Green and environment-friendly composite construction type tundish dry material and preparation method thereof

Abstract

The invention discloses an environment-friendly composite construction type tundish dry material and a preparation method thereof, and belongs to the technical field of refractory castable. The invention relates to an environment-friendly composite construction type tundish dry material which is divided into the following three parts according to tundish function partition and damage mechanism difference: a tundish bottom dry material, a tundish wall dry material and a tundish slag line dry material, the ladle bottom dry material is a forsterite dry material; the ladle wall dry material is in Rlt of molten steel in the ladle; when R of the molten steel in the ladle is larger than or equal to 1, the dry material is a ladle wall aluminum-silicon dry material, and when R is larger than or equal to 1, the dry material is a ladle wall magnesium dry material; the ladle slag line dry material is in Rlt of molten steel in the ladle; when R of the molten steel in the ladle is greater than or equal to 1, the dry material is a slag ladle line aluminum-silicon dry material, and when R of the molten steel in the ladle is greater than or equal to 1, the dry material is a slag ladle line magnesium-calcium dry material. According to different damage mechanisms of the tundish bottom, the tundish wall and the slag line area and the potential of hydrogen of molten steel, different dry materials are designed respectively, and through chemical compatibility matching of materials and working conditions, collaborative strengthening of permeation resistance of the tundish bottom, thermal shock resistance of the tundish wall and erosion resistance of the slag line is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of refractory castable, in particular to a green and environment-friendly composite construction type tundish dry mix and a preparation method thereof. BACKGROUND

[0002] The tundish is a container between the ladle and the mould in the continuous casting system, mainly used for distributing molten steel, stabilizing flow, removing inclusions and preventing secondary oxidation, and its performance directly affects the efficiency of continuous casting and the quality of billets. The working lining, as the inner lining material of the tundish, directly contacts with high-temperature molten steel and slag, and needs to have properties such as high-temperature resistance, corrosion resistance and thermal shock resistance. With the rapid rise of China's steel industry, the requirements for tundish refractories are becoming higher and higher.

[0003] In order to adapt to the development trend of long service life of tundish, it is necessary to use higher quality raw materials to improve the performance of refractories. However, the use of high-purity magnesia, spinel and other high-end raw materials significantly increases the production cost of refractories, which poses a serious challenge to the operation of refractory enterprises which are already in a state of small profit.

[0004] Patent CN105837230B provides a tundish composite working lining, a manufacturing method thereof and a tundish. The inner layer of the tundish composite working lining is a dry mix layer, and the outer layer of the composite working lining is a daubing layer. By combining the dry mix layer and the daubing layer into a composite working lining, the advantages of the dry mix layer and the daubing layer are combined, such as convenient construction, not easy to sinter, easy to turn over, and reducing carbon deposition. However, the composition of the dry mix and the daubing layer is different, which can easily cause the tundish working lining to be layered, and it is not easy to realize industrial application.

[0005] Patent CN101823888A provides a working lining with an environmentally friendly binder for a continuous steel casting tundish. The patent uses 92 sintered magnesia 70%, 96 fused magnesia 26-27.5%, SiO2micropowder 0.2%, boric acid 0.8%, and sodium metasilicate nonahydrate 1.5%-3% as raw materials to prepare a working lining made of a dry mix binder made of sodium metasilicate nonahydrate, silica micropowder and boric acid, which eliminates the problem of carbon deposition of molten steel and environmental pollution, but the cost of raw materials is high, and it is not easy to mass produce and apply. Therefore, it is urgent to provide a preparation method of tundish dry mix, which can meet the requirements of large-scale industrial production, has excellent strength, slag erosion resistance, good heat preservation performance and low cost, is suitable for tundish working lining refractories, and can effectively improve the production efficiency. SUMMARY

[0006] The present application provides a green and environment-friendly composite construction type tundish dry mix and a preparation method thereof, which can solve the problem of the preparation method of the tundish dry mix in the prior art that is not conducive to large-scale production and application.

[0007] The object of the present application can be achieved by the following technical solutions: In a first aspect, the present application provides a green and environmentally friendly composite construction intermediate ladle dry material, which is divided into the following three parts according to the functional partitioning of the intermediate ladle and the difference in damage mechanism: bottom dry material, wall dry material and slag line dry material. The bottom dry material is forsterite dry material. The wall dry material is wall aluminum-silicon dry material when the R of the molten steel in the ladle is less than 1, and is wall magnesium dry material when the R of the molten steel in the ladle is greater than or equal to 1. The slag line dry material is slag line aluminum-silicon dry material when the R of the molten steel in the ladle is less than 1, and is slag line magnesium-calcium dry material when the R of the molten steel in the ladle is greater than or equal to 1.

[0008] Further, the forsterite dry material comprises the following raw materials in percentage by weight: Main material: 60-70% of forsterite, 25-35% of RH gunning material rebound material; auxiliary material: 3-5% of inorganic binder.

[0009] Further, the particle size distribution of the forsterite is that the particle size distribution of 5-3mm accounts for 20% of the forsterite, the particle size distribution of 3-1mm accounts for 30% of the forsterite, the particle size distribution of 1-0.088mm accounts for 32% of the forsterite, and the particle size distribution of ≤0.088mm accounts for 18% of the forsterite.

[0010] Further, the RH gunning material rebound material is unreacted refractory material in RH gunning material with a particle size of 5-0mm.

[0011] Further, the inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate, and magnesium sulfate.

[0012] Further, the wall aluminum-silicon dry material comprises the following raw materials in percentage by weight: Main material: 20-30% of high alumina bauxite, 40-50% of high alumina brick regenerated material, and 20-30% of white corundum; auxiliary material: 4-6% of inorganic binder compounded nano silicon dioxide powder binder.

[0013] Further, the particle size distribution of the high alumina bauxite is that the particle size distribution of 3-1mm accounts for 15% of the high alumina bauxite, the particle size distribution of 1-0.088mm accounts for 25% of the high alumina bauxite, and the particle size distribution of ≤0.088mm accounts for 60% of the high alumina bauxite. Further, the particle size distribution of the high alumina brick regenerated material is that the particle size distribution of 5-3mm accounts for 70% of the high alumina brick regenerated material, the particle size distribution of 3-1mm accounts for 25% of the high alumina brick regenerated material, and the particle size distribution of 1-0.088mm accounts for 5% of the high alumina brick regenerated material. Further, the white corundum is white corundum fine powder with a particle size of ≤0.088 mm; Further, the inorganic bonding agent is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate, and magnesium sulfate. Further, the mass ratio of the inorganic bonding agent to the nano-silicon dioxide powder is 3:7.

[0014] Further, the white corundum is white corundum fine powder with a particle size of ≤0.088 mm; Main materials: 15-25% of fused magnesite, 20-25% of fused skin sand, 35-45% of RH gunning material rebound material, and 5-8% of magnesium aluminate spinel; auxiliary materials: 7-9% of solid resin compounded inorganic bonding agent.

[0015] Further, the fused magnesite is fused magnesite with a MgO content of ≥97%. The particle size distribution of the fused magnesite is: 5-3 mm accounts for 25% of the fused magnesite, 3-1 mm accounts for 25% of the fused magnesite, 1-0.088 mm accounts for 23% of the fused magnesite, and ≤0.088 mm accounts for 27% of the fused magnesite.

[0016] Further, the fused skin sand is fused skin sand with a MgO content of ≥92%. The particle size distribution of the fused skin sand is: 3-1 mm accounts for 60% of the fused skin sand, and 3-1 mm accounts for 40% of the fused skin sand.

[0017] Further, the RH gunning material rebound material is unreacted refractory material in RH gunning material with a particle size of 5-0 mm.

[0018] Further, the magnesium aluminate spinel is magnesium aluminate spinel fine powder with a particle size of ≤0.088 mm; Further, the solid resin is 4012 type solid phenolic resin; the inorganic bonding agent is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate, and magnesium sulfate; and the mass ratio of the solid resin to the inorganic bonding agent is 3:2.

[0019] Further, the slag line alumina-silica dry material, by weight percentage, comprises the following raw materials: Main materials: 60-70% of high bauxite, 18-28% of white corundum, and 1-2% of chromium oxide; auxiliary materials: 4-10% of inorganic bonding agent compounded nano-silicon dioxide sol powder bonding agent.

[0020] Further, the particle size distribution of the high bauxite is: 3-1 mm accounts for 20% of the high bauxite, 1-0.088 mm accounts for 30% of the high bauxite, and ≤0.088 mm accounts for 50% of the high bauxite. Further, the particle size distribution of the white corundum is that 3-1mm accounts for 35% of the white corundum, 1-0.088mm accounts for 40% of the white corundum, and <=0.088mm accounts for 25% of the white corundum. Further, the chromium oxide is Cr2O3>=97%, and the particle size is <=0.045mm. Further, the inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate, and magnesium sulfate. The mass ratio of the inorganic binder to the nano-silica sol powder is 3:7.

[0021] Further, the slag line magnesium-calcium dry material comprises the following raw materials in percentage by weight: Main material: 65-75% of fused magnesite, and 23-30% of light-burned dolomite; auxiliary material: 2-5% of inorganic binder compounded with organic binder.

[0022] Further, the fused magnesite is MgO content >=97%, and the particle size distribution of the fused magnesite is that 5-3mm accounts for 22% of the fused magnesite, 3-1mm accounts for 25.5% of the fused magnesite, 1-0.088mm accounts for 15% of the fused magnesite, and <=0.088mm accounts for 37.5% of the fused magnesite. Further, the particle size distribution of the light-burned dolomite is that 3-1mm accounts for 30% of the light-burned dolomite, and 1-0.088mm accounts for 70% of the light-burned dolomite. Further, the inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate, and magnesium sulfate; the organic binder is one or more of monohydrate glucose, polyhydroxy sugar, and PVP; and the mass ratio of the inorganic binder to the organic binder is 1:3.

[0023] In a second aspect, the application provides a preparation method of a green and environment-friendly composite construction type tundish dry material, which comprises the following steps: The main material and the auxiliary material are mixed and stirred, the mixed powder is put into a ton bag with a plastic liner and sealed for preservation, and a tundish dry material is obtained.

[0024] The application has the following beneficial effects: 1. Functionally divided and accurately matched with material: magnesium / magnesia-silica, forsterite / high-alumina, and aluminous / magnesium-calcium dry materials are respectively designed for different damage mechanisms and steel acid-base degrees of tundish bottom, tundish wall, and slag line, so that the chemical compatibility of material and working condition is matched, and the synergistic strengthening of tundish bottom anti-permeation, tundish wall anti-thermal shock, and slag line anti-erosion is realized.

[0025] 2. Environmentally friendly system: The dry material system for the bottom and wall of this invention incorporates some recycled and rebound materials as raw materials, reducing material costs and alleviating waste disposal problems. At the same time, the rough and porous surface of the used brick particles can form a mechanical interlocking structure when combined with new materials, improving the overall density and impermeability of the material, making it suitable for scenarios where the bottom of the bag is resistant to molten steel erosion.

[0026] 3. The invention has significant comprehensive benefits. Industrial verification has shown that this technology reduces the cost of refractory materials per ton of steel and reduces baking energy consumption, thus combining economic efficiency with environmental friendliness.

[0027] 4. This invention uses highly active magnesium olivine and multi-graded magnesia (0.1-3mm accounting for ≥75%) to form a "skeleton-micropore" gradient structure through particle stacking optimization.

[0028] 5. This invention introduces lightly calcined dolomite compounded with phosphate binder into the dry feed of magnesium-calcium slag line. Through low-temperature pre-baking, a calcium silicate-organic composite film layer is generated in situ on the surface of the dolomite, which blocks the contact between CaO and air moisture, reduces the hydration rate of the calcium source, and significantly improves the stability of the material. Detailed Implementation

[0029] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0030] Example 1

[0031] A method for preparing a green and environmentally friendly composite construction-type dry material for tundishes, applicable to the bottom of tundishes, wherein the dry material for the bottom is a magnesium olivine dry material. The preparation method described in this embodiment is as follows: The raw materials consist of 65% forsterite, 31% RH shot refractory rebound material, and 4% inorganic binder. The forsterite particle size distribution is as follows: 20% forsterite with a particle size of 5-3mm, 30% forsterite with a particle size of 3-1mm, 32% forsterite with a particle size of 1-0.088mm, and 18% forsterite with a particle size of ≤0.088mm. The RH shot refractory rebound material is the unreacted refractory material in the RH shot refractory with a particle size of 5-0mm. The inorganic binder contains sodium hexametaphosphate, boric acid, and magnesium sulfate in a mass ratio of 0.5:1.5:2.

[0032] Mix the above raw materials evenly in a V-type mixer for 5 minutes, put the mixed powder into a ton bag with a plastic inner liner and seal it for storage, and you will get the green and environmentally friendly composite construction type intermediate tundish bottom magnesium olivine dry material powder.

[0033] Example 2

[0034] The application discloses a preparation method of a green and environment-friendly composite construction type tundish dry charge, which is suitable for a tundish wall with slag acid-base degree R<1, and the tundish wall dry charge is an alumina-silica dry charge. The green and environment-friendly composite construction type tundish dry charge is prepared from 26% of high bauxite, 44% of high alumina brick regenerated material, 25% of white corundum and 5% of inorganic binder compounded nano silicon dioxide sol powder as raw materials.

[0035] The above raw materials are uniformly stirred in a V-type mixing mill for 5 min, the mixed powder is placed in a ton bag with a plastic liner and sealed, and the green and environment-friendly composite construction type tundish bottom magnesio-olivine dry charge powder is obtained.

[0036] Example 3

[0037] The application discloses a preparation method of a green and environment-friendly composite construction type tundish dry charge, which is suitable for a tundish wall with slag acid-base degree R≥1, and the tundish wall dry charge is an alumina-silica dry charge. The green and environment-friendly composite construction type tundish dry charge is prepared from 26% of high bauxite, 44% of high alumina brick regenerated material, 25% of white corundum and 5% of inorganic binder compounded nano silicon dioxide sol powder as raw materials.

[0038] The above raw materials are stirred uniformly in a V-type mixing mill for 5 min, and the mixed powder is placed in a ton bag with a plastic liner and sealed for preservation, to obtain the green and environmentally friendly composite construction type magnesio-olivine dry material powder for tundish bottom.

[0039] Example 4

[0040] The application discloses a preparation method of a green and environmentally friendly composite construction type tundish dry material, which is suitable for a tundish slag line with a slag acid-alkalinity R<1, and the slag line dry material is an aluminum-silicon dry material. The inorganic binder is prepared by compounding nano-silica sol powder with 65% high bauxite, 28% white corundum, 2% chromium oxide and 5% inorganic binder. The particle size distribution of the high bauxite is that 20% of the high bauxite is 3-1 mm, 30% of the high bauxite is 1-0.088 mm, and 50% of the high bauxite is less than 0.088 mm; the particle size distribution of the white corundum is that 35% of the white corundum is 3-1 mm, 40% of the white corundum is 1-0.088 mm, and 25% of the white corundum is less than 0.088 mm; the chromium oxide is Cr2O3≥97% and the particle size is less than 0.045 mm; the mass ratio of the nano-silica sol powder in the inorganic binder is 3:7; and the mass ratio of sodium hexametaphosphate to boric acid in the inorganic binder is 1:2.

[0041] The above raw materials are stirred uniformly in a V-type mixing mill for 5 min, and the mixed powder is placed in a ton bag with a plastic liner and sealed for preservation, to obtain the green and environmentally friendly composite construction type magnesio-olivine dry material powder for tundish bottom.

[0042] Example 5

[0043] The application discloses a preparation method of a green and environmentally friendly composite construction type tundish dry material, which is suitable for a tundish slag line with a slag acid-alkalinity R<1, and the slag line dry material is an aluminum-silicon dry material. The green environmental protection composite construction type magnesia olivine dry material powder is prepared by using 73% of fused magnesia, 23% of light-burned dolomite and 4% of inorganic binder compounded with organic binder as raw materials. The fused magnesia has a MgO content of greater than or equal to 97%, and the particle size distribution of the fused magnesia is as follows: 5-3 mm, accounting for 22% of the fused magnesia; 3-1 mm, accounting for 25.5% of the fused magnesia; 1-0.088 mm, accounting for 15% of the fused magnesia; and less than 0.088 mm, accounting for 37.5% of the fused magnesia. The particle size distribution of the light-burned dolomite is as follows: 3-1 mm, accounting for 30% of the light-burned dolomite; and 1-0.088 mm, accounting for 70% of the light-burned dolomite. The inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate and magnesium sulfate. The organic binder is one or more of glucose monohydrate, polyhydroxy sugar and PVP. The mass ratio of the inorganic binder compounded with the organic binder is 1:3. The mass ratio of sodium hexametaphosphate to boric acid in the inorganic binder is 1:1. The mass ratio of glucose monohydrate to polyhydroxy sugar in the organic binder is 3:1.

[0044] The above raw materials are stirred uniformly in a V-type mixing mill for 5 min, and the mixed powder is placed in a ton bag with a plastic liner and sealed for preservation, thereby obtaining the green environmental protection composite construction type magnesia olivine dry material powder for tundish bottom.

[0045] Test Example 1

[0046] The dry material powders prepared in Examples 1-5 and Comparative Examples 1 and 2 are tested for performance, the cold compressive strength after 1600 DEG C x 3h firing is tested according to GB / T5072-2018, the permanent linear change rate after 1600 DEG C x 3h heat treatment is tested according to GB / T5988-2022, and the slag erosion depth is tested according to GB / T8931-2007 using the static crucible method at 1550 DEG C for 3h, and the test results are shown in Table 1. Table 1

[0047] As shown in Table 1, the dry material powders obtained in Examples 1-5 have excellent performance.

[0048] Test Example 2

[0049] The green environmental protection composite construction type tundish dry material prepared in Examples 1, 3 and 5 is used in the 3# tundish of the 3# continuous casting machine of the Ma Steel Long Material Project Department, and the specific construction process is as follows. Step 1, clean the residual working lining material of the tundish for continuous casting; Step 2, put 1000 kg of the green environmental protection composite construction type tundish dry material into the tundish, flatten and tamp, and the thickness is 90-110 mm. Step 3, the tire mold is hoisted into the tundish and the distance between the tire mold and the permanent lining is adjusted to 90-110mm, then 2000kg green environment-friendly composite construction tundish dry material is put into the tire mold and the permanent lining and vibrated; Step 4, the construction body is baked with 200-300℃ coal gas fire for 2h, and after the tire mold is cooled to room temperature, it is hoisted out and can be put into use.

[0050] According to the field statistics, the green environment-friendly composite construction tundish dry material prepared in examples 1, 3 and 5 is used for 68 furnaces (24 hours and 40 minutes) in total, and the residual thickness is 85mm. From the use of the permanent layer and the residual situation on the surface of the casting, it can be seen that the use is normal, and it is easy to turn the tundish.

[0051] The above disclosed are only several specific embodiments of the present application, but the embodiments of the present application are not limited to this. Any changes that can be thought of by any person skilled in the art shall fall within the protection scope of the present application.

Claims

1. A green and environmentally friendly composite construction type tundish dry mix, characterized by, According to the functional partition of the tundish and the damage mechanism difference, it is divided into the following three parts: dry material of the tundish bottom, dry material of the tundish wall and dry material of the tundish slag line. The dry material of the tundish bottom is forsterite dry material; The dry material of the tundish wall is aluminum-silicon dry material when R<1 of the molten steel in the tundish, and is magnesium dry material when R≥1 of the molten steel in the tundish; The dry material of the tundish slag line is aluminum-silicon dry material when R<1 of the molten steel in the tundish, and is magnesium-calcium dry material when R≥1 of the molten steel in the tundish.

2. The green and environment-friendly composite construction intermediate dry mix according to claim 1, characterized in that, The forsterite dry material comprises the following raw materials in percentage by weight: Main material: 60-70% of forsterite, 25-35% of RH gunning material rebound material; Auxiliary material: 3-5% of inorganic binder.

3. The green and environment-friendly composite construction intermediate dry mix of claim 2, characterized in that, The particle size distribution of the forsterite is that 20% of the forsterite is 5-3mm, 30% of the forsterite is 3-1mm, 32% of the forsterite is 1-0.088mm, and 18% of the forsterite is ≤0.088mm; The RH gunning material rebound material is unreacted refractory material in RH gunning material with particle size of 5-0mm; The inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate and magnesium sulfate.

4. The green and environment-friendly composite construction intermediate dry mix of claim 1, characterized in that, The aluminum-silicon dry material of the tundish wall comprises the following raw materials in percentage by weight: Main material: 20-30% of high alumina bauxite, 40-50% of high alumina brick regenerated material, 20-30% of white corundum; auxiliary material: 4-6% of inorganic binder compounded nano silicon dioxide powder binder.

5. The green and environment-friendly composite construction intermediate dry mix according to claim 4, characterized in that, The particle size distribution of the high alumina bauxite is that 15% of the high alumina bauxite is 3-1mm, 25% of the high alumina bauxite is 1-0.088mm, and 60% of the high alumina bauxite is ≤0.088mm; The particle size distribution of the high alumina brick regenerated material is that 70% of the high alumina brick regenerated material is 5-3mm, 25% of the high alumina brick regenerated material is 3-1mm, and 5% of the high alumina brick regenerated material is 1-0.088mm; The white corundum is white corundum powder with particle size ≤0.088mm; The inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate and magnesium sulfate; The mass ratio of the inorganic binder compounded nano silicon dioxide powder is 3:

7.

6. The green and environment-friendly composite construction intermediate dry mix of claim 1, characterized in that, The magnesium dry material of the tundish wall comprises the following raw materials in percentage by weight: Main material: 15-25% of fused magnesia, 20-25% of fused skin sand, 35-45% of RH gunning material rebound material, 5-8% of magnesium aluminate spinel; auxiliary material: 7-9% of solid resin compounded inorganic binder.

7. The green and environment-friendly composite construction intermediate dry mix according to claim 6, characterized in that, The fused magnesia is fused magnesia with MgO content ≥97%, and the particle size distribution of the fused magnesia is that 25% of the fused magnesia is 5-3mm, 25% of the fused magnesia is 3-1mm, 23% of the fused magnesia is 1-0.088mm, and 27% of the fused magnesia is ≤0.088mm; The fused skin sand is fused skin sand with MgO content ≥92%, and the particle size distribution of the fused skin sand is that 60% of the fused skin sand is 3-1mm, and 40% of the fused skin sand is 3-1mm. The RH gunning material rebound material is unreacted refractory material in the RH gunning material with a particle size of 5-0 mm; The magnesium aluminate spinel is magnesium aluminate spinel powder with a particle size of ≤0.088 mm; The solid resin is a 4012 type solid phenolic resin; The inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate, and magnesium sulfate; The mass ratio of the solid resin to the inorganic binder is 3:

2.

8. The green and environment-friendly composite construction intermediate dry mix of claim 1, characterized in that, The slag line aluminum-silicon dry material includes the following raw materials in percentage by weight: Main material: 60-70% of high bauxite, 18-28% of white corundum, and 1-2% of chromium oxide; Auxiliary material: 4-10% of inorganic binder compounded nano-silica sol powder binder; The slag line magnesium-calcium dry material includes the following raw materials in percentage by weight: Main material: 65-75% of fused magnesite, and 23-30% of light-burned dolomite; Auxiliary material: 2-5% of inorganic binder compounded organic binder.

9. The green and environment-friendly composite construction intermediate dry mix of claim 8, characterized in that, The particle size distribution of the high bauxite is that 3-1 mm accounts for 20% of the high bauxite, 1-0.088 mm accounts for 30% of the high bauxite, and ≤0.088 mm accounts for 50% of the high bauxite; The particle size distribution of the white corundum is that 3-1 mm accounts for 35% of the white corundum, 1-0.088 mm accounts for 40% of the white corundum, and ≤0.088 mm accounts for 25% of the white corundum; The chromium oxide is chromium oxide powder with Cr2O3≥97% and a particle size of ≤0.045 mm; The inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate, and magnesium sulfate; The mass ratio of the inorganic binder to the nano-silica sol powder is 3:7; The fused magnesite is fused magnesite with MgO content ≥97%, and the particle size distribution of the fused magnesite is that 5-3 mm accounts for 22% of the fused magnesite, 3-1 mm accounts for 25.5% of the fused magnesite, 1-0.088 mm accounts for 15% of the fused magnesite, and ≤0.088 mm accounts for 37.5% of the fused magnesite; The particle size distribution of the light-burned dolomite is that 3-1 mm accounts for 30% of the light-burned dolomite, and 1-0.088 mm accounts for 70% of the light-burned dolomite; The inorganic binder is one or more of sodium hexametaphosphate, boric acid, sodium borate decahydrate, and magnesium sulfate; the organic binder is one or more of monohydrate glucose, polyhydroxy sugar, and PVP; and the mass ratio of the inorganic binder to the organic binder is 1:

3.

10. A method for preparing a green and environmentally friendly composite construction type tundish dry mix for preparing the tundish dry mix according to any one of claims 1 to 9, characterized in that, The method includes the following steps: Mixing and stirring the main material and the auxiliary material, placing the mixed powder into a ton bag with a plastic liner, sealing the ton bag, and obtaining the tundish dry material.

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