High-strength intermediate package dry material and preparation method thereof

Abstract

The application relates to the technical field of refractory materials, and discloses a high-strength tundish dry mix and a preparation method thereof. The tundish dry mix comprises the following components in parts by weight: sintered magnesite 150 parts, hydroxyapatite 40-60 parts, silica fume 20-40 parts, a binding agent 8-12 parts, and a curing agent 0.5-1 part. The binding agent comprises phenolic resin and polymeric ferric sulfate. Through the technical scheme, the problem of poor normal-temperature compressive strength of the tundish dry mix in the related art is solved.

Description

Technical Field

[0001] This invention relates to the field of refractory materials technology, specifically to a high-strength dry tundish material and its preparation method. Background Technology

[0002] In the steel production process, the tundish plays a crucial role as the transition device between molten steel and the crystallizer. As the lining material of the tundish, the performance of the tundish dry lining directly affects the overall performance and service life of the tundish. For example, if the strength of the tundish dry lining is insufficient, it is prone to cracking and spalling under frequent thermal shock and mechanical vibration.

[0003] With the continuous promotion of high-efficiency continuous casting technology, the working conditions of tundishes have become more demanding. The strength of traditional tundish dry feedstock can no longer meet market requirements. There is an urgent need to develop tundish dry feedstock with higher strength to ensure stable operation of the tundish in harsh environments. Summary of the Invention

[0004] This invention proposes a high-strength dry tundish material and its preparation method, which solves the problem of poor room temperature compressive strength of dry tundish materials in related technologies.

[0005] The technical solution of the present invention is as follows:

[0006] This invention proposes a high-strength intermediate dry material, comprising the following components in parts by weight: 150 parts sintered magnesia, 40-60 parts hydroxyapatite, 20-40 parts silica fume, 8-12 parts binder, and 0.5-1 part curing agent;

[0007] The binder includes phenolic resin and polyferric sulfate.

[0008] As a further technical solution, the weight ratio of the phenolic resin to the polyferric sulfate is 3:2 to 9:1.

[0009] In this invention, when the weight ratio of phenolic resin to polyferric sulfate is 3:2 to 9:1, it helps to further improve the room temperature compressive strength of the dry material in the tundish.

[0010] As a further technical solution, the hydroxyapatite is modified hydroxyapatite.

[0011] In this invention, by modifying hydroxyapatite, the bonding between hydroxyapatite and sintered magnesia during sintering can be enhanced, further promoting the densification of the dry tundish material, thereby further improving the room temperature compressive strength of the dry tundish material.

[0012] As a further technical solution, the modified hydroxyapatite comprises the following components: hydroxyapatite, ferric acetylacetone, and ferric stearate.

[0013] In this invention, the inventors discovered that modifying hydroxyapatite with ferric acetylacetone and ferric stearate can further improve the room temperature compressive strength of dry tundish fillers. It is speculated that this is because ferric acetylacetone and ferric stearate can improve the sintering activity of hydroxyapatite, promoting the bonding between hydroxyapatite and sintered magnesia.

[0014] As a further technical solution, the preparation method of the modified hydroxyapatite includes the following steps: dissolving ferric acetylacetone and ferric stearate in ethanol, adding hydroxyapatite, dispersing evenly, and drying to obtain the modified hydroxyapatite.

[0015] As a further technical solution, the weight ratio of the hydroxyapatite and ferric acetylacetone to ferric stearate is 10.5~13:1:1.

[0016] In this invention, when the weight ratio of hydroxyapatite to ferric acetylacetone and ferric stearate is 10.5~13:1:1, it helps to further improve the room temperature compressive strength of the dry tundish material.

[0017] As a further technical solution, the melting temperature is 40~50℃.

[0018] As a further technical solution, the particle size of the sintered magnesia, hydroxyapatite and silica fume is independently 100~600 mesh.

[0019] As a further technical solution, the particle size of the sintered magnesia is 100-200 mesh; and / or

[0020] The hydroxyapatite has a particle size of 250-325 mesh; and / or

[0021] The silica fume has a particle size of 400-600 mesh.

[0022] In this invention, by designing the particle size distribution of sintered magnesia, hydroxyapatite, and silica fume, the density of the dry tundish material can be improved, thereby further enhancing the room temperature compressive strength of the dry tundish material.

[0023] As a further technical solution, the mass fraction of magnesium oxide in the sintered magnesia is ≥95%.

[0024] As a further technical solution, the mass fraction of silicon dioxide in the silica ash is ≥95%.

[0025] As a further technical solution, the curing agent includes one of hexamethylenetetramine, p-toluenesulfonic acid, and 2-methylimidazole.

[0026] The present invention also proposes a method for preparing the high-strength tundish dry material, comprising the following steps: mixing the components evenly to obtain the tundish dry material.

[0027] The working principle and beneficial effects of this invention are as follows:

[0028] In this invention, the tundish dry material has advantages such as readily available raw materials, simple preparation, and a favorable construction environment. Specifically, by using phenolic resin and polyferric sulfate as binders, the synergistic effect of organic and inorganic polymers allows the tundish dry material to form a robust three-dimensional mesh structure after baking, significantly improving its room-temperature compressive strength. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Unless otherwise specified, in the following examples and comparative examples, the particle size of sintered magnesia is 100 mesh and the mass fraction of magnesium oxide is 95.16%; the particle size of hydroxyapatite is 325 mesh and the calcium-to-phosphorus ratio is 1.67; the particle size of silica fume is 600 mesh and the silica content is 98.24%; the phenolic resin is PF-2123; and the polyferric sulfate is YT-0104.

[0031] Example 1

[0032] A method for preparing a high-strength tundish dry material includes the following steps: by weight, 150 parts of sintered magnesia, 40 parts of hydroxyapatite, 20 parts of silica fume, 4 parts of phenolic resin, 4 parts of polyferric sulfate and 0.5 parts of hexamethylenetetramine are mixed evenly to obtain the tundish dry material.

[0033] Example 2

[0034] A method for preparing a high-strength tundish dry material includes the following steps: by weight, 150 parts of sintered magnesia, 60 parts of hydroxyapatite, 40 parts of silica fume, 6 parts of phenolic resin, 6 parts of polyferric sulfate and 1 part of hexamethylenetetramine are mixed evenly to obtain the tundish dry material.

[0035] Example 3

[0036] A method for preparing a high-strength tundish dry material includes the following steps: by weight, 150 parts of sintered magnesia, 50 parts of hydroxyapatite, 30 parts of silica fume, 5 parts of phenolic resin, 5 parts of polyferric sulfate and 0.75 parts of hexamethylenetetramine are mixed evenly to obtain the tundish dry material.

[0037] Example 4

[0038] The only difference between this embodiment and Embodiment 3 is that in this embodiment, the phenolic resin has a weight of 9.5 parts and the polyferric sulfate has a weight of 0.5 parts.

[0039] Example 5

[0040] The only difference between this embodiment and Embodiment 3 is that in this embodiment, the phenolic resin has 6 parts by weight and the polyferric sulfate has 4 parts by weight.

[0041] Example 6

[0042] The only difference between this embodiment and Embodiment 3 is that in this embodiment, the phenolic resin is 9 parts by weight and the polyferric sulfate is 1 part by weight.

[0043] Example 7

[0044] The only difference between this embodiment and Embodiment 6 is that in this embodiment, the hydroxyapatite is modified hydroxyapatite. The preparation method of modified hydroxyapatite includes the following steps: dissolving 2 parts of ferric stearate in ethanol at 45°C, adding 48 parts of hydroxyapatite, dispersing evenly, and drying to obtain modified hydroxyapatite.

[0045] Example 8

[0046] The only difference between this embodiment and Embodiment 6 is that in this embodiment, the hydroxyapatite is modified hydroxyapatite. The preparation method of modified hydroxyapatite includes the following steps: dissolving 2 parts of acetylacetone iron in ethanol at 45°C, adding 48 parts of hydroxyapatite, dispersing evenly, and drying to obtain modified hydroxyapatite.

[0047] Example 9

[0048] The only difference between this embodiment and Embodiment 6 is that in this embodiment, the hydroxyapatite is modified hydroxyapatite. The preparation method of modified hydroxyapatite includes the following steps: dissolving 1 part of ferric acetylacetone and 1 part of ferric stearate in ethanol at 45°C, adding 48 parts of hydroxyapatite, dispersing evenly, and drying to obtain modified hydroxyapatite.

[0049] Example 10

[0050] The only difference between this embodiment and Embodiment 9 is that, in this embodiment, when preparing modified hydroxyapatite, the weight parts of iron acetylacetone are 5 parts, the weight parts of iron stearate are 5 parts, and the weight parts of hydroxyapatite are 40 parts.

[0051] Example 11

[0052] The only difference between Example 9 and Example 1 is that in this example, when preparing modified hydroxyapatite, the weight parts of iron acetylacetone are 2 parts, the weight parts of iron stearate are 2 parts, and the weight parts of hydroxyapatite are 46 parts.

[0053] Example 12

[0054] The only difference between Example 9 and Example 1 is that in this example, when preparing modified hydroxyapatite, the weight parts of iron acetylacetone are 4 parts, the weight parts of iron stearate are 4 parts, and the weight parts of hydroxyapatite are 42 parts.

[0055] Comparative Example 1

[0056] The only difference between this comparative example and Example 1 is that in this comparative example, polyferric sulfate was not added, and the weight of phenolic resin added was 8 parts.

[0057] Comparative Example 2

[0058] The only difference between this comparative example and Example 1 is that no phenolic resin was added in this comparative example, and the amount of polyferric sulfate added was 8 parts by weight.

[0059] Comparative Example 3

[0060] The only difference between this comparative example and Example 1 is that in this comparative example, polyferric sulfate is replaced with an equal amount of ferric sulfate.

[0061] The tundish dry vibratory refractories prepared in Examples 1-12 and Comparative Examples 1-3 were used to prepare specimens according to the specifications in GB / T 4513.5-2017 "Unshaped Refractory Materials - Part 5: Specimen Preparation and Pretreatment". The specimens were 50 mm in diameter and 50 mm in height, and then the following performance tests were performed:

[0062] ① Compressive strength at room temperature after sintering at 200℃ for 2 hours: The compressive strength at room temperature was determined according to GB / T 4513.6-2017 "Unshaped refractories - Part 6: Determination of physical properties";

[0063] ② Compressive strength at room temperature after sintering at 1500℃ for 3 hours: The compressive strength at room temperature was determined in accordance with GB / T 4513.6-2017 "Unshaped Refractory Materials - Part 6: Determination of Physical Properties".

[0064] The test results are shown in Table 1 below.

[0065] Table 1 Results of room temperature compressive strength test

[0066]

[0067] A comparison of Examples 1 and Comparative Examples 1-3 shows that using phenolic resin and polyferric sulfate as binders, the synergistic effect of the two can significantly improve the room temperature compressive strength of the tundish dry material. A comparison of Examples 3-4 and Examples 5-6 shows that when the weight ratio of phenolic resin to polyferric sulfate is 3:2 to 9:1, it helps to further improve the room temperature compressive strength of the tundish dry material. A comparison of Examples 6 and Examples 7-12 shows that modification of hydroxyapatite further improves the room temperature compressive strength of the tundish dry material. A comparison of Examples 7-8 and Examples 9 shows that modification of hydroxyapatite with ferric acetylacetone and ferric stearate can further improve the room temperature compressive strength of the tundish dry material. A comparison of Examples 9-10 and Examples 11-12 shows that when the weight ratio of hydroxyapatite to ferric acetylacetone and ferric stearate is 10.5 to 13:1:1, it helps to further improve the room temperature compressive strength of the tundish dry material.

[0068] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-strength tundish dry-type material, characterized in that, The product comprises the following components in parts by weight: 150 parts sintered magnesia, 40-60 parts modified hydroxyapatite, 20-40 parts silica fume, 8-12 parts binder, and 0.5-1 parts curing agent; the binder comprises phenolic resin and polyferric sulfate in a weight ratio of 3:2-9:1; the modified hydroxyapatite comprises the following components: hydroxyapatite, ferric acetylacetone, and ferric stearate; the preparation method of the modified hydroxyapatite comprises the following steps: dissolving ferric acetylacetone and ferric stearate in ethanol, adding hydroxyapatite, dispersing evenly, and drying to obtain the modified hydroxyapatite; the weight ratio of hydroxyapatite to ferric acetylacetone and ferric stearate is 10.5-13:1:

1.

2. A high-strength tundish dry-type material according to claim 1, characterized in that, The particle size of the sintered magnesia, hydroxyapatite, and silica fume is independently 100-600 mesh.

3. A high-strength tundish dry-type material according to claim 2, characterized in that, The sintered magnesia has a particle size of 100-200 mesh; and / or The hydroxyapatite has a particle size of 250-325 mesh; and / or The silica fume has a particle size of 400-600 mesh.

4. The high-strength tundish dry material according to claim 1, characterized in that, The curing agent includes one of hexamethylenetetramine, p-toluenesulfonic acid, and 2-methylimidazole.

5. A method for preparing high-strength tundish dry-type material as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Mix all components thoroughly to obtain the dry intermediate package material.

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