Magnesium-silicon-aluminum submersed nozzle lining material and application

Abstract

The invention discloses a magnesium-silicon-aluminum submersed nozzle lining material which comprises the following components in percentage by mass: 88%-98% of a base material, 1-10% of an additive; 0.5%-3% of a melting point regulator; the matrix material comprises MgO-SiO2-Al2O3 ternary components which are distributed in a range limited by a connecting line of four specific points A, B, C and D of a MgO-SiO2-Al2O3 ternary phase diagram and two liquidus lines at 1600 DEG C and 1700 DEG C; the method can be applied to continuous casting submersed nozzles, can also be applied to the high-temperature-resistant industry fields such as anti-blocking of steel ladle long nozzles adopting aluminum deoxidized steel and anti-nodulation of tundish stopper rods, and solves the problem that the submersed nozzles are easy to nodulate and block in the pouring process of aluminum deoxidized steel such as automobile sheets at present; the volume density of the magnesium-silicon-aluminum submersed nozzle lining material is 2.65-2.80 g / cm < 3 >, the apparent porosity is 10-15%, and the thermal shock resistance is gt; and 10 times (1100 DEG C-water cooling) are carried out, and the number of continuous casting furnaces in the actual use process is 8-15 times.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steelmaking continuous casting, and particularly relates to a submerged nozzle inner lining material and application. BACKGROUND

[0002] As an important process in steelmaking production, the continuous casting crystallizer determines the quality of the final casting blank. The use of the submerged nozzle in the crystallizer plays a crucial role, and its main functions include: preventing secondary oxidation and splashing of molten steel, preventing molten steel from being wrapped in slag, improving the flow field, temperature field and injection speed of molten steel in the continuous casting crystallizer, ensuring uniform growth of the continuous casting blank, and having a certain effect on the removal of inclusions and gas in the molten steel, preventing inclusions from being wrapped into the molten steel to cause molten steel inclusions. Submerged nozzle blockage not only causes the crystallizer steel flow to be disorderly, but more importantly, it is easy to produce crystallizer slag wrapping, which ultimately reduces the quality of the casting blank.

[0003] From the published literature, it can be found that Japanese patent (Tokukaihei 3-81057) proposes a method for preventing alumina from adhering to the submerged nozzle in molten steel continuous casting. The method mainly blows inert gas into the inner wall of the submerged nozzle or blows inert gas from the tundish slide gate control position to achieve the effect of cleaning the inner wall, thereby reducing the enrichment of alumina on the inner wall. In actual use, as the pouring time is prolonged, the anti-blocking effect is not good in the later pouring period. Subsequently, Chinese patent (CN106396711B) proposes a submerged nozzle magnesium-zirconium eutectic side hole material. The invention mainly uses magnesium-zirconium sand and graphite powder as the main raw material for preparation. It is reported that the invention can greatly improve the thermal shock resistance and erosion resistance of the submerged nozzle. This nozzle will have a certain effect in the early pouring stage, but since the bulk material mainly consists of Mg-C, in the process of pouring aluminum-killed steel, Mg and Al will react, which will accelerate the enrichment of alumina on the inner wall of the nozzle in the later stage, and still cause the nozzle to be blocked. Therefore, the development of a new type of submerged nozzle anti-blocking material to reduce the blockage of the continuous casting submerged nozzle is of great significance to improve the efficiency of continuous casting production. SUMMARY

[0004] In view of the above technical problems, the present application provides a magnesium-silicon-aluminum submerged nozzle inner lining material and application. The material has the characteristics of good anti-blocking effect and long service life during use, and can not only be applied to continuous casting submerged nozzles, but also can be applied to high-temperature resistant industry fields such as steel ladle long nozzle anti-blocking and tundish stopper anti-nodulation for aluminum-killed steel, overcoming the problem of easy nodulation and nozzle blockage of the submerged nozzle in the process of pouring aluminum-killed steel such as automobile panel, and is expected to be widely used in large-scale production and application.

[0005] To achieve the above purpose, the technical scheme is as follows: A magnesium-silicon-aluminum submerged nozzle inner lining material, which comprises the following components in terms of mass percentage: Base material 88-98%; additives 1-10%; melting point regulator 0.5-3%; The base material comprises MgO-SiO2-Al2O3 ternary components, and the content is above 90%wt; wherein the ratio of MgO, SiO2 and Al2O3 is within the range defined by the line connecting four points A, B, C and D in the MgO-SiO2-Al2O3 ternary phase diagram; wherein the composition of point A is Al2O3 content of 4wt%, SiO2 content of 89wt% and MgO content of 7wt%; the composition of point B is Al2O3 content of 10wt%, SiO2 content of 85wt% and MgO content of 5wt%; the composition of point C is Al2O3 content of 6wt%, SiO2 content of 68wt% and MgO content of 26wt%; and the composition of point D is Al2O3 content of 2wt%, SiO2 content of 68wt% and MgO content of 30wt%.

[0006] In the optimized scheme, the composition is as follows in terms of mass percentage: Base material 90-98%; additives 3-7%; melting point regulator 1-3%.

[0007] In the optimized scheme, the ratio of MgO, SiO2 and Al2O3 is between the two liquidus lines of 1600℃ and 1700℃ in the MgO-SiO2-Al2O3 ternary phase diagram.

[0008] According to the above scheme, the ratio of each raw material in the base material is calculated according to the composition point component in the ternary phase diagram, and the base material raw material is selected from corundum, light-burned or sintered magnesite, silica or quartz; wherein the particle size range of the base material is 3-1mm 20-30%, 1-0.5mm 30-40%, 0.5-0.088mm 20-35%, and less than 0.088mm 10-15%.

[0009] According to the above scheme, the additives are one or a combination of several of MgAlON, AlON, SiAlON and MgAl2O4; the particle size range is 1-0.5mm 35-65% and 0.5-0.088mm 35-65%.

[0010] According to the above scheme, the melting point regulator uses one or a combination of several of TiO2, CaF2, Na2O, MnO, FeO and ZrO2 to adjust and control the melting point of the lining material compound, and the particle size range is 0.3-0.088mm.

[0011] The application also provides a clogging-preventing submerged nozzle, comprising an outer layer, a body and an inner lining, wherein the inner lining is sintered from the magnesium-silicon-aluminum submerged nozzle lining material, and the thickness of the inner lining after sintering is 8-15 mm; the outer layer material is refractory fiber, and the body material is aluminum-carbon, zirconium-carbon or aluminum-zirconium-carbon.

[0012] The application also provides a preparation method of the clogging-preventing submerged nozzle, comprising the following steps: (1) selecting a base material, additives and a melting point regulator according to the design ratio of the magnesium-silicon-aluminum submerged nozzle lining material to obtain the lining material; (2) arranging the body first and then the lining material, and then forming by isostatic pressing; (3) sintering by nitrogen protection, argon protection or carbon embedding; (4) after sintering, binding the prefabricated refractory fiber to the outer side of the body to form an outer layer heat preservation structure, and finally obtaining the clogging-preventing submerged nozzle.

[0013] According to the above scheme, in step (1), the raw materials of the lining material are mixed by a planetary ball mill, and the mixing is alternately performed in forward and reverse directions at a speed of 200-300 r / min, and the direction is changed every 5 min, and the mixing time is 30-60 min.

[0014] According to the above scheme, in step (2), the isostatic pressing pressure is 150-300 MPa, and the pressure maintaining time is 10-25 min.

[0015] According to the above scheme, in step (3), the sintering temperature is 1480-1580 ℃, and the holding time is 3-5 h.

[0016] According to the above scheme, in step (4), the refractory fiber is aluminum silicate fiber or aluminum oxide fiber.

[0017] Compared with the prior art, the application has the following beneficial effects: The clogging-preventing lining material of the application is designed in a phase diagram, and in actual production, the enrichment of aluminum oxide increases and reacts with the clogging-preventing material. According to the phase diagram principle, the reaction product moves along the composition design point and Al2O3 line to the low melting point area, and is melted and lost into the crystallizer under the driving of the steel flow, so that the aluminum oxide is not enriched in the inner wall of the nozzle, thereby eliminating the nozzle clogging.

[0018] The additive is one or a combination of MgAlON, AlON, SiAlON and MgAl2O4, and the AlON material has small wettability with molten steel, so that the slag erosion resistance of the lining material can be improved by using MgAlON, AlON, SiAlON and MgAl2O4 as the second phase additive. Meanwhile, Al2O3 is a trigonal system, and AlON is mainly a spinel cubic system, and the interface energy between the two is high, so that the Al2O3 inclusions in the molten steel are not easy to be enriched on the surface of the lining material during high-temperature use, so as to achieve the purpose of reducing the nozzle blockage.

[0019] The melting point regulator adopts one or a combination of TiO2, CaF2, Na2O, MnO, FeO and ZrO2, and the function of the melting point regulator is to maintain the high temperature refractoriness of the mixture in the temperature range formed by the connection line of A, B, C and D points, so that even if the Al2O3 reacts with the lining material during use, the melting point of the reaction product will move to the low melting point area, so as to be melted and dropped under the driving of the high-temperature molten steel, and also play a role in preventing blockage.

[0020] The present application has the characteristics of good anti-blocking effect during use and long service life. Not only can it be applied to continuous casting submerged nozzles, but also can be applied to high-temperature industry fields such as steel ladle long nozzle anti-blocking and tundish stopper anti-nodulation, and can overcome the problem of easy nodulation and blockage of submerged nozzles during the pouring process of aluminum deoxidized steel such as automobile plate, and is expected to be widely used in large-scale production and application.

[0021] The bulk density of the magnesium-silicon-aluminum submerged nozzle lining material of the present application is 2.65-2.80 g / cm 3 , the apparent porosity is 10-15%, the thermal shock stability is >10 times (1100℃-water cooling), and the actual use process is 8-15 times of continuous casting. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The ternary phase ratio adopted by the present application is in the range of MgO-SiO2-Al2O3 ternary phase diagram.

[0023] Figure 2 The structure diagram of the anti-blocking submerged nozzle for crystallizer of the present application is shown.

[0024] Figure 3 The position of the ternary phase ratio adopted in examples 1-4 in the MgO-SiO2-Al2O3 ternary phase diagram.

[0025] Figure 4 The SEM micrograph of the magnesium-silicon-aluminum lining material in example 1. DETAILED DESCRIPTION

[0026] The following embodiments further illustrate the technical solution of the present invention, but are not intended to limit the scope of protection of the present invention.

[0027] A specific embodiment provides a magnesium-silicon-aluminum lining material, wherein the ternary phase ratio of the matrix material is within the range of the MgO-SiO2-Al2O3 ternary phase diagram, as shown in the appendix. Figure 1 As shown. The matrix material composition of the magnesium-silicon-aluminum lining material is located in... Figure 1 The yellow area in the phase diagram, which is between the liquidus lines 1600-1700℃, is a component-controlled region consisting of the two liquidus lines at 1600℃ and 1700℃, and points A, B, C, and D. Point A has the following composition: Al₂O₃ 4wt%, SiO₂ 89wt%, and MgO 7wt%; point B has 10wt% Al₂O₃ 85wt% SiO₂ 5wt%; point C has 6wt% Al₂O₃ 68wt% SiO₂ 26wt% MgO; and point D has 2wt% Al₂O₃ 68wt% SiO₂ 30wt% MgO.

[0028] The matrix material accounts for 85%-98% of the total matrix material, and the proportion of each raw material in the matrix material is calculated based on the composition points on the phase diagram. In specific embodiments, the available matrix materials are: corundum (Al2O3% content greater than 95%), lightly calcined or sintered magnesia (MgO content greater than 92%), and silica or quartz (SiO2 content greater than 95%). The particle size distribution of the matrix material is as follows: 3-1mm 20-30%, 1-0.5mm 30-40%, 0.5-0.088mm 20-35%, and less than 0.088mm 10-15%.

[0029] The additives comprise 1-10% of the total composition, consisting of one or more of MgAlON, AlON, SiAlON, and MgAl2O4. The particle sizes of the additives are as follows: 1-0.5 mm (35-65%), 0.5-0.088 mm (35-65%).

[0030] The melting point modifier accounts for 0.5%-3% of the total content. The melting point of the lining material compound is adjusted and controlled by adding one or more of TiO2, CaF2, Na2O, MnO, FeO, and ZrO2. The particle size of the melting point modifier is 0.3-0.088 mm.

[0031] A specific embodiment provides a crystallizer anti-clogging immersion water inlet, as shown in the attached document. Figure 2As shown, including outer layer, body and inner liner, wherein the inner liner is sintered from the above magnesium-silicon-aluminum lining material, and the thickness of the inner liner after sintering is 8-15 mm. The outer layer is a certain thickness of refractory fiber (aluminum silicate fiber or alumina fiber), and the body is aluminum carbon, zirconium carbon or aluminum-zirconium carbon.

[0032] The specific embodiment also provides a preparation method of the above anti-blocking submerged nozzle: Preparation of the inner liner mixture: select the matrix material, additives and melting point adjuster according to the designed composition and particle size gradation, mix the materials by using a planetary ball mill, and alternately reverse the rotation at a speed of 200-300 r / min every 5 min, and the mixing time is 30-60 min. The mixed inner liner material and the nozzle body material are arranged in the order of the body and then the inner liner mixture, and then formed by using isostatic pressing, the forming pressure is 150-300 MPa, and the pressure maintaining time is 10-25 min. Subsequently, the submerged nozzle is prepared by nitrogen protection or argon protection or carbon embedding sintering, the final sintering temperature is 1480-1580℃, and the holding time is 3-5 h. After sintering, the thickness of the inner liner material needs to be ensured to be 8-15 mm. After the body and the inner liner combined material are sintered, the prefabricated refractory fiber is bound to the outside of the nozzle body by using a high-temperature adhesive to form an outer layer insulation structure, and finally an anti-blocking submerged nozzle applicable to actual production is obtained.

[0033] Example 1 (1) Design by MgO-SiO2-Al2O3 ternary phase diagram, so that the anti-blocking inner liner material composition is located at the E point in the yellow area of the phase diagram, and the E point composition is Al2O3 content 8wt%, SiO2 content 84wt% and MgO content 8wt%. Figure 3

[0034] (2) Selection of matrix material: the matrix material accounts for 90%, and the corresponding raw materials are selected according to the E point composition. Corundum 8wt% (Al2O3 content 96%), sintered magnesia 8wt% (MgO content 95%) and quartz 84wt% (SiO2 content 96%). Among them, the particle size composition of the matrix material is as follows: 3-1mm 25%, 1-0.5mm 35%, 0.5-0.088mm 30%, and less than 0.088mm 10%.

[0035] (3) Additives: 8%, MgAlON and AlON are combined and added at a ratio of 1:1. The particle size of the additives is as follows: 1-0.5mm 50%, 0.5-0.088mm 50%.

[0036] ​(4) Melting point regulator: 2%, TiO2, CaF2, and MnO are added in a ratio of 1:1:1 to adjust and control the melting point of the lining material compound. The particle size of the melting point regulator is 0.1 mm.

[0037] (5) In this embodiment, the lining is the above-mentioned material, the outer layer is an alumina ceramic fiber, and the body is an aluminum carbonaceous material.

[0038] (6) Preparation of the lining mixture: the base material, additives, and melting point regulator are selected according to the designed composition and particle size gradation, and a planetary ball mill is used for mixing. The mixing is carried out with forward and reverse rotation alternately, the rotation speed is 220 r / min, the direction is changed every 5 min, and the mixing time is 35 min.

[0039] (7) The mixed lining material and the body material are arranged in the order of the body first and then the lining mixture, and then isostatic pressing is used for forming. The forming pressure is 200 MPa, and the pressure holding time is 15 min.

[0040] (8) Subsequently, a submerged entry nozzle is sintered by using nitrogen protection. The final sintering temperature is 1560°C, and the holding time is 3.5 h. After sintering, the thickness of the lining material needs to be ensured to be 10 mm.

[0041] (9) After the body and lining combined material are sintered, the pre-prepared alumina ceramic fiber is bound to the outside of the nozzle body with a high-temperature adhesive to form an outer insulation structure, and finally a practical anti-blocking submerged entry nozzle is obtained.

[0042] (10) Performance test of the magnesium-silicon-aluminum lining material in this embodiment: the volume density of the anti-blocking material is 2.75 g / cm 3 , the apparent porosity is 12%, the thermal shock stability is 15 times (1100°C-water cooling), and the actual use process is 9 times of continuous casting.

[0043] The SEM micrograph of the magnesium-silicon-aluminum lining material obtained in this embodiment is shown in FIG. 1. As can be seen from the figure, the base large particles are wrapped by the second phase, and most of the pores are closed pores. Figure 4

[0044] Example 2 (1) Through the MgO-SiO2-Al2O3 ternary phase diagram design, the anti-blocking lining material composition is located at the F point in the yellow area of the phase diagram. Figure 3 The F point composition is Al2O3 content 10wt%, SiO2 content 77wt%, and MgO content 13wt%; ​(2) Matrix material selection: matrix material accounts for 95%, according to the F point composition to select the corresponding raw materials. Corundum 10wt% (Al2O3 content 97%), sintered magnesia 13wt% (MgO content 94%) and quartz 77wt% (SiO2 content 96%). Among them, the particle size composition of the matrix material is as follows: 3-1mm 20%, 1-0.5mm 37%, 0.5-0.088mm 32%, less than 0.088mm 11%; (3) Additives: 4%, MgAlON and SiAlON are combined and added according to 1:2. The particle size of the additive is as follows: 1-0.5mm 60%, 0.5-0.088mm 40%.

[0045] (4) Melting point regulator: 1%, add TiO2, Na2O and MnO, add according to 2:1:1, adjust and control the melting point of the lining material compound. The particle size of the melting point regulator is 0.2mm.

[0046] (5) In this embodiment, the lining is the above-mentioned material, the outer layer is aluminum silicate ceramic fiber, and the body is aluminum zirconium carbon.

[0047] (6) Preparation of lining mixture: select matrix material, additives and melting point regulator according to the designed composition point and particle size gradation, mix with planetary ball mill, adopt forward and reverse rotation alternately during mixing, rotation speed 260r / min, change direction every 5min, mixing time 30min.

[0048] (7) The mixed lining material and the body material are arranged in the order of body first and then lining mixture, and then formed by isostatic pressing, forming pressure 250MPa, pressure holding time 20min.

[0049] (8) Then, sinter the prepared submerged entry nozzle in argon protection mode, the final sintering temperature is 1550℃, the holding time is 4h, after sintering, the thickness of the lining material needs to be ensured to be 12mm.

[0050] (9) After the body and lining combined material are sintered, the prefabricated aluminum silicate ceramic fiber is bound outside the nozzle body with high temperature adhesive to form an outer insulation structure, and finally a anti-blocking submerged entry nozzle for actual production application is obtained.

[0051] (10) Performance test of magnesium silicon aluminum lining material in this embodiment: the volume density of the anti-blocking material is 2.72g / cm 3 , apparent porosity 13%, thermal shock resistance 16 times (1100℃-water cooling), actual use process continuous casting furnace number 10 times.

[0052] Example 3 (1) The base component is designed through the MgO-SiO2-Al2O3 ternary phase diagram, so that the anti-blocking lining material component is located at the G point in the yellow area of the phase diagram, and the G point component is Al2O3 content of 7wt%, SiO2 content of 75wt%, and MgO content of 18wt%; Figure 3 (2) Base material selection: the base material accounts for 93%, and the corresponding raw materials are selected according to the G point composition. Corundum 7wt% (Al2O3 content 96%), light burned magnesite 18wt% (MgO content 93%), and silica 75wt% (SiO2 content 96.5%). Among them, the particle size composition of the base material is as follows: 3-1mm 28%, 1-0.5mm 34%, 0.5-0.088mm 25%, and less than 0.088mm 13%;

[0053] (4) Melting point regulator: 2%, TiO2, CaF2, and ZrO2 are added according to 2:1:1 to adjust and control the melting point of the lining material compound. The particle size of the melting point regulator is 0.15mm.

[0054] (5) In this embodiment, the lining is the above-mentioned material, the outer layer is alumina ceramic fiber, and the body is zirconium carbon.

[0055] (6) Preparation of lining mixture: select the base material, additive and melting point regulator according to the designed composition point and particle size gradation, mix with a planetary ball mill, and use forward and reverse rotation alternately during mixing, with a speed of 280r / min, change direction every 5min, and mixing time is 40min.

[0056] (7) The mixed lining material and the body material are arranged in the order of body first and then lining mixture, and then formed by isostatic pressing, with a forming pressure of 180MPa and a pressure holding time of 25min.

[0057] (8) Then, the submerged entry nozzle is sintered by carbon-protected sintering, the final sintering temperature is 1580℃, the holding time is 4.5h, and after sintering, the lining material thickness needs to be ensured to be 13mm.

[0058] (9) After the body and lining combined material is sintered, the pre-prepared alumina ceramic fiber is bound outside the nozzle body with high temperature adhesive to form an outer insulation structure, and finally an anti-blocking submerged entry nozzle for actual production application is obtained.

[0059] ​​(10) The performance of the magnesium-silicon-aluminum lining material in this embodiment is tested: the volume density of the anti-blocking material is 2.68 g / cm 3 , the apparent porosity is 14%, the thermal shock resistance is 12 times (1100°C-water cooling), and the continuous casting furnace number during actual use is 8.

[0060] Example 4 (1) The base component is designed through the MgO-SiO2-Al2O3 ternary phase diagram, so that the anti-blocking lining material component is located at point H in the yellow area of the phase diagram. The H point component is Al2O3 content of 6wt%, SiO2 content of 73wt%, and MgO content of 21wt%; Figure 3 (2) Base material selection: base material accounts for 96%, and the corresponding raw materials are selected according to the H point composition. Corundum 6wt% (Al2O3 content 97%), sintered magnesia 21wt% (MgO content 95%), and silica 73wt% (SiO2 content 96%). Among them, the particle size composition of the base material is as follows: 3-1mm 24%, 1-0.5mm 36%, 0.5-0.088mm 26%, and less than 0.088mm 14%; (3) Additives: 3%, AlON, SiAlON, and MgAl2O4 are combined and added according to the ratio of 2:2:1. The particle size of the additives is as follows: 1-0.5mm 45%, 0.5-0.088mm 55%.

[0061] (4) Melting point regulator: 1%, CaF2, MnO, FeO, and ZrO2 are added according to the ratio of 1:1:1:1 to adjust and control the melting point of the lining material compound. The particle size of the melting point regulator is 0.15mm.

[0062] (5) In this embodiment, the lining is the above-mentioned material, the outer layer is zirconium silicate ceramic fiber, and the body is aluminum-zirconium-carbon.

[0063] (6) Preparation of lining mixture: select the base material, additives, and melting point regulator according to the designed composition point and particle size gradation, mix the materials using a planetary ball mill, and use forward and reverse rotation alternately during mixing, with a speed of 230r / min, changing direction every 5min, and mixing time of 50min.

[0064] (7) The mixed lining material and the body material are arranged in the order of body first and then lining mixture, and then formed by isostatic pressing, with a forming pressure of 270MPa and a pressure holding time of 18min.

[0065] ​(8) Then, the sintering of the immersion nozzle is carried out under the protection of nitrogen, the final sintering temperature is 1520℃, the holding time is 4.2h, and after sintering, the thickness of the inner lining material is required to be 14mm.

[0066] (9) After the sintering of the body and the inner lining material is completed, the prefabricated zirconium silicate ceramic fiber is bound to the outside of the nozzle body with a high-temperature adhesive to form an outer thermal insulation structure, and finally an anti-blocking immersion nozzle for actual production application is obtained.

[0067] Performance test of the magnesium-silicon-aluminum lining material in this embodiment: the bulk density is 2.73g / cm 3 , the apparent porosity is 13.6%, the thermal shock resistance is 12 times (1100℃-water cooling), and the number of continuous casting furnaces in actual use is 12 times.

[0068] Comparative Example 1 Repeat Example 1, the composition of the MgO-SiO2-Al2O3 ternary phase is designed as Al2O3 content 4.2wt%, SiO2 content 63.63wt% and MgO content 32.17wt%, and the rest of the process remains unchanged.

[0069] Performance test of the magnesium-silicon-aluminum lining material in this embodiment: the bulk density is 2.85g / cm 3 , the apparent porosity is 17%, the thermal shock resistance is 8 times (1100℃-water cooling), and the number of continuous casting furnaces in actual use is 4 times.

[0070] Comparative Example 2 Repeat Example 1, cancel the addition of the melting point regulator, and the rest of the process remains unchanged.

[0071] The performance test of the lining material shows that the bulk density is 2.62g / cm 3 , the apparent porosity is 19%, the thermal shock resistance is 6 times (1100℃-water cooling), and the number of continuous casting furnaces in actual use is 3 times.

[0072] Comparative Example 3 Repeat Example 1, cancel the addition of the additive, and the rest of the process remains unchanged.

[0073] The performance test of the lining material shows that the bulk density is 2.52g / cm 3 , the apparent porosity is 25%, the thermal shock resistance is 3 times (1100℃-water cooling), and the number of continuous casting furnaces in actual use is 2 times.

Claims

1. A magnesium-silicon-aluminum immersion nozzle liner material, characterized in that... The composition, expressed as a percentage by mass, is as follows: Matrix material 88%-98%; Additives 1-10%; Melting point modifier 0.5%-3%; The matrix material comprises a ternary composition of MgO-SiO2-Al2O3, with a content of over 90% wt. The proportions of MgO, SiO2, and Al2O3 fall within the range defined by the lines connecting points A, B, C, and D of the MgO-SiO2-Al2O3 ternary phase diagram. Specifically, point A contains 4 wt% Al2O3, 89 wt% SiO2, and 7 wt% MgO; point B contains 10 wt% Al2O3, 85 wt% SiO2, and 5 wt% MgO; point C contains 6 wt% Al2O3, 68 wt% SiO2, and 26 wt% MgO; and point D contains 2 wt% Al2O3, 68 wt% SiO2, and 30 wt% MgO. In an optimized formulation, the matrix material comprises 90%-98% MgO, additives 3-7%, and melting point modifiers 1%-3%.

2. The magnesium-silicon-aluminum immersion nozzle liner material as described in claim 1, characterized in that... The ratio of MgO, SiO2, and Al2O3 lies between the two liquidus lines at 1600℃ and 1700℃ in the MgO-SiO2-Al2O3 ternary phase diagram.

3. The magnesium-silicon-aluminum immersion nozzle liner material as described in claim 1, characterized in that... The proportions of each raw material in the matrix material are calculated based on the composition of the ternary phase diagram. The raw materials of the matrix material are selected from corundum, lightly calcined or sintered magnesia, silica or quartz. The particle size range of the matrix material is: 3-1mm 20-30%, 1-0.5mm 30-40%, 0.5-0.088mm 20-35%, and less than 0.088mm 10-15%.

4. The magnesium-silicon-aluminum immersion nozzle liner material as described in claim 1, characterized in that... The additive is one or a combination of several of MgAlON, AlON, SiAlON and MgAl2O4; particle size range: 1-0.5mm 35-65%, 0.5-0.088mm 35-65%.

5. The magnesium-silicon-aluminum immersion nozzle liner material as described in claim 1, characterized in that... The melting point regulator is one or a combination of several of TiO2, CaF2, Na2O, MnO, FeO and ZrO2, with a particle size range of 0.3-0.088 mm.

6. A clog-resistant immersion water inlet, characterized in that... It includes an outer layer, a body, and an inner lining, wherein the inner lining is sintered from the magnesium-silicon-aluminum immersion nozzle lining material described in claim 1, and the thickness of the inner lining after sintering is 8-15mm; the outer layer material is refractory fiber, and the body material is aluminum-carbon, zirconium-carbon, or aluminum-zirconium-carbon.

7. The method for preparing the anti-clogging submersible water inlet according to claim 6, characterized in that... Includes the following steps: (1) Select the matrix material, additives and melting point modifier according to the design ratio of the magnesium-silicon-aluminum immersion nozzle liner material according to claim 1, and mix them to obtain the liner material; (2) The inner lining material and the sprue body material are laid out in the manner of first arranging the body and then arranging the inner lining material, and then formed by isostatic pressing. (3) Sintering treatment is carried out by nitrogen protection, argon protection, or carbon embedding sintering; (4) After sintering, the pre-made refractory fiber is bound to the outside of the nozzle body with a high-temperature adhesive to form an outer heat insulation structure, and finally an anti-clogging immersion nozzle is obtained.

8. The method for preparing the anti-clogging submersible water inlet as described in claim 7, characterized in that... In step (1), the raw materials of the lining material are mixed using a planetary ball mill. The mixing process is carried out by alternating forward and reverse rotation at a speed of 200-300 r / min. The direction is changed every 5 minutes, and the mixing time is 30-60 minutes.

9. The method for preparing the anti-clogging submersible water inlet as described in claim 7, characterized in that... In step (2), the medium static pressure molding pressure is between 150-300MPa, and the holding time is 10-25min.

10. The method for preparing the anti-clogging submersible water inlet as described in claim 7, characterized in that... In step (3), the sintering temperature is 1480~1580℃ and the holding time is 3-5h.

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