Carbon-free ladle lining repair material produced by adding solid waste material and preparation method thereof

Abstract

The present application relates to a kind of carbon-free ladle wall repair material of solid waste material production and preparation method, the repair material is prepared from the following weight parts of raw materials: 6~3mm sintered corundum granular material 10~30 parts, 3~1mm sintered corundum granular material 10~30 parts, ≤1mm fused white corundum granular material 10~30 parts, ≤1mm 97 fused magnesite granular material 1~10 parts, fused white corundum powder 240 mesh 10~20 parts, 97 fused magnesite powder 240 mesh 1~10 parts, aluminate cement 3~10 parts, calcined alumina micro powder 3~10 parts, silica ultrafine powder 1~5 parts, guangxi white mud 1~5 parts, polypropylene fiber 0.1~0.5 parts, waste ceramic powder 2~8 parts, vanadium-titanium ore slag powder 2~8 parts.The present application introduces solid waste-waste ceramic powder material, vanadium-titanium ore slag material in ladle wall repair material, form ceramic phase and high temperature liquid phase through medium-high temperature, reinforcing and toughening, significantly improve the medium-high temperature strength of repair material, improve its matrix bonding property.

Description

Technical Field

[0001] This invention relates to the field of refractory repair and maintenance for steel smelting, and particularly to a carbon-free steel ladle wall repair material produced by adding solid waste materials and its preparation method. Background Technology

[0002] With the rapid development of the steel industry and the continuous advancement of steelmaking technology, the variety of steel products is increasing, and the requirements for steel quality are becoming increasingly stringent. The refining technology of steel ladles and the development and production of ultra-low carbon steel have placed higher demands on the refractory materials used for ladle working linings. Ladle working linings are developing towards low-carbon, ultra-low-carbon, and carbon-free technologies, while the service life of these linings is also required to be continuously improved. Currently, low-carbon magnesia-carbon bricks are commonly used for the refractory materials in the slag line area of ​​refining ladles in large domestic steel plants. The refractory materials for the ladle walls and bottom are often of amorphous form, such as carbon-free precast blocks or monolithic castable corundum spinel refractory. Among these, monolithic castable corundum spinel refractory for the ladle walls and bottom has a wider application range, ensuring the extended service life of ladle refractory materials.

[0003] For the working lining of a steel ladle, factors such as high steelmaking and refining temperatures, complex refining processes, and the smelting of different steel grades cause rapid erosion of the working lining, leading to a continuous reduction in the service life of the ladle refractory material and making it a weak link in the operation of the ladle. Specifically, the working lining refractory material of the ladle wall can also experience localized rapid melting during the refining process, resulting in cracks and spalling due to rapid heating and cooling. Local repairs are necessary, meaning that cracks and depressions on the surface of the ladle wall castable are repaired and maintained with ladle wall repair material. Otherwise, molten steel can easily penetrate the working layer, causing steel leakage at these defects and increasing the risk factor of ladle operation.

[0004] During each working interval of the ladle, repeated spraying maintenance can be performed to provide comprehensive and routine care for the refractory lining of the ladle wall, extending its service life. Simultaneously, it can also repair locally damaged ladle wall linings or increase the thickness of the lining in key areas, eliminating potential hazards and accidents related to the lining.

[0005] Local repair is a mature refractory maintenance technology that is widely used in the steel smelting process due to its simple construction process, low cost, strong targeting and high efficiency. Various types of steel ladle wall repair materials are the most commonly used maintenance and repair materials. Their main performance indicators include corrosion resistance, sintering properties, adhesion and fluidity. The quality of these indicators will directly affect the service life of the steel container using this refractory spraying material.

[0006] Current ladle wall repair materials generally use aluminum, aluminum-magnesium, or magnesium-based materials. The binders often employ single silicate, phosphate, or sol-gel binders, or composite binders, making it difficult to achieve excellent corrosion resistance, sintering properties, adhesion, and flowability. Current problems include: when using ladle wall repair materials for localized repairs, poor adhesion and high-temperature sintering results, along with poor density, leading to material shedding and excessively rapid melting during use. Summary of the Invention

[0007] The purpose of this invention is to provide a carbon-free steel ladle wall repair material produced by adding solid waste materials and its preparation method. Solid waste materials, such as waste ceramic powder and vanadium-titanium slag, are introduced into the steel ladle wall repair material. Through medium and high temperature, a ceramic phase and a high temperature liquid phase are formed, which strengthens and toughens the material, significantly improves its medium and high temperature strength, and improves its matrix bonding performance.

[0008] To achieve the above objectives, the present invention employs the following technical solution:

[0009] A carbon-free steel ladle wall repair material produced by adding solid waste materials, wherein the repair material is prepared from the following raw materials in parts by weight: 10-30 parts of 6-3mm sintered corundum particles, 10-30 parts of 3-1mm sintered corundum particles, 10-30 parts of ≤1mm fused white corundum particles, 1-10 parts of ≤1mm 97 fused magnesia particles, 10-20 parts of 240-mesh fused white corundum powder, 1-10 parts of 240-mesh 97 fused magnesia powder, 3-10 parts of aluminate cement, 3-10 parts of calcined alumina micro powder, 1-5 parts of silica ultrafine powder, 1-5 parts of Guangxi white clay, 0.1-0.5 parts of polypropylene fiber, 2-8 parts of waste ceramic powder, and 2-8 parts of vanadium-titanium slag powder.

[0010] The waste ceramic powder contains 65%–70% SiO2, 19%–23% Al2O3, 3%–5% K2O+Na2O, less than 0.2% moisture, and 150–180 mesh particles, of which less than 5% are larger than 0.2 mm.

[0011] The vanadium-titanium ore slag powder contains 20%–30% CaO, 19%–32% SiO2, 13%–17% Al2O3, 7%–9% MgO, 0.3%–1.2% MnO, 1.2%–1.9% FeO, 0.2%–0.9% S, 6%–31% TiO2, 0.06%–1% V2O5, less than 0.2% moisture, and a particle size of 150–180 mesh, of which less than 5% are particles larger than 0.2 mm.

[0012] In the raw materials, sintered corundum contains more than 99% alumina and less than 0.35% potassium oxide + sodium oxide. 97% fused magnesia contains more than 97% magnesium oxide and has a calcium-to-silicon ratio greater than 1.6. Fused white corundum contains more than 98% magnesium oxide and less than 0.35% potassium-to-sodium ratio. Aluminate cement is CA-50. Calcined alumina powder contains more than 99% alumina, with a D50 less than 5μm and a D90 less than 10μm.

[0013] Waste ceramic powder can be purchased directly, provided its chemical composition and moisture content meet the standards, and its particle size is 150-180 mesh. Alternatively, ceramic fragments that meet the chemical composition standards can be purchased, sorted to remove impurities, dried with an electric drying drum until the residual moisture meets the standards, then crushed into fine particles using a hammer crusher, and finally ground into 150-180 mesh fine powder using a ball mill for later use.

[0014] Vanadium-titanium ore slag powder can be purchased directly, provided that its chemical composition and moisture content meet the standards and its particle size is 150-180 mesh. Alternatively, vanadium-titanium ore slag blocks that meet the chemical composition standards can be purchased, sorted to remove impurities, dried with an electric drying drum until the residual moisture meets the standards, then crushed into fine particles using a hammer crusher, and finally ground into 150-180 mesh fine powder using a ball mill for later use.

[0015] The working principle of introducing solid waste—waste ceramic powder and vanadium-titanium slag—in this invention is as follows:

[0016] 1) Introduce solid waste of commonly used building ceramics—waste ceramic powder material—into refractory materials. Based on the original silicate cement + micro powder combination, utilize the liquid ceramic phase formed by the waste ceramic powder material between 870-1250℃. This ceramic phase acts as a cementing material, which can greatly enhance the medium-temperature cohesiveness of the material and improve the medium- and high-temperature strength of the repair material. It effectively overcomes the shortcomings of the original repair material in terms of poor strength and weak erosion resistance during use.

[0017] 2) Introducing solid waste—vanadium-titanium slag—into refractory materials as a sintering reinforcing agent for ladle wall repair materials utilizes its characteristic of softening at 1450-1510℃ to form a large amount of viscous liquid phase, thereby improving the sintering performance and bonding strength of the repair material matrix, reducing the size and number of pores, and enhancing the overall bonding strength, toughness, impact resistance, and spalling resistance of the repair material at high temperatures, thus extending the service life of the repair material. This effectively meets the process requirements for ladle wall spraying and repair in steel smelting operations.

[0018] 3) Waste ceramic powder forms a liquid ceramic phase between 870-1250℃, where it functions. Vanadium-titanium ore slag softens between 1450-1510℃, where it also functions. Therefore, in specific applications, the proportions of waste ceramic powder and vanadium-titanium ore slag can be adjusted according to the specific smelting conditions, i.e., the type of steel in the ladle, which leads to different temperatures of the molten steel. For example, when the temperature of the molten steel is higher, the proportion of waste ceramic powder should be reduced, while the proportion of vanadium-titanium ore slag should be appropriately increased. This ratio of repair material can adapt to higher application conditions, thus extending its service life. Conversely, when the temperature of the molten steel is lower, the proportions of waste ceramic powder and vanadium-titanium ore slag should be adjusted in the opposite way.

[0019] For steel ladles with a tapping temperature of 1500℃ to 1580℃, 5 parts < waste ceramic powder ≤ 8 parts, and 2 parts ≤ vanadium-titanium slag powder < 5 parts.

[0020] For steel ladles with a tapping temperature between 1580℃ and 1670℃, the following components are required: 2 parts ≤ waste ceramic powder ≤ 5 parts, and 5 parts ≤ vanadium-titanium slag powder ≤ 8 parts.

[0021] The temperature of the molten steel in the ladle is generally related to the temperature at which it taps from the converter. A higher tapping temperature results in a higher temperature for the molten steel in the ladle throughout the continuous casting process, and vice versa. Converter tapping temperatures are generally divided into two ranges: 1500–1580℃ and 1580–1670℃. At the lower tapping temperature of 1500–1580℃, the proportion of waste ceramic powder added can be higher (5–8 parts), while the proportion of vanadium-titanium slag powder added can be lower (2–5 parts). At the higher tapping temperature of 1580–1670℃, the proportion of waste ceramic powder added must be lower (2–5 parts), while the proportion of vanadium-titanium slag powder added can be higher (5–8 parts).

[0022] A method for preparing a carbon-free steel ladle wall repair material by adding solid waste materials, comprising the following steps:

[0023] The mixing equipment for finished repair materials is generally a horizontal twin-shaft mixer. First, sintered corundum granules and polypropylene fibers are added to the twin-shaft mixer and mixed for 3-8 minutes. After stopping the mixer, fused white corundum granules, 97 fused magnesia granules, 240-mesh fused white corundum powder, 240-mesh 97 fused magnesia powder, aluminate cement, calcined alumina micro powder, silica ultrafine powder, Guangxi white clay, waste ceramic powder, and vanadium-titanium slag powder are added to the twin-shaft mixer and mixed again for 5-10 minutes to obtain carbon-free steel ladle wall repair material. After stopping the mixer, the material is discharged, bagged, and inspected for compliance before being stored and shipped.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1) This invention introduces solid waste materials—waste ceramic powder and vanadium-titanium slag—into the ladle wall repair material for the first time. Through medium- and high-temperature processes, a ceramic phase and a high-temperature liquid phase are formed, which strengthens and toughens the material, significantly improving its medium- and high-temperature strength. At the same time, the vanadium-titanium material also forms a viscous liquid phase at this temperature, sealing its pores and resisting the penetration and erosion of acidic and alkaline molten steel, thus enhancing the erosion resistance of the repair material.

[0026] 2) The waste ceramic powder and vanadium-titanium slag materials introduced in this invention are common and inexpensive solid waste materials. By introducing refractory materials through this invention, the cost of raw materials can be greatly reduced and the competitiveness of products can be improved. At the same time, a large amount of waste solid waste materials can be effectively consumed, the environment can be improved, and green and sustainable development can be achieved.

[0027] The performance indicators of the product of this invention are shown in Table 1 below;

[0028] Table 1 Physical performance indicators of the product of this invention

[0029]

[0030] Attached Figure Description

[0031] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0032] The specific embodiments of the present invention will be further described below with reference to examples:

[0033] Example 1:

[0034] The steelmaking area of ​​a steel rolling mill in East China mainly consists of converter process, refining process and continuous casting process. The main equipment includes three 300-ton top and bottom combined blowing converters, three online alloy fine-tuning stations, three LF, two RH, and three straight arc high-efficiency slab continuous casting machines.

[0035] Product structure includes carbon structural steel, low alloy high-strength structural steel, ship structural steel, ultra-low carbon steel, medium carbon alloy steel, weathering steel, pressure vessel steel, boiler steel, automotive structural steel, bridge steel, automotive sheet steel, appliance steel, duplex steel, spring steel, pipeline steel, silicon steel, etc.

[0036] The main equipment parameters are shown in Table 2:

[0037] Table 2

[0038]

[0039]

[0040] The current steel molten steel treatment process route is shown in Table 3:

[0041] Table 3

[0042] Equipment Name Production ratio Pure argon blowing time Ladle processing time range Converter - Alloy Fine-tuning Station - Continuous Casting Machine 15％ 16min 80-130 minutes Converter - Alloy Fine-tuning Station - LF Furnace - Continuous Casting Machine 30％ 70min 140–220 minutes Converter - Alloy Fine-tuning Station - RH - Continuous Casting Machine 50％ 30min 140-200 minutes Converter - Alloy Fine-tuning Station - LF Furnace - RH - Continuous Casting Machine 5％ 90min 180–260 minutes

[0043] Because steel mills primarily smelt various types of steel, the tapping temperature is relatively high, typically between 1580 and 1650°C. Therefore, to achieve the aforementioned production goals, this ladle wall repair material can be implemented through the following technical solution. A carbon-free ladle wall repair material produced by adding solid waste materials is composed of the following raw materials in the following weight proportions: 16 parts sintered corundum 6-3mm granules, 18 parts sintered corundum 3-1mm granules, 10 parts fused white corundum 1-0mm granules, 3 parts 97 fused magnesia 1-0mm granules, 15 parts fused white corundum powder 240 mesh, 5 parts 97 fused magnesia powder 240 mesh, 10 parts aluminate cement, 5 parts calcined alumina micro powder, 5 parts silica ultrafine powder, 2 parts Guangxi white clay, 0.1 parts polypropylene fiber, 3 parts waste ceramic powder, and 7.9 parts vanadium-titanium slag powder.

[0044] In this embodiment, the ladle smelting temperature range is 1580–1650°C, and the addition ratio of waste ceramic powder to vanadium-titanium slag powder is 3:7.9.

[0045] Waste ceramic powder can be purchased directly, provided that its chemical composition and moisture content meet the standards and its particle size is 150-180 mesh. Alternatively, ceramic fragments that meet the chemical composition standards can be purchased, sorted to remove impurities, dried with an electric drying drum until the residual moisture meets the standards, then crushed into fine particles using a hammer crusher, and finally ground into 150-180 mesh fine powder using a ball mill for later use.

[0046] Vanadium-titanium ore slag powder can be purchased directly, provided that its chemical composition and moisture content meet the standards and its particle size is 150-180 mesh. Alternatively, vanadium-titanium ore slag blocks that meet the chemical composition standards can be purchased, sorted to remove impurities, dried with an electric drying drum until the residual moisture meets the standards, then crushed into fine particles using a hammer crusher, and finally ground into 150-180 mesh fine powder using a ball mill for later use.

[0047] The relevant parameters and specifications of the waste ceramic powder and vanadium-titanium slag powder in Example 1 are shown in Table 4;

[0048] Table 4

[0049]

[0050] The production method of the novel steel ladle wall repair material in this embodiment is shown in the process flow diagram. Figure 1 The specific method is as follows:

[0051] 1. Accurately weigh the following materials according to their weight ratios: sintered corundum 6-3mm granules, sintered corundum 3-1mm granules, fused white corundum 1-0mm granules, 97 fused magnesia 1-0mm granules, fused white corundum powder 240 mesh, 97 fused magnesia powder 240 mesh, aluminate cement, calcined alumina micro powder, silica ultrafine powder, Guangxi white clay, polypropylene fiber, waste ceramic powder, and vanadium-titanium slag powder. Pack them into bags and set aside for later use.

[0052] 2. For mixing finished repair materials, a horizontal twin-shaft mixer is generally selected. The weighed 6-3mm sintered corundum granules, 3-1mm sintered corundum granules, and polypropylene fibers are added to the twin-shaft mixer and mixed for 6 minutes. After stopping the mixer, the remaining weighed 1-0mm fused white corundum granules, 1-0mm fused magnesia granules, 240-mesh fused white corundum powder, 240-mesh fused magnesia powder, aluminate cement, calcined alumina micro powder, silica ultrafine powder, Guangxi white clay, waste ceramic powder, and vanadium-titanium slag powder are added to the twin-shaft mixer and mixed again for 10 minutes. After stopping the mixer, the material is discharged, bagged, and inspected for quality before being stored and shipped.

[0053] The ladle wall repair material of Example 1 was tested on two 300-ton ladles in the steelmaking area of ​​a steel rolling mill in East China. Ten repair operations were performed. Compared with the original ladle wall repair material, the high-temperature strength performance was improved, the material's corrosion resistance was enhanced, and the service life of the repair material of this invention was significantly extended. Simultaneously, due to the use of some solid waste materials, the cost per ton of the ladle wall repair material of this invention was reduced by 220 yuan / ton, greatly improving the material's cost-effectiveness.

[0054] The physical properties of the repaired ladle wall are shown in Table 7.

[0055] Example 2:

[0056] Taking a 120-ton steel ladle from a steel plant in Liaoning, Northeast China, as an example, the main technical parameters are shown in Table 5 below: ordinary carbon structural steel, high-quality carbon structural steel, low-alloy steel, some corrosion-resistant steel, and pipeline steel. The converter tapping temperature range is 1500–1580℃.

[0057] Table 5. Process Technical Parameters of 120t Converter

[0058]

[0059]

[0060] To achieve the above production goals, the ladle wall repair material can be implemented through the following technical solution. A carbon-free ladle wall repair material produced by adding solid waste materials is composed of the following raw materials in the following weight proportions: 12 parts sintered corundum 6-3mm granules, 24 parts sintered corundum 3-1mm granules, 10 parts fused white corundum 1-0mm granules, 2 parts 97 fused magnesia 1-0mm granules, 16 parts fused white corundum powder 240 mesh, 4 parts 97 fused magnesia powder 240 mesh, 8 parts aluminate cement, 5 parts calcined alumina micro powder, 4 parts silica ultrafine powder, 3 parts Guangxi white clay, 0.2 parts polypropylene fiber, 8 parts waste ceramic powder, and 3.8 parts vanadium-titanium slag powder.

[0061] In this embodiment, the ladle smelting temperature range is 1500~1580℃, and the addition ratio of waste ceramic powder to vanadium-titanium slag powder is 8:3.8.

[0062] Waste ceramic powder can be purchased directly, provided that its chemical composition and moisture content meet the standards and its particle size is 150-180 mesh. Alternatively, ceramic fragments that meet the chemical composition standards can be purchased, sorted to remove impurities, dried with an electric drying drum until the residual moisture meets the standards, then crushed into fine particles using a hammer crusher, and finally ground into 150-180 mesh fine powder using a ball mill for later use.

[0063] Vanadium-titanium ore slag powder can be purchased directly, provided that its chemical composition and moisture content meet the standards and its particle size is 150-180 mesh. Alternatively, vanadium-titanium ore slag blocks that meet the chemical composition standards can be purchased, sorted to remove impurities, dried with an electric drying drum until the residual moisture meets the standards, then crushed into fine particles using a hammer crusher, and finally ground into 150-180 mesh fine powder using a ball mill for later use.

[0064] The relevant parameters and specifications of the waste ceramic powder and vanadium-titanium slag powder in Example 2 are shown in Table 6;

[0065] Table 6

[0066]

[0067]

[0068] The production method of the novel steel ladle wall repair material in this embodiment is shown in the process flow diagram. Figure 1 The specific method is as follows:

[0069] 1. Accurately weigh the following materials according to their weight ratios: sintered corundum 6-3mm granules, sintered corundum 3-1mm granules, fused white corundum 1-0mm granules, 97 fused magnesia 1-0mm granules, fused white corundum powder 240 mesh, 97 fused magnesia powder 240 mesh, aluminate cement, calcined alumina micro powder, silica ultrafine powder, Guangxi white clay, polypropylene fiber, waste ceramic powder, and vanadium-titanium slag powder. Pack them into bags and set aside for later use.

[0070] 2. For mixing finished repair materials, a horizontal twin-shaft mixer is generally selected. The weighed 6-3mm sintered corundum granules, 3-1mm sintered corundum granules, and polypropylene fibers are added to the twin-shaft mixer and mixed for 8 minutes. After stopping the mixer, the remaining weighed 1-0mm fused white corundum granules, 1-0mm fused magnesia granules, 240-mesh fused white corundum powder, 240-mesh fused magnesia powder, aluminate cement, calcined alumina micro powder, silica ultrafine powder, Guangxi white clay, waste ceramic powder, and vanadium-titanium slag powder are added to the twin-shaft mixer and mixed again for 10 minutes. After stopping the mixer, the material is discharged, bagged, and inspected for quality before being stored and shipped.

[0071] The ladle wall repair material of Example 2 was tested on two 120-ton ladles in the steelmaking area of ​​a steel plant in Liaoning, Northeast China. After six repair operations, compared with the original ladle wall repair material, the medium-temperature strength performance was improved, the material's corrosion resistance was enhanced, and the service life of the repair material of this invention was significantly extended. Simultaneously, due to the use of some solid waste materials, the cost per ton of the ladle wall repair material of this invention was reduced by 296 yuan / ton, greatly improving the material's cost-effectiveness.

[0072] The physical properties of the steel ladle wall after repair are shown in Table 7;

[0073] Table 7

[0074]

[0075]

Claims

1. A carbon-free steel ladle wall repair material produced by adding solid waste materials, characterized in that, The repair material is prepared from the following raw materials in parts by weight: 10-30 parts of 6-3mm sintered corundum particles, 10-30 parts of 3-1mm sintered corundum particles, 10-30 parts of ≤1mm fused white corundum particles, 1-10 parts of ≤1mm 97 fused magnesia particles, 10-20 parts of 240-mesh fused white corundum powder, 1-10 parts of 240-mesh 97 fused magnesia powder, 3-10 parts of aluminate cement, 3-10 parts of calcined alumina micro powder, 1-5 parts of silica ultrafine powder, 1-5 parts of Guangxi white clay, 0.1-0.5 parts of polypropylene fiber, waste ceramic powder, and vanadium-titanium slag powder; For steel ladles with a tapping temperature of 1500°C to 1580°C, 5 parts < waste ceramic powder ≤ 8 parts, and 2 parts ≤ vanadium-titanium slag powder < 5 parts; For steel ladles with a tapping temperature of 1580°C to 1670°C, 2 parts to 5 parts of waste ceramic powder and 5 parts to 8 parts of vanadium-titanium slag powder are required. The waste ceramic powder contains 65%–70% SiO2, 19%–23% Al2O3, and 3%–5% K2O+Na2O. The vanadium-titanium ore slag powder contains 20%–30% CaO, 19%–32% SiO2, 13%–17% Al2O3, 7%–9% MgO, 0.3%–1.2% MnO, 1.2%–1.9% FeO, 0.2%–0.9% S, 6%–31% TiO2, and 0.06%–1% V2O5.

2. The carbon-free steel ladle wall repair material produced by adding solid waste materials according to claim 1, characterized in that, The particle size of the waste ceramic powder is 150-180 mesh.

3. The carbon-free steel ladle wall repair material produced by adding solid waste materials according to claim 1, characterized in that, The particle size of the vanadium-titanium slag powder is 150-180 mesh.

4. A method for preparing a carbon-free steel ladle wall repair material produced by adding solid waste materials as described in any one of claims 1-3, characterized in that, Including the following methods: First, mix and stir sintered corundum granules and polypropylene fibers for 3-8 minutes. After stopping the machine, add fused white corundum granules, 97 fused magnesia granules, fused white corundum powder (240 mesh), 97 fused magnesia powder (240 mesh), aluminate cement, calcined alumina micro powder, silica ultrafine powder, Guangxi white mud, waste ceramic powder, and vanadium-titanium slag powder to the mixer and mix again for 5-10 minutes to obtain carbon-free steel ladle wall repair material.

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