Replaceable integral tapping hole brick and preparation method thereof

Abstract

The invention discloses a replaceable integral tapping hole brick and a preparation method thereof, and belongs to the technical field of refractory materials for converter tapping and slag blocking, the replaceable integral tapping hole brick comprises an integral assembly tapping hole and a repairing material for replacing the tapping hole, and is characterized in that the integral assembly tapping hole comprises a metal steel pipe, a filler seam and a tapping hole sleeve brick, the tapping hole sleeve brick comprises a web brick, a large-head brick, an inlaid matched brick and an inner water gap, and the tapping hole sleeve brick is composed of granular materials and fine powder materials. According to the replaceable integral tapping hole brick and the preparation method thereof, the graphite is subjected to granulation treatment in advance, the granulated graphite with Al-C wrapped MgO particles is obtained, the carbon content is reduced, and meanwhile the high-temperature strength of the tapping hole brick is improved; and meanwhile, the assembly mode of the whole tapping hole brick is optimized and improved, the tapping hole sleeve brick is assembled by adopting a web brick, a large-head brick, an embedded matched brick and an inner nozzle mode, the slag-stopping tapping process requirement of the converter sliding plate mechanism is met, and meanwhile the service life of the tapping hole can be further prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of refractory materials for slag blocking for converter tapping, and in particular to a replaceable integral tapping hole brick and a preparation method thereof. Background Art

[0002] With the development of steelmaking technology and the improvement of smelting process of various types of steel, the slide gate valve slag blocking technology is the preferred choice for domestic medium and large converters when tapping steel. Through equipment transformation, an integral slide mechanism is installed at the tail of the tapping port, and infrared slag detection + PCL automatic control slide slag blocking technology is used. It can not only effectively reduce the amount of slag in the converter tapping process, improve the cleanliness of molten steel and increase the alloy yield, but also can significantly reduce the damage to equipment such as ladle cars and cables caused by slag falling, reduce the overall smelting cost of the steel plant and improve the alloy yield.

[0003] As an important component of the converter tapping slide slag blocking system, the tapping hole brick not only bears the chemical erosion and physical scouring of the high-temperature molten steel during the tapping process, but also at the moment of the end of the tapping, the infrared slag detection system detects the slag, and the PCL system automatically controls the slide mechanism to close the slide in 1s to block the converter slag in the tapping hole. At this time, the tapping hole sleeve brick needs to withstand the erosion of high-temperature alkaline slag; at the same time, the replacement process of the overall tapping hole brick takes 90 to 120 minutes, which has a great impact on the output and smelting rhythm of the steel plant; therefore, with the popularization of the slide slag blocking technology, higher requirements are put forward for the corrosion resistance and use of the overall tapping hole. The tapping hole sleeve bricks currently used are basically made of fused magnesia, flake graphite, antioxidants, etc. as the main materials, which can meet the requirements of the tapping hole bricks for the corrosion resistance of alkaline slag, but a large amount of flake graphite needs to be added, which reduces the high-temperature strength of the tapping hole bricks and affects the service life. At the same time, it causes high water carbon increase, which is not conducive to the production of clean steel.

[0004] After searching, Chinese patent CN107365160B discloses an integral steel tapping port casing brick for rapid steel smelting and its production method. The patent is based on 0-12 parts of large crystalline magnesia particles with a particle size of 8-5mm, 5-20 parts of large crystalline magnesia particles with a particle size of 5-3mm, 20-35 parts of large crystalline magnesia particles with a particle size of 3-1mm, 20-35 parts of large crystalline magnesia particles with a particle size of 1-0mm, and 1 large crystalline magnesia powder with a particle size of 200 mesh. 3-20 parts, 895 mesh flake graphite 6-10 parts, 200 mesh 99 metal aluminum powder 0-3 parts, 0-3 parts of metal silicon powder, 325 mesh boron carbide 0-2 parts, 325 mesh calcium boride 0-1 parts, high temperature resin powder 0-2 parts, solid resin powder 0-2 parts, solid aluminum dihydrogen phosphate + complex magnesium aluminum binder 0.2-2 parts, nano ceramic material 0-0.2 parts, liquid resin 2-5 parts; prepared by fine powder premixing, mud mixing, and molding process. The patent introduces phosphate and magnesium aluminum binder, which are easy to react chemically with alkaline slag at high temperature, accelerate the erosion and peeling of the steel outlet bricks, and reduce the service life; and the overall steel outlet brick type designed by the patent is an integrated assembly, without replaceable inlaid bricks and inner water nozzles, not only has a low service life, but also cannot be used in conjunction with the converter slag retaining mechanism.

[0005] In addition, Chinese patent CN110863081A discloses a repair device and method for a converter tapping port. The repair method adopted in the patent is to set a grouting hole and a grouting connecting pipe, and to deliver the pressed material into the tapping port for repair through pressure delivery by a pressure device. However, the patent adopts a high-pressure delivery method, and there is an uneven ratio of the added pressed material and the binder water during the delivery process, resulting in inconsistent density of the repaired tapping port material at different parts, partial erosion of the tapping port, and a reduction in the overall service life of the tapping port.

[0006] In summary, how to improve the service life of existing steel outlet bricks with high carbon content, and how to avoid affecting the steelmaking time and rhythm by frequently replacing the steel outlet at one time due to the long replacement time of each steel outlet, is a technical problem to be solved. Summary of the invention

[0007] The object of the present invention is to provide a replaceable integral steel-tap hole brick and a preparation method thereof. By pre-granulating graphite, granulated graphite with Al-C wrapped MgO particles is obtained, the carbon content is reduced and the high-temperature strength of the steel-tap hole brick is improved; at the same time, the assembly method of the integral steel-tap hole brick is optimized and improved, and the steel-tap hole sleeve brick is assembled by belly brick, big head brick, inlaid matching brick and inner water inlet, which meets the slag blocking and steel-tapping process requirements of the converter slide mechanism and can further improve the service life of the steel-tap hole; in the later stage of the use of the steel-tap hole, a steel pipe + a matching bottom mold is inserted into the steel-tap hole, and the pre-mixed steel-tap hole repair slurry is poured into the steel-tap hole through a special introduction flow channel. After being sintered for a short time at the residual temperature in the converter, the steel-tap hole brick can continue to be used, which improves the service life of the steel-tap hole brick as a whole and solves the problems raised in the above-mentioned background technology.

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a replaceable integral tapping hole brick, comprising an integrally assembled tapping hole and a replacement tapping hole repair material, the integrally assembled tapping hole comprises a metal steel pipe, a filler seam and a tapping hole sleeve brick, the tapping hole sleeve brick comprises a belly brick, a large head brick, an inlaid matching brick and an inner water outlet, the tapping hole sleeve brick is composed of granular material and fine powder material, and the replacement tapping hole repair material is composed of granular material and fine powder material.

[0009] The granular material of the outlet sleeve brick is composed of the following mass percentages: 15% to 25% of 98 large crystal fused magnesia particles with a particle size of 3 to 1 mm, 25% to 30% of 98.2 large crystal fused magnesia particles with a particle size of 1 to 0.5 mm, and 14% to 22% of 98.2 large crystal fused magnesia particles with a particle size of 0.5 to 0 mm;

[0010] The fine powder material of the outlet sleeve brick is composed of the following mass percentages: 10% to 12% of 98.2 large crystal fused magnesia fine powder with a particle size of 0 to 0.045 mm, 18% to 22% of granulated graphite, 2% to 3% of antioxidant, and 1% to 1.5% of high-temperature asphalt powder;

[0011] The total weight percentage of the granular material and the fine powder material of the outlet sleeve brick is 100%, and also includes an external binder, which accounts for 3% to 4% of the total weight of the thermosetting liquid phenolic resin.

[0012] The antioxidant is silicon carbide and boron carbide, wherein silicon carbide accounts for 70% to 80% of the total weight of the antioxidant. The preparation method of granulated graphite in the steel outlet sleeve brick comprises the following steps:

[0013] S1, dispersing the degreased aluminum powder in an anhydrous ethanol solution by ultrasonication to prepare an aluminum powder dispersion with a concentration of 5% to 8%;

[0014] S2, putting -198 flake graphite into the aluminum powder dispersion prepared in step 1, turning on magnetic stirring to obtain a graphite suspension, wherein the mass percentage of -198 flake graphite to the aluminum powder dispersion is 2 to 3:10;

[0015] S3, placing the graphite suspension prepared in step 2 into an oven to remove the organic solvent to obtain Al-C graphite powder;

[0016] S4. Put 98 large crystal fused magnesia fine powder with a particle size of 0.074-0 mm into a granulator, add liquid phenolic resin and stir for 5-10 minutes, then add the Al-C graphite powder prepared in step 3, stir for 1-2 hours to obtain granulated graphite with a particle size of ≤1 mm.

[0017] The preparation method of the tap hole sleeve brick comprises the following steps:

[0018] S1. Fine powder mixing: Mix large crystal fused magnesia fine powder with a particle size of 0 to 0.045 mm, antioxidant, and high temperature asphalt powder in proportion, and the mixing time is 15 to 25 minutes;

[0019] S2, granular material batching: large crystalline fused magnesia particles with a particle size of 3 to 1 mm, large crystalline fused magnesia particles with a particle size of 1 to 0.5 mm, and large crystalline fused magnesia particles with a particle size of 0.5 to 0 mm are batched according to weight percentage;

[0020] S3, mud mixing: put the granular material in step 2 into a roller mill and mix and stir for 1 to 2 minutes, add the thermosetting liquid phenolic resin as a binder and continue to stir for 3 to 5 minutes, then add the granulated graphite and continue to stir for 4 to 6 minutes, then add the fine powder mixed in step 1 and continue to mix and grind for 20 to 30 minutes to obtain mud;

[0021] S4, brick forming: pour the mud obtained in step 3 into a mold, and form it on an electric screw press to obtain a brick, and the pressure of the electric screw press is ≥1250T;

[0022] S5, heat treatment: heat treatment of the bricks obtained in step 4 in a heating furnace; the heat treatment temperature is 200-250°C;

[0023] S6, impregnation treatment: putting the brick blank obtained after the heat treatment in step 5 into an asphalt impregnation tank for impregnation treatment to obtain a steel outlet sleeve brick.

[0024] A method for preparing a replaceable integral tapping hole brick comprises the following steps:

[0025] S1. According to the assembly method required by the drawing, the prepared steel outlet sleeve bricks are assembled in sequence, using epoxy resin as a binder;

[0026] S2. Place the metal pipe into the assembled outlet sleeve brick, and fill the gap between the two with 3-0mm recycled magnesium carbon granules.

[0027] The granular material for replacing the tapping hole repair material is composed of the following mass percentages: 30% to 35% of fused magnesia particles with a particle size of 3 to 1 mm, and 33% to 36% of fused magnesia particles with a particle size of 1 to 0 mm;

[0028] The fine powder material for replacing the steel outlet repair material is composed of the following mass percentages: 18% to 23% of fused magnesia fine powder with a particle size of 0 to 0.045 mm, 2% to 4% of spherical asphalt, 2% to 3% of silicon micropowder, 3% to 5% of modified graphite, 2% to 3% of antioxidant, 0.5% to 1% of water reducer, and 0.1% of explosion-proof fiber. The total weight percentage of the granular material and the fine powder material for replacing the steel outlet repair material is 100%.

[0029] The MgO content of the fused magnesia particles and fused magnesia fine powder is ≥97%, the antioxidant is two of metal aluminum powder, metal silicon powder, silicon carbide and boron carbide, and the water reducer is carboxymethyl cellulose.

[0030] The preparation method for replacing modified graphite in a tapping hole repair material comprises the following steps:

[0031] S1. Dissolve the surfactant cetylpyridinium chloride in distilled water, wherein the mass percentage of cetylpyridinium chloride to distilled water is 5-10:100;

[0032] S2, putting -198 flake graphite into the solution obtained in step 1, turning on magnetic stirring, stirring time ≥ 16h, the C content of flake graphite ≥ 98%;

[0033] S3. The suspension solution obtained in step 2 is allowed to stand for 1 to 2 hours, the upper clear liquid is removed, and the mixture is dried in a drying oven at 90 to 100° C. to obtain modified graphite.

[0034] The preparation method for replacing the tapping hole repair material comprises the following steps:

[0035] S1. Mixing of fine powder: Mix fused magnesia fine powder with a particle size of 0.045-0 mm, spherical asphalt, silicon powder, modified graphite, antioxidant, water reducing agent, explosion-proof fiber in proportion, and mix for 10-20 minutes;

[0036] S2, granular material batching: fused magnesia particles with a particle size of 3 to 1 mm and fused magnesia particles with a particle size of 1 to 0 mm are batched according to weight percentage;

[0037] S3, mixing: put the granular material in step 2 into a grinding mill and mix and stir for 1 to 2 minutes, then add the fine powder mixed in step 1 and continue mixing and grinding for 10 to 15 minutes to obtain the steel outlet replacement repair material.

[0038] The construction method of the integrally assembled steel outlet comprises the following steps:

[0039] S1. Boring: When replacing the tap hole bricks according to the steel mill plan, the used tap hole sleeve bricks are drilled out with special boring equipment;

[0040] S2. Installation of the steel outlet: Place the prepared integrally assembled steel outlet into the steel outlet seat brick after boring, and fill the gap between the two with special gunning material;

[0041] S3, use of the steel tapping port: the steel tapping port installed in step 2 is used for normal steelmaking and steel tapping operations;

[0042] S4. Tap hole repair: When the tap hole is used for a long time and the hole expansion of the inner wall of the tap hole meets the technical requirements, the tap hole repair operation is started;

[0043] S5. During repair, the prepared steel outlet repair material is put into a wet mixer, stirred at a low speed for 2 to 3 minutes, and then 6 to 7% by mass of binder water is added, and stirred at a low speed for 10 to 15 minutes to prepare a steel outlet repair slurry;

[0044] S6. Insert the steel pipe into the tapping hole seat brick, and use the matching mold at the bottom to fix the steel pipe on the tapping hole flange;

[0045] S7, placing the tap hole repair slurry prepared in step 5 into the gap between the steel pipe and the remaining tap hole sleeve brick along the special guide groove;

[0046] S8. After the slurry is sintered for 10 to 15 minutes using the residual heat of the converter, the converter can continue normal smelting and steelmaking operations.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The present invention proposes a replaceable integral taphole brick and a preparation method thereof. Compared with the prior art, the taphole sleeve brick of the present invention uses granulated graphite instead of traditional flake graphite, which not only reduces the carbon content, but also increases the high-temperature strength and improves the service life of the taphole brick; the granulated graphite is evenly dispersed in the degreased metal aluminum powder liquid by ultrasonic dispersion + electromagnetic stirring technology, and Al-C flake graphite is obtained after drying. The metal aluminum powder and the flake graphite are evenly and tightly combined, which can not only effectively prevent the high-temperature oxidation of graphite, but also react with C, N, and O at high temperature to generate high-strength Al4C3, AlN, Al2O3 and other substances, thereby improving the high-temperature strength of the taphole brick; the above-mentioned Al-C flake graphite is spherically granulated by a granulator and electric-melted large-crystal magnesia fine powder, and the obtained granulated graphite has stable chemical properties, strong resistance to alkaline slag erosion, and a long service life of the taphole brick.

[0049] 2. The present invention proposes a replaceable integral steel-tipping brick and a preparation method thereof. Compared with the prior art, the integral steel-tipping brick of the present invention optimizes the overall assembly method, and the sleeve bricks are assembled by bonding belly bricks, large head bricks, inlaid matching bricks, and inner water nozzles with epoxy resin. During use, the service life of the steel-tipping brick can be further improved by replacing the inner water nozzle and inlaid matching bricks multiple times; at the same time, the assembly method can also be used in combination with the converter slide plate slag blocking process equipment.

[0050] 3. The present invention proposes a replaceable integral steel-tipping port brick and a preparation method thereof. Compared with the prior art, the replacement steel-tipping port repair material of the present invention introduces modified graphite as the main carbon source, and the graphite surface is modified by cetylpyridinium chloride, which increases the surface wettability of graphite and water, so that the graphite can be effectively and evenly dispersed in the repair material slurry, while reducing the amount of binder water added, thereby improving the density and corrosion resistance of the repair material; at the same time, spherical asphalt is introduced as a secondary carbon source to increase the fluidity of the repair material, so that the repair brick can be poured into the steel-tipping port through the backflow trough; at the same time, the presence of spherical asphalt also reduces the sintering time of the repair material, and can achieve rapid sintering (10 to 15 minutes) under the action of the residual temperature of the converter, and the converter can be put into steelmaking operation, which has little effect on the converter steelmaking time and steelmaking rhythm.

[0051] 4. The present invention proposes a replaceable integral steel-tipping port brick and a preparation method thereof. Compared with the prior art, the replacement steel-tipping port repair material of the present invention is prepared by premixing granular materials and fine powder materials into bulk materials through a mixer within the company, and then using a special mixing mortar machine at the construction site, adding binder water and then evenly stirring again. The prepared repair material is uniform and stable. Compared with the traditional pressure spraying process, there is no problem of uneven density of the repair material due to inconsistent material and water during construction, and partial erosion during use, which leads to a reduced service life of the steel-tipping port.

[0052] 5. The present invention proposes a replaceable integral steel-tap hole brick and a preparation method thereof. Compared with the prior art, the replaceable integral steel-tap hole brick of the present invention does not require boring and integral replacement of the steel-tap hole in the later stage of normal use of the converter steel-tap hole. Instead, a steel pipe is inserted into the steel-tap hole and a bottom matching mold is fixed. The pre-mixed steel-tap hole repair material slurry is poured into the steel-tap hole through a special introduction flow channel, and the repair material is sintered by preheating in the converter to obtain a dense repaired steel-tap hole. The overall life of the steel-tap hole brick is increased by 50% to 70%. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a schematic diagram of the overall assembly of the steel outlet of the present invention;

[0054] Figure 2 This is a schematic diagram of the installation of the integral steel outlet of the present invention;

[0055] Figure 3 It is a schematic diagram of the repaired steel outlet of the present invention.

[0056] In the figure: 1. Overall assembly of the tapping port; 2. Converter shell; 3. Converter lining bricks; 4. Ramming material; 5. Tapping port seat bricks; 6. Flange; 7. Gunning material; 8. Converter slide slag retaining mechanism; 101. Metal steel pipe; 102. Filling seam; 103. Belly bricks; 104. Big head bricks; 105. Inlaid matching bricks; 106. Inner water inlet; 107. Replacement of tapping port repair material; 108. Remaining sleeve bricks of the tapping port. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Example 1

[0059] See also Figure 1-Figure 3 A replaceable integral tapping hole brick and a preparation method thereof, comprising an integrally assembled tapping hole 1 and a replacement tapping hole repair material 107, wherein the integrally assembled tapping hole 1 comprises a metal steel pipe 101, a filler seam 102 and a tapping hole sleeve brick, the tapping hole sleeve brick comprises a belly brick 103, a large head brick 104, an inlaid matching brick 105 and an inner water outlet 106, the tapping hole sleeve brick is composed of granular material and fine powder material, and the replacement tapping hole repair material 107 is composed of granular material and fine powder material.

[0060] The granular material of the steel outlet sleeve brick is composed of the following mass percentages: 15% of 98 large crystal fused magnesia particles with a particle size of 3 to 1 mm, 27.5% of 98.2 large crystal fused magnesia particles with a particle size of 1 to 0.5 mm, and 22% of 98.2 large crystal fused magnesia particles with a particle size of 0.5 to 0 mm;

[0061] The fine powder material of the taphole sleeve brick is composed of the following mass percentages: 10% of 98.2 large crystal fused magnesia fine powder with a particle size of 0 to 0.045 mm, 22% of granulated graphite, 2.5% of antioxidant, and 1% of high-temperature asphalt powder;

[0062] The total weight percentage of the granular material and the fine powder material of the tap hole sleeve brick is 100%, and also includes an external binder, a thermosetting liquid phenolic resin accounting for 3% of the total weight.

[0063] The antioxidants are silicon carbide and boron carbide, wherein silicon carbide accounts for 70% of the total weight of the antioxidants. The preparation method of granulated graphite in the tapping port sleeve brick comprises the following steps:

[0064] S1, dispersing the degreased aluminum powder in an anhydrous ethanol solution by ultrasonication to prepare an aluminum powder dispersion with a concentration of 5%;

[0065] S2, putting -198 flake graphite into the aluminum powder dispersion prepared in step 1, turning on magnetic stirring to obtain a graphite suspension, wherein the mass percentage of -198 flake graphite to aluminum powder dispersion is 2:10;

[0066] S3, placing the graphite suspension prepared in step 2 into an oven to remove the organic solvent to obtain Al-C graphite powder;

[0067] S4. Put 98 large crystal fused magnesia fine powder with a particle size of 0.074-0 mm into a granulator, add liquid phenolic resin and stir for 5 minutes, then add the Al-C graphite powder prepared in step 3, stir for 1 hour to obtain granulated graphite with a particle size of ≤1 mm.

[0068] The preparation method of the tap hole sleeve brick comprises the following steps:

[0069] S1. Fine powder mixing: Mix large crystal fused magnesia fine powder with a particle size of 0.045-0 mm, antioxidant, and high temperature asphalt powder in proportion, and the mixing time is 15 minutes;

[0070] S2, granular material batching: large crystalline fused magnesia particles with a particle size of 3 to 1 mm, large crystalline fused magnesia particles with a particle size of 1 to 0.5 mm, and large crystalline fused magnesia particles with a particle size of 0.5 to 0 mm are batched according to weight percentage;

[0071] S3, mud material mixing: put the granular material in step 2 into a roller mill and mix and stir for 1 minute, add the thermosetting liquid phenolic resin as a binder and continue to stir for 3 minutes, then add the granulated graphite and continue to stir for 4 minutes, then add the fine powder mixed in step 1 and continue to mix and grind for 20 minutes to obtain mud material;

[0072] S4, brick forming: pour the mud obtained in step 3 into a mold, and form it on an electric screw press to obtain a brick, and the pressure of the electric screw press is ≥1250T;

[0073] S5, heat treatment: heat treatment the bricks obtained in step 4 in a heating furnace; the heat treatment temperature is 200°C;

[0074] S6, impregnation treatment: putting the brick blank obtained after the heat treatment in step 5 into an asphalt impregnation tank for impregnation treatment to obtain a steel outlet sleeve brick.

[0075] The preparation method of the integral tapping hole brick comprises the following steps:

[0076] S1. According to the assembly method required by the drawing, the prepared steel outlet sleeve bricks are assembled in sequence, using epoxy resin as a binder;

[0077] S2. Place the metal pipe into the assembled outlet sleeve brick, and fill the gap between the two with 3-0 mm recycled magnesium carbon granules.

[0078] The granular material for replacing the tap hole repair material 107 is composed of the following mass percentages: 30% of fused magnesia particles with a particle size of 3 to 1 mm and 35% of fused magnesia particles with a particle size of 1 to 0 mm;

[0079] The fine powder material for replacing the tapping mouth repair material 107 is composed of the following mass percentages: 23% of fused magnesia fine powder with a particle size of 0-0.045mm, 2% of spherical asphalt, 2% of silicon micropowder, 5% of modified graphite, 2% of antioxidant, 1% of water reducer, and 0.1% of explosion-proof fiber. The total weight percentage of the granular material and fine powder material for replacing the tapping mouth repair material 107 is 100%.

[0080] The MgO content of the fused magnesia particles and fused magnesia fine powder is ≥97%, the antioxidants are metal aluminum powder and silicon carbide, and the water reducing agent is carboxymethyl cellulose.

[0081] The preparation method for replacing the modified graphite in the tapping hole repair material 107 comprises the following steps:

[0082] S1. Dissolve the surfactant cetylpyridinium chloride in distilled water, wherein the mass percentage of cetylpyridinium chloride to distilled water is 5:100;

[0083] S2, putting -198 flake graphite into the solution obtained in step 1, turning on magnetic stirring, stirring time ≥ 16h, the C content of flake graphite ≥ 98%;

[0084] S3. The suspension solution obtained in step 2 is allowed to stand for 1 hour, the upper clear liquid is removed, and the mixture is dried in a drying oven at 90° C. to obtain modified graphite.

[0085] The preparation method for replacing the tapping hole repair material 107 comprises the following steps:

[0086] S1. Mixing of fine powder: Mix fused magnesia fine powder with a particle size of 0.045-0 mm, spherical asphalt, silicon powder, modified graphite, antioxidant, water reducing agent, explosion-proof fiber in proportion, and mix for 10 minutes;

[0087] S2, granular material batching: fused magnesia particles with a particle size of 3 to 1 mm and fused magnesia particles with a particle size of 1 to 0 mm are batched according to weight percentage;

[0088] S3, material mixing: the granular material in step 2 is put into a grinding mill and mixed and stirred for 1 minute, and then the fine powder mixed in step 1 is added and mixed and ground for 10 minutes to obtain the steel outlet replacement repair material 107.

[0089] The construction method of the integrally assembled steel outlet 1 comprises the following steps:

[0090] S1. Boring: When replacing the tap hole bricks according to the steel mill plan, the used tap hole sleeve bricks are drilled out with special boring equipment;

[0091] S2. Installation of the steel outlet: Place the prepared integrally assembled steel outlet 1 into the bored steel outlet seat brick 5, and fill the gap between the two with a special gunning material 7;

[0092] S3, use of the steel tapping port: the steel tapping port installed in step 2 is used for normal steelmaking and steel tapping operations;

[0093] S4. Tap hole repair: When the tap hole is used for a long time and the hole expansion of the inner wall of the tap hole meets the technical requirements, the tap hole repair operation is started;

[0094] S5. During repair, the prepared replacement tapping hole repair material 107 is placed in a wet mixer, stirred at a low speed for 2 minutes, and then 6% by mass of binder water is added, and stirred at a low speed for 10 minutes to prepare a tapping hole repair slurry;

[0095] S6, insert the steel pipe into the outlet brick 5, and use a matching mold at the bottom to fix the steel pipe on the outlet flange 6;

[0096] S7, placing the tap hole repair slurry prepared in step 5 into the gap between the steel pipe and the remaining tap hole sleeve brick along the special guide groove;

[0097] S8. After the slurry is sintered for 10 minutes using the residual heat of the converter, the converter can continue normal smelting and steelmaking operations.

[0098] Example 2

[0099] The granular material of the taphole sleeve brick is composed of the following mass percentages: 25% of 98 large crystal fused magnesia particles with a particle size of 3 to 1 mm, 25% of 98.2 large crystal fused magnesia particles with a particle size of 1 to 0.5 mm, and 16.7% of 98.2 large crystal fused magnesia particles with a particle size of 0.5 to 0 mm;

[0100] The fine powder material of the taphole sleeve brick is composed of the following mass percentages: 12% of 98.2 large crystal fused magnesia fine powder with a particle size of 0.045-0mm, 18% of granulated graphite, 2% of antioxidant, and 1.3% of high-temperature asphalt powder;

[0101] The total weight percentage of the granular material and the fine powder material of the tap hole sleeve brick is 100%, and also includes an external binder, a thermosetting liquid phenolic resin accounting for 4% of the total weight.

[0102] The antioxidants are silicon carbide and boron carbide, wherein silicon carbide accounts for 80% of the total weight of the antioxidants. The preparation method of granulated graphite in the tapping port sleeve brick comprises the following steps:

[0103] S1, dispersing the degreased aluminum powder in an anhydrous ethanol solution by ultrasonication to prepare an aluminum powder dispersion with a concentration of 8%;

[0104] S2, putting -198 flake graphite into the aluminum powder dispersion prepared in step 1, turning on magnetic stirring to obtain a graphite suspension, wherein the mass percentage of -198 flake graphite to aluminum powder dispersion is 3:10;

[0105] S3, placing the graphite suspension prepared in step 2 into an oven to remove the organic solvent to obtain Al-C graphite powder;

[0106] S4. Put 98 large crystal fused magnesia fine powder with a particle size of 0.074-0 mm into a granulator, add liquid phenolic resin and stir for 10 minutes, then add the Al-C graphite powder prepared in step 3, and stir for 2 hours to obtain granulated graphite with a particle size of ≤1 mm.

[0107] The preparation method of the tap hole sleeve brick comprises the following steps:

[0108] S1. Fine powder mixing: Mix large crystal fused magnesia fine powder with a particle size of 0.045-0 mm, antioxidant, and high temperature asphalt powder in proportion, and the mixing time is 25 minutes;

[0109] S2, granular material batching: large crystalline fused magnesia particles with a particle size of 3 to 1 mm, large crystalline fused magnesia particles with a particle size of 1 to 0.5 mm, and large crystalline fused magnesia particles with a particle size of 0.5 to 0 mm are batched according to weight percentage;

[0110] S3, mud mixing: put the granular material in step 2 into a roller mill and mix and stir for 2 minutes, add the thermosetting liquid phenolic resin as a binder and continue to stir for 5 minutes, then add the granulated graphite and continue to stir for 6 minutes, then add the fine powder mixed in step 1 and continue to mix and grind for 30 minutes to obtain mud;

[0111] S4, brick forming: pour the mud obtained in step 3 into a mold, and form it on an electric screw press to obtain a brick, and the pressure of the electric screw press is ≥1250T;

[0112] S5, heat treatment: heat treatment the bricks obtained in step 4 in a heating furnace; the heat treatment temperature is 250°C;

[0113] S6, impregnation treatment: putting the brick blank obtained after the heat treatment in step 5 into an asphalt impregnation tank for impregnation treatment to obtain a steel outlet sleeve brick.

[0114] The preparation method of the integral tapping hole brick comprises the following steps:

[0115] S1. According to the assembly method required by the drawing, the prepared steel outlet sleeve bricks are assembled in sequence, using epoxy resin as a binder;

[0116] S2. Place the metal pipe into the assembled outlet sleeve brick, and fill the gap between the two with 3-0 mm recycled magnesium carbon granules.

[0117] The granular material for replacing the tap hole repair material 107 is composed of the following mass percentages: 35% of fused magnesia particles with a particle size of 3 to 1 mm and 33% of fused magnesia particles with a particle size of 1 to 0 mm;

[0118] The fine powder material for replacing the tapping mouth repair material 107 is composed of the following mass percentages: 18% of fused magnesia fine powder with a particle size of 0.045-0mm, 4% of spherical asphalt, 3% of silica powder, 3% of modified graphite, 3% of antioxidant, 0.8% of water reducer, and 0.1% of explosion-proof fiber. The total weight percentage of the granular material and fine powder material for replacing the tapping mouth repair material 107 is 100%.

[0119] The MgO content of the fused magnesia particles and fused magnesia fine powder is ≥97%, the antioxidants are metal aluminum powder and boron carbide, and the water reducer is carboxymethyl cellulose.

[0120] The preparation method for replacing the modified graphite in the tapping hole repair material 107 comprises the following steps:

[0121] S1. Dissolve the surfactant cetylpyridinium chloride in distilled water, wherein the mass percentage of cetylpyridinium chloride to distilled water is 10:100;

[0122] S2, putting -198 flake graphite into the solution obtained in step 1, turning on magnetic stirring, stirring time ≥ 16h, the C content of flake graphite ≥ 98%;

[0123] S3. The suspension solution obtained in step 2 is allowed to stand for 2 hours, the upper clear liquid is removed, and the mixture is dried in a drying oven at 100° C. to obtain modified graphite.

[0124] The preparation method for replacing the tapping hole repair material 107 comprises the following steps:

[0125] S1. Mixing of fine powder: Mix fused magnesia fine powder with a particle size of 0.045-0 mm, spherical asphalt, silicon powder, modified graphite, antioxidant, water reducing agent, explosion-proof fiber in proportion, and mix for 20 minutes;

[0126] S2, granular material batching: fused magnesia particles with a particle size of 1 mm and fused magnesia particles with a particle size of 0 mm are batched according to weight percentage;

[0127] S3, material mixing: the granular material in step 2 is put into a grinding mill and mixed for 2 minutes, and then the fine powder mixed in step 1 is added and mixed and ground for 15 minutes to obtain the steel outlet replacement repair material 107.

[0128] The construction method of the integrally assembled steel outlet 1 comprises the following steps:

[0129] S1. Boring: When replacing the tap hole bricks according to the steel mill plan, the used tap hole sleeve bricks are drilled out with special boring equipment;

[0130] S2. Installation of the steel outlet: Place the prepared integrally assembled steel outlet 1 into the bored steel outlet seat brick 5, and fill the gap between the two with a special gunning material 7;

[0131] S3, use of the steel tapping port: the steel tapping port installed in step 2 is used for normal steelmaking and steel tapping operations;

[0132] S4. Tap hole repair: When the tap hole is used for a long time and the hole expansion of the inner wall of the tap hole meets the technical requirements, the tap hole repair operation is started;

[0133] S5. During repair, the prepared replacement taphole repair material 107 is placed in a wet mixer, stirred at a low speed for 3 minutes, and then 7% by mass of binder water is added, and stirred at a low speed for 15 minutes to prepare a taphole repair slurry;

[0134] S6, insert the steel pipe into the outlet brick 5, and use a matching mold at the bottom to fix the steel pipe on the outlet flange 6;

[0135] S7, placing the tap hole repair slurry prepared in step 5 into the gap between the steel pipe and the remaining tap hole sleeve brick along the special guide groove;

[0136] S8. After the slurry is sintered for 15 minutes using the residual heat of the converter, the converter can continue normal smelting and steelmaking operations.

[0137] Example 3

[0138] The granular material of the taphole sleeve brick is composed of the following mass percentages: 20.5% of 98 large crystal fused magnesia particles with a particle size of 3 to 1 mm, 30% of 98.2 large crystal fused magnesia particles with a particle size of 1 to 0.5 mm, and 14% of 98.2 large crystal fused magnesia particles with a particle size of 0.5 to 0 mm;

[0139] The fine powder material of the taphole sleeve brick is composed of the following mass percentages: 11% of 98.2 large crystal fused magnesia fine powder with a particle size of 0.045-0mm, 20% of granulated graphite, 3% of antioxidant, and 1.5% of high-temperature asphalt powder;

[0140] The total weight percentage of the granular material and the fine powder material of the tap hole sleeve brick is 100%, and also includes an external binder, a thermosetting liquid phenolic resin accounting for 3.5% of the total weight.

[0141] The antioxidants are silicon carbide and boron carbide, wherein silicon carbide accounts for 75% of the total weight percentage of the antioxidants. The preparation method of granulated graphite in the tapping port sleeve brick comprises the following steps:

[0142] S1, dispersing the degreased aluminum powder in an anhydrous ethanol solution by ultrasonication to prepare an aluminum powder dispersion with a concentration of 6.5%;

[0143] S2, putting -198 flake graphite into the aluminum powder dispersion prepared in step 1, turning on magnetic stirring to obtain a graphite suspension, wherein the mass percentage of -198 flake graphite to aluminum powder dispersion is 2.5:10;

[0144] S3, placing the graphite suspension prepared in step 2 into an oven to remove the organic solvent to obtain Al-C graphite powder;

[0145] S4. Put 98 large crystal fused magnesia fine powder with a particle size of 0.074-0 mm into a granulator, add liquid phenolic resin and stir for 7 minutes, then add the Al-C graphite powder prepared in step 3, stir for 1.5 hours to obtain granulated graphite with a particle size of ≤1 mm.

[0146] The preparation method of the tap hole sleeve brick comprises the following steps:

[0147] S1. Fine powder mixing: Mix large crystal fused magnesia fine powder with a particle size of 0.045-0 mm, antioxidant, and high temperature asphalt powder in proportion, and the mixing time is 20 minutes;

[0148] S2, granular material batching: large crystalline fused magnesia particles with a particle size of 3 to 1 mm, large crystalline fused magnesia particles with a particle size of 1 to 0.5 mm, and large crystalline fused magnesia particles with a particle size of 0.5 to 0 mm are batched according to weight percentage;

[0149] S3, mud mixing: put the granular material in step 2 into a roller mill and mix and stir for 1.5 minutes, add the thermosetting liquid phenolic resin as a binder and continue to stir for 4 minutes, then add the granulated graphite and continue to stir for 5 minutes, then add the fine powder mixed in step 1 and continue to mix and grind for 25 minutes to obtain mud;

[0150] S4, brick forming: pour the mud obtained in step 3 into a mold, and form it on an electric screw press to obtain a brick, and the pressure of the electric screw press is ≥1250T;

[0151] S5, heat treatment: heat treatment the bricks obtained in step 4 in a heating furnace; the heat treatment temperature is 225°C;

[0152] S6, impregnation treatment: putting the brick blank obtained after the heat treatment in step 5 into an asphalt impregnation tank for impregnation treatment to obtain a steel outlet sleeve brick.

[0153] The preparation method of the integral tapping hole brick comprises the following steps:

[0154] S1. According to the assembly method required by the drawing, the prepared steel outlet sleeve bricks are assembled in sequence, using epoxy resin as a binder;

[0155] S2. Place the metal pipe into the assembled outlet sleeve brick, and fill the gap between the two with 3-0 mm recycled magnesium carbon granules.

[0156] The granular material for replacing the tap hole repair material 107 is composed of the following mass percentages: 31.5% of fused magnesia particles with a particle size of 3 to 1 mm and 36% of fused magnesia particles with a particle size of 1 to 0 mm;

[0157] The fine powder material for replacing the tapping mouth repair material 107 is composed of the following mass percentages: 20% of fused magnesia fine powder with a particle size of 0.045-0mm, 3% of spherical asphalt, 2.5% of silicon micropowder, 4% of modified graphite, 2.5% of antioxidant, 0.5% of water reducer, and 0.1% of explosion-proof fiber. The total weight percentage of the granular material and fine powder material for replacing the tapping mouth repair material 107 is 100%.

[0158] The MgO content of the fused magnesia particles and fused magnesia fine powder is ≥97%, the antioxidant is metal aluminum powder and metal silicon powder, and the water reducing agent is carboxymethyl cellulose.

[0159] The preparation method for replacing the modified graphite in the tapping hole repair material 107 comprises the following steps:

[0160] S1. Dissolve the surfactant cetylpyridinium chloride in distilled water, wherein the mass percentage of cetylpyridinium chloride to distilled water is 7:100;

[0161] S2, putting -198 flake graphite into the solution obtained in step 1, turning on magnetic stirring, stirring time ≥ 16h, the C content of flake graphite ≥ 98%;

[0162] S3. The suspension solution obtained in step 2 is allowed to stand for 1.5 hours, the upper clear liquid is removed, and the mixture is dried in a drying oven at 95° C. to obtain modified graphite.

[0163] The preparation method for replacing the tapping hole repair material 107 comprises the following steps:

[0164] S1. Mixing of fine powder: Mix fused magnesia fine powder with a particle size of 0.045-0 mm, spherical asphalt, silicon powder, modified graphite, antioxidant, water reducing agent, explosion-proof fiber in proportion, and mix for 15 minutes;

[0165] S2, granular material batching: fused magnesia particles with a particle size of 3 to 1 mm and fused magnesia particles with a particle size of 1 to 0 mm are batched according to weight percentage;

[0166] S3, material mixing: the granular material in step 2 is put into a grinding mill and mixed and stirred for 1.5 minutes, and then the fine powder mixed in step 1 is added and mixed and ground for 12 minutes to obtain the steel outlet replacement repair material 107.

[0167] The construction method of the integrally assembled steel outlet 1 comprises the following steps:

[0168] S1. Boring: When replacing the tap hole bricks according to the steel mill plan, the used tap hole sleeve bricks are drilled out with special boring equipment;

[0169] S2. Installation of the steel outlet: Place the prepared integrally assembled steel outlet 1 into the bored steel outlet seat brick 5, and fill the gap between the two with a special gunning material 7;

[0170] S3, use of the steel tapping port: the steel tapping port installed in step 2 is used for normal steelmaking and steel tapping operations;

[0171] S4. Tap hole repair: When the tap hole is used for a long time and the hole expansion of the inner wall of the tap hole meets the technical requirements, the tap hole repair operation is started;

[0172] S5. During repair, the prepared replacement tapping hole repair material 107 is placed in a wet mixer, stirred at a low speed for 2.5 minutes, and then 6.5% by mass of binder water is added, and stirred at a low speed for 12 minutes to prepare a tapping hole repair slurry;

[0173] S6, insert the steel pipe into the outlet brick 5, and use a matching mold at the bottom to fix the steel pipe on the outlet flange 6;

[0174] S7, placing the tap hole repair slurry prepared in step 5 into the gap between the steel pipe and the remaining tap hole sleeve brick along the special guide groove;

[0175] S8. After the slurry is sintered for 12 minutes using the residual heat of the converter, the converter can continue normal smelting and steelmaking operations.

[0176] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A replaceable integral tapping hole brick, including integrally assembled tapping holes and replacement of tapping hole repair materials, characterized in that: The integrally assembled steel outlet comprises a metal steel pipe, a filler seam and steel outlet sleeve bricks, the steel outlet sleeve bricks comprise belly bricks, large head bricks, inlaid matching bricks and inner water outlets, the steel outlet sleeve bricks are composed of granular materials and fine powder materials, and the replacement steel outlet repair material is composed of granular materials and fine powder materials.

2. The replaceable integral tapping hole brick according to claim 1, characterized in that: The granular material of the outlet sleeve brick is composed of the following mass percentages: 15% to 25% of 98 large crystal fused magnesia particles with a particle size of 3 to 1 mm, 25% to 30% of 98.2 large crystal fused magnesia particles with a particle size of 1 to 0.5 mm, and 14% to 22% of 98.2 large crystal fused magnesia particles with a particle size of 0.5 to 0 mm; The fine powder material of the outlet sleeve brick is composed of the following mass percentages: 10% to 12% of 98.2 large crystal fused magnesia fine powder with a particle size of 0 to 0.045 mm, 18% to 22% of granulated graphite, 2% to 3% of antioxidant, and 1% to 1.5% of high-temperature asphalt powder; The total weight percentage of the granular material and the fine powder material of the outlet sleeve brick is 100%, and also includes an external binder, which accounts for 3% to 4% of the total weight of the thermosetting liquid phenolic resin.

3. The replaceable integral tapping hole brick according to claim 2, characterized in that: The antioxidant is silicon carbide and boron carbide, wherein silicon carbide accounts for 70% to 80% of the total weight of the antioxidant. The preparation method of granulated graphite in the steel outlet sleeve brick comprises the following steps: S1, dispersing the degreased aluminum powder in an anhydrous ethanol solution by ultrasonication to prepare an aluminum powder dispersion with a concentration of 5% to 8%; S2, putting -198 flake graphite into the aluminum powder dispersion prepared in step 1, turning on magnetic stirring to obtain a graphite suspension, wherein the mass percentage of -198 flake graphite to the aluminum powder dispersion is 2 to 3:10; S3, placing the graphite suspension prepared in step 2 into an oven to remove the organic solvent to obtain Al-C graphite powder; S4. Put 98 large crystal fused magnesia fine powder with a particle size of 0.074-0 mm into a granulator, add liquid phenolic resin and stir for 5-10 minutes, then add the Al-C graphite powder prepared in step 3, stir for 1-2 hours to obtain granulated graphite with a particle size of ≤1 mm.

4. The replaceable integral tapping hole brick according to claim 3, characterized in that: The preparation method of the tap hole sleeve brick comprises the following steps: S1. Fine powder mixing: Mix large crystal fused magnesia fine powder with a particle size of 0 to 0.045 mm, antioxidant, and high temperature asphalt powder in proportion, and the mixing time is 15 to 25 minutes; S2, granular material batching: large crystalline fused magnesia particles with a particle size of 3 to 1 mm, large crystalline fused magnesia particles with a particle size of 1 to 0.5 mm, and large crystalline fused magnesia particles with a particle size of 0.5 to 0 mm are batched according to weight percentage; S3, mud mixing: put the granular material in step 2 into a roller mill and mix and stir for 1 to 2 minutes, add the thermosetting liquid phenolic resin as a binder and continue to stir for 3 to 5 minutes, then add the granulated graphite and continue to stir for 4 to 6 minutes, then add the fine powder mixed in step 1 and continue to mix and grind for 20 to 30 minutes to obtain mud; S4, brick forming: pour the mud obtained in step 3 into a mold, and form it on an electric screw press to obtain a brick, and the pressure of the electric screw press is ≥1250T; S5, heat treatment: heat treatment of the bricks obtained in step 4 in a heating furnace; the heat treatment temperature is 200-250°C; S6, impregnation treatment: putting the brick blank obtained after the heat treatment in step 5 into an asphalt impregnation tank for impregnation treatment to obtain a steel outlet sleeve brick.

5. The replaceable integral tapping hole brick according to claim 4, characterized in that: The granular material for replacing the taphole repair material is composed of the following mass percentages: 30% to 35% of fused magnesia particles with a particle size of 3 to 1 mm, and 33% to 36% of fused magnesia particles with a particle size of 1 to 0 mm; The fine powder material for replacing the steel outlet repair material is composed of the following mass percentages: 18% to 23% of fused magnesia fine powder with a particle size of 0 to 0.045 mm, 2% to 4% of spherical asphalt, 2% to 3% of silicon micropowder, 3% to 5% of modified graphite, 2% to 3% of antioxidant, 0.5% to 1% of water reducer, and 0.1% of explosion-proof fiber. The total weight percentage of the granular material and the fine powder material for replacing the steel outlet repair material is 100%.

6. The replaceable integral tapping hole brick according to claim 5, characterized in that: The MgO content of the fused magnesia particles and fused magnesia fine powder is ≥97%, the antioxidant is two of metal aluminum powder, metal silicon powder, silicon carbide and boron carbide, and the water reducer is carboxymethyl cellulose.

7. The replaceable integral tapping hole brick according to claim 6, characterized in that: The preparation method for replacing modified graphite in a tapping hole repair material comprises the following steps: S1. Dissolve the surfactant cetylpyridinium chloride in distilled water, wherein the mass percentage of cetylpyridinium chloride to distilled water is 5-10:100; S2, putting -198 flake graphite into the solution obtained in step 1, turning on magnetic stirring, stirring time ≥ 16h, the C content of flake graphite ≥ 98%; S3. The suspension solution obtained in step 2 is allowed to stand for 1 to 2 hours, the upper clear liquid is removed, and the mixture is dried in a drying oven at 90 to 100° C. to obtain modified graphite.

8. The replaceable integral tapping hole brick according to claim 7, characterized in that: The preparation method for replacing the tapping hole repair material comprises the following steps: S1. Mixing of fine powder: Mix fused magnesia fine powder with a particle size of 0 to 0.045 mm, spherical asphalt, silicon powder, modified graphite, antioxidant, water reducing agent, explosion-proof fiber in proportion, and mix for 10 to 20 minutes; S2, granular material batching: fused magnesia particles with a particle size of 3 to 1 mm and fused magnesia particles with a particle size of 1 to 0 mm are batched according to weight percentage; S3, mixing: put the granular material in step 2 into a grinding mill and mix and stir for 1 to 2 minutes, then add the fine powder mixed in step 1 and continue mixing and grinding for 10 to 15 minutes to obtain the steel outlet replacement repair material.

9. The method for preparing a replaceable integral tapping hole brick according to claim 8, characterized in that: The steps include: S1. According to the assembly method required by the drawing, the prepared steel outlet sleeve bricks are assembled in sequence, using epoxy resin as a binder; S2. Place the metal pipe into the assembled outlet sleeve brick, and fill the gap between the two with 3-0mm recycled magnesium carbon granules.

10. The replaceable integral tapping hole brick according to claim 9, characterized in that: The construction method of the integrally assembled steel outlet comprises the following steps: S1. Boring: When replacing the tap hole bricks according to the steel mill plan, the used tap hole sleeve bricks are drilled out with special boring equipment; S2. Installation of the steel outlet: Place the prepared integrally assembled steel outlet into the steel outlet seat brick after boring, and fill the gap between the two with special gunning material; S3, use of the steel tapping port: the steel tapping port installed in step 2 is used for normal steelmaking and steel tapping operations; S4. Tap hole repair: When the tap hole is used for a long time and the hole expansion of the inner wall of the tap hole meets the technical requirements, the tap hole repair operation is started; S5. During repair, the prepared steel outlet repair material is put into a wet mixer, stirred at a low speed for 2 to 3 minutes, and then 6 to 7% by mass of binder water is added, and stirred at a low speed for 10 to 15 minutes to prepare a steel outlet repair slurry; S6. Insert the steel pipe into the tapping hole seat brick, and use the matching mold at the bottom to fix the steel pipe on the tapping hole flange; S7, placing the tap hole repair slurry prepared in step 5 into the gap between the steel pipe and the remaining tap hole sleeve brick along the special guide groove; S8. After the slurry is sintered for 10 to 15 minutes using the residual heat of the converter, the converter can continue normal smelting and steelmaking operations.

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