC, and the exhaust pan 30 full at the 1st MURC is taken out of the furnace and emptied again. It will be shorter than the time required to carry it into the furnace. As a result, after the end of the first MURC, the second MURC can not be started immediately, and it is necessary to wait for the discharge pan 30 to be carried into the furnace to perform the intermediate MUCU process of the second MURC. Therefore, in MURC method which should realize carrying out de-P treatment and de-deposition treatment continuously in the same converter 2 in order to improve production efficiency, non-operation for waiting for loading and unloading of the discharge pan 30 It takes time to prevent the improvement of productivity.

  Further, the waste pan 30 accommodates both the de-P-slag 15 a discharged in the middle-displacement step and the de-C slag 15 b discharged in the complete-displacement step. As described above, the de-P-slag 15a is obtained by oxidizing Si (silicon) and P (phosphorus) in the hot metal, and the de-C slag 15 b is obtained by oxidizing C (carbon) in the hot metal. That is, in the waste ladle 30, two types of slag (de-P-slag 15a and de-C-slag 15b) having different components are mixed and contained, which is not preferable in consideration of the reuse of the slag and the like.

  As described above, in view of the findings described with reference to FIGS. 3 and 4, the present inventors diligently studied the configuration of the drainage pan used in the intermediate displacement process and the complete displacement process, and By using the existing equipment, we developed a converter operation method that improves the production efficiency more than before without increasing the equipment cost. Hereinafter, the operation method of the converter according to the embodiment of the present invention will be described with reference to the drawings.

  FIG. 5 is a schematic explanatory view of the operation method of the converter according to the present embodiment. In the following description, components having the same functional configuration as that of the above-described conventional configuration (see FIG. 3) will be denoted by the same reference symbols as those of the components shown in FIG. is there.

  As shown in FIG. 5, the point that the waste pan is movable along the track 20 is the same as the conventional one, but the configuration of the waste pan is different from the conventional one, and the first waste pan 40 and the second waste ladle 50 are connected in series by the connecting portion 55, and are integrally movable on the path of the rail 20 integrally. Each waste pan 40, 50 has a pan portion 40a, 50a having an opening at the top, a pedestal portion 40b supporting the pan portion 40a, 50a and having a configuration (for example, a wheel etc.) movable on the rail 20, It consists of 50b. That is, when the discharge pan is carried in and out of the converter 2, the two discharge pans (the first discharge pan 40 and the second discharge pan 50) are integrally carried in and out. ing.

  Next, the displacement process implemented in the structure shown in FIG. 5 is demonstrated with reference to FIG.6 (a)-(f). Here, the case where the converter hot metal pretreatment by the MURC method is performed twice continuously (ie, the first MURC, the second MURC) is illustrated and described, and (a) to (d) are the first MURC, (e), (e), (F) shows the second MURC. Moreover, when slag (de-P-slag 15a or de-C-slag 15b) is contained in each waste pan 40, 50, the situation is also illustrated for the purpose of illustration.

  First, as shown in FIG. 6A, after the end of the de-P treatment in the first MURC, the de-P slag 15a is discharged to the second discharge pan 50 in the intermediate displacement step. Then, as shown in FIG. 6 (b), during the de-C treatment in the first MURC, the two connected drainage pans 40, 50 move the path on the track 20 in the predetermined direction (right direction in the drawing) And the first discharge pan 40 is located below the converter 2. Subsequently, as shown in FIG. 6C, after completion of the decarburization process, the processed molten steel 10 ′ is tapped from the inside of the converter 2 through the tapping hole 6 to a ladle (not shown). Then, as shown in FIG. 6 (d), after steel removal, the de-C slag 15 b remaining in the converter 2 is discharged to the first discharge pan 40. As mentioned above, the process shown to Fig.6 (a)-(d) is a converter hot metal preparatory process in 1st MURC. Incidentally, by the end of the first MURC, the de-P-slag 15a is discharged once for the second waste pan 50, and the de-C-slag 15b is discharged for one pass into the first waste pan 40, but As described above, since the discharge pans 40 and 50 have a capacity capable of containing twice the amount of slag discharged in each discharge step, both of the first discharge pan 40 and the second discharge pan 50 are full. For example, about 1/2 of the capacity is accommodated in the slag.

Subsequently, as shown in FIG. 6 (e), the two connected waste ladles 40 and 50 move the path on the rail 20 in a predetermined direction (left direction in the figure), and Arrangement is made such that the two discharge pans 50 are located. Then, the de-P treatment in the second MURC is performed, and the de-P slag 15a after the de-P treatment is discharged to the second waste pan 50 in the intermediate displacement step. Although not shown in the figure, after the intermediate displacement step, de-carbonizing treatment and tapping of molten steel in the second MURC are performed, and the time required for de-carbonizing treatment and tapping of molten steel (required time t2) is, for example, about 25 minutes Therefore, it is sufficient time to carry out the waste ladle 40, 50 out of the furnace, carry out slag treatment, and return it to the furnace. The waste ladle 40, 50 in the state in which the slag discharged by FIG.6 (e) in this time t2 is accommodated is carried out out of a furnace, and slag treatment is performed.
On the other hand, as shown in FIG. 6 (f), at the start of the complete displacement process in the second MURC, empty new exhaust pans 40 and 50 are carried into the furnace, and recovery of slag is carried out in each subsequent exhaust process. Is done in the same way. That is, the work of replacing the waste pans 40 and 50 is performed during the de-C treatment of the second MURC and the tapping of the molten steel.

According to the present embodiment described above with reference to FIG. 6, a total of three displacement steps (the first MURC intermediate displacement step, the first MURC complete displacement step, the second MURC) for the drainage pans 40 and 50 The second displacement pan 50 in a state in which the de-P-slag 15a of, for example, about 1/2 of the capacity is accommodated in the first MURC) The P slag 15a is accommodated, and it is almost full. On the other hand, in the first MURC, for example, the first discharge pan 40 in a state in which the de-C slag 15 b of about one half of the capacity is accommodated goes to the slag treatment outside the furnace as it is. Therefore, only the de-C-slag 15b is contained in the first waste pan 40, and only the de-P-slag 15a is contained in the second waste pan 50, which makes it possible to separate and collect the slag. .

In addition, in the first MURC and second MURC, which are two consecutive converter hot metal pretreatments, the waste ladle 40, 50 is carried out of the furnace through two converter hot metal pretreatments to carry out slag treatment Since the number of replacement operations of the waste pans 40 and 50 can be limited to one, the number of slag processes can be reduced compared to the conventional method, and the production efficiency can be improved. Furthermore, since waste ladle 40, 50 can be replaced during decarburization treatment and tapping in converter 2, efficient waste treatment can be performed without producing downtime of converter 2. Can.

  Moreover, converter hot metal pre-treatment by MURC method may be carried out semipermanently continuously in some cases, and in such a case, slag can be discharged by the same method. So, below, with reference to FIG. 7, the operation method of the converter in case more converter hot metal pre-processings are repeatedly implemented is demonstrated easily.

  FIG. 7 is an explanatory view showing an operation schedule when four converter hot metal pre-treatments from the first MURC to the fourth MURC are continuously performed. In addition, although FIG. 7 illustrates the case where the converter hot metal pretreatment is performed four times in a row, the converter hot metal pretreatment is performed continuously any number of times, and four times is an example thereof. It is. Moreover, the display method of FIG. 7 is the same as that of FIG. Furthermore, for the purpose of explanation, the intermediate displacement steps from the first MURC to the fourth MURC are referred to as the first intermediate displacement step M1 to the fourth intermediate displacement step M4, and the complete displacement steps from the first MURC to the fourth MURC are the first complete. It is referred to as a displacement step F1 to a fourth complete displacement step F4.

  In the first MURC to the second MURC, as described above with reference to FIG. 6, the slag discharged in the first intermediate displacement step M1, the first complete displacement step F1, and the second intermediate displacement step M2 Slag treatment (slag removal from the furnace and treatment thereof) is performed at timing T1 stored in the pots 40, 50. At this timing T1, that is, at a predetermined time t2 until the end of the second complete displacement process F2, the displacement of the drainage pans 40, 50 is carried out together with the slag treatment, and the empty drainage pans 40, 50 are in the furnace. It is carried in.

Subsequently, in the second complete displacement step F2, the third intermediate displacement step M3, the third complete displacement step F3, and the fourth intermediate displacement step M4 between timing T1 and timing T2 shown in FIG. The discharged slag is stored in the first waste pan 40 in the same manner as in FIG. 6 so that only the deC slag 15b is contained, and only the deP slag 15a is stored in the second waste pan 50. A dredging process is performed. That is, in the first waste pan 40, the de-C slag 15b in the second complete waste phase F2 and the third complete waste phase F3 is accommodated, and in the second waste pan 50, the third intermediate The de-P slag 15b in the displacement step M3 and the fourth middle displacement step M4 is accommodated.
And the slag process of the slag accommodated in the waste pan 40, 50 is performed in timing T2, and replacement | exchange of the waste pan 40, 50 is implemented further.
Although the case where the converter hot metal pretreatment is performed four times continuously has been described here, if the converter hot metal pretreatment is continuously performed semipermanently, refer to FIG. 7. The evacuation step according to the method described above is repeated.

According to the operation method of the converter according to the present embodiment described above, as described with reference to FIGS. 6 and 7, the converter hot metal pretreatment by the MURC method is continuously performed twice or more in the same converter. It is possible to carry out the waste ladle pan out of the furnace and carry out the slag treatment once in every two converter hot metal pre-treatments when replacing the waste ladle with the conventional method. The number of times and the number of times of slag treatment can be reduced. In addition, it is possible to reduce the non-operation time and the like of the converter accompanying the replacement of the waste pan compared to the prior art. As a result, it becomes possible to carry out the refining process of hot metal more efficiently than in the past, and the improvement of productivity is realized.
In addition, when carrying out the method of operating the converter according to the present embodiment, there is no need to invest in equipment such as upsizing of the waste ladle or expansion of rails installed in the converter, which is also useful in cost. is there.

Further, in the operation method of the converter according to the present embodiment, only the de-C slag 15b is accommodated in the first discharge pan 40, and only the de-P slag 15a is accommodated in the second exhaust pan 50. It is structured to go to slag processing. That is, two types of slag (de-C-slag and de-P-slag) having different components are separately contained, and it is possible to realize the efficiency and cost reduction of the slag processing performed for reuse and the like.

  Although the example of the embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is obvious that those skilled in the art can conceive of various modifications or alterations within the scope of the idea described in the claims, and they are naturally within the technical scope of the present invention. It is understood that.

  For example, although MURC method was illustrated and explained as a converter hot metal pre-treatment in the above-mentioned embodiment, the present invention is applicable also to converter hot metal pre-processing other than MURC method. That is, it is applicable also to LD-ORP method etc. of the double charge type of the hot metal which takes out a molten metal from a converter once after performing dephosphorization, and charges a molten metal to a converter again at the time of de-C.

  For example, with the double-charger converter hot metal pretreatment method such as the LD-ORP method, after performing de-P treatment in the converter, the molten metal is once transferred from the converter to a ladle, It is a method to carry out the de-C treatment by removing the de-P slag and then returning the hot metal that has been taken out to the converter that has become empty. In the converter hot metal pre-treatment of such a method, in the case of using a configuration in which two sets of waste ladles are connected, de-C slag and de-P slag in two waste ladles as in the above embodiment. It is possible to separate and accommodate two types of slag.

  The present invention relates to a method of operating a converter for smelting treatment such as removal of P and de-C of hot metal, and can be applied to an operation method of a converter for discharging slag using two discharge pots. .

2 ... Converter 3 ... Converter container 4 ... Refractory lining 5 ... Opening 6 ... Steel hole 9 ... Scrap 10 ... Hot metal 10 '... Hot metal (processed)
12 ... Acid sending mechanism 15a ... De-P slag 15 b ... De-C slag 20 ... Rail 30 ... Exhaust pan 40 ... First exhaust pan 50 ... Second exhaust pan 55 ... Connection part

Claims (4)

A method of operating a converter which performs dephosphorization, decarburization and waste treatment on hot metal in the same converter,
The above-mentioned displacement treatment is carried out using two displacement pots which are integrally connected and movable on the same rail,
The decarburized slag generated in the decarburization treatment is accommodated in a first waste pan,
The dephosphorization slag generated in the dephosphorization treatment is accommodated in a second discharge pan ,
The method is characterized in that a carrying in / out process for carrying out the two waste ladles out of the converter and carrying in two new waste ladles is carried out during the time required for the decarburizing treatment and tapping of the molten steel. , How to operate the converter. The hot metal is subjected to dephosphorization treatment, dephosphorization slag removal treatment, decarburization treatment, and decarburization slag discharge treatment in this order.
The discharge treatment of the decarburized slag is performed by disposing the first discharge pan below the converter,
The method for operating a converter according to claim 1, wherein the dephosphorization treatment of the dephosphorized slag is performed by disposing the second discharge pot below the converter. It has a carrying in / out process for carrying out the two waste ladles while carrying out the new two waste ladles outside the converter.
When the series of processes is repeatedly performed a plurality of times including the dephosphorization treatment, the dephosphorization slag removal treatment, the decarburization treatment, and the decarburization slag removal treatment as a series of steps, the loading and unloading process includes two units. The operation of the converter according to claim 1 or 2, which is performed when at least one of the discharge pans is full or when both of the two discharge pans are full. Method. The capacity of one waste ladle is set to a capacity capable of accommodating at least twice the amount of slag generated in one decarburization treatment or the dephosphorization treatment. The operating method of the converter as described in any one of these.

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