Hot gunning material for ladle and preparation method thereof

Abstract

The present invention provides a hot gunning material for a ladle and a preparation method thereof, belonging to the field of oilfield chemical technology. The method comprises the following steps: Step S1: immersing alumina fibers in a nano-zirconia suspension of a certain concentration and drying to obtain a composite material; adding boric acid to the silica sol and stirring uniformly to obtain a modified silica sol; Step S2: mixing magnesia and pretreated steel slag, adding pre-dispersed nano-alumina, continuing stirring, then adding barium zirconate, the composite material, calcium feldspar powder, chromium oxide, borax, yttrium oxide, and a water reducer, stirring at room temperature to obtain a mixed material; Step S3: sequentially adding aluminum dihydrogen phosphate, the modified silica sol, and a sulfonated lignin solution to the mixed material, mixing uniformly, and ultrasonically dispersing to obtain a hot gunning material for a ladle. The present invention can achieve the purpose of a hot gunning material for a ladle having corrosion resistance and good adhesion.

Description

Technical Field

[0001] The invention relates to the technical field of gunning materials, and in particular to a hot gunning material for a ladle and a preparation method thereof. Background Art

[0002] During the steelmaking process, the widespread use of off-furnace refining has led to longer residence times for molten steel within the ladle, increasing the temperature of the ladle lining from 1550°C to over 1700°C. This has widened the fluctuation range of slag alkalinity, exacerbating chemical attack on the magnesia material. Repeated impacts from the molten steel can easily lead to increased mechanical wear in the slag line area. Furthermore, thermal shock and temperature differences can easily induce crack propagation in the lining, making traditional gunning layers susceptible to flaking and deteriorating the ladle's corrosion resistance. Existing gunning materials often have a weak interface with the old ladle lining, typically relying on physical interlocking rather than chemical bonding. The gunning material and lining only make point contact, making it difficult to form a ceramic bond, which can lead to the gunning material easily falling off.

[0003] Patent application publication number CN106007751A discloses a small ladle gunning material, which is prepared by uniformly mixing the following weight percentages: 8%-10% alumina (8-12 mm), 11%-15% alumina (5-8 mm), 12%-15% forsterite (3-5 mm), 10%-15% magnesium spinel (1-3 mm), 30%-35% magnesium spinel (≤1 mm), 3%-5% ZrC powder, 1% Ni2GeO4 powder, 1%-5% plasticizer, and 3-6% binder; the binder is one or a combination of hydrated alumina and sodium hexametaphosphate; the plasticizer is ball clay or dextrin. This invention can repair ladles to a certain extent, but the gunning material prepared by this invention has significantly insufficient resistance to slag erosion and cannot guarantee sufficient adhesion.

[0004] Therefore, it is necessary to provide a method for preparing hot gunning material for ladle to solve the problems existing in the above-mentioned prior art. Summary of the Invention

[0005] In view of this, the present invention provides a hot gunning material for a ladle and a preparation method thereof, which can achieve the purpose of the hot gunning material for a ladle being resistant to corrosion and having good adhesion.

[0006] The specific scheme of the present invention is as follows: a method for preparing hot gunning material for a ladle, comprising the following steps:

[0007] Step S1, immersing alumina fiber in a nano-zirconia suspension with a concentration of 1.5,000,000, and drying to obtain a composite material; adding boric acid to the silica sol and stirring evenly to obtain a modified silica sol;

[0008] Step S2, mixing magnesia and pretreated steel slag, adding pre-dispersed nano-alumina, continuing to stir, then adding barium zirconate, composite material, calcium feldspar powder, chromium oxide, borax, yttrium oxide and water reducer, stirring at room temperature to obtain a mixed material;

[0009] Step S3: adding aluminum dihydrogen phosphate, modified silica sol and sulfonated lignin solution to the mixed material in sequence, mixing evenly, and ultrasonically dispersing the mixture to obtain a hot gunning material for a ladle.

[0010] Magnesia, the primary aggregate, maintains volume stability at high temperatures, provides structural support, and forms a refractory framework. The magnesium oxide in the magnesia reacts with the calcium oxide in the slag to form a high-melting-point phase, which imparts high refractoriness and resists erosion from hot molten steel, enhancing the ladle's heat resistance. Magnesia also reacts with the silicon dioxide in the slag to form forsterite, reducing slag penetration and improving the ladle's erosion resistance.

[0011] Replacing part of the magnesia with pretreated slag reduces costs. The calcium oxide in the slag reacts with alumina to form calcium hexaaluminate, which fills pores and promotes sintering of the gunning mix. Pre-dispersed nano-alumina, used as a secondary aggregate, fills gaps in the primary aggregate, reduces porosity and pores, and shortens sintering time. It also reacts with magnesia to form magnesia-alumina spinel, enhancing the ladle's resistance to high temperatures.

[0012] The barium zirconate in the mixed material has a melting point of 2500-2600°C, far exceeding the ladle's operating temperature. This allows it to maintain structural stability at high temperatures. Furthermore, the high Zr-O bond energy in the barium zirconate lattice makes it less susceptible to dissociation by slag components. This allows it to form an isolation layer on the surface of the gunning layer, preventing slag from penetrating the interior and improving corrosion resistance. Furthermore, barium zirconate forms a gradient matching the thermal expansion coefficient of the primary aggregate, magnesia, buffering thermal stress and reducing crack propagation caused by sudden temperature changes.

[0013] Alumina fiber can inhibit crack propagation through bridging and pull-out mechanisms. After compounding with nano-zirconia to form a composite material, the surface defects of the alumina fiber are filled, thereby enhancing the toughness of the composite material; calcium feldspar powder can form a low-viscosity glass phase at high temperature, fill microcracks, and improve air tightness; manganese oxide and chromium oxide serve as sintering aids, among which manganese ions and chromium ions have high diffusion rates, which can accelerate grain boundary migration and reduce the sintering temperature of the gunning material.

[0014] Borax can reduce the viscosity of the glass phase, promote crack healing, and accelerate the formation of ceramic phase; Y in yttrium oxide 3+It can promote grain boundary stability and enhance thermal shock resistance. Aluminum dihydrogen phosphate can dehydrate to form an AlPO4 network, providing initial adhesion during spraying. Silica sol can provide nano-SiO2 to fill micropores. Moreover, after modification with boric acid (H3BO3), silica sol can form a B2O3-SiO2 glassy phase precursor, further enhancing the adhesion of the gunning material. Polycarboxylate water reducers can disperse particles through electrostatic repulsion, reduce water demand, minimize drying shrinkage, and reduce porosity, thus promoting sintering.

[0015] Preferably, in step S1, the concentration of the nano zirconium oxide solution is 1-3 wt %.

[0016] Nano-chromium oxide helps to isolate oxygen, inhibit oxidation, and prevent phase change of alumina fibers.

[0017] Preferably, in step S1, the stirring speed is 200-300 rpm and the stirring time is 20-40 min.

[0018] Preferably, in step S2, the preparation of pretreated steel slag comprises the following steps: removing iron from the steel slag, crushing it, screening it, and then calcining it at a temperature of 600-700° C. for 1.5-2.5 hours to obtain pretreated steel slag.

[0019] Removing ferrous oxide from the surface of steel slag can prevent the gunning material from falling off due to high-temperature oxidation.

[0020] Preferably, in step S2, the mixing speed is 250-350 rpm and the time is 5-10 min.

[0021] Preferably, in step S2, the preparation of pre-dispersed nano-alumina comprises the following steps: uniformly mixing nano-alumina and sodium polyacrylate in a ratio of 20:1 to obtain pre-dispersed nano-alumina.

[0022] By using sodium polyacrylate to modify nano-alumina, modified nano-alumina is obtained, the dispersibility of the nano-alumina is enhanced, and the modified nano-alumina can be evenly distributed in the gunning material to avoid agglomeration.

[0023] Preferably, in step S2, the stirring speed at room temperature is 400-600 rpm and the stirring time is 10-20 min.

[0024] Preferably, in step S3, the concentration of the sulfonated lignin solution is 18-23 wt%.

[0025] Sulfonated lignin is used as a bio-based dispersant to improve the dispersibility of the gunning material, reduce the rebound of the gunning material during the gunning process, and improve the toughness of the gunning material after high-temperature carbonization.

[0026] To achieve the above object, the present invention further provides a hot gunning material for a ladle prepared by the above method for preparing a hot gunning material for a ladle, comprising the following components in parts by weight:

[0027] 100-120 parts of mixed materials, 6-10 parts of aluminum dihydrogen phosphate, 3-5 parts of modified silica sol and 10-20 parts of sulfonated lignin solution.

[0028] The components of the present invention are used in the above-mentioned weight proportions to achieve better corrosion resistance and high temperature resistance of the gunning material.

[0029] Preferably, the mixed material includes the following components in parts by weight: 60-70 parts of magnesia, 10-15 parts of pretreated steel slag, 3-5 parts of pre-dispersed nano-alumina, 1-3 parts of barium zirconate, 0.5-1 part of yttrium oxide and 0.5-1 part of water reducer.

[0030] Preferably, the water reducing agent is a polycarboxylate.

[0031] The above technical solution of the present invention includes at least the following beneficial effects:

[0032] (1) Magnesia is stable in volume at high temperatures and can form a refractory skeleton. It can also form a high melting point phase with calcium oxide and silicon dioxide in steel slag, which can resist the erosion of high-temperature molten steel, reduce slag penetration, and improve the high temperature resistance and erosion resistance of the ladle.

[0033] (2) Pre-dispersed nano-alumina as an auxiliary aggregate can fill the gaps between the main aggregates, reduce pores, shorten the sintering time, and generate magnesium-aluminum spinel with magnesium oxide, thereby improving the high temperature resistance of the ladle.

[0034] (3) The melting point of barium zirconate is as high as 2500-2600℃, which is far higher than the working temperature of the ladle. It can maintain structural stability at high temperatures. The Zr-O bond energy in the barium zirconate lattice is high and is not easily decomposed by the slag components. It can form an isolation layer on the surface of the spraying layer to prevent the slag from penetrating into the interior and improve the corrosion resistance. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0036] Example 1

[0037] Steel slag is magnetically separated to remove iron, then crushed and sieved to select slag with a particle size of 0.1-0.5 mm. The slag is then calcined at 650°C for 2 hours to obtain pretreated slag. Nanoalumina and sodium polyacrylate are mixed at a mass ratio of 20:1 and dry-mixed at 300 rpm for 5 minutes to obtain pre-dispersed nanoalumina. Alumina fibers are immersed in a 2wt% nanozirconia suspension, stirred, filtered, washed, and dried at 120°C for 2 hours to obtain a composite material. 0.2g of boric acid is added to 10g of silica sol, heated to 60°C, and stirred at 250 rpm for 30 minutes to obtain a modified silica sol.

[0038] 65 g of magnesia and 12 g of pretreated steel slag were mixed, stirred at 300 rpm for 10 min, 4 g of pre-dispersed nano-alumina was added, and stirring was continued for 5 min. 2 g of barium zirconate, 3 g of composite material, 1.5 g of calcium feldspar powder, 1 g of chromium oxide, 1 g of borax, 0.5 g of yttrium oxide and 0.5 g of water reducer polycarboxylate were added, and stirred at 500 rpm for 15 min to obtain a mixed material.

[0039] 8 g of aluminum dihydrogen phosphate, 4 g of modified silica sol and 15 g of 20 wt% sulfonated lignin solution were added to the mixed material in sequence, mixed evenly, and dispersed by ultrasonication to obtain a hot gunning material for a ladle.

[0040] Example 2

[0041] Steel slag is magnetically separated to remove iron, then crushed and sieved to select slag with a particle size of 0.1-0.5 mm. The slag is then calcined at 700°C for 1.5 hours to obtain pretreated slag. Nanoalumina and sodium polyacrylate are mixed at a mass ratio of 20:1 and dry-mixed at 300 rpm for 5 minutes to obtain pre-dispersed nanoalumina. Alumina fibers are immersed in a 1wt% nanozirconia suspension, stirred, filtered, washed, and dried at 120°C for 2 hours to obtain a composite material. 0.2g of boric acid is added to 10g of silica sol, heated to 60°C, and stirred at 200 rpm for 40 minutes to obtain a modified silica sol.

[0042] 70 g of magnesia and 10 g of pretreated steel slag were mixed, stirred at a speed of 250 rpm for 10 min, 5 g of pre-dispersed nano-alumina was added, and stirring was continued for 5 min. 1 g of barium zirconate, 2 g of composite material, 2 g of calcium feldspar powder, 1 g of chromium oxide, 1 g of borax, 0.5 g of yttrium oxide and 0.5 g of water reducer polycarboxylate were added, and stirring was continued at a speed of 400 rpm for 20 min to obtain a mixed material.

[0043] 6 g of aluminum dihydrogen phosphate, 5 g of modified silica sol and 15 g of 23 wt% sulfonated lignin solution were added to the mixed material in sequence, mixed evenly, and dispersed by ultrasonication to obtain a hot gunning material for a ladle.

[0044] Example 3

[0045] Steel slag is magnetically separated to remove iron, then crushed and sieved to select a particle size of 0.1-0.5 mm. The slag is then calcined at 600°C for 2.5 hours to obtain pretreated slag. Nanoalumina and sodium polyacrylate are mixed at a mass ratio of 20:1 and dry-mixed at 300 rpm for 5 minutes to obtain pre-dispersed nanoalumina. Alumina fibers are immersed in a 3wt% nanozirconia suspension, stirred, filtered, washed, and dried at 120°C for 2 hours to obtain a composite material. 0.2g of boric acid is added to 10g of silica sol, heated to 60°C, and stirred at 300 rpm for 20 minutes to obtain a modified silica sol.

[0046] 60 g of magnesia and 15 g of pretreated steel slag were mixed, stirred at 350 rpm for 5 min, 3 g of pre-dispersed nano-alumina was added, and stirring was continued for 5 min. 2 g of barium zirconate, 2 g of composite material, 2 g of calcium feldspar powder, 1 g of chromium oxide, 1 g of borax, 0.5 g of yttrium oxide and 0.5 g of water reducer polycarboxylate were added, and stirring was continued at 600 rpm for 10 min to obtain a mixed material.

[0047] 10 g of aluminum dihydrogen phosphate, 4 g of modified silica sol and 10 g of 23 wt% sulfonated lignin solution were added to the mixed material in sequence, mixed evenly, and dispersed by ultrasonication to obtain a hot gunning material for a ladle.

[0048] Example 4

[0049] Steel slag is magnetically separated to remove iron, then crushed and sieved to select slag with a particle size of 0.1-0.5 mm. The slag is then calcined at 700°C for 1.5 hours to obtain pretreated slag. Nanoalumina and sodium polyacrylate are mixed at a mass ratio of 20:1 and dry-mixed at 300 rpm for 5 minutes to obtain pre-dispersed nanoalumina. Alumina fibers are immersed in a 1.5wt% nanozirconia suspension, stirred, filtered, washed, and dried at 120°C for 2 hours to obtain a composite material. 0.2g of boric acid is added to 10g of silica sol, heated to 60°C, and stirred at 300 rpm for 25 minutes to obtain a modified silica sol.

[0050] 70 g of magnesia and 15 g of pretreated steel slag were mixed, stirred at a speed of 250 rpm for 10 min, 4 g of pre-dispersed nano-alumina was added, and stirring was continued for 5 min. 3 g of barium zirconate, 2 g of composite material, 1 g of calcium feldspar powder, 1 g of chromium oxide, 1 g of borax, 0.5 g of yttrium oxide and 0.5 g of water reducer polycarboxylate were added, and stirred at a speed of 450 rpm for 15 min to obtain a mixed material.

[0051] 8 g of aluminum dihydrogen phosphate, 3 g of modified silica sol and 20 g of 18 wt% sulfonated lignin solution were added to the mixed material in sequence, mixed evenly, and dispersed by ultrasonication to obtain a hot gunning material for a ladle.

[0052] Example 5

[0053] Steel slag is magnetically separated to remove iron, then crushed and sieved to select slag with a particle size of 0.1-0.5 mm. This slag is then calcined at 650°C for 2 hours to obtain pretreated slag. Nanoalumina and sodium polyacrylate are mixed at a mass ratio of 20:1 and dry-mixed at 300 rpm for 5 minutes to obtain pre-dispersed nanoalumina. Alumina fibers are immersed in a 2wt% nanozirconia suspension, stirred, filtered, washed, and dried at 120°C for 2 hours to obtain a composite material. 0.2g of boric acid is added to 10g of silica sol, heated to 60°C, and stirred at 200 rpm for 35 minutes to obtain a modified silica sol.

[0054] 65 g of magnesia and 10 g of pretreated steel slag were mixed, stirred at 350 rpm for 5 min, 5 g of pre-dispersed nano-alumina was added, and stirring was continued for 5 min. 3 g of barium zirconate, 3 g of composite material, 2 g of calcium feldspar powder, 1 g of chromium oxide, 1 g of borax, 0.5 g of yttrium oxide and 0.5 g of water reducer polycarboxylate were added, and stirring was continued at 550 rpm for 10 min to obtain a mixed material.

[0055] 10 g of aluminum dihydrogen phosphate, 3 g of modified silica sol and 15 g of 18 wt% sulfonated lignin solution were added to the mixed material in sequence, mixed evenly, and dispersed by ultrasonication to obtain a hot gunning material for a ladle.

[0056] Example 6

[0057] Steel slag is magnetically separated to remove iron, then crushed and sieved to select a particle size of 0.1-0.5 mm. The slag is then calcined at 600°C for 2.5 hours to obtain pretreated slag. Nanoalumina and sodium polyacrylate are mixed at a mass ratio of 20:1 and dry-mixed at 300 rpm for 5 minutes to obtain pre-dispersed nanoalumina. Alumina fibers are immersed in a 2wt% nanozirconia suspension, stirred, filtered, washed, and dried at 120°C for 2 hours to obtain a composite material. 0.2g of boric acid is added to 10g of silica sol, heated to 60°C, and stirred at 250 rpm for 30 minutes to obtain a modified silica sol.

[0058] 70 g of magnesia and 12 g of pretreated steel slag were mixed, stirred at a speed of 300 rpm for 5 min, 4 g of pre-dispersed nano-alumina was added, and stirring was continued for 5 min. 2.5 g of barium zirconate, 3 g of composite material, 1.5 g of calcium feldspar powder, 1 g of chromium oxide, 1 g of borax, 0.5 g of yttrium oxide and 0.5 g of water reducer polycarboxylate were added, and stirred at a speed of 500 rpm for 15 min to obtain a mixed material.

[0059] 8 g of aluminum dihydrogen phosphate, 5 g of modified silica sol and 10 g of 20 wt% sulfonated lignin solution were added to the mixed material in sequence, mixed evenly, and dispersed by ultrasonication to obtain a hot gunning material for a ladle.

[0060] Example 7

[0061] Steel slag is magnetically separated to remove iron, then crushed and sieved to select slag with a particle size of 0.1-0.5 mm. This slag is then calcined at 600°C for 2.5 hours to obtain pretreated slag. Nanoalumina and sodium polyacrylate are mixed at a mass ratio of 20:1 and dry-mixed at 300 rpm for 5 minutes to obtain pre-dispersed nanoalumina. Alumina fibers are immersed in a 1.5wt% nanozirconia suspension, stirred, filtered, washed, and dried at 120°C for 2 hours to obtain a composite material. 0.2g of boric acid is added to 10g of silica sol, heated to 60°C, and stirred at 200 rpm for 40 minutes to obtain a modified silica sol.

[0062] 60 g of magnesia and 10 g of pretreated steel slag were mixed, stirred at 350 rpm for 5 min, 5 g of pre-dispersed nano-alumina was added, and stirring was continued for 5 min. 3 g of barium zirconate, 4 g of composite material, 2 g of calcium feldspar powder, 1 g of chromium oxide, 1 g of borax, 0.5 g of yttrium oxide and 0.5 g of water reducer polycarboxylate were added, and stirring was continued at 600 rpm for 10 min to obtain a mixed material.

[0063] 6 g of aluminum dihydrogen phosphate, 5 g of modified silica sol and 20 g of 23 wt% sulfonated lignin solution were added to the mixed material in sequence, mixed evenly, and dispersed by ultrasonication to obtain a hot gunning material for a ladle.

[0064] Example 8

[0065] Steel slag is magnetically separated to remove iron, then crushed and sieved to select slag with a particle size of 0.1-0.5 mm. This slag is then calcined at 700°C for 1.5 hours to obtain pretreated slag. Nanoalumina and sodium polyacrylate are mixed at a mass ratio of 20:1 and dry-mixed at 300 rpm for 5 minutes to obtain pre-dispersed nanoalumina. Alumina fibers are immersed in a 2.5wt% nanozirconia suspension, stirred, filtered, washed, and dried at 120°C for 2 hours to obtain a composite material. 0.2g of boric acid is added to 10g of silica sol, heated to 60°C, and stirred at 300 rpm for 20 minutes to obtain a modified silica sol.

[0066] 70 g of magnesia and 15 g of pretreated steel slag were mixed, stirred at a speed of 250 rpm for 10 min, 3 g of pre-dispersed nano-alumina was added, and stirring was continued for 5 min. 3 g of barium zirconate, 2 g of composite material, 2 g of calcium feldspar powder, 1 g of chromium oxide, 1 g of borax, 0.5 g of yttrium oxide and 0.5 g of water reducer polycarboxylate were added, and stirring was carried out at a speed of 400 rpm for 20 min to obtain a mixed material.

[0067] 10 g of aluminum dihydrogen phosphate, 4 g of modified silica sol and 15 g of 18 wt% sulfonated lignin solution were added to the mixed material in sequence, mixed evenly, and dispersed by ultrasonication to obtain a hot gunning material for a ladle.

[0068] The present invention also carried out comparative examples and related tests.

[0069] Comparative Example 1

[0070] The only difference between Comparative Example 1 and Example 1 is that no composite material is prepared in Comparative Example 1. Other compositions and preparation methods are the same as those in Example 1, and a hot gunning material for a ladle is prepared.

[0071] Comparative Example 2

[0072] The difference between Comparative Example 2 and Example 1 is that barium zirconate is not used in the preparation of the mixed material in Comparative Example 2, and other compositions and preparation methods are the same as those in Example 1, and a hot gunning material for a ladle is prepared.

[0073] Comparative Example 3

[0074] The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, pretreated steel slag is not used when preparing the mixed material, but magnesia is used instead. The other compositions and preparation methods are the same as those in Example 1, and hot gunning material for ladle is prepared.

[0075] Performance testing

[0076] The test standard for flexural strength adopts GB / T 3001-2017 "Test method for flexural strength of refractory materials at room temperature". In a 110°C drying oven, the gunning material samples prepared in Examples 1-8 and Comparative Examples 1-3 were weighed to a constant weight, cooled to room temperature, and vertically loaded until fracture occurred. The load strength at fracture was recorded. The test results are shown in Table 1 below.

[0077] The gunning materials prepared in Examples 1-8 and Comparative Examples 1-3 were tested for apparent porosity using GB / T 2997-2015 “Test method for bulk density, apparent porosity and true porosity of dense shaped refractory products”. The test results are shown in Table 1 below.

[0078] The gunning materials prepared in Examples 1-8 and Comparative Examples 1-3 were tested for slag erosion resistance using the crucible method in accordance with GB / T 8931-2007 "Test method for slag resistance of refractory materials". The test results are shown in Table 1 below.

[0079] The adhesion test method is as follows: the gunning materials prepared in Examples 1-8 and Comparative Examples 1-3 are sprayed on the wall panel surface using a self-propelled spray gun with a spraying amount of 10 kg. The weight of the coating after spraying is measured to calculate the adhesion rate. The test results are shown in Table 1 below.

[0080] Table 1

[0081]

[0082] According to Table 1 above, the flexural strength of the gunning material prepared in Comparative Example 1 is significantly different from that of the gunning material prepared in Example 4, indicating that the preparation of the composite material helps to improve the toughness of the gunning material; the gunning material prepared in Comparative Example 2 shows obvious erosion and penetration, and the slag penetration is serious, indicating that barium zirconate helps to form an isolation layer and significantly improves the erosion resistance; the adhesion rate and apparent porosity of the gunning material prepared in Comparative Example 3 are significantly reduced compared with those in Example 4, indicating that pre-treating the steel slag can effectively reduce the porosity and promote the sintering of the gunning material.

[0083] The above is a preferred embodiment of the present invention. Those skilled in the art may make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing hot gunning material for ladle, characterized in that: The following steps are involved: Step S1, immersing alumina fibers in a nano-zirconia suspension, stirring uniformly, filtering, washing, and drying to obtain a composite material; adding boric acid to a silica sol, stirring uniformly to obtain a modified silica sol; Step S2, mixing magnesia and pretreated steel slag, adding pre-dispersed nano-alumina, continuing stirring, then adding barium zirconate, composite material, calcium feldspar powder, chromium oxide, borax, yttrium oxide and water reducer, stirring at room temperature to obtain a mixed material; the preparation of the pretreated steel slag includes the following steps: removing iron from the steel slag, crushing, screening, and calcining at a temperature of 600-700° C. for 1.5-2.5 hours to obtain the pretreated steel slag; Step S3: adding aluminum dihydrogen phosphate, modified silica sol and sulfonated lignin solution to the mixed material in sequence, mixing evenly, and ultrasonically dispersing the mixture to obtain a hot gunning material for a ladle.

2. The method for preparing a hot gunning material for a ladle according to claim 1, wherein: In step S1, the concentration of the nano-zirconia suspension is 1-3 wt %.

3. The method for preparing a hot gunning material for a ladle according to claim 1, wherein: In step S1, the stirring speed is 200-300 rpm and the stirring time is 20-40 min.

4. The method for preparing a hot gunning material for a ladle according to claim 1, wherein: In step S2, the mixing speed is 250-350 rpm and the time is 5-10 min.

5. The method for preparing a hot gunning material for a ladle according to claim 1, wherein: In step S2, the preparation of pre-dispersed nano-alumina includes the following steps: mixing nano-alumina and sodium polyacrylate in a ratio of 20:1 to obtain pre-dispersed nano-alumina.

6. The method for preparing a hot gunning material for a ladle according to claim 1, wherein: In step S2, the stirring speed at room temperature is 400-600 rpm and the stirring time is 10-20 min.

7. The method for preparing a hot gunning material for a ladle according to claim 1, wherein: In step S3, the concentration of the sulfonated lignin solution is 18-23 wt%.

8. A hot gunning material for a ladle, characterized in that: The hot gunning material for a ladle is prepared by the method for preparing the hot gunning material according to any one of claims 1 to 7, and comprises the following components in parts by weight: 100-120 parts of mixed materials, 6-10 parts of aluminum dihydrogen phosphate, 3-5 parts of modified silica sol and 10-20 parts of sulfonated lignin solution.

9. The hot gunning material for ladle according to claim 8, characterized in that: The mixed material comprises the following components in parts by weight: 60-70 parts of magnesia, 10-15 parts of pretreated steel slag, 3-5 parts of pre-dispersed nano-alumina, 1-3 parts of barium zirconate, 0.5-1 parts of yttrium oxide and 0.5-1 parts of water reducer.

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