JP5726614B2 - Refractory brick cooling structure and method for converter - Google Patents

Description

  The present invention relates to a cooling structure for a refractory brick of a converter and a method thereof, and more particularly, to suppress the wear rate due to overheating of the refractory brick of the converter, particularly the refractory brick near the tuyere, thereby extending the life of the converter. The present invention relates to a refractory brick cooling structure for a converter and a method thereof.

For example, in copper smelting, dry fine powder concentrate is blown into a flash furnace with a concentrate burner simultaneously with oxygen-enriched air or high-temperature hot air, separated into mats and slag, and extracted from the tap hole of the flash furnace. The obtained mat is accommodated in a PS converter, and crude copper is obtained by blowing air or oxygen-enriched air from a plurality of tuyere. The operation in this PS converter is a batch type, which is divided into a forging period and a copper-making period. In the period of forming, iron sulfide in the mat is oxidized and separated and removed as molten slag (calami). Then, the PS converter after discharging the slag is newly charged with a mat from the flash smelting furnace, and the operation in the converter building period is repeated. This forming period is repeated 2 to 3 times, and after the produced mat (white glue) reaches a certain amount, it enters the copper forming period to obtain crude copper. In addition, since 3-10% of copper is contained in the slag obtained in the manufacturing process, the copper content is separated and concentrated by flotation, and further the copper content is recovered. The heat source uses the heat of oxidation of sulfides in both the steelmaking and coppermaking periods and is basically not required. In particular, since the reaction heat becomes excessive during the copper making stage, the temperature rises by charging the anode casting material (electrolytic residue copper) generated during electrolysis, repetitive materials in the smelter, and copper scrap. Adjust. Moreover, 7 to 12% of SO ₂ is contained in the exhaust gas generated during operation, and sulfuric acid is recovered.

  The furnace body of PS converter is a cylindrical horizontal type and is lined with magnesite or chrome magnesite brick, and the side of the furnace body is provided with charging / discharging ports, which are tilted back and forth by a motor. The mat is inserted and the crude copper is discharged. In addition, a large number of tuyere are provided in the lateral direction on the side of the furnace body, and about 100 kPa of pressurized air or oxygen-enriched air is blown into the molten mat from the tuyere. The tip of the tuyere is easily clogged with solid iron oxide or the like, so an iron bar is inserted and the tuyere is punched.

  By the way, when pressurized air or oxygen-enriched air is blown into the converter from the tuyere, the vicinity of the tuyere becomes very hot due to the reaction with the mat, and the refractory bricks near the tuyere are markedly melted. For this reason, it is necessary to replace the refractory bricks near the worn tuyere, and if the frequency of refractory brick replacement is high, the operation efficiency will decrease, so it is hoped that the life of the refractory bricks near the tuyere will be extended. It was rare. For example, in patent document 1, since the shape of the refractory brick used for a tuyere part is a special shape, since construction and repair work of refractory brick required a lot of labor, construction was easy and long-term use was required. It has been proposed to cast an indeterminate refractory around the tuyere pipe so that it can withstand.

  In Patent Document 2, conventionally, a protective layer is formed by a repair body by performing spraying repair, baking repair, or spray repair while blowing bottom blowing gas from the tuyere, and this protective layer relaxes the thermal shock. The service life of the blow tuyere was extended, but if the flow rate of bottom blowing gas is increased at the start of blowing after repair, the repaired body easily peels off and falls off the tuyere brick surface. Since the surface of tuyere bricks is exposed to molten steel due to falling off, the tuyere bricks generate thermal spalling and exfoliate cracks to increase the wear rate, and the repair effect is not fully demonstrated. Therefore, repair of a converter-type smelting vessel having a gas blowing tuyere, characterized in that hot repair is performed while passing a bottom blowing gas from the tuyere in a linear flow velocity range of 50 Nm / sec to 500 Nm / sec. Suggest a way To have.

  Furthermore, in Cited Document 3, oxygen gas is injected from the central flow path in the inner tube of the tuyere, and cooling gas is injected from the annular flow channel in the outer tube of the tuyere, and the inner tube is made of Cr. : By using austenitic stainless steel containing 20-26 mass%, Ni: 10-25 mass%, the tuyere life in refining furnaces such as bottom-blowing converters or top-bottom-blowing converters, and the life of converter furnace bottoms Can be remarkably improved.

JP-A-6-50671 Japanese Patent No. 2876955 JP 2005-264291 A

  However, in most cases, the converter life is determined by the wear of the tuyere bricks near the tuyere. Therefore, suppressing the wear rate of tuyere bricks greatly contributes to the extension of the converter life. However, the use of bricks with higher heat resistance increases costs, and if a complex structure is used to improve heat resistance, repair work will be time consuming and the time to restart will be increased over a long period of time. It can be reduced.

  Therefore, the present invention has been made in view of such a problem, and effectively reduces the rate of wear due to overheating of tuyere bricks while having a simpler structure, thereby extending the life of the converter than before. An object of the present invention is to provide a cooling structure for a refractory brick near the tuyeres of a converter and a method therefor.

In order to solve the above-mentioned problems, the present invention according to claim 1 is a cooling structure for a refractory brick of a converter, wherein a gap for ventilation is provided between an inner refractory brick and an outer wall material forming a furnace body of the converter. And forming a plurality of holes in the outer wall material of the portion where the gap is formed, and providing an opening in a part of the tuyere pipe for blowing air or oxygen-enriched air into the molten metal The refractory brick is cooled by ventilating a part of the air or oxygen-enriched air blown into the molten metal from the opening through the gap and exhausting it from the hole .

In order to solve the above-mentioned problem, the present invention described in claim 2 provides a cooling structure for a refractory brick according to claim 1 , wherein the opening diameter of the hole portion is a tuyere that blows air or oxygen-enriched air into the molten metal. The size is 30 to 60% of the opening diameter .

In order to solve the above-mentioned problem, the present invention described in claim 3 is the cooling structure for a refractory brick according to claim 1 or 2 , wherein a plurality of holes are arranged in the horizontal direction on the side surface of the furnace body. It is characterized by being 10 to 40% of the number of tuyere.

In order to solve the above-mentioned problem, the present invention according to claim 4 is the cooling structure for a refractory brick according to any one of claims 1 to 3, wherein a plurality of holes are provided in a horizontal direction on a side surface of the furnace body. It arrange | positions along the arrangement direction of the arrange | positioned tuyere.

In order to solve the above-mentioned problem, the present invention according to claim 5 is the cooling structure for a refractory brick of a converter according to any one of claims 1 to 4, wherein the interval between the holes is a side surface of the furnace body. It is characterized by being 2.5 to 7.5 times the interval between the tuyere arranged in the horizontal direction.

In order to solve the above-mentioned problem, the present invention according to claim 6 is a method for cooling a refractory brick of a converter, wherein a gap for ventilation is provided between an inner refractory brick and an outer wall material forming a furnace body of the converter. And forming a plurality of holes in the outer wall material of the portion where the gap is formed, and providing an opening in a part of the tuyere pipe for blowing air or oxygen-enriched air into the molten metal The refractory brick is cooled by ventilating a part of the air or oxygen-enriched air blown into the molten metal from the opening through the gap and exhausting it from the hole .

  According to the cooling structure and method of a refractory brick for a converter according to the present invention, the life of the converter can be effectively reduced by effectively suppressing the rate of wear due to overheating of the brick near the tuyere while having a simple structure. Can also be extended.

It is a front view of the converter which shows the cooling structure of the refractory brick of the converter which concerns on this invention. It is side surface partial sectional drawing of the converter of FIG. It is a partially expanded sectional view of a tuyere vicinity.

[Configuration of cooling structure for refractory bricks in converters]
Hereinafter, the cooling structure and method of a refractory brick for a converter according to the present invention will be described in detail based on a preferred embodiment. FIG. 1 is a front view of a converter showing a refractory brick cooling structure for a converter according to the present invention, and FIG.

  The converter shown in FIG.1 and FIG.2 is the PS converter 1, and the outline | summary is demonstrated first. The PS converter 1 generally includes a cylindrical horizontal furnace body 2, and a charging / discharging port 3 is formed on an upper surface portion thereof. The inside of the furnace body 2 is lined with a heat-resistant material, for example, a heat-resistant brick 7 such as magnesite or chrome magnesite brick, and the outer outer wall material is called a cell 8 and is covered with a metal material such as SS. . Moreover, the rollers 1a and 1a rotated by the electric motor 1b are arranged so as to contact the side surface of the furnace body 2, whereby the furnace body 2 can be tilted. By tilting the furnace body 2 by such a tilting mechanism, charging of mats, cold materials, etc., or discharging of slag, crude copper, etc. is performed. Note that the charging of the mat or the like into the furnace body 2 is performed by tilting the furnace body 2 so that the charging / discharging port 3 is positioned outside the exhaust gas hood 5, and the contents are moved out of the furnace body 2. When discharging, the furnace body 2 is further tilted to flow out from the charging / discharging port 3.

  An exhaust gas hood 5 is disposed above the PS converter 1, and a front hood 6 that opens and closes while sliding along the exhaust gas hood 5 is disposed in front of the exhaust gas hood 5. The front hood 6 is opened and closed by pulling up or pulling down the wire W attached to the front hood 6 toward the ceiling. During operation, as shown in FIG. 2, the furnace body 2 is rotated so that the charging / discharging port 3 of the furnace body 2 is located inside the exhaust gas hood 5, and the front hood 6 is closed and generated in the furnace. The gas to be sent is sent to a waste heat boiler (not shown) connected to the exhaust gas hood 5. The recovered exhaust gas is transported to a sulfuric acid factory for use in the production of sulfuric acid. On the other hand, when charging a mat or cold material into the furnace body 2, the front hood 6 is opened, the furnace body 2 is tilted forward, and the charging / discharging port 3 is positioned from the inside to the outside of the exhaust gas hood 5. And charged into the furnace body 2 by the ladle 9.

  A plurality of tuyere 20 are provided along the horizontal direction below the side surface of the furnace body 2, and air or oxygen-enriched air is blown into the molten metal from the tuyere 20. Here, the structure of the tuyere 20 is shown in FIG. The tuyere 20 includes an air introduction part 23 for introducing air or oxygen-enriched air provided in a tuyere box 21 which is a main body. The tuyere box 21 is connected to a tuyere stand 27 via a base 25. It is fixed to the furnace body 2 in a connected state. The tuyere box 21 is firmly fixed to the furnace body 2 by a fixing member 29 arranged so as to penetrate the tuyere stand 27, the base 25 and the cell 8. And the tuyere pipe 22 extended in the furnace so that the cell 8 and the refractory brick 7 may be penetrated to the air introduction part 23 is attached. A mortar 23 is filled around the tuyere pipe 22 and fixed. The tuyere box 21 and the tuyere stand 27 are connected by bolts 21a, and a seal or the like (not shown) is interposed in the connecting part to improve sealing performance and prevent leakage of air or oxygen-enriched air. doing.

  A gap 9 is formed between the cell 8 and the refractory brick 7. To form the gap 9, for example, a pedestal 29a of a fixing member 29 disposed between the cell 8 and the refractory brick 7 is used. By using this thickness, the cell 8 and the refractory brick 7 can be provided by forming a space where they do not contact. In addition, a plurality of holes 8a (see FIG. 1) are provided in a portion of the cell 8 corresponding to the portion where the gap 9 is formed. In this way, by forming the gap 9 between the cell 8 and the refractory brick 7, the air is introduced into the gap 9 from some holes 8a and exhausted from the other holes 8a. Thus, the refractory brick 7 can be cooled by heat exchange accompanying the air flow. In particular, by providing such a structure in the vicinity of the tuyere 20, it is possible to efficiently cool the refractory bricks 7 near the tuyere 20 that are easily exposed to high temperatures.

Moreover, it is preferable to arrange | position the hole part 8a along the arrangement direction of the tuyere 20 as shown in FIG. This is because the air heated in the gap 9 between the cell 8 and the refractory brick 7 is efficiently exhausted from the hole 8a . The opening diameter of the hole 8a is preferably about 30 to 60% of the opening diameter of the tuyere 20. In order to sufficiently support the refractory brick 7, the size of the hole 8a formed in the cell 8 is preferably as small as possible, while the air in the gap 9 needs to be exhausted sufficiently. Furthermore, the number of the holes 8a is preferably 10 to 40% of the number of the tuyere 20. Specifically, the diameter of the hole 8a is approximately φ20 mm, and is preferably provided at intervals of 0.5 to 1.5 m. This is because the heat from the refractory brick 7 is exhausted from the hole 8a in a state where the air is sufficiently absorbed by the air. In FIG. 1, the hole 8 a is continuously provided in a straight line along the arrangement direction of the tuyere 20 in the upper furnace body 2 at a predetermined distance from the tuyere 20. It is also possible to arrange them in a zigzag shape by shifting the position instead of the shape. Further, it can be provided below the tuyere 20, and can be provided both above and below the tuyere 20.

Other embodiments include the following. That is, the opening 24 is provided on the side surface of the tuyere pipe 22 that is located just in the gap 9 among the tuyere pipes 22 arranged so as to penetrate between the cells 8 and the refractory bricks 7. Alternatively, a part of the air or oxygen-enriched air blown into the furnace is ventilated through the gap 9, and the refractory brick 7 can be cooled by exhausting from the hole 8a. Since air or oxygen-enriched air having a capacity of 550 to 750 Nm ³ / min is introduced into the furnace, in this case, a part of the air or oxygen-enriched air is more actively ventilated into the gap 9. Therefore, a great cooling effect can be expected. In addition, about the magnitude | size of the hole part 8a, a number, arrangement | positioning place, etc., it can be made the same as that of the above-mentioned embodiment. The oxidation reaction caused by the blowing of air or oxygen-enriched air occurs most actively near the tip of the tuyere 20, so that the refractory brick 7 near the tuyere has the highest wear rate. In order to suppress the wear rate of the refractory bricks 7, and thus to prolong the life of the converter furnace wall, it is considered that the cooling structure and the method thereof are most effective.

[Method for cooling refractory bricks in converters]
Next, the method for cooling a refractory brick for a converter according to the present invention will be described together with the description of the operation of the cooling structure for the refractory brick for the converter described above. First, air or oxygen-enriched air is blown into the furnace from the tuyere 20 in a state where the molten metal is charged into the PS converter 1 and the exhaust gas hood 5 g is closed. Since air or oxygen-enriched air is blown into the furnace from the tuyere pipe 22, the temperature near the tuyere 20 becomes relatively high. At this time, air is sucked into the gap 9 from a part of the plurality of holes 8a provided in the cell 8, and heat exchange is performed by the air sucked by the heat of the refractory brick 7 inside the gap 9, thereby cooling the refractory brick 7 In addition, the heated air is exhausted from the other hole 8a and exhausted to the outside of the furnace. By repeating this sequentially, the refractory bricks 7 near the tuyere 20 that tend to be relatively hot are efficiently cooled.

  Further, a method for cooling the refractory brick 7 by actively blowing a part of air or oxygen-enriched air from the opening 24 of the tuyere pipe 22 into the gap 9 will be described together with the operation of the above-described embodiment. In this embodiment, the air or oxygen-enriched air sent from the air introduction unit 23 is blown into the molten metal in the furnace through the tuyere pipe 22, but part of the air or oxygen-enriched air is tuyere pipe. The air is positively ventilated from the opening 24 provided in 22 to the gap 9. The air or oxygen-enriched air introduced into the gap 9 exchanges heat with the heat of the refractory bricks 7 to cool the refractory bricks 7, and the air or oxygen-enriched air in the gaps 9 is heated and exhausted from the holes 8a. The As a result, the refractory bricks 7 are actively cooled, and the wear rate of the refractory bricks 7 near the tuyere 20 where the wear rate is the highest is effectively suppressed, thereby extending the life of the converter. It becomes possible.

[Effect of the embodiment]
By implementing the present invention, it was possible to reduce the number of repair work of refractory bricks than before. In particular, when a part of the air or oxygen-enriched air is ventilated from the opening 24 provided in the tuyere pipe to the gap 9, it is necessary to replace the refractory brick until the next replacement. The number of operations has increased by about 10%. That is, the operating efficiency has increased by 10%.

  As described above, the preferred embodiment of the present invention has been described in detail. However, the present invention is not limited to the specific embodiment, and within the scope of the gist of the present invention described in the claims, Needless to say, various modifications and changes are possible.

W wire 1 PS converter 2 furnace body 3 charging / discharging port 5 exhaust gas hood 6 front hood 7 refractory brick 8 cell 8a hole 9 gap 20 tuyere 21 tuyere box 21a bolt 22 tuyere pipe 23 air introduction part 24 opening Part 25 base 27 tuyere stand 29 fixing member 29a pedestal part

Claims (6)

In the refractory brick cooling structure of the converter,
To form a gap for ventilation between the inside of the refractory bricks and external walls forming a furnace body of the converter is provided with a plurality of holes in the external walls of the portion where the gap is formed, the molten metal An opening is provided in a part of the tuyere pipe for blowing air or oxygen-enriched air therein, and a part of the air or oxygen-enriched air blown into the molten metal from the tuyere is passed through the opening to the gap. The refractory brick cooling structure for a converter is characterized in that the refractory brick is cooled by exhausting from the hole . In the cooling structure of the refractory brick according to claim 1 ,
Opening diameter of the hole, to the opening diameter of the tuyeres for blowing air or oxygen-enriched air into the molten metal, from 30 to 60% of the refractory bricks of the converter, characterized in that a size cooling Construction. In the cooling structure of the refractory brick according to claim 1 or 2,
The number of pre Kiana portion, the cooling structure of the refractory bricks of the converter, characterized in that the side surface of the furnace body 10 to 40% of said blade number of units in which a plurality arranged in a horizontal direction. In the cooling structure of the refractory brick of any one of Claims 1-3,
The cooling structure for a refractory brick of a converter, wherein the hole is arranged along the arrangement direction of the tuyere arranged in the horizontal direction on the side surface of the furnace body. In the cooling structure of the refractory brick of the converter of any one of Claims 1-4 ,
The cooling structure of a refractory brick for a converter, wherein the interval between the holes is 2.5 to 7.5 times the interval between the tuyere arranged in the horizontal direction on the side surface of the furnace body. In the method of cooling refractory bricks in converters,
To form a gap for ventilation between the inside of the refractory bricks and external walls forming a furnace body of the converter is provided with a plurality of holes in the external walls of the portion where the gap is formed, the molten metal An opening is provided in a part of the tuyere pipe for blowing air or oxygen-enriched air therein, and a part of the air or oxygen-enriched air blown into the molten metal from the tuyere is passed through the opening to the gap. And cooling the refractory brick by exhausting from the hole .

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