A skateboard brick and its preparation method

Abstract

The present invention discloses a skateboard brick and a preparation method thereof, relating to the technical field of skateboard bricks. The skateboard brick comprises the following raw materials in parts by weight: 30-50 parts of tabular corundum, 20-30 parts of white corundum, 8-12 parts of graphite, 2-5 parts of carbon black, 3-5 parts of metallic aluminum powder, 4-6 parts of binder, and 2-4 parts of silicon carbide. In the present invention, a hydroxyl group in sodium alginate reacts with a chlorine atom in 4-chlorophenylboronic acid under the action of potassium carbonate to generate boric acid-modified sodium alginate; a boric acid bond in the boric acid-modified sodium alginate reacts with a hydroxyl group in tannic acid to generate tannic acid composite sodium alginate; a hydroxyl group in the tannic acid composite sodium alginate reacts with a silicon hydroxyl group in triphenylhydroxysilane under the action of phosphoric acid to generate a binder. The skateboard brick prepared by the present invention has good compressive strength and high-temperature flexural strength.

Description

Technical Field

[0001] The present invention relates to the technical field of skate bricks, and particularly relates to a skate brick and a preparation method thereof. Background Art

[0002] As an indispensable refractory material in the steelmaking process, skate bricks are mainly used in key links such as slag blocking in converters, molten steel ladle and tundish flow control. With the rapid development of steel refining technology, the performance requirements for skate bricks are becoming increasingly stringent. During actual use, skate bricks need to withstand the chemical erosion and physical scouring of high-temperature molten steel for a long time and repeatedly, and at the same time, they also have to face the tests of high thermal shock and mechanical wear. Therefore, they must have high wear resistance, high-temperature strength, corrosion resistance, thermal shock resistance and oxidation resistance.

[0003] The skate bricks widely used in current steel mills mainly include aluminocarbon, alumina-zirconia-carbon and magnesia skate bricks, etc. Generally, corundum and zirconium-containing raw materials are used as the main components, and phenolic resin or epoxy resin is used as the binder. However, ordinary aluminocarbon skate bricks are difficult to meet the requirements of modern steelmaking processes in terms of performance; although magnesia skate bricks have good corrosion resistance to highly corrosive steel grades, their thermal expansion coefficient is relatively large, resulting in low strength and unsatisfactory corrosion resistance. In summary, developing a skate brick with excellent comprehensive performance, especially outstanding wear resistance and mechanical strength, has become the key to meeting the high-efficiency production needs of the modern steelmaking industry.

[0004] Chinese invention patent with the publication number of CN105967702A discloses a skate brick and a preparation method thereof. The skate brick includes: 80wt%-89.9wt% magnesite, 5wt%-10wt% metallic aluminum, 1wt%-3wt% carbon black, 1wt%-3wt% additive, 3wt%-5wt% resin. This skate brick has a high refractoriness and good thermal shock stability, but its compressive strength and high-temperature flexural strength are poor. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a skate brick and a preparation method thereof.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0007] A skate brick, the skate brick comprises the following raw materials in parts by weight:

[0008] Tabular corundum 30-50 parts, white corundum 20-30 parts, graphite 8-12 parts, carbon black 2-5 parts, metallic aluminum powder 3-5 parts, binder 4-6 parts, silicon carbide 2-4 parts;

[0009] The binder is prepared by the following method:

[0010] S1: Under nitrogen protection, sodium alginate and 4-chlorophenylboric acid react with potassium carbonate to generate boric acid-modified sodium alginate;

[0011] S2: boric acid modified sodium alginate reacts with tannic acid to form tannic acid composite sodium alginate;

[0012] S3: Under nitrogen protection, tannic acid-complexed sodium alginate and triphenylhydroxysilane react with phosphoric acid to generate a binder.

[0013] In the step S1, the mass ratio of sodium alginate to 4-chlorophenylboric acid is 10:(2-3).

[0014] In step S2, the mass ratio of boric acid-modified sodium alginate to tannic acid is 6:(1.5-2).

[0015] In the step S3, the mass ratio of tannic acid-complexed sodium alginate to triphenylhydroxysilane is 10:(0.5-0.8).

[0016] The plate-shaped corundum includes three different particle sizes: particle size 0.6-2.0 mm.

[0017] The particle size of the white corundum is 0.1-1 mm.

[0018] The graphite is dense crystalline graphite.

[0019] The carbon black is furnace black.

[0020] A method for preparing a skateboard brick comprises the following steps:

[0021] (1) Weigh by weight: 30-50 parts of plate-shaped corundum, 20-30 parts of white corundum, 8-12 parts of graphite, 2-5 parts of carbon black, 3-5 parts of metal aluminum powder, 4-6 parts of binder, and 2-4 parts of silicon carbide;

[0022] (2) Drying the plate-shaped corundum, white corundum, graphite, carbon black, metal aluminum powder and silicon carbide respectively to remove the moisture in the raw materials, and then crushing, grinding and sieving the raw materials for later use; adding the pretreated raw materials into a mixer according to the above ratio, adding a binder at the same time, and fully mixing them so that the raw materials are evenly dispersed, and the mixing time is 10-20 minutes; adding the mixed materials into a mold, pressing them at a pressure of 100-200 MPa to obtain a skateboard brick body;

[0023] (3) Finally, the green body is subjected to gradient drying, with an initial baking at 80-120°C for 8-12 hours and a final baking at 200-260°C for 24-48 hours, and then surface grinding to obtain a finished skateboard brick.

[0024] Due to the adoption of the above technical solution, the beneficial effects of the present invention include:

[0025] (1) The present invention comprises the following steps: the hydroxyl group in sodium alginate reacts with the chlorine atom in 4-chlorophenylboric acid under the action of potassium carbonate to generate boric acid-modified sodium alginate; the boric acid in the boric acid-modified sodium alginate reacts with the hydroxyl group in tannic acid to generate tannic acid-composite sodium alginate; and the hydroxyl group in the tannic acid-composite sodium alginate reacts with the silanol group in triphenylhydroxysilane under the action of phosphoric acid to generate a binder.

[0026] (2) The binder prepared by the present invention is based on sodium alginate, which reacts with 4-chlorophenylboronic acid to form a dynamic borate bond network, and reacts with tannic acid and triphenylhydroxysilane to construct a multiple cross-linked structure. The dynamic borate bond network can dissipate stress by breaking and reorganizing the bonds when the material is under pressure, thereby avoiding brittle fracture caused by local stress concentration. In the multiple cross-linked structure, the phenolic hydroxyl groups of tannic acid are further cross-linked with boric acid-modified sodium alginate to form a three-dimensional network structure. These structures work synergistically to make the skateboard bricks exhibit higher deformation resistance and compressive strength when subjected to mechanical loads. At the same time, the borate bond remains stable at high temperatures, and the dynamic reversibility can repair microcracks; the Si-O bond introduced by triphenylhydroxysilane has high bond energy and excellent high-temperature oxidation resistance, which can inhibit the degradation of molecular chains at high temperatures. DETAILED DESCRIPTION

[0027] The invention will be further described below in conjunction with the embodiments, but the invention is not limited to these embodiments.

[0028] Example 1 Preparation of binder: S1: Under nitrogen protection, add 500 ml of a mixed solution of DMSO and H2O (DMSO:H2O (V / V)=1:1), 100 g of sodium alginate, and 5 g of potassium carbonate into a reactor, stir and mix, then slowly drop 4-chlorophenylboric acid DMSO solution (20 g of 4-chlorophenylboric acid is dissolved in 500 ml of DMSO), drop for 1 hour, heat to 100°C, react for 12 hours, cool to room temperature, add 10 wt% dilute hydrochloric acid to adjust the pH to neutral, add 500 ml of anhydrous ethanol and stir evenly, let stand for 30 minutes, precipitate, collect the precipitate by centrifugation, and dry in vacuo at 70°C for 4 hours to obtain boric acid-modified sodium alginate;

[0029] S2: Add 400 ml of deionized water, 60 g of boric acid-modified sodium alginate, and 15 g of tannic acid to the reactor, stir and mix, then add 10 ml of 0.1 M phosphate buffer (pH = 5.0), heat to 40 ° C, react for 8 h (use a water separator to remove the generated water during the reaction), add 0.1 M NaOH solution to adjust the pH to neutral, then add 500 ml of anhydrous ethanol for precipitation, stir and mix, let stand for 30 min, precipitate, collect the precipitate by centrifugation, and dry it in vacuum at 50 ° C for 6 h to obtain tannic acid-complexed sodium alginate;

[0030] S3: Under nitrogen protection, add 500 ml of toluene, 100 g of tannic acid composite sodium alginate, and 5 g of triphenylhydroxysilane into the reactor, stir to mix evenly, heat up to 50 °C, then add 5 ml of 85 wt% phosphoric acid, react for 4 h, then perform vacuum distillation at 60 °C for 3 h, recrystallize three times with acetone (500 g of acetone is used each time), and dry in vacuum at 60 °C for 5 h to obtain the binder.

[0031] Example 2 Preparation of the binder: S1: Under nitrogen protection, add a mixed solution of 500 ml of DMSO and H2O (DMSO:H2O (V / V) = 1:1), 100 g of sodium alginate, and 5 g of potassium carbonate into the reactor, stir to mix evenly, then slowly dropwise add a DMSO solution of 4-chlorophenylboronic acid (25 g of 4-chlorophenylboronic acid is dissolved in 500 ml of DMSO), the dropping time is 1.5 h, heat up to 110 °C, after reacting for 14 h, cool to room temperature, add 10 wt% dilute hydrochloric acid to adjust the pH to neutral, add 500 ml of absolute ethanol and stir evenly, let stand for 30 min, precipitate, centrifuge to collect the precipitate, and dry in vacuum at 60 °C for 5 h to obtain boric acid-modified sodium alginate;

[0032] S2: Add 400 ml of deionized water, 60 g of boric acid-modified sodium alginate, and 18 g of tannic acid into the reactor, stir to mix evenly, then add 15 ml of 0.1 M phosphate buffer solution (pH = 5.0), heat up to 50 °C, after reacting for 6 h (use a water separator to remove the generated water during the reaction), add 0.1 M NaOH solution to adjust the pH to neutral, then add 500 ml of absolute ethanol to precipitate, stir to mix evenly, let stand for 30 min, precipitate, centrifuge to collect the precipitate, and dry in vacuum at 50 °C for 6 h to obtain tannic acid composite sodium alginate;

[0033] S3: Under nitrogen protection, add 500 ml of toluene, 100 g of tannic acid composite sodium alginate, and 6 g of triphenylhydroxysilane into the reactor, stir to mix evenly, heat up to 60 °C, then add 5 ml of 85 wt% phosphoric acid, react for 3 h, then perform vacuum distillation at 60 °C for 3 h, recrystallize three times with acetone (500 g of acetone is used each time), and dry in vacuum at 60 °C for 5 h to obtain the binder.

[0034] Example 3 Preparation of binder: S1: Under nitrogen protection, add 500 ml of a mixed solution of DMSO and H2O (DMSO:H2O (V / V)=1:1), 100 g of sodium alginate, and 5 g of potassium carbonate into a reactor, stir and mix, then slowly drop 4-chlorophenylboric acid DMSO solution (30 g of 4-chlorophenylboric acid dissolved in 500 ml of DMSO), drop for 2 hours, heat to 110°C, react for 16 hours, cool to room temperature, add 10 wt% dilute hydrochloric acid to adjust the pH to neutral, add 500 ml of anhydrous ethanol and stir evenly, let stand for 30 minutes, precipitate, collect the precipitate by centrifugation, and dry in vacuo at 50°C for 6 hours to obtain boric acid-modified sodium alginate;

[0035] S2: Add 400 ml of deionized water, 60 g of boric acid-modified sodium alginate, and 20 g of tannic acid to the reactor, stir and mix, then add 15 ml of 0.1 M phosphate buffer (pH = 5.0), heat to 60 ° C, react for 5 h (use a water separator to remove the generated water during the reaction), add 0.1 M NaOH solution to adjust the pH to neutral, then add 500 ml of anhydrous ethanol for precipitation, stir and mix, let stand for 30 min, precipitate, collect the precipitate by centrifugation, and dry it under vacuum at 50 ° C for 6 h to obtain tannic acid-complexed sodium alginate;

[0036] S3: Under nitrogen protection, add 500 ml of toluene, 100 g of tannic acid composite sodium alginate, and 8 g of triphenylhydroxysilane into the reactor, stir and mix, heat to 70°C, then add 5 ml of 85 wt% phosphoric acid, react for 2 h, distill at 60°C under reduced pressure for 3 h, recrystallize with acetone three times (using 500 g of acetone each time), and vacuum dry at 60°C for 5 h to obtain the binder.

[0037] Example 4 Preparation of skateboard bricks: (1) Weigh: 300 g of plate-shaped corundum (particle size 0.6-2.0 mm), 200 g of white corundum (particle size 0.1-1 mm), 80 g of graphite (dense crystalline graphite), 20 g of carbon black (furnace black), 30 g of metal aluminum powder (particle size 10-30 μm), 40 g of binder (prepared in Example 1), and 20 g of silicon carbide (particle size 40-70 μm);

[0038] (2) Dry the plate-shaped corundum, white corundum, graphite, carbon black, metal aluminum powder, and silicon carbide separately to remove the moisture in the raw materials, then crush and grind the raw materials, sieve to remove the materials with a particle size greater than 1 mm for later use; add the pretreated raw materials into a mixer according to the above ratio, add a binder at the same time, mix them thoroughly, and make the raw materials evenly dispersed, and the mixing time is 10 minutes; add the mixed materials into a mold, and press them at a pressure of 100 MPa to obtain a skateboard brick body;

[0039] (3) Finally, the green body is subjected to gradient drying, initially dried at 80 °C for 12 h, finally dried at 200 °C for 48 h, and then surface-ground to obtain the finished skateboard brick.

[0040] Preparation of skateboard brick in Example 5: (1) Weigh: 400 g of tabular corundum (particle size 0.6 - 2.0 mm), 250 g of white corundum (particle size 0.1 - 1 mm), 100 g of graphite (dense crystalline graphite), 30 g of carbon black (furnace black), 40 g of metallic aluminum powder (particle size 10 - 30 μm), 50 g of binder (prepared in Example 2), and 30 g of silicon carbide (particle size 40 - 70 μm);

[0041] (2) The tabular corundum, white corundum, graphite, carbon black, metallic aluminum powder, and silicon carbide are respectively dried to remove the moisture in the raw materials, and then each raw material is crushed, ground, and screened to remove substances with a particle size greater than 1 mm for standby; the pretreated raw materials are added to a blender according to the above ratios, and at the same time, the binder is added and fully mixed to make each raw material evenly dispersed. The mixing time is 15 min; the mixed material is added to a mold and pressed at a pressure of 150 MPa to obtain a skateboard brick green body;

[0042] (3) Finally, the green body is subjected to gradient drying, initially dried at 100 °C for 10 h, finally dried at 230 °C for 36 h, and then surface-ground to obtain the finished skateboard brick.

[0043] Preparation of skateboard brick in Example 6: (1) Weigh: 500 g of tabular corundum (particle size 0.6 - 2.0 mm), 30 g of white corundum (particle size 0.1 - 1 mm), 120 g of graphite (dense crystalline graphite), 50 g of carbon black (furnace black), 50 g of metallic aluminum powder (particle size 10 - 30 μm), 60 g of binder (prepared in Example 3), and 40 g of silicon carbide (particle size 40 - 70 μm);

[0044] (2) The tabular corundum, white corundum, graphite, carbon black, metallic aluminum powder, and silicon carbide are respectively dried to remove the moisture in the raw materials, and then each raw material is crushed, ground, and screened to remove substances with a particle size greater than 1 mm for standby; the pretreated raw materials are added to a blender according to the above ratios, and at the same time, the binder is added and fully mixed to make each raw material evenly dispersed. The mixing time is 20 min; the mixed material is added to a mold and pressed at a pressure of 200 MPa to obtain a skateboard brick green body;

[0045] (3) Finally, the green body is subjected to gradient drying, initially dried at 120 °C for 8 h, finally dried at 260 °C for 24 h, and then surface-ground to obtain the finished skateboard brick.

[0046] Comparative Example 1: The raw material composition and process of the skateboard brick are basically the same as those of Example 5, except that the binder added in the components is replaced with thermosetting phenolic resin of equal weight, and its model is PF5323.

[0047] Comparative Example 2: The raw material composition and process of the skateboard brick are basically the same as those of Example 5, except that the binder is replaced with tannic acid composite sodium alginate prepared in Step S2 of Example 2 of equal weight.

[0048] Comparative Example 3: The raw material composition and process of the skateboard brick are basically the same as those of Example 5, except that the binder is replaced with a binder prepared by the following method of equal weight:

[0049] S1: Under nitrogen protection, add a mixed solution of 500 ml of DMSO and H2O (DMSO:H2O (V / V) = 1:1), 100 g of sodium alginate, and 5 g of potassium carbonate to the reactor, stir and mix evenly, then slowly dropwise add a DMSO solution of 4-chlorophenylboronic acid (25 g of 4-chlorophenylboronic acid dissolved in 500 ml of DMSO), the dropping time is 1.5 h, raise the temperature to 110 °C, after reacting for 14 h, cool to room temperature, add 10 wt% dilute hydrochloric acid to adjust the pH to neutral, add 500 ml of absolute ethanol, stir evenly, let stand for 30 min, precipitate, collect the precipitate by centrifugation, and vacuum dry at 60 °C for 5 h to obtain boric acid-modified sodium alginate;

[0050] S2: Under nitrogen protection, add 500 ml of toluene, 100 g of boric acid-modified sodium alginate, and 6 g of triphenylhydroxysilane to the reactor, stir and mix evenly, raise the temperature to 60 °C, then add 5 ml of 85 wt% phosphoric acid, react for 3 h, carry out vacuum distillation at 60 °C for 3 h, and then recrystallize three times with acetone (500 g of acetone is used each time), and vacuum dry at 60 °C for 5 h to obtain the binder.

[0051] Comparative Example 4: The raw material composition and process of the skateboard brick are basically the same as those of Example 5, except that the binder is replaced with a binder prepared by the following method of equal weight:

[0052] The preparation method of the binder in this comparative example is basically the same as that of Example 2, except that 4-chlorophenylboronic acid in Step S1 is replaced with p-chlorobenzoic acid.

[0053] Comparative Example 5: The raw material composition and process of the skateboard brick are basically the same as those of Example 5, except that the binder is replaced with a binder prepared by the following method of equal weight:

[0054] The preparation method of the binder in this comparative example is basically the same as that of Example 2, except that sodium alginate in Step S1 is replaced with carboxymethyl chitosan of equal weight.

[0055] Comparative Example 6: The raw material composition and process of the skateboard brick are basically the same as those of Example 5, except that the binder is replaced with an equal weight of a binder prepared by the following method:

[0056] The preparation method of the binder in this comparative example is basically the same as that of Example 2, except that the triphenylhydroxysilane in step S3 is replaced with γ-aminopropyltriethoxysilane.

[0057] Comparative Example 7: A skateboard brick was made using the raw material composition and process in Example 4 of the Chinese invention patent with the publication number CN105967702A.

[0058] In the examples and comparative examples of this application, the sodium alginate used has a molecular weight of 10,000 and is purchased from Shanghai Chuangsai Technology Co., Ltd.; the carboxymethyl chitosan has a molecular weight of 9,000 and is purchased from Hubei Rishengchang New Material Technology Co., Ltd.; the tabular corundum and white corundum are purchased from Henan Sicheng Grinding Technology Co., Ltd.; the carbon black has a model of N330 and a particle size of 20 - 50 nm and is purchased from Jiangxi Black Cat Carbon Black Co., Ltd.; the graphite has a particle size of 0.02 - 0.075 mm and is purchased from BETR New Energy Materials Co., Ltd.; the silicon carbide has a particle size of 40 - 70 μm and is purchased from Anyang Qiansheng Metallurgical Refractory Co., Ltd.; the metallic aluminum powder has a particle size of 10 - 30 μm and a grade of LFT1 and is purchased from AISG Micro Aluminum Powder Co., Ltd.

[0059] The skateboard bricks prepared in Examples 4 - 6 and Comparative Examples 1 - 7 of this application were subjected to performance tests, and the test results are shown in Table 1.

[0060] The normal temperature compressive strength test was carried out according to GB / T 5072 - 2008; the high temperature flexural strength test was carried out according to GB / T 3002 - 2017; the test results are shown in Table 1.

[0061] Table 1 Performance Test Table

[0062]

[0063] It can be seen from Table 1 that the skateboard bricks prepared in Examples 4 - 6 of this application have excellent compressive strength and high temperature flexural strength.

[0064] Comparative Example 1 is a comparative example where the added binder is thermosetting phenolic resin. It can be seen from the data in Table 1 that the high temperature flexural strength is not as good as that of this application.

[0065] The binder added in Comparative Example 2 is the tannic acid composite sodium alginate prepared in step S2 of Example 2. As can be seen from Table 1, the high-temperature flexural performance is poor. This is because triphenylhydroxysilane condenses under the catalysis of phosphoric acid to form a three-dimensional siloxane network, which provides a rigid skeleton. The high bond energy of the Si-O bond enhances the rigidity of the material and resists compression deformation. The siloxane network remains stable at high temperatures, while traditional organic binders (such as phenolic resins) decompose at around 300°C. The high temperature resistance of siloxane significantly improves the flexural strength of the skateboard bricks in high temperature environments.

[0066] In the preparation process of the binder added in Comparative Example 3, tannic acid is not added. As can be seen from Table 1, the high-temperature flexural resistance is poor. This is because the polyphenolic hydroxyl groups of tannic acid can form multiple hydrogen bonds and esterification crosslinks with the carboxyl groups of sodium alginate and the silanol groups of triphenylhydroxysilane, significantly improving the three-dimensional network density of the binder. The rigid aromatic ring structure of tannic acid can be embedded in the grain boundaries of the skateboard brick raw materials (corundum, silicon carbide), and the interfacial bonding force between the inorganic phase and the organic phase is enhanced through π-π stacking and coordination bonds, inhibiting crack propagation. Tannic acid is partially carbonized at high temperature to generate a graphite-like carbon layer with high thermal conductivity, which covers the surface of the skateboard brick particles, reducing oxidation erosion and thermal stress concentration.

[0067] In the preparation process of the binder added in Comparative Example 4, 4-chlorophenylboric acid in step S1 is replaced with p-chlorobenzoic acid. As can be seen from Table 1, the compressive strength and high-temperature flexural strength are not as good as those of the present application. This is because the boric acid-modified sodium alginate forms a reversible borate ester bond with the catechol hydroxyl group in tannic acid, which gives the material dynamic cross-linking ability. Under the action of external force, the dynamic bond can be broken and reorganized to disperse stress concentration and avoid brittle fracture, thereby improving toughness and compressive strength; and the borate ester bond still maintains a certain stability at high temperature, and the dynamic reversibility can repair microcracks.

[0068] In the preparation process of the binder added in Comparative Example 5, the sodium alginate in step S1 is replaced with an equal weight of carboxymethyl chitosan. It can be seen from Table 1 that the compressive strength and high-temperature flexural strength are not as good as those of the present application. This is because sodium alginate has a linear structure composed of β-D-mannuronic acid and α-L-guluronic acid units, the molecular chains are arranged in an orderly manner, the crystallinity is high, and it can withstand greater tensile stress, while the glucosamine units of chitosan have a stronger disordered molecular chain due to the difference in deacetylation degree, and the tensile strength is lower.

[0069] In Comparative Example 6, during the preparation of the added binder, triphenylhydroxysilane in Step S3 was replaced with γ-aminopropyltriethoxysilane. As can be seen from Table 1, the performance of the prepared skateboard bricks was not ideal. This is because triphenylhydroxysilane contains three phenyl groups and a hydroxyl group. The phenyl group is a rigid aromatic ring structure, providing excellent thermal stability and antioxidant properties. The conjugation effect of the phenyl group enhances the molecular thermal stability, and the decomposition temperature can reach above 300°C. The hydroxyl group can participate in the cross-linking reaction to form a stable Si-O-Si network, while the ethoxy group in γ-aminopropyltriethoxysilane hydrolyzes at high temperatures, resulting in the breakage of the molecular chain. The amino group is easily decomposed in a high-temperature oxidation environment, limiting its long-term high-temperature stability.

[0070] Comparative Example 7 is a skateboard brick prepared with the raw material composition and process in Example 4 of the Chinese invention patent CN105967702A. As can be seen from Table 1, the high-temperature flexural strength and the normal-temperature compressive strength are not as good as those of the present application.

[0071] As described above, the above are only the preferred embodiments of the present invention and are not used to limit the present invention. However, for those of ordinary skill in the art, without departing from the scope of the technical solution of the present invention, any equivalent changes such as slight modifications, evolutions, and variations made using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A skateboard brick, characterized in that: The invention comprises the following raw materials in parts by weight: 30-50 parts of plate-shaped corundum, 20-30 parts of white corundum, 8-12 parts of graphite, 2-5 parts of carbon black, 3-5 parts of metal aluminum powder, 4-6 parts of binder, 2-4 parts of silicon carbide; The binder is prepared by the following method: S1: Under nitrogen protection, sodium alginate and 4-chlorophenylboric acid react with potassium carbonate to generate boric acid-modified sodium alginate; S2: boric acid-modified sodium alginate reacts with tannic acid to generate tannic acid-complexed sodium alginate; S3: Under nitrogen protection, tannic acid-complexed sodium alginate reacts with triphenylhydroxysilane under the action of phosphoric acid to generate a binder.

2. A skateboard brick according to claim 1, characterized in that: In the step S1, the mass ratio of sodium alginate to 4-chlorophenylboric acid is 10:(2-3).

3. A skateboard brick according to claim 1, characterized in that: In step S2, the mass ratio of boric acid-modified sodium alginate to tannic acid is 6:(1.5-2).

4. A skateboard brick according to claim 1, characterized in that: In the step S3, the mass ratio of tannic acid-complexed sodium alginate to triphenylhydroxysilane is 10:(0.5-0.8).

5. The skateboard brick according to claim 1, characterized in that: The particle size of the plate-like corundum is 0.6-2.0 mm.

6. The skateboard brick according to claim 1, characterized in that: The particle size of the white corundum is 0.1-1 mm.

7. The skateboard brick according to claim 1, characterized in that: The graphite is dense crystalline graphite.

8. The skateboard brick according to claim 1, characterized in that: The carbon black is furnace black.

9. A method for preparing a skateboard brick according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Weigh by weight: 30-50 parts of plate-shaped corundum, 20-30 parts of white corundum, 8-12 parts of graphite, 2-5 parts of carbon black, 3-5 parts of metal aluminum powder, 4-6 parts of binder, and 2-4 parts of silicon carbide; (2) Drying the plate-shaped corundum, white corundum, graphite, carbon black, metal aluminum powder and silicon carbide respectively to remove the moisture in the raw materials, and then crushing, grinding and sieving the raw materials for later use; adding the pretreated raw materials into a mixer according to the above ratio, adding a binder at the same time, and fully mixing them so that the raw materials are evenly dispersed, and the mixing time is 10-20 minutes; adding the mixed materials into a mold, pressing them at a pressure of 100-200 MPa to obtain a skateboard brick body; (3) Finally, the green body is subjected to gradient drying, with an initial baking at 80-120°C for 8-12 hours and a final baking at 200-260°C for 24-48 hours, and then surface grinding to obtain a finished skateboard brick.

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