Sliding plate brick and preparation method thereof

Abstract

The invention discloses a sliding plate brick and a preparation method thereof, and relates to the technical field of sliding plate bricks. The sliding plate 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 metal aluminum powder, 4-6 parts of a binder and 2-4 parts of silicon carbide. The preparation method comprises the following steps: reacting hydroxyl in sodium alginate with chlorine atoms in 4-chlorophenylboronic acid under the action of potassium carbonate to generate boric acid modified sodium alginate; boric acid bonds in the boric acid modified sodium alginate react with hydroxyl groups in tannic acid to generate tannic acid composite sodium alginate; hydroxyl in the tannic acid composite sodium alginate reacts with silicon hydroxyl in the triphenyl hydroxysilane under the action of phosphoric acid to generate the binder. The prepared sliding plate brick has good compression strength and high-temperature fracture resistance.

Description

Technical Field

[0001] The invention relates to the technical field of skateboard bricks, and in particular to a skateboard brick and a preparation method thereof. Background Art

[0002] As an indispensable refractory material in the steelmaking process, skateboard bricks are mainly used in key links such as converter slag retaining, molten steel tank and tundish flow control. With the rapid development of steel refining technology, the performance requirements for skateboard bricks are becoming more and more stringent. In actual use, skateboard bricks need to withstand the chemical erosion and physical erosion of high-temperature molten steel for a long time and repeatedly, and also have to cope with the test 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 skateboard bricks widely used in various steel mills at present mainly include aluminum carbon, aluminum zirconium carbon and magnesium skateboards. Generally, corundum and zirconium-containing raw materials are used as the main components, and phenolic resin or epoxy resin is used as a binder. However, ordinary aluminum carbon skateboard bricks are difficult to meet the requirements of modern steelmaking process in terms of performance; although magnesium skateboard bricks have good corrosion resistance to highly corrosive steel grades, their thermal expansion coefficient is large, resulting in low strength and unsatisfactory corrosion resistance. In summary, the development of a skateboard brick with excellent comprehensive performance, especially outstanding wear resistance and mechanical strength, has become the key to meeting the efficient production needs of the modern steelmaking industry.

[0004] A Chinese invention patent with publication number CN105967702A discloses a skateboard brick and a preparation method thereof. The skateboard brick comprises: 80wt%-89.9wt% of magnesia, 5wt%-10wt% of metallic aluminum, 1wt%-3wt% of carbon black, 1wt%-3wt% of additives, and 3wt%-5wt% of resin. The skateboard brick has high refractoriness and good thermal shock stability, but its pressure resistance and high-temperature flexural resistance are poor. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention aims to provide a skateboard brick and a preparation method thereof.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions: A skateboard brick, comprising 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 form boric acid-modified sodium alginate; S2: boric acid modified sodium alginate reacts with tannic acid to form tannic acid composite sodium alginate; S3: Under nitrogen protection, tannic acid-complexed sodium alginate reacts with triphenylhydroxysilane under the action of phosphoric acid to generate a binder.

[0007] In the step S1, the mass ratio of sodium alginate to 4-chlorophenylboric acid is 10:(2-3).

[0008] In step S2, the mass ratio of boric acid-modified sodium alginate to tannic acid is 6:(1.5-2).

[0009] In the step S3, the mass ratio of tannic acid-complexed sodium alginate to triphenylhydroxysilane is 10:(0.5-0.8).

[0010] The plate-shaped corundum includes three different particle sizes: particle size 0.6-2.0 mm.

[0011] The particle size of the white corundum is 0.1-1 mm.

[0012] The graphite is dense crystalline graphite.

[0013] The carbon black is furnace black.

[0014] A method for preparing a skateboard brick comprises the following steps: (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.

[0015] Due to the adoption of the above technical solution, the beneficial effects of the present invention include: (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.

[0016] (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

[0017] The invention will be further described below in conjunction with the embodiments, but the invention is not limited to these embodiments.

[0018] 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; 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; 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 and mix, heat to 50°C, then add 5 ml of 85 wt% phosphoric acid, react for 4 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.

[0019] Example 2 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 (25 g of 4-chlorophenylboric acid is dissolved in 500 ml of DMSO), drop for 1.5 hours, heat to 110°C, react for 14 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 60°C for 5 hours to obtain boric acid-modified sodium alginate; S2: Add 400 ml of deionized water, 60 g of boric acid-modified sodium alginate, and 18 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 50 ° C, react 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 anhydrous ethanol for precipitation, stir and mix, let stand for 30 min, precipitate, collect the precipitate by centrifugation, and dry under vacuum at 50 ° C for 6 h to obtain tannic acid-complexed sodium alginate; 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 and mix, heat to 60°C, then add 5 ml of 85 wt% phosphoric acid, react for 3 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 a binder.

[0020] 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; 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; 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.

[0021] 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); (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; (3) Finally, the green body is subjected to gradient drying, with an initial baking at 80°C for 12 hours and a final baking at 200°C for 48 hours, and then surface grinding to obtain a finished skateboard brick.

[0022] Example 5 Preparation of skateboard bricks: (1) Weigh: 400 g of plate-shaped 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 carbon black), 40 g of metal 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); (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 15 minutes; add the mixed materials into a mold, press them at a pressure of 150 MPa to obtain a skateboard brick body; (3) Finally, the green body is subjected to gradient drying, with an initial baking at 100°C for 10 hours and a final baking at 230°C for 36 hours, and then surface grinding to obtain a finished skateboard brick.

[0023] Example 6 Preparation of skateboard bricks: (1) Weigh: 500 g of plate-shaped 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 carbon black), 50 g of metal 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); (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, and 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, and add a binder at the same time, mix them thoroughly, so that the raw materials are evenly dispersed, and the mixing time is 20 minutes; add the mixed materials into a mold, and press them at a pressure of 200 MPa to obtain a skateboard brick body; (3) Finally, the green body is subjected to gradient drying, with an initial baking at 120°C for 8 hours and a final baking at 260°C for 24 hours, and then surface grinding to obtain a finished skateboard brick.

[0024] In 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 by an equal weight of thermosetting phenolic resin, whose model is PF5323.

[0025] In 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 by an equal weight of tannic acid composite sodium alginate prepared in step S2 of Example 2.

[0026] In 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 by an equal weight of a binder prepared by the following method: 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 to the reactor, stir and mix, then slowly drop 4-chlorophenylboric acid DMSO solution (25 g of 4-chlorophenylboric acid dissolved in 500 ml of DMSO), drop for 1.5 h, heat to 110 ° C, react for 14 h, 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 min, precipitate, collect the precipitate by centrifugation, and dry in vacuo at 60 ° C for 5 h to obtain boric acid-modified sodium alginate; S2: Under nitrogen protection, add 500 ml of toluene, 100 g of boric acid-modified sodium alginate, and 6 g of triphenylhydroxysilane into the reactor, stir and mix, heat to 60°C, then add 5 ml of 85 wt% phosphoric acid, react for 3 h, distill at 60°C under reduced pressure for 3 h, then recrystallize three times with acetone (500 g of acetone each time), and vacuum dry at 60°C for 5 h to obtain the binder.

[0027] In 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 by an equal weight of a binder prepared by the following method: The preparation method of the binder in this comparative example is basically the same as that in Example 2, except that 4-chlorophenylboric acid in step S1 is replaced by p-chlorobenzoic acid.

[0028] In 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 by an equal weight of a binder prepared by the following method: The preparation method of the binder in this comparative example is basically the same as that in Example 2, except that the sodium alginate in step S1 is replaced by an equal weight of carboxymethyl chitosan.

[0029] In 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 by an equal weight of a binder prepared by the following method: The preparation method of the binder in this comparative example is substantially the same as that in Example 2, except that the triphenylhydroxysilane in step S3 is replaced by γ-aminopropyltriethoxysilane.

[0030] Comparative Example 7, a skateboard brick made using the raw material composition and process in Example 4 of Chinese invention patent publication number CN105967702A.

[0031] The molecular weight of sodium alginate used in the examples and comparative examples of the present application is 10,000, purchased from Shanghai Chuangsai Technology Co., Ltd.; the molecular weight of carboxymethyl chitosan is 9,000, purchased from Hubei Rishengchang New Materials Technology Co., Ltd.; plate-shaped corundum and white corundum are purchased from Henan Sicheng Grinding Technology Co., Ltd.; the model of carbon black is N330, the particle size is 20-50nm, purchased from Jiangxi Black Cat Carbon Black Co., Ltd.; the particle size of graphite is 0.02-0.075mm, purchased from Beite New Materials Group Co., Ltd.; the particle size of silicon carbide is 40-70μm, purchased from Anyang Qiansheng Metallurgical Refractory Co., Ltd.; the particle size of metal aluminum powder is 10-30μm, the brand is LFT1, purchased from Angang Industrial Fine Aluminum Powder Co., Ltd.

[0032] The skateboard bricks prepared in Examples 4-6 of the present application and Comparative Examples 1-7 were subjected to performance tests, and the test results are shown in Table 1.

[0033] The room 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.

[0034] Table 1 Performance test table

[0035] It can be seen from Table 1 that the skateboard bricks prepared in Examples 4-6 of the present application have excellent compressive strength and high-temperature flexural strength.

[0036] Comparative Example 1 is a comparative example in which the added binder is a 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 the present application.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] In the preparation process of the binder added in Comparative Example 6, the triphenylhydroxysilane in step S3 is replaced with γ-aminopropyltriethoxysilane. It can be seen from Table 1 that the performance of the prepared skateboard bricks is not ideal. This is because triphenylhydroxysilane contains three phenyl groups and hydroxyl groups. The phenyl group is a rigid aromatic ring structure, which provides excellent thermal stability and antioxidant properties. The conjugated effect of the phenyl group enhances the thermal stability of the molecule, 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, and the ethoxy group in γ-aminopropyltriethoxysilane hydrolyzes at high temperature, resulting in molecular chain breakage; the amino group is easily decomposed in a high-temperature oxidizing environment, limiting its long-term high-temperature stability.

[0042] Comparative Example 7 is a skateboard brick made 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 room-temperature compressive strength are not as good as those of the present application.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. However, any equivalent changes, modifications and evolutions made by ordinary technicians in the field without departing from the scope of the technical solution of the present invention by 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 essential technology of the present invention are still 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 form 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 and triphenylhydroxysilane react with 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 separately to remove moisture from 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, and 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, and 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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