A coating material for the outer wall of a molten iron ladle and its preparation and application method

Abstract

This invention belongs to the field of refractory materials for molten iron insulation in the steel industry, specifically relating to a coating material for the outer wall of a molten iron ladle and its preparation and application method. The coating material is mainly composed of industrial alumina, fused silica, iron scale, and metallic iron powder, with AC foaming agent, P2O5, and B2O3 as additives, and kaolinite and calcium aluminate cement as binders. This material is used for molten iron ladle insulation. This coating material reduces the average temperature of the molten iron ladle's outer wall by more than 130°C, greatly enhancing the ladle's insulation effect and meeting all-weather on-site usage conditions. It also has advantages such as convenient construction (manual application without any equipment), high bonding strength with the outer wall, and long service life.

Description

Technical Field

[0001] This invention belongs to the field of refractory materials for heat preservation of molten iron in the steel industry, specifically relating to a coating material for the outer wall of a molten iron ladle and its preparation and application method. Background Technology

[0002] Ladles, or molten iron ladles, are crucial components of the "iron-steel interface" in the long ironmaking-steelmaking process, serving as devices for receiving, transporting, and buffering molten iron. Especially in the increasingly popular "one-ladle-to-the-end" technology, the receiving, transporting, storing, buffering, and KR desulfurization of molten iron are all completed within the same ladle, making it the sole connecting device between the ironmaking and steelmaking sections. During storage and transport, the temperature of the molten iron within the ladle affects the material and energy consumption in KR desulfurization and converter steelmaking processes. Excessive temperature drop not only negatively impacts subsequent dephosphorization but also reduces the scrap ratio, increasing production costs. Therefore, effectively increasing the molten iron temperature ensures KR desulfurization and achieves a more reasonable scrap ratio and dephosphorization effect in subsequent refining processes. As a vital container in the metallurgical industry, the ladle stores, transfers, and performs KR desulfurization, with the molten iron remaining in the ladle for a considerable time. During transport, the molten iron dissipates heat through the ladle, resulting in heat loss.

[0003] To address the existing problems, this invention provides a coating material for the outer wall of molten iron ladles. This coating material has a low thermal conductivity and good heat insulation effect. It also possesses advantages such as high temperature resistance, all-weather applicability, high bonding strength with steel plates, and long service life. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a low-cost, high-performance coating material for the outer wall of molten iron ladles. This material has the advantages of low cost, good heat insulation effect, high temperature resistance, all-weather applicability, high bonding strength, and long service life.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] The material is made primarily of industrial alumina, fused silica, iron scale, and metallic iron powder, with AC foaming agent, P2O5, and B2O3 as additives, and kaolinite and calcium aluminate cement as binders. This material is used for heat preservation of molten iron ladles.

[0007] The technical problem to be solved by the present invention is achieved by the following technical solution: a coating material for the outer wall of a molten iron ladle, the coating material comprising the following raw materials in parts by weight:

[0008] Industrial alumina with a particle size of 0mm to 1mm: 10 to 30 parts;

[0009] Fused silica with a particle size of 0 mm to 1 mm: 15 to 30 parts;

[0010] Iron scale with a particle size of 0 mm to 0.5 mm: 19 to 39 parts;

[0011] Metallic iron powder with a particle size of 0mm to 0.5mm: 5 to 10 parts;

[0012] AC foaming agent with a particle size of 180 mesh: 6-10 parts;

[0013] P2O5 with a particle size of 180 mesh: 3-5 parts;

[0014] B2O3 with a particle size less than 0.088 mm: 1 to 3 parts;

[0015] Kaolinite with a particle size of 200 mesh: 1-3 parts;

[0016] Calcium aluminate cement with a particle size of 200 mesh: 2-4 parts.

[0017] According to a preferred embodiment of the present invention, the coating material comprises the following raw materials in parts by weight:

[0018] Industrial alumina with a particle size of 0mm to 1mm: 16 to 25 parts;

[0019] Fused silica with a particle size of 0 mm to 1 mm: 18 to 23 parts;

[0020] Iron scale with a particle size of 0 mm to 0.5 mm: 25 to 32 parts;

[0021] Metallic iron powder with a particle size of 0mm to 0.5mm: 5 to 9 parts;

[0022] AC foaming agent with a particle size of 180 mesh: 7-10 parts;

[0023] P2O5 with a particle size of 180 mesh: 3-4 parts;

[0024] B2O3 with a particle size less than 0.088 mm: 1 to 3 parts;

[0025] Kaolinite with a particle size of 200 mesh: 2-3 parts;

[0026] Calcium aluminate cement with a particle size of 200 mesh: 2-3 parts.

[0027] According to a preferred embodiment of the present invention, the coating material comprises the following raw materials in parts by weight:

[0028] Industrial alumina with a particle size of 0mm to 1mm: 20 to 24 parts;

[0029] Fused silica with a particle size of 0 mm to 1 mm: 20 to 23 parts;

[0030] Iron scale with a particle size of 0 mm to 0.5 mm: 27 to 31 parts;

[0031] Metallic iron powder with a particle size of 0mm to 0.5mm: 5 to 7 parts;

[0032] AC foaming agent with a particle size of 180 mesh: 8-10 parts;

[0033] P2O5 with a particle size of 180 mesh: 3-4 parts;

[0034] B2O3 with a particle size less than 0.088 mm: 2-3 parts;

[0035] Kaolinite with a particle size of 200 mesh: 2-3 parts;

[0036] Calcium aluminate cement with a particle size of 200 mesh: 2-3 parts.

[0037] According to a preferred embodiment of the present invention, the coating material comprises the following raw materials in parts by weight:

[0038] Industrial alumina with a particle size of 0mm to 1mm: 22 to 24 parts;

[0039] Fused silica with a particle size of 0 mm to 1 mm: 21 to 22 parts;

[0040] Iron scale with a particle size of 0 mm to 0.5 mm: 27 to 30 parts;

[0041] Metallic iron powder with a particle size of 0mm to 0.5mm: 6 to 7 parts;

[0042] AC foaming agent with a particle size of 180 mesh: 8-9 parts;

[0043] P2O5 with a particle size of 180 mesh: 3-4 parts;

[0044] B2O3 with a particle size less than 0.088 mm: 2-3 parts;

[0045] Kaolinite with a particle size of 200 mesh: 2-3 parts;

[0046] Calcium aluminate cement with a particle size of 200 mesh: 2-3 parts.

[0047] The present invention also discloses a method for preparing the above-mentioned coating material for the outer wall of the molten iron ladle. According to their respective proportions, industrial alumina, fused silica, iron scale, metallic iron powder, AC foaming agent, P2O5, B2O3, kaolinite and calcium aluminate cement are poured into a mixer and mixed for 6 to 8 minutes to obtain a uniform coating material.

[0048] The present invention also discloses a method for using the above-mentioned coating material on the outer wall of the molten iron ladle. Add water of 8% to 10% of the total weight of the coating material to the coating material, stir for 7 to 10 minutes, and after stirring well, brush the material onto the outer wall surface of the molten iron ladle, spread it evenly and flat, and let it air dry naturally before putting it into use.

[0049] According to a preferred embodiment of the present invention, the coating thickness is 1.5–2 mm. To ensure both the heat insulation effect and the bonding strength of the coating, the coating thickness is controlled to be 1.5–2 mm.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0051] 1. Compared with a blank molten iron ladle, the molten iron ladle coated with the coating material of this application can have its outer wall temperature reduced by an average of more than 130°C.

[0052] 2. The coating material of this application has a long service life and is synchronized with the shell of the molten iron ladle.

[0053] 3. The coating material of this application is simple to apply and can be applied manually without the need for equipment.

[0054] 4. It will not affect the hoisting, transportation, or use of the molten iron ladle.

[0055] 5. The coating material for the outer wall of this molten iron ladle is suitable for the working requirements of the molten iron ladle, and its main physical and chemical properties are as follows:

[0056] Detailed Implementation

[0057] The following embodiments are further illustrations of the present invention, but the present invention is not limited thereto.

[0058] Example 1

[0059] Example 1 provides a coating material for the outer wall of a molten iron ladle, the raw material formula of which is shown in Table 1:

[0060] Weigh out the various materials according to the proportions described in Table 1, put them into a mixer and mix for 6 to 8 minutes to obtain a uniform coating material.

[0061] Add water (8%–10% of the total weight of the mixture) to the coating material and continue mixing for 7–10 minutes. After mixing, apply the material to the outer surface of the molten iron container, spreading it evenly and smoothly to a thickness of about 2 mm. Allow it to air dry naturally before use.

[0062] Its main physicochemical properties are as follows:

[0063]

[0064]

[0065] Example 2

[0066] Example 2 provides a coating material for the outer wall of a molten iron ladle, the raw material formula of which is shown in Table 1:

[0067] The preparation and application method of the coating material for the outer wall of the molten iron ladle in this embodiment are the same as in Example 1, and its main physicochemical properties are as follows:

[0068]

[0069] Example 3

[0070] Example 3 provides a coating material for the outer wall of a molten iron ladle, the raw material formula of which is shown in Table 1:

[0071] The preparation and application method of the coating material for the outer wall of the molten iron ladle in this embodiment are the same as in Example 1, and its main physicochemical properties are as follows:

[0072]

[0073] Example 4

[0074] Example 4 provides a coating material for the outer wall of a molten iron ladle, the raw material formula of which is shown in Table 1:

[0075] The preparation and application method of the coating material for the outer wall of the molten iron ladle in this embodiment are the same as in Example 1, and its main physicochemical properties are as follows:

[0076]

[0077]

[0078] Example 5

[0079] Example 5 provides a coating material for the outer wall of a molten iron ladle, the raw material formula of which is shown in Table 1:

[0080] The preparation and application method of the coating material for the outer wall of the molten iron ladle in this embodiment are the same as in Example 1, and its main physicochemical properties are as follows:

[0081]

[0082] Example 6

[0083] Example 6 provides a coating material for the outer wall of a molten iron ladle, the raw material formula of which is shown in Table 1:

[0084] The preparation and application method of the coating material for the outer wall of the molten iron ladle in this embodiment are the same as in Example 1, and its main physicochemical properties are as follows:

[0085]

[0086] Example 7

[0087] Example 7 provides a coating material for the outer wall of a molten iron ladle, the raw material formula of which is shown in Table 1:

[0088] The preparation and application method of the coating material for the outer wall of the molten iron ladle in this embodiment are the same as in Example 1, and its main physicochemical properties are as follows:

[0089]

[0090] Table 1. Raw material formulas for Examples 1-7. Unit: parts by mass.

[0091]

[0092] Since the temperature of the outer wall of the molten iron ladle is usually between 300 and 370°C, based on the physicochemical properties of the coating material on the outer wall of the molten iron ladle, it can be concluded that the coating material on the outer wall of the molten iron ladle in Examples 1-7 can be directly applied to the outer wall of the molten iron ladle, and has the advantages of good heat preservation, high temperature resistance, all-weather applicability, high bonding strength and long service life, which can effectively reduce the heat loss of molten iron in the molten iron ladle.

Claims

1. A coating material for the outer wall of a molten iron ladle, characterized in that, The coating material is made from the following raw materials in parts by weight: Industrial alumina with a particle size of 0mm to 1mm: 10 to 30 parts; Fused silica with a particle size of 0 mm to 1 mm: 15 to 30 parts; Iron scale with a particle size of 0 mm to 0.5 mm: 19 to 39 parts; Metallic iron powder with a particle size of 0mm to 0.5mm: 5 to 10 parts; AC foaming agent with a particle size of 180 mesh: 6-10 parts; P2O5 with a particle size of 180 mesh: 3-5 parts; B2O3 with a particle size less than 0.088 mm: 1 to 3 parts; Kaolinite with a particle size of 200 mesh: 1-3 parts; Calcium aluminate cement with a particle size of 200 mesh: 2-4 parts; The coating material for the outer wall of the molten iron ladle is suitable for the working requirements of the molten iron ladle, and its main physical and chemical properties are as follows: Refractory temperature > 500℃; The bulk density is ≤0.9 g / cm³ after being kept at 110℃ for 24 hours. 3 The bulk density is ≤1.1 g / cm³ after being kept at 500℃ for 24 hours. 3 ; The bonding strength is ≥8MPa after maintaining a temperature of 500℃ for 24 hours. Thermal conductivity < 0.032 W / m·K; The linear change after burning at 500℃ for 24 hours was ±0.1%; Thermal shock resistance >19 cycles after 500℃ water cooling treatment.

2. The coating material for the outer wall of the molten iron ladle according to claim 1, characterized in that, The coating material is made from the following raw materials in parts by weight: Industrial alumina with a particle size of 0 mm to 1 mm: 16 to 25 parts; Fused silica with a particle size of 0 mm to 1 mm: 18 to 23 parts; Iron scale with a particle size of 0 mm to 0.5 mm: 25 to 32 parts; Metallic iron powder with a particle size of 0mm to 0.5mm: 5 to 9 parts; AC foaming agent with a particle size of 180 mesh: 7-10 parts; P2O5 with a particle size of 180 mesh: 3-4 parts; B2O3 with a particle size less than 0.088 mm: 1 to 3 parts; Kaolinite with a particle size of 200 mesh: 2-3 parts; Calcium aluminate cement with a particle size of 200 mesh: 2-3 parts.

3. The coating material for the outer wall of the molten iron ladle according to claim 1, characterized in that, The coating material is made from the following raw materials in parts by weight: Industrial alumina with a particle size of 0mm to 1mm: 20 to 24 parts; Fused silica with a particle size of 0 mm to 1 mm: 20 to 23 parts; Iron scale with a particle size of 0 mm to 0.5 mm: 27 to 31 parts; Metallic iron powder with a particle size of 0 mm to 0.5 mm: 5 to 7 parts; AC foaming agent with a particle size of 180 mesh: 8-10 parts; P2O5 with a particle size of 180 mesh: 3-4 parts; B2O3 with a particle size less than 0.088 mm: 2-3 parts; Kaolinite with a particle size of 200 mesh: 2-3 parts; Calcium aluminate cement with a particle size of 200 mesh: 2-3 parts.

4. The coating material for the outer wall of the molten iron ladle according to claim 1, characterized in that, The coating material is made from the following raw materials in parts by weight: Industrial alumina with a particle size of 0mm to 1mm: 22 to 24 parts; Fused silica with a particle size of 0 mm to 1 mm: 21 to 22 parts; Iron scale with a particle size of 0 mm to 0.5 mm: 27 to 30 parts; Metallic iron powder with a particle size of 0mm to 0.5mm: 6 to 7 parts; AC foaming agent with a particle size of 180 mesh: 8-9 parts; P2O5 with a particle size of 180 mesh: 3-4 parts; B2O3 with a particle size less than 0.088 mm: 2-3 parts; Kaolinite with a particle size of 200 mesh: 2-3 parts; Calcium aluminate cement with a particle size of 200 mesh: 2-3 parts.

5. A method for preparing the coating material for the outer wall of a molten iron ladle according to any one of claims 1 to 4, characterized in that: According to their respective proportions, industrial alumina, fused silica, iron scale, metallic iron powder, AC foaming agent, P2O5, B2O3, kaolinite, and calcium aluminate cement are poured into a mixer and mixed for 6 to 8 minutes to obtain a uniform coating material.

6. A method of using the coating material for the outer wall of a molten iron ladle according to any one of claims 1 to 4, characterized in that: Add 8% to 10% water by weight of the coating material to the coating material, stir for 7 to 10 minutes. After stirring, apply the material to the outer surface of the molten iron tank, spreading it evenly and evenly. Let it air dry naturally before use.

7. The method of using the coating material for the outer wall of the molten iron ladle according to claim 6, characterized in that: The coating thickness is 1.5–2 mm.

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