Sliding plate brick for slag stopping of converter and preparation method of sliding plate brick

Abstract

The invention discloses a sliding plate brick for converter slag stopping 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: 30-60 parts of tabular corundum, 20-30 parts of zirconium mullite, 10-15 parts of graphite, 2-5 parts of carbon black, 3-6 parts of metal aluminum powder, 4-8 parts of a binder and 2-5 parts of silicon carbide. The preparation method comprises the following steps: reacting 3, 6-dibromo pyromellitic dianhydride with (9Z, 12Z, 15Z)-9, 12, 15-octadecatriene-1-alcohol to generate four-arm acid ester; enabling the four-arm acid ester to react with dodecyl heptapolyethylene glycol ether to generate a long-chain compound; reacting the long-chain compound with formic acid to generate an epoxy compound; and reacting the epoxy compound with isobutyric anhydride to generate the binder. The prepared sliding plate brick for stopping slag of the converter has good compression strength and high-temperature fracture resistance.

Description

Technical Field

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

[0002] The converter slag stopping technology plays a crucial role in the modern steel smelting process. By introducing the skate automatic slag stopping technology, the amount of slag flowing into the ladle during the tapping process of the converter can be effectively reduced, thereby improving the cleanliness of the molten steel, increasing the recovery rate of alloys, and reducing the smelting cost. At present, this technology has been widely applied in medium and large-sized converters in China and has achieved good use effects.

[0003] However, there are still some problems in the actual application of the existing converter skate slag stopping technology. On the one hand, the performance of the existing skate bricks still needs to be improved. For example, the widely used high-temperature fired skate bricks made of aluminum-carbon or aluminum-zirconium-carbon, although meeting the use requirements to a certain extent, their high-temperature resistance, erosion resistance, scouring resistance, and thermal shock stability are still not ideal. On the other hand, under high-temperature conditions, the skate bricks are easily chemically eroded and physically scoured by the molten steel, and at the same time, they have to withstand high thermal shocks and mechanical wear, resulting in serious loss of material strength and low service life. This not only increases the production cost but also affects the production efficiency.

[0004] Chinese invention patent with publication number CN103864444A discloses a new type of skate brick for an automatic slag stopping sliding nozzle in a converter and a preparation method thereof. The skate brick includes: 58%-68% tabular corundum, 6%-8% 98 magnesite, 8%-11% fused spinel, 3%-5% graphite, 4%-7% a-aluminum oxide micropowder, 1%-2% sintering agent, 4%-7% aluminum-silicon alloy powder, and 4%-5% resin. The production process of this skate brick is simple, but its pressure resistance 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 for slag stopping in a converter and a preparation method thereof.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions: A skate brick for slag stopping in a converter, comprising raw materials in the following weight parts: 30-60 parts of tabular corundum, 20-30 parts of zircon mullite, 10-15 parts of graphite, 2-5 parts of carbon black, 3-6 parts of metallic aluminum powder, 4-8 parts of binder, 2-5 parts of silicon carbide; The binder is prepared by the following method: S1: 3,6-dibromopyromellitic dianhydride and (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol are catalyzed by p-toluenesulfonic acid to generate a four-arm ester; S2: The four-arm acid ester reacts with dodecyl heptapolyethylene glycol ether under the action of potassium carbonate to form a long-chain compound; S3: Long-chain compounds react with formic acid and H2O2 to form epoxy compounds; S4: The epoxy compound and isobutyric anhydride react to form a binder.

[0007] In the step S1, the molar ratio of 3,6-dibromopyromellitic dianhydride to (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol is 1:(4-5).

[0008] In the step S2, the molar ratio of the four-arm acid ester to the dodecyl heptapolyethylene glycol ether is 1:(2-3).

[0009] In step S3, the mass ratio of the long-chain compound to formic acid is (12-16):4.

[0010] In the step S4, the feed mass ratio of the epoxy compound to isobutyric anhydride is 1:(1.2-1.6).

[0011] The particle size of the plate-like corundum is 0.6-2.0 mm.

[0012] The zirconium mullite has a particle size of 0.1-1 mm.

[0013] The graphite is dense crystalline graphite.

[0014] The carbon black is furnace black.

[0015] A method for preparing a slide brick for converter slag blocking comprises the following steps: (1) Weigh by weight: 30-60 parts of plate-shaped corundum, 20-30 parts of zirconium mullite, 10-15 parts of graphite, 2-5 parts of carbon black, 3-6 parts of metal aluminum powder, 4-8 parts of binder, and 2-5 parts of silicon carbide; (2) Drying the plate-shaped corundum, zirconium mullite, 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, initially dried at 80 - 120°C for 8 - 12 h, and finally dried at 200 - 260°C for 24 - 48 h, followed by surface grinding to obtain the finished slide gate brick for converter slag stopping.

[0016] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include: The binder prepared by the present invention has significant advantages in terms of compressive strength and high-temperature flexural strength. The rigid benzene rings and multiple reaction sites of tetra-armed acid esters are conducive to the formation of cross-linked structures, and the polar groups enhance the intermolecular forces, improving the compressive strength; the flexible chain segments of long-chain compounds buffer energy, and the steric hindrance makes the structure compact and orderly, enhancing the compressive and high-temperature flexural strengths; the introduced isobutyric anhydride reduces water penetration through the hydrophobic isobutyryl group, avoiding volume expansion or structural damage caused by water vapor at high temperatures; the various parts interact synergistically, combining rigidity, toughness, and binding force, comprehensively enhancing the mechanical properties of the slide gate brick. Description of the Drawings

[0017] Figure 1 1H NMR spectrum of the tetra-armed acid ester prepared in step S1 of Example 1; Figure 2 1H NMR spectrum of the long-chain compound prepared in step S2 of Example 1; Figure 3 1H NMR spectrum of the epoxy compound prepared in step S3 of Example 1; Figure 4 1H NMR spectrum of the binder prepared in step S4 of Example 1; Figure 5 High-resolution mass spectrum of the binder prepared in step S4 of Example 1. Detailed Description of the Invention

[0018] The following is further illustrated with reference to examples, but the present invention is not limited to these examples.

[0019] Example 1 Preparation of the Binder: S1: Under nitrogen protection, 800 ml of DMF, 0.4 mol of (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol are added to the reactor, and 0.1 mol of 3,6-dibromopyromellitic dianhydride is added in batches (0.05 mol each time, with a batch interval of 10 min). After stirring and mixing evenly, the temperature is raised to 90°C and kept warm for 1 h. Then, 15 g of p-toluenesulfonic acid is added, and the temperature is slowly raised to 110°C at a rate of 20°C / h, and then slowly raised to 130°C at a rate of 10°C / h. After holding the reaction for 6 h, the temperature is lowered, and vacuum distillation is carried out at 80°C for 2 h, and vacuum drying is carried out at 50°C for 6 h to obtain the tetra-armed acid ester; the reaction equation is shown as follows:

[0020] The data of its hydrogen nuclear magnetic resonance spectrum are as follows: 1 H NMR (500 MHz, Chloroform-d) δ 5.53 – 5.30 (m, 24H), 4.26 (t, J =6.1 Hz, 8H), 2.51 – 2.36 (m, 16H), 2.12 – 1.98 (m, 16H), 1.81 – 1.72 (m, 8H),1.48 – 1.34 (m, 8H), 1.34 – 1.20 (m, 32H), 0.96 (td, J = 7.4, 1.0 Hz, 12H).

[0021] S2: Add 500 ml of DMSO, 0.1 mol of tetra-armed acid ester, and 20 g of potassium carbonate into the reactor, stir and mix evenly, then slowly dropwise add the DMSO solution of dodecyl heptaethylene glycol ether (0.2 mol of dodecyl heptaethylene glycol ether dissolved in 500 ml of DMSO, heated to 50 °C), the dropping time is 1 h, raise the temperature to 100 °C, after reacting for 12 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, centrifuge to collect the precipitate, and dry it in vacuum at 70 °C for 4 h to obtain the long-chain compound; the reaction equation is shown as follows:

[0022] The data of its hydrogen nuclear magnetic resonance spectrum are as follows: 1 H NMR (500 MHz, Chloroform-d) δ 5.55 – 5.30 (m, 24H), 4.33 – 4.20(m, 12H), 3.78 (t, J = 4.9 Hz, 4H), 3.71 – 3.58 (m, 56H), 3.50 (t, J = 6.1Hz, 4H), 2.56 – 2.33 (m, 16H), 2.11 – 1.91 (m, 16H), 1.83 – 1.68 (m, 8H),1.56 (ttd, J = 7.5, 6.1, 0.4 Hz, 4H), 1.48 – 1.35 (m, 8H), 1.33 – 1.23 (m,60H), 1.06 – 0.78 (m, 18H).

[0023] S3: Add 800 ml of DMF, 120 g of long-chain compound, and 10 g of strong acid cation exchange resin into the reactor, stir to mix evenly, heat up to 50 °C, then mix 40 g of formic acid and 160 g of 30 wt% H2O2 solution evenly, slowly add the mixed solution of formic acid and H2O2 solution, dropwise add for 20 min, after reacting for 8 h, cool to room temperature, transfer the upper clear liquid to a separatory funnel, let it stand and drain the lower inorganic liquid, and add deionized water for extraction three times (200 ml each time), distill under reduced pressure at 70 °C for 3 h, and dry in vacuum at 50 °C for 5 h to obtain an epoxide; the reaction equation is shown as follows:

[0024] The 1H NMR data are as follows: 1 H NMR (500 MHz, Chloroform-d) δ 4.35 – 4.16 (m, 12H), 3.78 (t, J =4.9 Hz, 4H), 3.70 (s, 40H), 3.69 – 3.67 (m, 10H), 3.65 – 3.62 (m, 4H), 3.50(t, J = 6.1 Hz, 4H), 3.32 – 3.24 (m, 16H), 3.18 (dt, J = 5.1, 4.1 Hz, 4H),3.13 (dh, J = 4.8, 1.6 Hz, 4H), 2.15 (ddt, J = 26.5, 13.6, 4.8 Hz, 8H), 1.95– 1.75 (m, 24H), 1.64 – 1.50 (m, 12H), 1.46 – 1.38 (m, 12H), 1.35 – 1.23 (m,58H), 0.94 – 0.86 (m, 18H).

[0025] S4: Add 800 ml of DMF, 100 g of epoxide, 120 g of isobutyric anhydride, and 10 g of strong acid cation exchange resin into the reactor, stir to mix evenly, heat up to 100 °C, after reacting for 8 h, cool to room temperature, transfer the upper clear liquid to a separatory funnel, and add deionized water for extraction three times (200 ml each time), distill under reduced pressure at 70 °C for 3 h, and dry in vacuum at 60 °C for 5 h to obtain a binder. The reaction equation is shown as follows:

[0026] The 1H NMR data are as follows: 11H NMR (500 MHz, Chloroform-d) δ 5.08 – 4.96 (m, 16H), 4.91 – 4.82(m, 8H), 4.31 – 4.23 (m, 12H), 3.78 (t, J = 4.9 Hz, 4H), 3.70 (s, 52H), 3.65– 3.60 (m, 4H), 3.50 (t, J = 6.1 Hz, 4H), 2.53 (p, J = 7.0 Hz, 24H), 2.46 –2.29 (m, 8H), 2.15 (ddd, J = 14.9, 7.4, 5.1 Hz, 8H), 1.85 – 1.72 (m, 16H),1.61 – 1.48 (m, 12H), 1.47 – 1.36 (m, 12H), 1.37 – 1.21 (m, 56H), 1.12 (dd, J= 15.6, 7.0 Hz, 144H), 0.98 (td, J = 7.9, 1.5 Hz, 12H), 0.91 – 0.85 (m, 6H).

[0027] The high-resolution mass spectrometry data is: HRMS (m / z): 4347.6452.

[0028] Example 2 Preparation of the binder: S1: Under nitrogen protection, add 800 ml of DMF and 0.45 mol of (9Z,12Z,15Z)-9,12,15-octadecatrien-1-ol to the reactor, and add 0.1 mol of 3,6-dibromopyromellitic dianhydride in batches (0.05 mol each time, with a batch interval of 10 min). Stir to mix evenly, heat up to 100 °C, keep warm for 1 h, then add 15 g of p-toluenesulfonic acid, slowly heat up to 120 °C at a rate of 20 °C / h, and then slowly heat up to 140 °C at a rate of 10 °C / h. After keeping warm and reacting for 5 h, cool down, carry out vacuum distillation at 80 °C for 2 h, and carry out vacuum drying at 50 °C for 6 h to obtain tetra-armed acid ester; S2: Add 500 ml of DMSO, 0.1 mol of tetra-armed acid ester, and 20 g of potassium carbonate to the reactor, stir to mix evenly, and then slowly dropwise add the DMSO solution of dodecyl heptaethylene glycol ether (0.25 mol of dodecyl heptaethylene glycol ether dissolved in 500 ml of DMSO, heated to 50 °C). The dropping takes 1 h, heat up to 120 °C, react for 10 h, then cool down 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 carry out vacuum drying at 70 °C for 4 h to obtain a long-chain compound; S3: Add 800 ml of DMF, 140 g of long-chain compound, and 10 g of strong acid cation exchange resin into the reactor, stir to mix evenly, heat up to 60 °C, then mix 40 g of formic acid and 160 g of 30 wt% H2O2 solution evenly, slowly add the mixed solution of formic acid and H2O2 solution, dropwise add for 20 min, react for 7 h, cool to room temperature, transfer the upper clear liquid to a separatory funnel, let stand and drain the lower inorganic liquid, and add deionized water for extraction three times (200 ml each time), distill under reduced pressure at 70 °C for 3 h, and dry in vacuum at 50 °C for 5 h to obtain the epoxy compound; S4: Add 800 ml of DMF, 100 g of epoxy compound, 140 g of isobutyric anhydride, and 10 g of strong acid cation exchange resin into the reactor, stir to mix evenly, heat up to 110 °C, react for 7 h, cool to room temperature, transfer the upper clear liquid to a separatory funnel, and add deionized water for extraction three times (200 ml each time), distill under reduced pressure at 70 °C for 3 h, and dry in vacuum at 60 °C for 5 h to obtain the binder.

[0029] Example 3 Preparation of binder: S1: Under nitrogen protection, add 800 ml of DMF, 0.5 mol of (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol into the reactor, add 0.1 mol of 3,6-dibromopyromellitic dianhydride in batches (0.05 mol each time, batch interval 10 min), stir to mix evenly, heat up to 100 °C, keep warm for 1 h, then add 15 g of p-toluenesulfonic acid, slowly heat up to 130 °C at a rate of 20 °C / h, and then slowly heat up to 140 °C at a rate of 10 °C / h, keep warm and react for 4 h, then cool down, distill under reduced pressure at 80 °C for 2 h, and dry in vacuum at 50 °C for 6 h to obtain the tetra-armed acid ester; S2: Add 500 ml of DMSO, 0.1 mol of tetra-armed acid ester, and 20 g of potassium carbonate into the reactor, stir to mix evenly, then slowly dropwise add the DMSO solution of dodecyl heptaethylene glycol ether (0.3 mol of dodecyl heptaethylene glycol ether dissolved in 500 ml of DMSO, heated to 50 °C), dropwise add for 1 h, heat up to 130 °C, react for 8 h, then 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 70 °C for 4 h to obtain the long-chain compound; S3: Add 800 ml of DMF, 160 g of long-chain compound, and 10 g of strong acid cation exchange resin into the reactor, stir to mix evenly, heat up to 70 °C, then mix 40 g of formic acid and 160 g of 30 wt% H2O2 solution evenly, slowly add the mixed solution of formic acid and H2O2 solution, add dropwise for 20 min, after reacting for 6 h, cool to room temperature, transfer the upper clear liquid to a separatory funnel, let stand and drain the lower inorganic liquid, and add deionized water for extraction three times (200 ml each time), distill under reduced pressure at 70 °C for 3 h, and dry in vacuum at 50 °C for 5 h to obtain the epoxy compound; S4: Add 900 ml of DMF, 100 g of epoxy compound, 160 g of isobutyric anhydride, and 10 g of strong acid cation exchange resin into the reactor, stir to mix evenly, heat up to 120 °C, after reacting for 6 h, cool to room temperature, transfer the upper clear liquid to a separatory funnel, and add deionized water for extraction three times (200 ml each time), distill under reduced pressure at 70 °C for 3 h, and dry in vacuum at 60 °C for 5 h to obtain the binder.

[0030] Preparation of slide plate brick in Example 4: (1) Weigh: 300 g of tabular corundum (particle size 0.6 - 2.0 mm), 200 g of zircon mullite (particle size 0.1 - 1 mm), 100 g of graphite (dense crystalline graphite), 20 g of carbon black (furnace black), 30 g of metallic 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) Respectively conduct drying treatment (dry in vacuum at 50 °C for 12 h) on tabular corundum, zircon mullite, graphite, carbon black, metallic aluminum powder, and silicon carbide to remove the moisture in the raw materials, then crush, grind the raw materials, and sieve to remove substances with particle size greater than 1 mm for standby; add the pretreated raw materials into a mixer according to the above ratio, and at the same time add the binder, and conduct sufficient mixing to make the raw materials evenly dispersed, and the mixing time is 10 min; add the mixed material into a mold and press at a pressure of 100 MPa to obtain the slide plate brick green body; (3) Finally, conduct gradient drying on the green body, initially dry at 80 °C for 12 h, finally dry at 200 °C for 48 h, and then conduct surface grinding to obtain the finished slide plate brick.

[0031] Preparation of slide plate brick in Example 5: (1) Weigh: 400 g of tabular corundum (particle size 0.6 - 2.0 mm), 250 g of zircon mullite (particle size 0.1 - 1 mm), 120 g of graphite (dense crystalline graphite), 30 g of carbon black (furnace black), 40 g of metallic aluminum powder (particle size 10 - 30 μm), 60 g of binder (prepared in Example 2), and 30 g of silicon carbide (particle size 40 - 70 μm); (2) Dry the plate-shaped corundum, zirconium mullite, graphite, carbon black, metal aluminum powder, and silicon carbide separately (vacuum drying at 50°C for 12 hours) 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, and 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.

[0032] Example 6 Preparation of skateboard bricks: (1) Weigh: 600 g of plate-like corundum (particle size 0.6-2.0 mm), 300 g of zirconium mullite (particle size 0.1-1 mm), 150 g of graphite (dense crystalline graphite), 50 g of carbon black (furnace black), 60 g of metal aluminum powder (particle size 10-30 μm), 80 g of binder (prepared in Example 3), and 50 g of silicon carbide (particle size 40-70 μm); (2) Dry the plate-shaped corundum, zirconium mullite, graphite, carbon black, metal aluminum powder, and silicon carbide (vacuum drying at 50°C for 12 hours) to remove moisture from the raw materials, then crush and grind the raw materials, sieve to remove 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 evenly disperse the raw materials. 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.

[0033] In comparative example 1, the raw material composition and process of the slide plate brick for converter slag blocking are basically the same as those in 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 3,6-dibromopyromellitic anhydride added in step S1 is replaced by an equal weight of 4-bromophthalic anhydride.

[0034] In comparative example 2, the raw material composition and process of the slide plate brick for converter slag blocking are basically the same as those in 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 dodecyl heptaethylene glycol ether added in step S2 is replaced with tetraethyleneglycol monomethyl ester of equal weight.

[0035] Comparative Example 3, the raw material composition and process of the slide gate brick for slag stopping in the converter are basically the same as those in Example 5, except that the binder is replaced with a binder prepared by the following method of equal weight: The preparation method of the binder in this comparative example is basically the same as that in Example 2, except that the dodecyl heptaethylene glycol ether added in step S2 is replaced with hexadecyl 1,3 - propanediol ether of equal weight.

[0036] Comparative Example 4, the raw material composition and process of the slide gate brick for slag stopping in the converter are basically the same as those in Example 5, except that the binder is replaced with a binder prepared by the following method of equal weight: S1: Under nitrogen protection, add 800 ml of DMF, 0.45 mol of (9Z,12Z,15Z)-9,12,15 - octadecatriene - 1 - ol into the reactor, and add 0.1 mol of 3,6 - dibromopyromellitic dianhydride in batches (0.05 mol each time, batch interval 10 min). Stir and mix evenly, heat up to 100 °C, keep warm for 1 h, then add 15 g of p - toluenesulfonic acid, slowly heat up to 120 °C at a rate of 20 °C / h, and then slowly heat up to 140 °C at a rate of 10 °C / h. After keeping warm and reacting for 5 h, cool down, carry out vacuum distillation at 80 °C for 2 h, and vacuum dry at 50 °C for 6 h to obtain tetra - arm acid ester; S2: Add 800 ml of DMF, 140 g of tetra - arm acid ester, and 10 g of strong acid cation exchange resin into the reactor, stir and mix evenly, heat up to 60 °C, then mix 40 g of formic acid and 160 g of 30 wt% H2O2 solution evenly, slowly add the mixed solution of formic acid and H2O2 solution, and drop - add for 20 min. After reacting for 7 h, cool to room temperature, transfer the upper clear liquid to a separating funnel, let it stand and drain the lower inorganic liquid, and add deionized water for extraction three times (200 ml each time). Carry out vacuum distillation at 70 °C for 3 h, and vacuum dry at 50 °C for 5 h to obtain Intermediate 1; S3: Add 800 ml of DMF, 100 g of Intermediate 1, 140 g of isobutyric anhydride, and 10 g of strong acid cation exchange resin into the reactor, stir and mix evenly, heat up to 110 °C, after reacting for 7 h, cool to room temperature, transfer the upper clear liquid to a separating funnel, and add deionized water for extraction three times (200 ml each time). Carry out vacuum distillation at 70 °C for 3 h, and vacuum dry at 60 °C for 5 h to obtain the binder.

[0037] Comparative Example 5, the raw material composition and process of the slide gate brick for slag stopping in the converter are basically the same as those in Example 5, except that the binder is replaced with a binder prepared by the following method of equal weight: The preparation method of the binder in this comparative example is basically the same as that in Example 2, except that the addition amount of (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol in step S1 is adjusted to 0.2 mol.

[0038] Comparative Example 6: A slide gate brick prepared with the raw material composition and process in Example 2 of the Chinese invention patent with the publication number CN103864444A.

[0039] The tabular corundum used in the examples and comparative examples of this application is purchased from Henan Sicheng Grinding Technology Co., Ltd.; the carbon black has the model N330 and the particle size is 20 - 50 nm, and it is purchased from Jiangxi Black Cat Carbon Black Co., Ltd.; the graphite has the particle size of 0.02 - 0.075 mm and is purchased from BETR New Energy Materials Co., Ltd.; the silicon carbide has the particle size of 40 - 70 μm and is purchased from Anyang Qiansheng Metallurgical Refractory Co., Ltd.; the metallic aluminum powder has the particle size of 10 - 30 μm and the grade is LFT1, and it is purchased from AISG Micro Aluminum Powder Co., Ltd.; the zircon mullite is purchased from Gongyi Shennan Special Refractory Material Factory, and its main chemical components (by weight) are 45.8% Al2O3, 36.5% ZrO2, and 17.1% SiO2; the strongly acidic cation exchange resin is a polymer of divinylbenzene and sodium vinylbenzenesulfonate, with the brand name Amberlite® IMACHP1110 resin, and it is purchased from Sinopharm Chemical Reagent Co., Ltd.

[0040] The slide gate bricks prepared in Examples 4 - 6 and Comparative Examples 1 - 6 of this application were subjected to performance tests, and the test results are shown in Table 1.

[0041] The cold crushing strength test was carried out according to GB / T 5072 - 2008; the hot bending strength test was carried out according to GB / T 3002 - 2017; the test results are shown in Table 1.

[0042] Table 1 Performance Test Table

[0043] It can be seen from Table 1 that the slide gate bricks for converter slag stopping prepared in Examples 4 - 6 of this application have excellent crushing strength and hot bending strength.

[0044] The binder prepared by the present invention has a rigid benzene ring structure by introducing 3,6-dibromopyromellitic dianhydride. The rigid benzene ring structure endows the material with a certain hardness and stability, enabling the material to resist deformation when subjected to pressure. At the same time, the four-arm structure provides multiple reaction sites for subsequent reactions, facilitating the formation of more chemical bonds and crosslinked structures. By introducing dodecyl heptaethylene glycol ether, long flexible chain segments are introduced; when the material is subjected to pressure, these flexible chain segments can bend and deform to a certain extent, acting as a buffer to absorb part of the energy and prevent the material from cracking due to local stress concentration; the cooperation of such flexible chain segments with the rigid structure (such as the benzene ring) enables the material to have good toughness while maintaining a certain hardness, thereby improving the compressive and flexural strengths. The long-chain structure increases the steric hindrance of the molecules and can form molecular entanglements with other substrates of the skateboard brick, making the molecules arrange more closely and orderly in the material, enhancing the bonding performance; at high temperatures, this closely ordered structure can better resist thermal expansion and thermal stress, reducing the generation of defects and cracks inside the material, which helps to improve the high-temperature flexural strength.

[0045] In Comparative Example 1, as can be seen from the data in Table 1, the high-temperature flexural strengths are all inferior to those of the present application. This is because 4-bromophthalic anhydride contains only two anhydride groups, and the resulting anhydride product has a two-arm structure instead of a four-arm structure; the reduction of crosslinking sites leads to a decrease in crosslinking density, the weakening of the intermolecular force, and easy deformation or even fracture when compressed; moreover, the two-arm structure has poor symmetry and low degree of branching, and stress is easily concentrated in local areas, resulting in rapid crack propagation.

[0046] In Comparative Example 2, the tetraethyl ethylene glycol monomethyl ester used has a significantly shortened chain length (only four polyethylene glycol units), and the reduction of flexible chain segments leads to an increase in the rigidity of the material and a decrease in the stress dispersion ability, and cracks are easily initiated and propagated due to local stress concentration when compressed. The number of short-chain polyether ether bonds decreases, and the hydrogen bond binding sites are insufficient, resulting in a reduction in the interfacial bonding strength.

[0047] Comparative Example 3 has poor high-temperature flexural performance because dodecyl heptaethylene glycol ether contains more long-chain ether bonds than hexadecyl-1,3-propanediol ether, and has better high-temperature stability and flexibility.

[0048] In Comparative Example 4, due to the absence of dodecyl heptaethylene glycol ether, the lack of flexible chain segments leads to the rigidification of the crosslinked network, and the brittleness of the material increases significantly. Cracks are easily initiated and propagated due to stress concentration when compressed, and the compressive strength decreases. The ether bonds in the polyether chain can form hydrogen bonds with the surface hydroxyl groups of inorganic fillers (such as Al2O3, SiO2) in the skateboard brick, enhancing the organic-inorganic interfacial bonding force. The absence of ether bonds and hydrophobic alkyl chains results in insufficient hydrogen bond binding sites and a reduction in the interfacial bonding strength.

[0049] The anhydride product of Comparative Example 5 has a two-armed or single-armed structure instead of a four-armed structure. The reduction of crosslinking sites leads to a decrease in crosslinking density and a weakening of the intermolecular force, making it prone to deformation and even fracture under pressure.

[0050] Comparative Example 6 is a skateboard brick prepared with the raw material composition and manufacturing process in Example 2 of the Chinese invention patent CN103864444A. It can be seen from Table 1 that its high-temperature flexural strength and normal-temperature compressive strength are inferior to those of the present application.

[0051] The above are only the preferred embodiments of the present invention and are not intended 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 minor changes, modifications, and equivalent 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 variations made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A slide brick for converter slag blocking, characterized in that: The invention comprises the following raw materials in parts by weight: 30-60 parts of plate-shaped corundum, 20-30 parts of zirconium mullite, 10-15 parts of graphite, 2-5 parts of carbon black, 3-6 parts of metal aluminum powder, 4-8 parts of binder, and 2-5 parts of silicon carbide; The binder is prepared by the following method: S1: 3,6-dibromopyromellitic dianhydride and (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol are catalyzed by p-toluenesulfonic acid to generate a four-arm ester; S2: The four-arm acid ester reacts with dodecyl heptapolyethylene glycol ether under the action of potassium carbonate to form a long-chain compound; S3: Long-chain compounds react with formic acid and H2O2 to form epoxy compounds; S4: The epoxy compound and isobutyric anhydride react to form a binder.

2. The slide brick for converter slag blocking according to claim 1, characterized in that: In the step S1, the molar ratio of 3,6-dibromopyromellitic dianhydride to (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol is 1:(4-5).

3. The slide brick for converter slag blocking according to claim 1, characterized in that: In the step S2, the molar ratio of the four-arm acid ester to the dodecyl heptapolyethylene glycol ether is 1:(2-3).

4. The slide brick for converter slag blocking according to claim 1, characterized in that: In step S3, the mass ratio of the long-chain compound to formic acid is (12-16):

4.

5. The slide brick for converter slag blocking according to claim 1, characterized in that: In the step S4, the feed mass ratio of the epoxy compound to isobutyric anhydride is 1:(1.2-1.6).

6. The slide block brick for converter slag blocking according to claim 1, characterized in that: The particle size of the plate-like corundum is 0.6-2.0 mm.

7. The slide block brick for converter slag blocking according to claim 1, characterized in that: The zirconium mullite has a particle size of 0.1-1 mm.

8. The slide block brick for converter slag blocking according to claim 1, characterized in that: The graphite is dense crystalline graphite.

9. The slide block brick for converter slag blocking according to claim 1, characterized in that: The carbon black is furnace black.

10. A method for preparing a sliding plate brick for converter slag retaining according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Weigh by weight: 30-60 parts of plate-shaped corundum, 20-30 parts of zirconium mullite, 10-15 parts of graphite, 2-5 parts of carbon black, 3-6 parts of metal aluminum powder, 4-8 parts of binder, and 2-5 parts of silicon carbide; (2) Drying the plate-shaped corundum, zirconium mullite, 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. The green body is then surface-ground to obtain a finished converter slag-blocking slide brick.

Images