Device for preventing slag winding in continuous casting tundish changing and production method thereof

Abstract

The present application belongs to the technical field of steel smelting continuous casting, and relates to a device for preventing slag winding during continuous casting tundish changing and a production method thereof. In view of the problems of secondary oxidation caused by the introduction of drainage sand into the tundish to pollute the molten steel and slag winding caused by the impact of the molten steel flow on the covering agent during the continuous casting tundish changing, the present application provides the following solutions: the device comprises a wooden sand discharge plate obliquely arranged on a fixed frame in the impact area of the tundish and slag removing plates arranged on both sides of the impact area; before casting, the ladle is at the highest position, and the slag removing plates extend to the junction between the covering agent and the molten steel surface; during casting, the drainage sand flows into the external collection groove along the sand discharge plate, and at the same time, the slag removing plates push the covering agent to both sides; after the drainage sand is completely discharged, the molten steel flows down to burn the sand discharge plate and enter the tundish, and then the ladle is lowered to make the long nozzle insert into the molten steel. The present application can not only completely discharge the drainage sand to prevent secondary oxidation, but also avoid slag winding caused by the impact of the molten steel on the covering agent, thereby significantly improving the purity of the molten steel.

Description

Technical Field

[0001] This invention belongs to the field of continuous casting technology in the iron and steel smelting process, specifically relating to a device for preventing slag entrapment during continuous casting ladle changing and its production method. Background Technology

[0002] Drainage sand is a special refractory material filled inside the bottom nozzle of a steel ladle. Its main function is to be added to the bottom nozzle of the ladle before receiving molten steel during the continuous casting process. After receiving the molten steel, drainage sand is added to prevent the molten steel from condensing inside the ladle nozzle. During the continuous casting process, the molten steel is guided to the tundish, which greatly improves the efficiency and safety of continuous casting.

[0003] Currently, the main types of guide sand include siliceous, chromium-based, magnesium-based, and zirconium-based sands. Their main chemical components typically include SiO2, Cr2O3, Fe2O3, and Al2O3. During the continuous casting process, acidic or oxidizing components in the guide sand can enter the tundish, leading to slag formation or oxidation of key elements in the steel, causing secondary oxidation of the molten steel and problems such as excessive inclusions or non-metallic inclusions. Therefore, preventing guide sand from entering the tundish has become a key research topic for metallurgists.

[0004] Currently, the common method for collecting guide sand is manual collection. Since the guide sand and molten steel are in direct contact, during the initial pouring process, the guide sand added to the bottom of the ladle nozzle will flow out prematurely, followed by the upper layer of guide sand flowing out almost simultaneously with the molten steel. This entire process typically takes only 1-2 seconds. Due to the extremely short duration of this simultaneous flow, manual collection is prone to delays, potentially causing a large amount of molten steel to splash. Therefore, manual collection often only collects a very small amount of guide sand, as a large amount entering the molten steel contaminates it. Furthermore, during the initial pouring process, because the molten steel is above the slag surface in the tundish, it inevitably impacts the covering agent on the molten steel surface when entering the tundish through the long nozzle. This causes the covering agent to be entrained into the molten steel. Although a slag-blocking wall is added inside the tundish to separate the impact zone and the pouring zone, some of the entrained covering agent can still enter the pouring zone through the wall holes and simultaneously enter the crystallizer through the tundish nozzle, leading to large inclusions.

[0005] While numerous devices and methods exist for removing sand from the tundish casting sluice, they still exhibit certain defects and limitations in practical application. Chinese patent applications CN201611022730.7 ("A Sand Removal Device and Method for Opening a Ladle in Continuous Casting") and CN201510526147.9 ("A Sand Removal Device and Method for Opening a Ladle in Continuous Casting") both involve removing the sand from the tundish casting position before transferring the ladle to the casting position for sand removal. This method firstly prolongs the continuous casting opening time, essentially employing a two-stage opening process. Secondly, after the initial sand removal and closing of the slide gate, molten steel is prone to solidifying on the slide gate and failing to open on its own. Although an argon-blown slide gate is used, argon is blown after the slide gate is closed, but the argon gas cools the molten steel during the blowing process, resulting in a condensation film inside the inlet when the casting resumes, leading to extremely low self-flow rates. Furthermore, using argon-blown slide gates requires a separate slide gate mechanism, which is costly and difficult to maintain.

[0006] The Chinese patent "A method and device for removing and recovering diverted sand" (application number CN202610261688.1) uses a sand suction cylinder to remove sand at the bottom of the long water nozzle during the pouring process. If the device absorbs all the diverted sand during the pouring process, the equipment is very easy to burn out because the diverted sand flows down with the molten steel almost simultaneously. The head suction cylinder suffers great wear and tear, and the equipment investment and maintenance costs are high.

[0007] Chinese patent “An external steel ladle sand diversion device and diversion method” (application number CN202210410013.0) guides the sand into the collection area, and then uses molten steel to penetrate the aluminum shell. After the molten steel penetrates the aluminum shell, the sand diversion collection bucket and the penetrated aluminum sheet will enter the molten steel, causing pollution to the molten steel.

[0008] The Chinese patent "A device for external discharge of molten sand from a continuous casting ladle and its usage method" (application number CN202310009849.4) uses a discharge cone and left and right sand chambers to collect discharge sand. After the molten steel flows down, it burns through the discharge cone and enters the molten steel. The discharge sand is made of sheet metal, which burns through and enters the ladle to contaminate the molten steel. The use of cardboard as the discharge cone has the problem of premature combustion failure before the discharge sand flows down or before the casting begins.

[0009] Chinese patent application CN202010541513.9, “Method for removing sand during the opening of continuous casting ladle,” describes setting up a refractory guide chute below the long nozzle before the start of casting. Since the guide sand and molten steel flow down almost simultaneously, the molten steel is prone to splashing after falling onto the guide chute, and on-site safety cannot be guaranteed.

[0010] In addition, there are currently no reports or improvement methods for the slag entrapment problem caused by the direct impact of molten steel on the covering agent when it enters the tundish from the long nozzle of the ladle.

[0011] Therefore, it is urgent to solve the problems of removing the diversion sand during continuous casting and the slag entrapment caused by the impact of molten steel on the covering agent during the initial pouring. Summary of the Invention

[0012] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a device and production method for preventing slag entrapment during continuous casting ladle replacement, which aims to solve the problems of slag entrapment caused by diversion sand contaminating molten steel and the impact covering agent during casting in the prior art.

[0013] The technical solution adopted by the present invention to solve its technical problem is: a device for preventing slag entrapment during continuous casting ladle replacement, including a sand removal device and a slag removal device installed in the impact zone of the tundish.

[0014] The sand discharge device includes a sand discharge plate, which is inclinedly mounted on a fixed frame in the impact zone of the tundish to guide the diverted sand to a collection trough outside the tundish.

[0015] The slag removal device includes slag removal plates and slag removal plate extension rods set on the left and right sides of the tundish impact zone. The slag removal plates extend to the junction of the covering agent and the molten steel surface directly below the ladle's long nozzle and can be switched between a closed state and an open state to push the covering agent to both sides before pouring.

[0016] Furthermore, the sand discharge plate is made of a wooden board with a thickness of 2-5mm, and its width is 2-3 times the outer diameter of the main water outlet. Sand-blocking side plates are provided on both sides of the width direction of the sand discharge plate.

[0017] Furthermore, the fixing frame includes a vertical beam, the bottom of which is fixed to the working layer of the impact zone of the tundish, and the top of which is a suspension beam. The sand discharge plate is suspended on the suspension beam through the fixing beam on its back, and the outlet end of the sand discharge plate rests on the working layer on the back of the tundish, so that the sand discharge plate forms an angle of 30 to 45 degrees with the horizontal plane.

[0018] Furthermore, after the slag removal plates are opened, the distance between the two slag removal plates is 2 to 3 times the outer diameter of the main water inlet.

[0019] Furthermore, the tundish is also equipped with a slag-retaining wall that separates the tundish impact zone and the casting zone.

[0020] A production method for preventing slag entrapment during continuous casting ladle changing using the above-mentioned device includes the following steps:

[0021] Step 1: After refining and smelting, the molten steel with the required composition and temperature is hoisted to the continuous casting ladle turret and rotated to the pouring position. When the ladle is at the highest pouring position, the ladle long nozzle is fitted onto the ladle bottom nozzle.

[0022] Step 2: Place the slag removal plate on the fixed frame in the tundish impact zone, and extend the slag removal plate directly below the long nozzle of the ladle in the tundish impact zone. The slag removal plate enters the interface between the molten steel surface and the covering agent on the molten steel surface. At this time, the slag removal plate is in the closed state.

[0023] Step 3: Open the ladle's long nozzle. The guide sand filling the bottom of the ladle at the bottom of the upper nozzle flows out. The guide sand flows along the sand discharge plate into the collection tank behind the tundish. At this time, open the slag removal plate in the impact zone of the tundish. When all the guide sand flows out, the molten steel flows down and breaks through or burns the sand discharge plate, allowing the molten steel to enter the tundish.

[0024] Step 4: The ladle is lowered to its lowest position, the long nozzle of the ladle is inserted into the molten steel in the impact zone, and the slag removal plate is retracted to the ready position, completing the ladle change and pouring operation.

[0025] Furthermore, the continuous casting ladle replacement refers to a process where, after the continuous casting tundish is started to pour, the service life of the tundish is longer than the time required to pour two or more heats of steel. After each heat of molten steel is poured, the ladle in the preparation position is moved to the pouring position with the refined and qualified molten steel. At the same time, the empty ladle in the pouring position is moved to the preparation position. After the full ladle of molten steel is started to pour, the molten steel is put into the tundish through the long nozzle of the ladle in a multi-heat continuous pouring mode until the tundish reaches the end of its service life.

[0026] Furthermore, in step 3, when the ladle nozzle is opened and the sand flows down, the slag removal plate extension rod is opened simultaneously. The slag removal plate retracts to both sides, and the slag removal plate removes all the covering agent on the surface of the molten steel in the impact zone. At this time, the distance between the two slag removal plates is greater than twice the outer diameter of the ladle nozzle.

[0027] Furthermore, in step 4, the slag removal plate is retracted to the ready position, that is, the telescopic rod retracts the slag removal plate to both sides of the tundish impact zone.

[0028] The beneficial effects of this invention are:

[0029] 1. This invention can both remove and recycle the diverting sand and reduce slag entrapment caused by the impact of molten steel on the covering agent. A wooden sand-discharging plate is set at a certain angle in the impact zone of the tundish. After the diverting sand flows down, it flows into the collection tank along the sand-discharging plate. When the molten steel flows out, it immediately impacts and burns the wooden board. After the wooden sand-discharging plate is burned, it will not cause pollution to the molten steel.

[0030] 2. In this invention, a slag-removing plate is used to clear the slag surface in the impact zone when the molten steel flows downstream. After the molten steel flows downstream, it directly impacts the surface of the molten steel without impacting the covering agent or only impacting a small amount of the covering agent floating on the surface of the molten steel, which greatly reduces the problem of slag entrapment in the impact zone.

[0031] 3. This invention solves the problems of long sand discharge time and reduced ladle self-opening rate in the prior art when using sand discharge devices for pouring sand outside the tundish; it also solves the safety hazards caused by molten steel splashing or contamination of molten steel by the sand discharge plate when using sand discharge devices during tundish pouring; and it solves the problems of easy equipment failure when using automatic sand suction devices.

[0032] 4. Based on the data from the example of continuous production of bearing steel for 10 heats, after adopting the present invention, the total number of inclusions is reduced by about 65-75%, the number of spinels is reduced by about 74-80%, the stopper rod and liquid surface curve are more stable during the casting process, and the purity of molten steel and casting stability are significantly improved. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 : Overall schematic diagram before ladle replacement and pouring.

[0035] Figure 2 : Front view of the impact zone of the tundish before ladle replacement and pouring.

[0036] Figure 3 Side view of the impact zone of the tundish before ladle replacement and pouring.

[0037] Figure 4 Top view of the impact zone of the tundish before ladle replacement and pouring.

[0038] Figure 5 : Schematic diagram of opening the ladle's long nozzle and slag removal plate during ladle replacement and pouring.

[0039] Figure 6 : A schematic diagram showing the ladle descending after the ladle is changed and the long nozzle of the ladle being inserted into the molten steel, and the slag removal plate being retracted to the ready position.

[0040] Figure 7 The bearing steel casting stopper rod and liquid level curve produced using this invention.

[0041] Figures 8-10 The ternary phase diagram projection of three furnaces randomly selected from the casting batches of bearing steel produced by the present invention was used to detect the total number of inclusions and the number of spinels.

[0042] Figure 11 The bearing steel casting plug and liquid level curve were not produced using the present invention, but rather using a normal manual sand receiving device.

[0043] Figures 12-14 The invention was not used; instead, the ternary phase diagram projection of three furnaces randomly selected from the bearing steel castings produced by the normal manual sand receiving device was tested to determine the total number of inclusions and the number of spinels.

[0044] The diagram is labeled as follows: 1. Tundish impact zone; 2. Sand removal device; 2-1. Sand removal plate; 2-2. Fixed crossbeam; 2-3. Vertical beam; 2-4. Bottom crossbeam; 2-5. Suspended crossbeam; 3. Slag removal device; 3-1. Slag removal plate telescopic rod; 3-2. Slag removal plate; 4. Ladle long nozzle; 5. Diverting sand; 6. Slag retaining wall; 7. Covering agent; 8. Steel ladle; 9. Tundish; 10. Collection tank. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] I. Device Structure

[0047] like Figures 1-6 As shown, the continuous casting ladle replacement device of the present invention includes a sand discharge device 2 and a slag removal device 3 disposed in the impact zone 1 of the tundish.

[0048] The sand discharge device 2 includes a sand discharge plate 2-1. The sand discharge plate 2-1 is made of a wooden board with a thickness of 2-5mm, and its width is 2-3 times the outer diameter of the main sprue nozzle 4. Sand-blocking side plates are provided on both sides of the width direction of the sand discharge plate to prevent the diverted sand from flowing into the intermediate tundish from both sides.

[0049] The sand discharge plate 2-1 is inclinedly mounted on a fixed frame in the impact zone 1 of the tundish. The fixed frame includes a vertical beam 2-3, with a bottom crossbeam 2-4 fixed to the working layer of the impact zone 1 of the tundish at the bottom of the vertical beam 2-3, and a suspension crossbeam 2-5 mounted on the top of the vertical beam 2-3. The sand discharge plate 2-1 is suspended from the suspension crossbeam 2-5 by the fixed crossbeam 2-2 on its back, and the outlet end of the sand discharge plate 2-1 rests on the working layer on the back of the tundish 9, so that the sand discharge plate 2-1 forms an angle of 30 to 45 degrees with the horizontal plane. The sand discharge plate 2-1 is used to guide the diverted sand 5 into the collection tank 10 outside the tundish 9.

[0050] The slag removal device 3 includes slag removal plates 3-2 and slag removal plate telescopic rods 3-1, which are located on the left and right sides of the tundish impact zone 1. The slag removal plates 3-2 extend to the interface between the covering agent 7 and the molten steel surface directly below the ladle long nozzle 4, and can be switched between a closed and an open state to push the covering agent to both sides before pouring. After the slag removal plates 3-2 are opened, the distance between the two slag removal plates is 2 to 3 times the outer diameter of the ladle long nozzle 4. A slag retaining wall 6 is also provided inside the tundish 9 to separate the tundish impact zone 1 and the pouring zone.

[0051] II. Production Methods

[0052] The present invention is illustrated by an example of continuous production of bearing steel in 10 heats (point A is the closed position of the ladle long nozzle, point B is the fully open position of the ladle long nozzle, d is the outer diameter of the ladle long nozzle, and L is the stroke of the slag removal plate when it is opened).

[0053] Before the first heat of bearing steel was poured, the second heat of bearing steel, after refining to ensure its composition and temperature met the requirements, was hoisted to the preparation position on the continuous casting ladle turret. After the first heat was poured, the empty ladle was raised to its highest position, the ladle's long nozzle 4 was removed, and the cold steel inside the long nozzle was cleaned to prevent damage to the protective gasket.

[0054] The bearing steel from the first heat of casting is moved to the preparation position via the ladle turret, while the ladle 8, filled with molten steel from the second heat, is moved to the casting position. At this time, the ladle is in its highest position, and the ladle nozzle 4 is fitted onto the ladle's lower nozzle.

[0055] Place the sand discharge plate 2-1 on the fixed frame. The thickness of the sand discharge plate is 3mm and the width is twice the outer diameter of the long nozzle 4 of the ladle, that is, the width of the sand discharge plate is 2d. The angle between the sand discharge plate 2-1 and the upper surface of the tundish is 45°. At the same time, the slag removal plate 3-2 extends to the junction of the molten steel surface in the covering agent 7 on the surface of the impact zone. The slag removal plate 3-2 is in the closed state.

[0056] Open the ladle's long nozzle 4 from position A to position B. The guide sand 5 at the bottom of the ladle 8 flows out from the long nozzle 4 to above the sand discharge plate 2-1, and then flows along the sand discharge plate 2-1 into the guide sand collection trough 10. At this time, open the slag skimmer 3-2 from the closed position to its maximum opening. When fully open, the stroke width L of the slag skimmer 3-2 is twice the outer diameter of the long nozzle 4, i.e., L equals 2d. After all the guide sand 5 has flowed out, the molten steel also flows down simultaneously. The high-temperature molten steel burns off the sand discharge plate 2-1, and the molten steel enters the tundish 9.

[0057] Lower the ladle 8 to its lowest position, insert the ladle's long nozzle 4 into the molten steel in the impact zone, and retract the slag removal plate 3-2 to the ready position to complete the ladle change and casting of the second heat of bearing steel.

[0058] After the second heat is poured, repeat the above steps to complete the third heat and change the ladle, until the tenth heat is poured and the tundish reaches the end of its service life and pouring stops.

[0059] III. Bag Replacement Instructions

[0060] The aforementioned continuous casting ladle replacement refers to a situation where, after the continuous casting tundish 9 begins casting, its service life exceeds the time required for the ladle 8 to cast more than two heats. After each heat of molten steel is poured into the ladle 8, the prepared ladle of refined and qualified molten steel is transferred to the casting position, while the empty ladle in the casting position is transferred to the prepared position. After the full ladle of molten steel begins casting, the molten steel is introduced into the tundish 9 through the ladle's long nozzle 4 in a multi-heat continuous casting mode until the tundish 9 reaches its service life.

[0061] IV. Experimental Comparison

[0062] The casting curve for producing bearing steel using this invention is shown below. Figure 7 During the casting process, the liquid level in the crystallizer and the stopper rod curve remained stable. Inclusions were randomly sampled from three tundishes for analysis, with each sample having an analysis area of ​​100 mm². The analysis results are shown below. Figures 8-10 The total number of inclusions is 59-81, and the number of spinels is 26-35 (the area within the circle in the phase diagram).

[0063] Bearing steel not produced using the apparatus and production method of this invention, i.e., using manual sand collection without removing slag from the impact zone, shows the crystallizer liquid level and stopper rod curve during production. Figure 11 During the casting process, the stopper rod rose, causing fluctuations in the liquid level. Three random samples were taken from the tundish for analysis of inclusions. The analyzed sample area was 100 mm². The inclusion analysis results are shown below. Figures 12-14 The total number of inclusions is 171-239, and the number of spinels is 111-135 (the area within the circle in the phase diagram).

[0064] The comparison shows that, by using the device and production method of the present invention, the total number of inclusions in bearing steel is reduced by about 65-75%, the number of spinels is reduced by about 74-80%, and the stopper rod and liquid level curve are more stable during the casting process. This indicates that the present invention effectively solves the problems of slag entrapment caused by the diversion sand contaminating the molten steel and the impact covering agent during the initial casting.

[0065] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for preventing slag entrapment during continuous casting ladle changing, characterized in that: Includes a sand removal device (2) and a slag removal device (3) installed in the tundish impact zone (1); The sand discharge device (2) includes a sand discharge plate (2-1), which is inclinedly set on a fixed frame in the impact zone (1) of the tundish, and is used to guide the diverting sand (5) flowing out of the drain outlet of the ladle (8) into the collection tank (10) outside the tundish (9); The slag removal device (3) includes a slag removal plate (3-2) and a slag removal plate telescopic rod (3-1) set on the left and right sides of the tundish impact zone (1). The slag removal plate extends to the junction of the covering agent (7) and the molten steel surface directly below the ladle long nozzle (4), and can be switched between closed and open states to push the covering agent to both sides before pouring.

2. The device for preventing slag entrapment during continuous casting ladle changing according to claim 1, characterized in that: The sand discharge plate (2-1) is made of a wooden board with a thickness of 2-5mm. Its width is 2-3 times the outer diameter of the large package long water outlet (4). Sand-blocking side plates are provided on both sides of the width direction of the sand discharge plate.

3. The device for preventing slag entrapment during continuous casting ladle changing according to claim 1, characterized in that: The fixed frame includes a vertical beam (2-3), and a bottom crossbeam (2-4) fixed on the working layer of the impact zone (1) of the tundish is installed at the bottom of the vertical beam (2-3). A suspension crossbeam (2-5) is installed at the top of the vertical beam (2-3). The sand discharge plate (2-1) is suspended on the suspension crossbeam (2-5) through the fixed crossbeam (2-2) on its back side, and the outlet end of the sand discharge plate (2-1) rests on the working layer on the back side of the tundish (9), so that the sand discharge plate (2-1) forms an angle of 30 to 45 degrees with the horizontal plane.

4. The device for preventing slag entrapment during continuous casting ladle changing according to claim 1, characterized in that: After the slag removal plates (3-2) are opened, the distance between the two slag removal plates is 2 to 3 times the outer diameter of the large package long water inlet (4).

5. The device for preventing slag entrapment during continuous casting ladle changing according to claim 1, characterized in that: The intermediate tundish (9) is also provided with a slag retaining wall (6) that separates the intermediate tundish impact zone (1) and the casting zone.

6. A production method for preventing slag entrapment during continuous casting ladle changing using the apparatus described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: After refining, the molten steel with the required composition and temperature is hoisted to the continuous casting ladle turret and the molten steel is rotated to the pouring position. When the ladle (8) is at the highest pouring position, the ladle long nozzle (4) is fitted onto the ladle bottom nozzle. Step 2: Place the sand removal plate (2-1) on the fixed frame of the tundish impact zone (1) and extend the slag removal plate (3-2) directly below the long nozzle (4) of the tundish impact zone (1). The slag removal plate (3-2) enters the interface between the molten steel surface and the covering agent (7) on the molten steel surface. At this time, the slag removal plate is in the closed state. Step 3: Open the long nozzle (4) of the ladle. The guide sand (5) filled at the bottom of the ladle and placed at the bottom of the upper nozzle flows out. The guide sand flows along the sand discharge plate (2-1) into the collection tank (10) after the tundish (9). At this time, open the slag removal plate (3-2) in the impact zone (1) of the tundish. When all the guide sand flows out, the molten steel flows down and breaks through or burns the sand discharge plate (2-1), and the molten steel enters the tundish (9). Step 4: The ladle (8) is lowered to the lowest position, the ladle long nozzle (4) is inserted into the molten steel in the impact zone, and the slag removal plate (3-2) is retracted to the ready position to complete the ladle change and pouring work.

7. The production method for preventing slag entrapment during continuous casting ladle replacement according to claim 6, characterized in that: The term "continuous casting ladle change" refers to the process where, after the continuous casting tundish (9) is started to be cast, the service life of the tundish (9) is longer than the time it takes for the ladle (8) to be cast for more than two heats. After each heat of molten steel is cast, the ladle (8) is prepared to be moved from the fully smelted ladle to the casting position, and the empty ladle in the casting position is moved to the preparation position. After the fully smelted ladle is started to be cast, the molten steel is put into the tundish (9) through the ladle long nozzle (4) in a multi-heat continuous casting mode until the tundish (9) reaches the end of its service life.

8. The production method for preventing slag entrapment during continuous casting ladle replacement according to claim 6, characterized in that: In step 3, when the large ladle nozzle is opened and the sand (5) flows down, the slag removal plate extension rod (3-1) is opened simultaneously, and the slag removal plate (3-2) retracts to both sides, and the slag removal plate removes all the coating agent (7) on the surface of the molten steel in the impact zone (1).

9. The production method for preventing slag entrapment during continuous casting ladle replacement according to claim 6, characterized in that: In step 4, the slag removal plate is retracted to the ready position, that is, the telescopic rod (3-1) retracts the slag removal plate (3-2) to both sides of the tundish impact zone (1).

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