A slide brick for slag stopping in a converter and its preparation method

Abstract

The present invention discloses a slide gate brick for converter slag blocking and a preparation method thereof, which relates to the technical field of slide gate bricks. The slide gate brick comprises the following raw materials in parts by weight: 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, and 2-5 parts of silicon carbide. In the present invention, tetra-armed acid ester is generated by the reaction of 3,6-dibromopyromellitic dianhydride and (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol; the tetra-armed acid ester reacts with dodecyl heptaethylene glycol ether to generate a long-chain compound; the long-chain compound reacts with formic acid to generate an epoxide compound; and the epoxide compound and isobutyric anhydride react to generate a binder. The slide gate brick for converter slag blocking 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 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 iron and steel smelting process. By introducing the automatic skate 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 achieved good usage 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 sintered skate bricks made of aluminum-carbon or aluminum-zirconium-carbon, although meeting the usage 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 shock 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% α-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:

[0007] A skate brick for slag stopping in a converter, comprising raw materials in the following weight parts:

[0008] 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;

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

[0010] S1: 3,6-dibromopyromellitic dianhydride and (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol react to form a tetra-armed acid ester under the catalysis of p-toluenesulfonic acid;

[0011] S2: The tetra-armed acid ester reacts with dodecyl heptaethylene glycol ether under the action of potassium carbonate to form a long-chain compound;

[0012] S3: The long-chain compound reacts to form an epoxy compound under the action of formic acid and H2O2;

[0013] S4: The epoxy compound reacts with isobutyric anhydride to form a binder.

[0014] 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).

[0015] In the step S2, the molar ratio of the tetra-armed acid ester to dodecyl heptaethylene glycol ether is 1:(2 - 3).

[0016] In the step S3, the mass ratio of the long-chain compound to formic acid is (12 - 16):4.

[0017] In the step S4, the mass ratio of the epoxy compound to isobutyric anhydride is 1:(1.2 - 1.6).

[0018] The particle size of the tabular corundum is 0.6 - 2.0 mm.

[0019] The particle size of the zircon mullite is 0.1 - 1 mm.

[0020] The graphite is dense crystalline graphite.

[0021] The carbon black is furnace black.

[0022] A preparation method of a slide gate brick for a converter slag stopper includes the following steps:

[0023] (1) Weigh by weight: 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, and 2 - 5 parts of silicon carbide;

[0024] (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;

[0025] (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.

[0026] Due to the adoption of the above technical solution, the beneficial effects of the present invention include:

[0027] The adhesive prepared by the present invention has significant advantages in terms of compressive strength and high-temperature flexural strength. The rigid benzene ring and multiple reaction sites of the four-arm acid ester are conducive to the formation of a cross-linked structure, and the polar groups enhance the intermolecular forces and improve the compressive strength; the flexible chain segments of the long-chain compounds buffer the energy, and the steric hindrance makes the structure compact and orderly, improving the compressive strength and high-temperature flexural strength; 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 to achieve both rigidity, toughness and bonding strength, and comprehensively enhance the mechanical properties of the skateboard bricks. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the four-arm ester prepared in step S1 of Example 1;

[0029] Figure 2 The hydrogen nuclear magnetic resonance spectrum of the long-chain compound prepared in step S2 of Example 1;

[0030] Figure 3 The hydrogen nuclear magnetic resonance spectrum of the epoxy compound prepared in step S3 of Example 1;

[0031] Figure 4 The hydrogen nuclear magnetic resonance spectrum of the binder prepared in step S4 of Example 1;

[0032] Figure 5 This is a high-resolution mass spectrum of the binder prepared in step S4 of Example 1. DETAILED DESCRIPTION

[0033] The invention will be further described below in conjunction with the embodiments, but the invention is not limited to these embodiments.

[0034] Example 1 Preparation of adhesive:

[0035] S1: Under nitrogen protection, add 800 ml of DMF and 0.4 mol of (9Z,12Z,15Z)-9,12,15-octadecatrien-1-ol into the reactor. 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 90 °C, keep the temperature for 1 h, then add 15 g of p-toluenesulfonic acid, slowly heat up to 110 °C at a rate of 20 °C / h, and then slowly heat up to 130 °C at a rate of 10 °C / h. After keeping the temperature for 6 h, cool down, distill under reduced pressure at 80 °C for 2 h, and dry in vacuum at 50 °C for 6 h to obtain tetra-arm acid ester. The reaction equation is shown as follows:

[0036]

[0037] The 1H NMR data are as follows:

[0038] 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).

[0039] S2: Add 500 ml of DMSO, 0.1 mol of tetra-arm 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 (0.2 mol of dodecyl heptaethylene glycol ether dissolved in 500 ml of DMSO, heated to 50 °C). The dropping takes 1 h, heat up to 100 °C, react for 12 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, centrifuge to collect the precipitate, and dry in vacuum at 70 °C for 4 h to obtain the long-chain compound. The reaction equation is shown as follows:

[0040]

[0041] The 1H NMR data are as follows:

[0042] 11H 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).

[0043] S3: Add 800 ml of DMF, 120 g of long-chain compound, and 10 g of strong acid cation exchange resin to the reactor, stir and 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 supernatant 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 the epoxy compound; the reaction equation is shown as follows:

[0044]

[0045] The 1H NMR data are as follows:

[0046] 11H 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).

[0047] S4: Add 800 ml of DMF, 100 g of epoxide, 120 g of isobutyric anhydride, and 10 g of strong acid cation exchange resin to 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 extract three times with deionized water (200 ml each time). Distill under reduced pressure at 70 °C for 3 h and dry in vacuo at 60 °C for 5 h to obtain the binder. The reaction equation is shown as follows:

[0048]

[0049] The 1H NMR data are as follows:

[0050] 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).

[0051] High-resolution mass spectrometry data: HRMS (m / z): 4347.6452.

[0052] Example 2 Preparation of the binder:

[0053] S1: Under nitrogen protection, 800 ml of DMF and 0.45 mol of (9Z,12Z,15Z)-9,12,15-octadecatrien-1-ol were added to the reactor, and 0.1 mol of 3,6-dibromopyromellitic dianhydride was added in batches (0.05 mol each time, with a batch interval of 10 min). After stirring and mixing evenly, the temperature was raised to 100 °C and kept warm for 1 h. Then 15 g of p-toluenesulfonic acid was added, and the temperature was slowly raised to 120 °C at a rate of 20 °C / h, and then slowly raised to 140 °C at a rate of 10 °C / h. After keeping the reaction at this temperature for 5 h, the temperature was lowered. The mixture was distilled under reduced pressure at 80 °C for 2 h and then dried in vacuo at 50 °C for 6 h to obtain tetra-armed acid ester;

[0054] S2: Add 500 ml of DMSO, 0.1 mol of tetra-arm 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 (0.25 mol of dodecyl heptaethylene glycol ether dissolved in 500 ml of DMSO, heated to 50 °C), add dropwise for 1 h, raise the temperature to 120 °C, after reacting for 10 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 dry it under vacuum at 70 °C for 4 h to obtain the long-chain compound;

[0055] 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 and mix evenly, raise the temperature 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, add dropwise for 20 min, after reacting 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 extract three times with deionized water (200 ml each time), distill under reduced pressure at 70 °C for 3 h, and dry under vacuum at 50 °C for 5 h to obtain the epoxy compound;

[0056] 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 and mix evenly, raise the temperature to 110 °C, after reacting for 7 h, cool to room temperature, transfer the upper clear liquid to a separatory funnel, and extract three times with deionized water (200 ml each time), distill under reduced pressure at 70 °C for 3 h, and dry under vacuum at 60 °C for 5 h to obtain the binder.

[0057] Example 3 Preparation of the binder:

[0058] 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 and mix evenly, raise the temperature to 100 °C, keep warm for 1 h, then add 15 g of p-toluenesulfonic acid, slowly raise the temperature to 130 °C at a rate of 20 °C / h, and then slowly raise the temperature to 140 °C at a rate of 10 °C / h, after keeping warm and reacting for 4 h, cool down, distill under reduced pressure at 80 °C for 2 h, and dry under vacuum at 50 °C for 6 h to obtain the tetra-arm acid ester;

[0059] S2: Add 500 ml DMSO, 0.1 mol tetra-arm acid ester, and 20 g potassium carbonate to the reactor, stir and mix, then slowly drop a DMSO solution of dodecyl heptapolyethylene glycol ether (0.3 mol dodecyl heptapolyethylene glycol ether is dissolved in 500 ml DMSO and heated to 50°C), drop for 1 hour, heat to 130°C, react for 8 hours, cool to room temperature, add 10 wt% dilute hydrochloric acid to adjust the pH to neutral, add 500 ml 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 a long-chain compound;

[0060] S3: Add 800 ml of DMF, 160 g of a long-chain compound, and 10 g of a strong acid cation exchange resin into the reactor, stir and mix, heat to 70°C, then mix 40 g of formic acid and 160 g of a 30 wt% H2O2 solution, slowly add a mixed solution of formic acid and H2O2 solution, dropwise add for 20 min, react for 6 h, cool to room temperature, transfer the upper clear liquid to a separatory funnel, let stand and remove the lower inorganic liquid, add deionized water for extraction three times (200 ml each time), distill at 70°C under reduced pressure for 3 h, and vacuum dry at 50°C for 5 h to obtain an epoxy compound;

[0061] S4: Add 900 ml DMF, 100 g epoxy compound, 160 g isobutyric anhydride and 10 g strong acid cation exchange resin into the reactor, stir and mix well, heat to 120°C, react for 6 hours, cool to room temperature, transfer the supernatant to a separatory funnel, add deionized water to extract three times (200 ml each time), distill under reduced pressure at 70°C for 3 hours, and vacuum dry at 60°C for 5 hours to obtain a binder.

[0062] Example 4 Preparation of skateboard bricks:

[0063] (1) Weigh: 300 g of plate-like corundum (particle size 0.6-2.0 mm), 200 g of zirconium mullite (particle size 0.1-1 mm), 100 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);

[0064] (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 10 minutes; add the mixed materials into a mold, and press them at a pressure of 100 MPa to obtain a skateboard brick body;

[0065] (3) Finally, the green body is subjected to gradient drying, with an initial drying at 80°C for 12 h and a final drying at 200°C for 48 h, followed by surface grinding to obtain the finished skateboard brick.

[0066] Preparation of skateboard brick in Example 5:

[0067] (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);

[0068] (2) The tabular corundum, zircon mullite, graphite, carbon black, metallic aluminum powder, and silicon carbide are respectively dried (vacuum drying at 50°C for 12 h) 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 mixer according to the above ratios, and at the same time, the binder is added, and sufficient mixing is carried out to make each raw material evenly dispersed, with a mixing time of 15 min; the mixed material is added to a mold and pressed at a pressure of 150 MPa to obtain the skateboard brick green body;

[0069] (3) Finally, the green body is subjected to gradient drying, with an initial drying at 100°C for 10 h and a final drying at 230°C for 36 h, followed by surface grinding to obtain the finished skateboard brick.

[0070] Preparation of skateboard brick in Example 6:

[0071] (1) Weigh: 600 g of tabular corundum (particle size 0.6 - 2.0 mm), 300 g of zircon mullite (particle size 0.1 - 1 mm), 150 g of graphite (dense crystalline graphite), 50 g of carbon black (furnace black), 60 g of metallic 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);

[0072] (2) The tabular corundum, zircon mullite, graphite, carbon black, metallic aluminum powder, and silicon carbide are respectively dried (vacuum drying at 50°C for 12 h) 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 mixer according to the above ratios, and at the same time, the binder is added, and sufficient mixing is carried out to make each raw material evenly dispersed, with a mixing time of 20 min; the mixed material is added to a mold and pressed at a pressure of 200 MPa to obtain the skateboard brick green body;

[0073] (3) Finally, gradient drying is carried out on the green body, with initial drying at 120°C for 8 h and final drying at 260°C for 24 h, followed by surface grinding to obtain the finished slide plate brick.

[0074] 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 with an equal weight of a binder prepared by the following method:

[0075] The preparation method of the binder in this comparative example is basically the same as that in Example 2, except that 3,6-dibromopyromellitic dianhydride added in step S1 is replaced with an equal weight of 4-bromophthalic anhydride.

[0076] 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 with an equal weight of a binder prepared by the following method:

[0077] The preparation method of the binder in this comparative example is basically the same as that in Example 2, except that dodecyl heptaethylene glycol ether added in step S2 is replaced with an equal weight of tetraethyl ethylene glycol monomethyl ether.

[0078] Comparative Example 3: 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 with an equal weight of a binder prepared by the following method:

[0079] The preparation method of the binder in this comparative example is basically the same as that in Example 2, except that dodecyl heptaethylene glycol ether added in step S2 is replaced with an equal weight of hexadecyl 1,3-propanediol ether.

[0080] Comparative Example 4: 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 with an equal weight of a binder prepared by the following method:

[0081] S1: Under nitrogen protection, add 800 ml of DMF, 0.45 mol of (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol to 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-armed acid ester;

[0082] S2: Add 800 ml of DMF, 140 g of tetra-armed acid ester, 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, after reacting for 7 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 Intermediate 1;

[0083] 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 to mix evenly, heat up to 110 °C, after reacting 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.

[0084] 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, the difference is that the binder is replaced with an equal weight of binder prepared by the following method:

[0085] The preparation method of the binder in this comparative example is basically the same as that in Example 2, the difference is that the addition amount of (9Z,12Z,15Z)-9,12,15-octadecatriene-1-ol in step S1 is adjusted to 0.2 mol.

[0086] Comparative Example 6: The slide gate brick is made of the raw material composition and process in Example 2 of the Chinese invention patent with the publication number CN103864444A.

[0087] 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 Materials Factory, and its main chemical composition (weight ratio) is 45.8% Al2O3, 36.5% ZrO2, 17.1% SiO2; the strong acidic cation exchange resin is a polymer of divinylbenzene and sodium vinylbenzenesulfonate, with the brand Amberlite® IMACHP1110 resin, and it is purchased from Sinopharm Chemical Reagent Co., Ltd.

[0088] The skate 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.

[0089] 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.

[0090] Table 1 Performance test table

[0091]

[0092] It can be seen from Table 1 that the skate bricks for converter slag stopping prepared in Examples 4-6 of this application have excellent compressive strength and high temperature flexural strength.

[0093] 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, which is conducive to the formation of more chemical bonds and cross-linked 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, playing a buffering role and absorbing a part of the energy to prevent the material from cracking due to local stress concentration; the cooperation of such flexible chain segments with rigid structures (such as benzene rings) 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 base materials of the skate 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, reduce the generation of defects and cracks inside the material, and contribute to improving the high temperature flexural strength.

[0094] For Comparative Example 1, it can be seen from the data in Table 1 that the high temperature flexural strengths are all inferior to those of this application. This is because 4-bromophthalic anhydride contains only two anhydride groups, and the generated anhydride product has a two-arm structure instead of a four-arm structure; the reduction of cross-linking sites leads to a decrease in cross-linking density and a weakening of the intermolecular force, and it is prone to deformation and 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.

[0095] In Comparative Example 2, tetraethyleneglycol monomethyl ether 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, a decrease in the stress dispersion ability, and it is prone to crack propagation 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 decrease in the interfacial bonding strength.

[0096] 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, resulting in better high-temperature stability and flexibility.

[0097] 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 cross-linked network, a significant increase in the brittleness of the material, and easy crack propagation due to stress concentration under compression, resulting in a decrease in compressive strength. 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 slide plate bricks, enhancing the organic-inorganic interfacial adhesion. The absence of ether bonds and hydrophobic alkyl chains leads to insufficient hydrogen bond binding sites and a decrease in interfacial adhesion strength.

[0098] The anhydride product of Comparative Example 5 is a two-arm structure or a single-arm structure instead of a four-arm structure. The reduction of cross-linking sites leads to a decrease in cross-linking density and a weakening of the intermolecular force, making it prone to deformation and even fracture under compression.

[0099] Comparative Example 6 is a slide plate brick made from the raw material composition and manufacturing process in Example 2 of the Chinese invention patent CN103864444A. As can be seen from Table 1, its high-temperature flexural strength and normal-temperature compressive strength are not as good as those of this application.

[0100] As mentioned 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 minor modifications, refinements, and evolutions 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 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 slag blocking in a converter, characterized in that, It includes raw materials in the following parts by weight: 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, 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 react to form a tetra - arm acid ester under the catalysis of p - toluenesulfonic acid; S2: The tetra - arm acid ester reacts with dodecyl heptaethylene glycol ether under the action of potassium carbonate to form a long - chain compound; S3: The long - chain compound reacts under the action of formic acid and H2O2 to form an epoxy compound; S4: The epoxy compound reacts with isobutyric anhydride to form the binder; In step S1, the molar ratio of 3,6 - dibromopyromellitic dianhydride to (9Z,12Z,15Z)-9,12,15 - octadecatriene - 1 - ol for feeding is 1:(4 - 5); In step S2, the molar ratio of the tetra - arm acid ester to dodecyl heptaethylene glycol ether for feeding is 1:(2 - 3); In step S3, the mass ratio of the long - chain compound to formic acid for feeding is (12 - 16):4; In step S4, the mass ratio of the epoxy compound to isobutyric anhydride for feeding is 1:(1.2 - 1.6).

2. The slide brick for slag stopping in a converter according to claim 1, characterized in that, The particle size of the tabular corundum is 0.6 - 2.0 mm.

3. The slide gate brick for slag stopping in a converter according to claim 1, characterized in that, The particle size of the zircon mullite is 0.1 - 1 mm.

4. A slide brick for slag stopping in a converter according to claim 1, characterized in that, The graphite is dense crystalline graphite.

5. The slide brick for slag stopping in a converter according to claim 1, characterized in that, The carbon black is furnace - black carbon black.

6. A preparation method of the slide gate brick for slag stopping in a converter according to any one of claims 1-5, characterized in that, It includes the following steps: (1) Weigh by parts by weight: 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, and 2 - 5 parts of silicon carbide; (2) Respectively conduct drying treatment on tabular corundum, zircon mullite, graphite, carbon black, metallic aluminum powder, and silicon carbide to remove moisture in the raw materials, then crush, grind, and sieve each raw material for standby; Add the pretreated raw materials to a mixer according to the above ratio, and at the same time add the binder, and conduct sufficient mixing to make each raw material evenly dispersed. The mixing time is 10 - 20 min; Add the mixed material to a mold and press it under a pressure of 100 - 200 MPa to obtain a slide plate brick blank; (3) Finally, conduct gradient drying on the blank, initially dry it at 80 - 120 °C for 8 - 12 h, finally dry it at 200 - 260 °C for 24 - 48 h, and then conduct surface grinding to obtain the finished slide plate brick for converter slag - blocking use.

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