Wet type large surface repairing material and preparation method thereof

Abstract

The invention discloses a wet-type large-surface repairing material and a preparation method thereof. The repairing material comprises the following components in percentage by mass: 20-30% of sintered magnesia coarse sand with the particle size of 10-5 mm and the mass percentage of 20-30%; the particle size of the sintered magnesia fine sand is 5-3mm, and the mass percent of the sintered magnesia fine sand is 5-15wt%; the grain size of the forsterite is 3-1 mm, and the mass percentage of the forsterite is 15-25 wt%; the particle size of the medium-grade magnesia is not greater than 2mm, and the mass percent is 15-25wt%; the particle size of the medium-grade magnesia fine powder is 150-200 meshes, the mass percent of the medium-grade magnesia fine powder is 10-15 wt%, the particle size of the magnesium-calcium-iron sand fine powder is 150-200 meshes, and the mass percent of the magnesium-calcium-iron sand fine powder is 1-8 wt%; 10 to 14 wt% of modified asphalt; and 0.5 to 1.5 wt% of industrial white oil. The repairing material disclosed by the invention is low in cost, environment-friendly and economical, has relatively high breaking strength, and is particularly suitable for a large-surface repairing material of a schreyerite steelmaking converter.

Description

Technical Field

[0001] This invention relates to the field of refractory materials technology, specifically to a wettable large-area repair material and its preparation method. Background Technology

[0002] In the smelting of vanadium-titanium magnetite, improper operation, excessively high temperatures, long smelting times, and slag erosion can lead to a short service life of steelmaking converters, increasing steelmaking costs. Therefore, improving the service life of steelmaking converters is an urgent problem to be solved in the field of vanadium-titanium smelting.

[0003] Chinese patent application CN201811601539.7 discloses an environmentally friendly rapid sintering converter surface repair material. The raw materials for this material include 50-70 parts sintered magnesia, 70-88 parts medium-grade magnesia, 70-88 parts fused magnesia, 10-20 parts asphalt, 1-5 parts white oil, 1-5 parts diesel oil, 1-5 parts engine oil, 1-5 parts caprolactam, 1-5 parts ethylene glycol, 1-5 parts metallic Al powder, and 1-5 parts metallic Si powder. This invention improves the high-temperature resistance and rapid sintering properties of the surface repair material. However, experiments have shown that it is not suitable for vanadium-titanium magnetite steelmaking converters due to its low flexural strength.

[0004] Therefore, developing a low-cost, environmentally friendly, and economical large-area repair material suitable for vanadium-titanium ore steelmaking converters, with high flexural strength and improved service life of steelmaking converters, has significant practical and economic value. Summary of the Invention

[0005] The purpose of this invention is to provide a wettable large-area repair material and its preparation method. Using sintered magnesia, medium-grade magnesia and forsterite as the main aggregates, and through specific component ratios and particle sizes, the obtained large-area repair material is suitable for vanadium-titanium magnetite steelmaking converters, which can significantly improve the service life of steelmaking converters, have high flexural strength, and have important economic and environmental value.

[0006] To achieve the above-mentioned objectives, this invention provides a wettable surface repair material, comprising aggregate, fine powder, modified bitumen, and industrial white oil; the aggregate includes sintered coarse magnesia sand, sintered fine magnesia sand, forsterite, and medium-grade magnesia sand; the fine powder includes medium-grade magnesia sand fine powder and magnesia-calcium-iron sand fine powder; the particle size and mass percentage of each component are as follows: The coarse sintered magnesia has a particle size of 10-5 mm and a mass percentage of 20-30 wt%; the fine sintered magnesia has a particle size of 5-3 mm and a mass percentage of 5-15 wt%; the forsterite has a particle size of 3-1 mm and a mass percentage of 15-25 wt%; the medium-grade magnesia has a particle size of no more than 2 mm and a mass percentage of 15-25 wt%; the medium-grade magnesia fine powder has a particle size of 150-200 mesh and a mass percentage of 10-15 wt%; the magnesium-calcium-iron sand fine powder has a particle size of 150-200 mesh and a mass percentage of 1-8 wt%; modified bitumen has a mass percentage of 10-14 wt%; and industrial white oil has a mass percentage of 0.5-1.5 wt%.

[0007] In this invention, both coarse and fine sintered magnesia are sintered magnesia, differing only slightly in particle size. This naming convention is for ease of distinction. The term "medium-grade magnesia with a particle size not exceeding 2mm" refers to excluding medium-grade magnesia with a particle size of 150-200 mesh and a particle size not exceeding 2mm.

[0008] During the smelting of vanadium-titanium magnetite, the resulting steel slag contains approximately 1-3% V₂O₅, hence it is called vanadium-containing steel slag. Compared to ordinary steel slag, vanadium-containing steel slag is characterized by high basicity, high R₀ phase, and high superheat. Current steelmaking converters employ a slag splashing protection process; therefore, the maintenance material formed by the large-area repair mix on the inner side of the converter must form a good bond with the vanadium-containing steel slag to achieve effective maintenance. There are specific requirements regarding the composition and particle size of the large-area repair mix.

[0009] According to the present invention, the wettable large-area repair material preferably has an aggregate mass percentage of 85-90 wt%.

[0010] According to the present invention, the wettable large-area repair material preferably has a particle size of 180 mesh.

[0011] According to the present invention, the wettable large-area repair material preferably has a particle size of 180 mesh in the medium-grade magnesia fine powder.

[0012] According to the present invention, in a wettable surface repair material, preferably, the particle size of the modified asphalt is not greater than 1 mm.

[0013] According to the present invention, the wettable large-area repair material preferably has the following mass percentages: sintered coarse magnesia sand 23 wt%, sintered fine magnesia sand 10 wt%, forsterite 20 wt%, and medium-grade magnesia sand 18 wt%.

[0014] According to the present invention, the wettable large-area repair material preferably has the following composition: the mass percentage of the medium-grade magnesia fine powder is 12 wt%; and the mass percentage of the magnesium-calcium-iron sand fine powder is 4-6 wt%.

[0015] According to the present invention, the modified asphalt has a mass percentage of 12.5-13.5 wt% in a wettable surface repair material.

[0016] In this invention, the use of the above-mentioned particle size composition can better improve the flexural strength of the large-area repair material.

[0017] In addition, the present invention also provides a method for preparing a wettable large-area repair material as described above, comprising the following steps: Step (1): Weigh out each component of the aggregate according to the proportion and mix them for the first time to obtain the mixed dry material; Step (2): First, add industrial white oil to the dry mixture and stir for a second time, then add modified asphalt and stir for a third time to obtain the wet mixture; Step (3): Add fine powder to the mixed wet material and mix for the third time to obtain a wet-type large-area repair material.

[0018] According to the present invention, in a method for preparing a wettable large-area repair material, preferably, the first stirring time in step (1) is 2 min.

[0019] As a more preferred technical solution of the present invention, the time for the second and third stirring in step (1) is 2 minutes. As another more preferred technical solution of the present invention, the fourth stirring time in step (3) is 2 min.

[0020] As a specific embodiment of the present invention, the first stirring time in step (1) is 2 minutes; the second and third stirring times in step (1) are 2 minutes; and the fourth stirring time in step (3) is 2 minutes.

[0021] The beneficial effects of this invention are: This invention discloses a wettable large-area repair material, which uses sintered magnesia, medium-grade magnesia, and forsterite as the main aggregates. By screening specific component ratios and particle sizes, the obtained large-area repair material is suitable for vanadium-iron iron ore steelmaking converters, which can significantly improve the service life of steelmaking converters and has high flexural strength. It has significant economic value for the preparation of refractory materials.

[0022] In addition, the preparation method of the present invention is simple to operate and has a short process. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples.

[0024] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0025] The large-area repair material prepared in the embodiments of the present invention is used on the inner side of the steelmaking converter of vanadium-titanium magnetite smelting equipment. The V2O5 content in the steel slag produced after vanadium-titanium magnetite smelting is about 1 to 3 wt%.

[0026] In the embodiments and comparative examples of the present invention, unless otherwise specified, the main physicochemical properties of the sintered magnesia, medium-grade magnesia, magnesium-calcium-iron sand, modified bitumen, and industrial white oil used are shown in Tables 1-3 below: Table 1. Main physicochemical properties of medium-grade magnesia, sintered magnesia, and magnesia-calcium-iron sand.

[0027] Table 2 Main Physicochemical Properties of Modified Asphalt

[0028] Table 3 Main Physicochemical Indicators of Industrial White Oil

[0029] Example 1 The large-area repair material in this embodiment was prepared according to the following method: Step (1): Weigh each component according to Table 4, mix sintered coarse magnesia sand, sintered fine magnesia sand, forsterite, and medium-grade magnesia sand with a particle size not greater than 2mm for the first stirring, stir for 2 minutes, and obtain mixed dry material. Step (2): First, add industrial white oil to the dry mixture and stir for a second time for 2 minutes. Then, add modified asphalt and stir for a third time for 2 minutes to obtain the wet mixture. Step (3): Add medium-grade magnesia fine powder and magnesia-calcium-iron sand fine powder to the mixed wet material for the third time, stir for 2 minutes to obtain wettable large-area repair material.

[0030] Table 4. Mass percentage and particle size of each component in Example 1

[0031] Example 2 The wettable large-area repair material of this embodiment was prepared according to the following preparation method: Step (1): Weigh each component according to Table 5, mix sintered coarse magnesia sand, sintered fine magnesia sand, forsterite, and medium-grade magnesia sand with a particle size not greater than 2mm for the first stirring, stir for 2 minutes, and obtain mixed dry material. Step (2): First, add industrial white oil to the dry mixture and stir for a second time for 2 minutes. Then, add modified asphalt and stir for a third time for 2 minutes to obtain the wet mixture. Step (3): Add medium-grade magnesia fine powder and magnesia-calcium-iron sand fine powder to the mixed wet material for the third time, stir for 2 minutes to obtain No. 2 wettable large surface repair material.

[0032] Table 5. Mass percentage and particle size of each component in Example 2

[0033] Example 3 The wettable large-area repair material of this embodiment was prepared according to the following preparation method: Step (1): Weigh each component according to Table 6, mix sintered coarse magnesia sand, sintered fine magnesia sand, forsterite, and medium-grade magnesia sand with a particle size not greater than 2mm for the first stirring, stir for 2 minutes, and obtain mixed dry material. Step (2): First, add industrial white oil to the dry mixture and stir for a second time for 2 minutes. Then, add modified asphalt and stir for a third time for 2 minutes to obtain the wet mixture. Step (3): Add medium-grade magnesia fine powder and magnesia-calcium-iron sand fine powder to the mixed wet material for the third time, stir for 2 minutes to obtain No. 3 wettable large surface repair material.

[0034] Table 6. Mass percentage and particle size of each component in Example 3

[0035] Comparative Example 1 The wettable large-area repair material of this comparative example was prepared according to the following preparation method: Step (1): Weigh each component according to Table 7, mix sintered coarse magnesia sand, sintered fine magnesia sand, forsterite, and medium-grade magnesia sand with a particle size not greater than 2mm for the first stirring, stir for 2 minutes, and obtain mixed dry material. Step (2): First, add industrial white oil to the dry mixture and stir for a second time for 2 minutes. Then, add modified asphalt and stir for a third time for 2 minutes to obtain the wet mixture. Step (3): Add medium-grade magnesia fine powder and magnesia-calcium-iron sand fine powder to the mixed wet material for the third time, stir for 2 minutes to obtain No. 4 wettable large surface repair material.

[0036] Table 7. Mass percentage and particle size of each component in Comparative Example 1

[0037] Comparative Example 2 The wettable large-area repair material of this comparative example was prepared according to the following preparation method: Step (1): Weigh each component according to Table 8, mix sintered coarse magnesia sand, sintered fine magnesia sand, forsterite, and medium-grade magnesia sand with a particle size not greater than 2mm for the first stirring, stir for 2 minutes, and obtain mixed dry material. Step (2): First, add industrial white oil to the dry mixture and stir for a second time for 2 minutes. Then, add modified asphalt and stir for a third time for 2 minutes to obtain the wet mixture. Step (3): Add medium-grade magnesia fine powder and magnesia-calcium-iron sand fine powder to the mixed wet material for the third time, stir for 2 minutes to obtain No. 5 wettable large surface repair material.

[0038] Table 8. Mass percentage and particle size of each component in Comparative Example 2

[0039] Comparative Example 3 The wettable surface repair material of this comparative example was prepared according to the formulation and method described in Example 1 of Chinese Patent Application No. CN201811601539.7, and 6# surface repair material was obtained.

[0040] The performance testing method is as follows: The 1-6# large-area repair materials prepared in Examples 1-3 and Comparative Examples 1-3 are respectively loaded into molds and compacted. Then, they are naturally sintered at 1100℃, 1400℃ and 1600℃ for 1 hour respectively. After being taken out and allowed to cool naturally to room temperature, standard samples are prepared for testing of flexural strength. The test results are shown in Tables 9-14 below: Table 9.1# Large-area repair culinary indicators

[0041] Table 102# Culinary Indicators for Large-Scale Repair

[0042] Table 11 3# Large-area repair culinary indicators

[0043] Table 12 4# Large-area repair culinary indicators

[0044] Table 13 5# Large-area repair culinary indicators

[0045] Table 14 Chemical Indicators for Large-Scale Repair on Surface #6

[0046] The experimental results show that the large-area repair material obtained by the present invention has high flexural strength, is suitable for vanadium-iron ore steelmaking converters, can significantly improve the service life of steelmaking converters, and has very important economic value.

[0047] It should be noted that the components or steps in the above embodiments can be interchanged, substituted, added, or deleted. Therefore, the combinations formed by these reasonable permutations and transformations should also fall within the protection scope of this invention, and the protection scope of this invention should not be limited to the above embodiments.

[0048] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0049] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A wetting-type large-area repair material, characterized in that, It includes aggregates, fine powder, modified bitumen, and industrial white oil; aggregates include sintered magnesia coarse sand, sintered magnesia fine sand, forsterite, and medium-grade magnesia; fine powder includes medium-grade magnesia fine powder and magnesia-calcium-iron sand fine powder; the particle size and mass percentage of each component are as follows: The coarse sintered magnesia has a particle size of 10-5 mm and a mass percentage of 20-30 wt%; the fine sintered magnesia has a particle size of 5-3 mm and a mass percentage of 5-15 wt%; the forsterite has a particle size of 3-1 mm and a mass percentage of 15-25 wt%; the medium-grade magnesia has a particle size of no more than 2 mm and a mass percentage of 15-25 wt%. Medium-grade magnesia fine powder has a particle size of 150-200 mesh and a mass percentage of 10-15 wt%; magnesium-calcium-iron sand fine powder has a particle size of 150-200 mesh and a mass percentage of 1-8 wt%. Modified asphalt 10-14 wt; industrial white oil 0.5-1.5 wt.

2. The wettable large-area repair material according to claim 1, characterized in that, The aggregate has a mass percentage of 85-90 wt%.

3. The wettable large-area repair material according to claim 1, characterized in that, The particle size of the magnesium-calcium-iron sand powder is 180 mesh.

4. The wettable large-area repair material according to claim 1, characterized in that, The particle size of the medium-grade magnesia fine powder is 180 mesh.

5. The wettable large-area repair material according to claim 1, characterized in that, The particle size of the modified asphalt is no greater than 1 mm.

6. The wettable large-area repair material according to claim 1, characterized in that, The mass percentage of the sintered coarse magnesia is 23 wt%, the mass percentage of the sintered fine magnesia is 10 wt%, the mass percentage of the forsterite is 20 wt%, and the mass percentage of the medium-grade magnesia is 18 wt%.

7. The wettable large-area repair material according to claim 1, characterized in that, The medium-grade magnesia fine powder has a mass percentage of 12 wt%; the magnesium-calcium-iron sand fine powder has a mass percentage of 4-6 wt%.

8. The wettable large-area repair material according to claim 1, characterized in that, The modified asphalt has a mass percentage of 12.5-13.5 wt%.

9. A method for preparing a wettable large-area repair material according to any one of claims 1-8, characterized in that, Includes the following steps: Step (1): Weigh out each component of the aggregate according to the proportion and mix them for the first time to obtain the mixed dry material; Step (2): First, add industrial white oil to the dry mixture and stir for a second time, then add modified asphalt and stir for a third time to obtain the wet mixture; Step (3): Add fine powder to the mixed wet material and mix for the third time to obtain a wet-type large-area repair material.

10. The method for preparing a wettable large-area repair material according to claim 9, characterized in that, The first stirring time in step (1) is 2 minutes; the second and third stirring times in step (1) are 2 minutes; and the fourth stirring time in step (3) is 2 minutes.

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