A high-strength, energy-saving refractory castable and its preparation method

Abstract

This invention discloses a high-strength, energy-saving refractory castable and its preparation method, relating to the field of refractory materials technology. The high-strength, energy-saving refractory castable comprises the following raw materials in parts by weight: 35-40 parts magnesium aluminum spinel, 25-30 parts millimeter-sized white fused alumina, 8-10 parts silica powder, 12-15 parts micron-sized white fused alumina powder, 5-7 parts binder, 0.3-0.4 parts dispersant, 4-5 parts stainless steel fiber, 0.3-0.4 parts water-reducing agent, and 3.5-4.5 parts deionized water. The high-strength, energy-saving refractory castable prepared by this invention exhibits low thermal conductivity, excellent mechanical properties, and slag resistance.

Description

Technical Field

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

[0002] Refractory castables are widely used in the linings of high-temperature industrial equipment in metallurgy, power, cement, and petrochemical industries, typically facing multiple harsh conditions including high temperatures, thermal shock, mechanical abrasion, and slag erosion. While existing high-alumina or magnesia-alumina spinel refractory castables possess high refractoriness and basic mechanical properties, they still suffer from weak interfacial bonding, insufficient high-temperature strength, and limited resistance to slag erosion. Furthermore, their predominance of high thermal conductivity crystalline phases such as corundum and magnesia-alumina spinel creates continuous heat transfer channels between particles, resulting in a high thermal conductivity that easily leads to heat loss from the furnace and increased energy consumption. Therefore, developing energy-saving refractory castables that combine excellent mechanical properties, erosion resistance, and low thermal conductivity is of great significance for improving the thermal energy utilization efficiency of high-temperature equipment.

[0003] Chinese invention patent CN113800894A discloses a lightweight, high-strength refractory castable comprising the following raw materials by weight percentage: 25-35% lightweight, high-strength microporous bauxite aggregate, 25-35% alumina hollow spheres, 3-5% cenospheres, 5-8% kyanite powder, 5-8% calcined bauxite fine powder, 5-8% silica fume, 6-9% α-Al₂O₃ micro powder, 5-10% bauxite cement, 3-5% refractory fiber, 0.1-0.3% composite water-reducing agent, and 0.02-0.05% water-based silicone polyether defoamer. This refractory castable can effectively reduce the water-cooled heat loss of the high-temperature water-cooled furnace rollers in tunnel-type heating furnaces for continuous casting and rolling of thin slabs, improve the thermal efficiency of the heating furnace, and extend the service life of the furnace roller insulation layer. It features stable performance, light weight, good mechanical properties, and excellent thermal insulation and thermal shock resistance. However, its slag resistance is still insufficient. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a high-strength, energy-saving refractory castable and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A high-strength, energy-saving refractory castable comprises the following raw materials in parts by weight:

[0007] 35-40 parts magnesium aluminum spinel, 25-30 parts millimeter-sized white fused alumina, 8-10 parts silica micro powder, 12-15 parts micron-sized white fused alumina micro powder, 5-7 parts binder, 0.3-0.4 parts dispersant, 4-5 parts stainless steel fiber, 0.3-0.4 parts water-reducing agent, and 3.5-4.5 parts deionized water;

[0008] The binder is prepared by the following method:

[0009] S1: Dimethyl(3-aminophenyl)phosphonate reacts with 4-(ethylene oxide-2-ylmethoxy)phenylboronic acid pinacol ester to generate intermediate 1, and the reaction equation is shown below:

[0010]

[0011] S2: Intermediate 1 reacts with 3-chloropropyltrimethoxysilane to generate intermediate 2, and the reaction equation is shown below:

[0012]

[0013] S3: Intermediate 2 and N 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 The reaction of bis(3-carboxypropyl)octane-1,8-diammonium bromide to form a binder is illustrated in the following equation:

[0014]

[0015] In step S1, the molar ratio of dimethyl (3-aminophenyl)phosphonate to 4-(ethylene oxide-2-ylmethoxy)phenylboronic acid pinacol ester is 1:(1.05-1.1).

[0016] In step S2, the molar ratio of intermediate 1 to 3-chloropropyltrimethoxysilane is 1:(1.03-1.05).

[0017] In step S3, the intermediate 2 and N 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 The molar ratio of bis(3-carboxypropyl)octane-1,8-diammonium bromide to the feed is (2.1-2.2):1.

[0018] The dispersant is prepared by the following method:

[0019] N1: 1-Decylimidazole reacts with dibromonepentyl glycol to generate intermediate A, and the reaction equation is shown below:

[0020]

[0021] N2: Intermediate A reacts with 12-oxododecanoic acid to generate intermediate B, and the reaction equation is shown below:

[0022]

[0023] N3: Intermediate B reacts with aminopentaethylene monomethyl ether to form a dispersant, and the reaction equation is shown below:

[0024]

[0025] In step N1, the molar ratio of 1-decylimidazole to dibromoneopentyl glycol is 2.05:1.

[0026] In step N2, the molar ratio of intermediate A to 12-oxododecanoic acid is 1:2.1.

[0027] In step N3, the molar ratio of intermediate B to aminopentaethylene monomethyl ether is 1:2.05.

[0028] The water-reducing agent is a polycarboxylate high-performance water-reducing agent.

[0029] A method for preparing a high-strength, energy-saving refractory castable includes the following steps:

[0030] (1) Weigh the following by weight: 35-40 parts magnesium aluminum spinel, 25-30 parts millimeter-sized white fused alumina, 8-10 parts silica powder, 12-15 parts micron-sized white fused alumina powder, 5-7 parts binder, 0.3-0.4 parts dispersant, 4-5 parts stainless steel fiber, 0.3-0.4 parts water-reducing agent, and 3.5-4.5 parts deionized water;

[0031] (2) Mix magnesium aluminum spinel, millimeter-sized white fused alumina, silica powder, micron-sized white fused alumina powder, binder, dispersant, stainless steel fiber, water-reducing agent and deionized water to obtain high-strength energy-saving refractory castable.

[0032] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0033] The high-strength, energy-saving refractory castable prepared by this invention has a low thermal conductivity, excellent mechanical properties, and slag resistance. The added binder contains benzene rings, quaternary ammonium salts, borate esters, siloxanes, and phosphate esters. Through chemical adsorption and chemical bonding, it exhibits a significant synergistic enhancement effect in the refractory castable system, improving the mechanical properties and slag erosion resistance of the refractory castable. The added dispersant contains long-chain alkyl groups, long flexible ether chains, imidazolium cations, and Schiff bases. The synergistic effect of these structures inhibits particle agglomeration and improves particle dispersibility. Attached Figure Description

[0034] Figure 1 The image shows the proton NMR spectrum of the binder prepared in Example 2.

[0035] Figure 2 The image shows the proton NMR spectrum of the dispersant prepared in Example 5. Detailed Implementation

[0036] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0037] Example 1 N 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 Preparation of bis(3-carboxypropyl)octane-1,8-diammonium bromide:

[0038] Mix 400 ml of anhydrous ethanol, 0.1 mol of 1,8-dibromooctane, and 0.205 mol of 4-(dibenzylamino)butyric acid, stir until homogeneous, heat to reflux, react for 24 h, cool to room temperature, and distill under reduced pressure at 50 °C for 2 h. Distill the mixture using 250 ml of a mixture of ethyl acetate and anhydrous ethanol (V... 乙酸乙酯 :V 无水乙醇 =8:2) recrystallized, dried under vacuum at 60℃ for 12 h, to obtain N 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 -bis(3-carboxypropyl)octane-1,8-diammonium bromide; its reaction equation is shown below:

[0039]

[0040] Its 1H NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6 ) δ 11.90 (s, 2H), 7.63 (dddd, J = 6.8, 2.9, 1.9, 1.2 Hz, 8H), 7.45-7.36 (m, 8H), 7.36-7.27 (m, 4H), 4.28 (t, J = 1.0 Hz, 8H), 3.32 (s, 8H), 2.35 (s, 4H), 2.03 (s, 4H), 1.79 (s,4H), 1.41 (s, 4H), 1.33 (s, 4H); HRMS (m / z):339.2036[M-2Br] 2+ .

[0041] Example 2 Preparation of the binder:

[0042] S1: Under nitrogen protection, 250 ml of anhydrous acetonitrile, 0.1 mol of dimethyl(3-aminophenyl)phosphonate, and 0.105 mol of 4-(ethylene oxide-2-ylmethoxy)phenylboronic acid pinacol ester were stirred and mixed. The mixture was heated to 65 °C and reacted for 8 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 50 °C for 1 h. 200 ml of cold anhydrous n-hexane was added and stirred to precipitate the product. The product was filtered, and the filter cake was washed with cold anhydrous n-hexane (3 × 50 ml). The product was then dried under vacuum at 50 °C for 8 h to obtain intermediate 1. Its 1H NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6 ) δ 7.85 (dt, J = 7.5, 2.0 Hz, 1H), 7.69-7.61 (m, 2H), 7.44 (t, J = 2.0 Hz,1H), 7.32 (t, J = 7.5 Hz, 1H), 6.84-6.77 (m, 2H), 6.59 (dt, J = 7.5, 2.0 Hz,1H), 5.27 (d, J = 1.5 Hz, 1H), 5.07 (d, J = 4.9 Hz, 1H), 4.05 (d, J = 5.0 Hz,1H), 4.03-3.96 (m, 2H), 3.69 (s, 6H), 3.37-3.14 (m, 2H), 1.34 (d, J = 14.1Hz, 12H);

[0043] S2: Under nitrogen protection, 400 ml of anhydrous N,N-dimethylformamide (DMF), 0.1 mol of intermediate 1, 0.103 mol of 3-chloropropyltrimethoxysilane, and 10 g of 4A molecular sieve were stirred and mixed. 0.012 mol of tetraethylammonium bromide and 0.12 mol of K₂CO₃ were added, and the mixture was heated to 65 °C and reacted for 7 h. After cooling to room temperature, the mixture was filtered and concentrated under reduced pressure at 65 °C for 2 h to obtain a concentrated solution. Under ice bath conditions, 400 ml of cold anhydrous diethyl ether was slowly added to the concentrated solution with stirring to precipitate a precipitate. The precipitate was filtered, and the filter cake was washed with cold anhydrous diethyl ether (3 × 80 ml). The precipitate was then washed with a mixture of 200 ml of anhydrous diethyl ether and anhydrous ethyl acetate (V... 无水乙醚 :V 无水乙酸乙酯 Recrystallization of (9:1) and vacuum drying at 60℃ for 8 h yielded intermediate 2; its 1H NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 7.85 (dt, J =7.5, 2.0 Hz, 1H), 7.69-7.61 (m, 2H), 7.42 (t, J = 2.0 Hz, 1H), 7.34 (t, J =7.5 Hz, 1H), 6.84-6.79 (m, 2H), 6.79-6.77 (m, 1H), 5.00 (d, J = 5.0 Hz, 1H), 4.04 (d, J = 2.2 Hz, 1H), 4.04-3.94 (m, 2H), 3.69 (s, 6H), 3.52 (s, 9H), 3.26-3.07 (m, 4H), 1.74 (d, J = 12.4 Hz, 1H), 1.59 (d, J = 12.4 Hz, 1H), 1.34 (d, J = 14.1 Hz, 12H), 1.16 (d, J = 1.8 Hz, 2H);

[0044] S3: Under nitrogen protection, 1200 ml of anhydrous tetrahydrofuran and 0.1 mol N2 were added. 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 - Bis(3-carboxypropyl)octane-1,8-diammonium bromide was stirred and mixed thoroughly. 0.22 mol of dicyclohexylcarbodiimide and 0.04 mol of 4-dimethylaminopyridine were added, and the mixture was stirred for 15 min. 0.21 mol of intermediate 2 was added, and the reaction was carried out at 25 °C for 18 h. The mixture was filtered, concentrated under reduced pressure at 40 °C for 2 h, and the crude product was purified by silica gel column chromatography (V... 石油醚 :V 乙酸乙酯 =1:1), distilled under reduced pressure at 40℃ for 1 h to obtain the binder; its proton NMR spectrum is as follows. Figure 1 As shown, the proton NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 7.85 (dt, J = 7.5, 2.0Hz, 2H), 7.69-7.58 (m, 12H), 7.46-7.27 (m, 16H), 6.79 (ddt, J = 9.5, 7.5, 2.2Hz, 6H), 4.72 (s, 2H), 4.33-4.18 (m, 12H), 3.69 (s, 12H), 3.52 (s, 18H), 3.49(d, J = 12.4 Hz, 2H), 3.39-3.22 (m, 14H), 2.33 (s, 4H), 2.10-1.97 (m, 4H),1.86-1.57 (m, 8H), 1.41 (s, 4H), 1.36 (s, 12H), 1.33 (s, 4H), 1.31 (s, 12H), 1.16 (d, J = 1.8 Hz, 4H); HRMS (m / z):960.8724[M-2Br] 2+ .

[0045] Example 3 Preparation of the binder:

[0046] S1: Under nitrogen protection, 250 ml of anhydrous acetonitrile, 0.1 mol of dimethyl (3-aminophenyl)phosphonate, and 0.108 mol of 4-(ethylene oxide-2-ylmethoxy)phenylboronic acid pinacol ester were stirred and mixed, heated to 65 °C and reacted for 8 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 50 °C for 1 h. 200 ml of cold anhydrous n-hexane was added and stirred to precipitate the precipitate. The precipitate was filtered, washed with cold anhydrous n-hexane (3 × 50 ml), and dried under vacuum at 50 °C for 8 h to obtain intermediate 1.

[0047] S2: Under nitrogen protection, 400 ml of anhydrous DMF, 0.1 mol of intermediate 1, 0.104 mol of 3-chloropropyltrimethoxysilane, and 10 g of 4A molecular sieve were stirred and mixed. 0.012 mol of tetraethylammonium bromide and 0.12 mol of K₂CO₃ were added, and the mixture was heated to 65 °C and reacted for 7 h. After cooling to room temperature, the mixture was filtered and concentrated under reduced pressure at 65 °C for 2 h to obtain a concentrated solution. Under ice bath conditions, 400 ml of cold anhydrous diethyl ether was slowly added to the concentrated solution with stirring to precipitate a precipitate. The precipitate was filtered, and the filter cake was washed with cold anhydrous diethyl ether (3 × 80 ml). The precipitate was then washed with a mixture of 200 ml of anhydrous diethyl ether and anhydrous ethyl acetate (V... 无水乙醚 :V 无水乙酸乙酯 =9:1) recrystallized, dried under vacuum at 60℃ for 8h, to obtain intermediate 2;

[0048] S3: Under nitrogen protection, 1200 ml of anhydrous tetrahydrofuran and 0.1 mol N2 were added. 1 N 1 N8 N 8 -Tetrabenzyl-N 1 N 8 - Bis(3-carboxypropyl)octane-1,8-diammonium bromide was stirred and mixed thoroughly. 0.22 mol of dicyclohexylcarbodiimide and 0.04 mol of 4-dimethylaminopyridine were added, and the mixture was stirred for 15 min. 0.215 mol of intermediate 2 was added, and the reaction was carried out at 25 °C for 18 h. The mixture was filtered, concentrated under reduced pressure at 40 °C for 2 h, and the crude product was purified by silica gel column chromatography (V... 石油醚 :V 乙酸乙酯 =1:1), distilled under reduced pressure at 40℃ for 1 hour to obtain the binder.

[0049] Example 4: Preparation of the binder:

[0050] S1: Under nitrogen protection, 250 ml of anhydrous acetonitrile, 0.1 mol of dimethyl(3-aminophenyl)phosphonate, and 0.11 mol of 4-(ethylene oxide-2-ylmethoxy)phenylboronic acid pinacol ester were stirred and mixed. The mixture was heated to 70 °C and reacted for 7 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 50 °C for 1 h. 200 ml of cold anhydrous n-hexane was added and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed with cold anhydrous n-hexane (3 × 50 ml). The mixture was dried under vacuum at 50 °C for 8 h to obtain intermediate 1.

[0051] S2: Under nitrogen protection, 400 ml of anhydrous DMF, 0.1 mol of intermediate 1, 0.105 mol of 3-chloropropyltrimethoxysilane, and 10 g of 4A molecular sieve were stirred and mixed. 0.012 mol of tetraethylammonium bromide and 0.12 mol of K₂CO₃ were added, and the mixture was heated to 70 °C and reacted for 6 h. After cooling to room temperature, the mixture was filtered and concentrated under reduced pressure at 65 °C for 2 h to obtain a concentrated solution. Under ice bath conditions, 400 ml of cold anhydrous diethyl ether was slowly added to the concentrated solution with stirring to precipitate a precipitate. The precipitate was filtered, and the filter cake was washed with cold anhydrous diethyl ether (3 × 80 ml). The precipitate was then washed with a mixture of 200 ml of anhydrous diethyl ether and anhydrous ethyl acetate (V... 无水乙醚 :V 无水乙酸乙酯 =9:1) recrystallized, dried under vacuum at 60℃ for 8h, to obtain intermediate 2;

[0052] S3: Under nitrogen protection, 1200 ml of anhydrous tetrahydrofuran and 0.1 mol N2 were added. 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8- Bis(3-carboxypropyl)octane-1,8-diammonium bromide was stirred and mixed thoroughly. 0.22 mol of dicyclohexylcarbodiimide and 0.04 mol of 4-dimethylaminopyridine were added, and the mixture was stirred for 15 min. 0.22 mol of intermediate 2 was added, and the reaction was carried out at 30 °C for 17 h. The mixture was filtered, concentrated under reduced pressure at 40 °C for 2 h, and the crude product was purified by silica gel column chromatography (V...). 石油醚 :V 乙酸乙酯 =1:1), distilled under reduced pressure at 40℃ for 1 hour to obtain the binder.

[0053] Example 5: Preparation of dispersant:

[0054] N1: Under nitrogen protection, 300 ml of dimethyl sulfoxide (DMSO), 0.1 mol of dibromoneopentyl glycol, and 0.205 mol of 1-decylimidazole were stirred and mixed. The mixture was heated to 130 °C and reacted for 24 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 80 °C for 1 h. 200 ml of a mixed solution of petroleum ether and tetrahydrofuran (V) was slowly added. 石油醚 :V 四氢呋喃 =1:4), stirred to precipitate, filtered, the filter cake was washed with tetrahydrofuran (3×50ml), and dried under vacuum at 40℃ for 8h to obtain intermediate A; its 1H NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6 ) δ 9.51 (s, 2H), 8.02 (s, 2H), 7.54 (s, 2H), 4.83 (t, J = 5.0 Hz,2H), 4.47 (d, J = 12.4 Hz, 2H), 4.30 (d, J = 12.4 Hz, 2H), 4.09 (s, 4H), 3.54(d, J = 5.0 Hz, 4H), 1.76 (s, 4H), 1.35-1.25 (m, 28H), 0.89 (s, 6H);

[0055] Under nitrogen protection, 800 ml of anhydrous DMF and 0.21 mol of 12-oxododecanoic acid were stirred and mixed thoroughly. Then, 0.21 mol of dicyclohexylcarbodiimide and 0.04 mol of 4-dimethylaminopyridine were added, and the mixture was stirred for 15 min. Then, 0.1 mol of intermediate A was added, and the reaction was carried out at 25 °C for 18 h. After filtration, the mixture was concentrated under reduced pressure at 70 °C for 2 h. The crude product was purified by silica gel column chromatography (V... 石油醚 :V 乙酸乙酯 The mixture was distilled at 40℃ under reduced pressure for 1 hour (r=1:1) to obtain intermediate B; its 1H NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 9.56 (s,2H), 9.35 (s, 2H), 8.04 (s, 2H), 7.54 (s, 2H), 4.38 (s, 4H), 4.29-4.16 (m,4H), 4.09 (s, 4H), 2.50 (s, 4H), 2.28 (s, 4H), 1.76 (s, 4H), 1.58 (d, J = 5.6Hz, 8H), 1.35-1.25 (m, 52H), 0.89 (s, 6H);

[0056] N3: Under nitrogen protection, 800 ml of anhydrous acetonitrile, 0.1 mol of intermediate B, and 0.205 mol of aminopentaethylene monomethyl ether were stirred and mixed thoroughly. The mixture was heated to reflux and reacted for 4 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 50 °C for 1 h. The crude product was purified by silica gel column chromatography (V... 二氯甲烷 :V 甲醇 =20:1), distilled under reduced pressure at 35℃ for 1 h to obtain the dispersant; its proton NMR spectrum is as follows. Figure 2 As shown, the proton NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6 ) δ 9.35 (s, 2H), 8.04 (s, 2H), 7.54 (s, 2H),7.31 (d, J = 13.9 Hz, 2H), 4.38 (s, 4H), 4.29-4.16 (m, 4H), 4.09 (s, 4H),3.68-3.53 HRMS (m / z):688.5423[M-2Br] 2+ .

[0057] Example 6: Preparation of high-strength, energy-saving refractory castable:

[0058] (1) Weigh the following by weight: 350g magnesium aluminum spinel, 250g millimeter-sized white fused alumina, 80g silica powder, 120g micron-sized white fused alumina powder, 50g binder (prepared in Example 2), 3g dispersant (prepared in Example 5), 40g stainless steel fiber, 3g water-reducing agent (polycarboxylate high-performance water-reducing agent), and 35g deionized water;

[0059] (2) Mix magnesium aluminum spinel, millimeter-sized white fused alumina, silica powder, micron-sized white fused alumina powder, binder, dispersant, stainless steel fiber, water-reducing agent and deionized water, and stir at 300 rpm for 20 min to obtain high-strength energy-saving refractory castable.

[0060] Example 7: Preparation of high-strength, energy-saving refractory castable:

[0061] (1) Weigh the following by weight: 380g magnesium aluminum spinel, 280g millimeter-sized white fused alumina, 90g silica powder, 135g micron-sized white fused alumina powder, 60g binder (prepared in Example 3), 3.5g dispersant (prepared in Example 5), 45g stainless steel fiber, 3.5g water-reducing agent (polycarboxylate high-performance water-reducing agent), and 40g deionized water;

[0062] (2) Mix magnesium aluminum spinel, millimeter-sized white fused alumina, silica powder, micron-sized white fused alumina powder, binder, dispersant, stainless steel fiber, water-reducing agent and deionized water, and stir at 300 rpm for 20 min to obtain high-strength energy-saving refractory castable.

[0063] Example 8: Preparation of high-strength, energy-saving refractory castable:

[0064] (1) Weigh the following by weight: 400g magnesium aluminum spinel, 300g millimeter-sized white fused alumina, 100g silica powder, 150g micron-sized white fused alumina powder, 70g binder (prepared in Example 4), 4g dispersant (prepared in Example 5), 50g stainless steel fiber, 4g water-reducing agent (polycarboxylate high-performance water-reducing agent), and 45g deionized water;

[0065] (2) Mix magnesium aluminum spinel, millimeter-sized white fused alumina, silica powder, micron-sized white fused alumina powder, binder, dispersant, stainless steel fiber, water-reducing agent and deionized water, and stir at 300 rpm for 20 min to obtain high-strength energy-saving refractory castable.

[0066] Comparative Example 1

[0067] The raw material composition and preparation method of the high-strength energy-saving refractory castable are basically the same as those in Example 7, except that the binder is replaced with an equal weight of binder prepared by the following method:

[0068] The preparation method of the binder is basically the same as that in Example 3, except that the dimethyl (3-aminophenyl)phosphonate in step S1 is replaced with an equimolar amount of dimethyl (2-aminoethyl)phosphonate.

[0069] Comparative Example 2

[0070] The raw material composition and preparation method of the high-strength energy-saving refractory castable are basically the same as those in Example 7, except that the binder is replaced with an equal weight of binder prepared by the following method:

[0071] The preparation method of the binder is basically the same as that in Example 3, except that the 3-chloropropyltrimethoxysilane in step S2 is replaced with an equimolar amount of 3-chloropropylmethyldimethoxysilane.

[0072] Comparative Example 3

[0073] The raw material composition and preparation method of the high-strength energy-saving refractory castable are basically the same as those in Example 7, except that the binder is replaced with an equal weight of binder prepared by the following method:

[0074] The preparation method of the binder is basically the same as that in Example 3, except that N in step S3 is used instead of N. 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 - bis(3-carboxypropyl)octane-1,8-diammonium bromide is replaced with an equimolar amount of N 1 N 8 -bis(3-carboxypropyl)-N 1 N 8 -dimethyl-N 1 N 8 -Diphenyloctane-1,8-diammonium bromide;

[0075] N 1 N 8 -bis(3-carboxypropyl)-N 1 N 8 -dimethyl-N 1 N 8 -Diphenyloctane-1,8-diammonium bromide is prepared by the following method:

[0076] 400 ml of anhydrous ethanol, 0.1 mol of 1,8-dibromooctane, and 0.205 mol of 4-(methyl(phenyl)amino)butyric acid (CAS No.: 26488-79-9) were stirred and mixed thoroughly. The mixture was heated to reflux and reacted for 24 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 50 °C for 2 h. The distillate was then distilled using a mixture of 250 ml of ethyl acetate and anhydrous ethanol (V... 乙酸乙酯 :V 无水乙醇 =8:2) recrystallized, dried under vacuum at 60℃ for 12 h, to obtain N 1 N 8 -bis(3-carboxypropyl)-N 1 N 8 -dimethyl-N1 N 8 -Diphenyloctane-1,8-diammonium bromide.

[0077] N 1 N 8 -bis(3-carboxypropyl)-N 1 N 8 -dimethyl-N 1 N 8 The chemical structural formula of 1,8-diphenyloctane-1,8-diammonium bromide is as follows:

[0078]

[0079] Comparative Example 4

[0080] The raw material composition and preparation method of the high-strength energy-saving refractory castable are basically the same as those in Example 7, except that the binder is replaced with an equal weight of binder prepared by the following method:

[0081] The preparation method of the binder is basically the same as that in Example 3, except that N in step S3 is used instead of N. 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 - Replace bis(3-carboxypropyl)octane-1,8-diammonium bromide with 0.2 mol of N,N-dibenzyl-N-(3-carboxypropyl)nonane-1-ammonium;

[0082] N,N-Dibenzyl-N-(3-Carboxypropyl)nonane-1-ammonium was prepared by the following method:

[0083] 400 ml of anhydrous ethanol, 0.1 mol of 1-bromononane, and 0.105 mol of 4-(dibenzylamino)butyric acid were stirred and mixed thoroughly. The mixture was heated to reflux and reacted for 24 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 50 °C for 2 h. The distillate was then distilled using a mixture of 250 ml of ethyl acetate and anhydrous ethanol (V... 乙酸乙酯 :V 无水乙醇 Recrystallization of N,N-dibenzyl-N-(3-carboxypropyl)nonane-1-ammonium was carried out at 60°C under vacuum for 12 h to obtain N,N-dibenzyl-N-(3-carboxypropyl)nonane-1-ammonium.

[0084] The chemical structural formula of N,N-dibenzyl-N-(3-carboxypropyl)nonane-1-ammonium is as follows:

[0085]

[0086] Comparative Example 5

[0087] The raw material composition and preparation method of the high-strength energy-saving refractory castable are basically the same as those in Example 7, except that the binder is replaced with 36g of intermediate 2 (prepared in step S2 of Example 3) and 24g of N. 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 A mixture of bis(3-carboxypropyl)octane-1,8-diammonium bromide.

[0088] Comparative Example 6

[0089] The raw material composition and preparation method of the high-strength energy-saving refractory castable are basically the same as those in Example 7, except that the dispersant is replaced with an equal weight of the dispersant prepared by the following method:

[0090] The preparation method of the dispersant is basically the same as that in Example 5, except that the 1-decylimidazole in step N1 is replaced with an equimolar amount of 1-propylimidazole.

[0091] Comparative Example 7

[0092] The raw material composition and preparation method of the high-strength energy-saving refractory castable are basically the same as those in Example 7, except that the dispersant is replaced with an equal weight of the dispersant prepared by the following method:

[0093] The preparation method of the dispersant is basically the same as that in Example 5, except that the dibromoneopentyl glycol in step N1 is replaced with 0.2 mol of 3-bromo-1-propanol; the amount of 12-oxododecanoic acid in step N2 is replaced with 0.11 mol; and the amount of aminopentaethylene monomethyl ether in step N3 is replaced with 0.105 mol.

[0094] Comparative Example 8

[0095] The raw material composition and preparation method of the high-strength energy-saving refractory castable are basically the same as those in Example 7, except that the dispersant is replaced with an equal weight of the dispersant prepared by the following method:

[0096] The preparation method of the dispersant is basically the same as that in Example 5, except that the aminopentaethylene monomethyl ether in step N3 is replaced with an equimolar amount of 2-methoxyethylamine.

[0097] The magnesium aluminum spinel used in the embodiments and comparative examples of this application is model MA-65, produced by Sanmenxia Shuntai Fused Alumina Co., Ltd.; the particle size of millimeter-sized white fused alumina is uniformly distributed between 1-3 mm; the particle size of silica micro powder is uniformly distributed between 20-25 μm; the particle size of micron-sized white fused alumina micro powder is uniformly distributed between 14-20 μm; the stainless steel fiber is stainless steel fiber 446; the polycarboxylate high-performance water-reducing agent is model SPC-100, produced by Liaoning Kelong Fine Chemical Co., Ltd.; the 4A molecular sieve is sodium-4A type molecular sieve, with a particle size uniformly distributed between 1.5-5.0 mm; and the CAS number of 12-oxododecanoic acid is 3956-80-7.

[0098] Mechanical properties and slag resistance of the high-strength energy-saving refractory castables prepared in Examples 6-8 and Comparative Examples 1-8 were tested, and thermal conductivity of the high-strength energy-saving refractory castables prepared in Examples 6-8 was tested. The test results are shown in Table 1.

[0099] Mechanical property testing: Sample preparation was performed according to Section 5.1 of GB / T 4513.5-2017 standard: The refractory castables prepared in Examples 6-8 and Comparative Examples 1-8 were placed in a PTFE mold with dimensions of 160mm × 40mm × 40mm. The molding method was vibration molding with an amplitude of 0.5mm. After vibration for 5 minutes, the mold was placed in a 100℃ oven for drying for 12 hours. After demolding, the mold was dried again at 100℃ for 24 hours, and then placed in a 110℃ drying oven for 18 hours. The samples were then naturally cooled to room temperature to obtain the specimens. The room temperature flexural strength was then tested according to GB / T 3001-2017 standard, "Test Method for Flexural Strength of Refractory Materials at Room Temperature," with a loading rate of 0.15MPa / s. (Referencing standard GB / T...) The high-temperature flexural strength test was conducted according to 3002-2017 "Test Method for High-Temperature Flexural Strength of Refractory Materials". The loading rate was 0.15 MPa / s, the test temperature was 1100℃, the heating rate was 5℃ / min, and the holding time was 0.5h.

[0100] Slag resistance test: Samples were prepared according to YB / T 5202.1-2003 standard: The refractory castables prepared in Examples 6-8 and Comparative Examples 1-8 were placed in a polytetrafluoroethylene mold with dimensions of 70mm×70mm×65mm. The molding method was vibration molding with an amplitude of 0.5mm. After vibration for 90s, the mold was placed in an oven at 110℃ for 12h. After demolding, it was dried at 110℃ for 24h and then naturally cooled to room temperature. A crucible sample with an inner diameter of 40mm and a depth of 30mm was drilled from the center of the top surface. The slag resistance test was carried out according to the static crucible method in standard GB / T 8931-2007 "Test Method for Slag Resistance of Refractory Materials".

[0101] Thermal conductivity test: Sample preparation was carried out in accordance with Section 5.1 of GB / T 4513.5-2017: The refractory castables prepared in Examples 6-8 were placed in a polytetrafluoroethylene mold with dimensions of 200mm×100mm×50mm. The molding method was vibration molding with an amplitude of 0.5mm. After vibration for 5 minutes, the mold was placed in an oven at 100℃ for 12 hours. After demolding, it was dried at 100℃ for 24 hours and then placed in a drying oven at 110℃ for 18 hours. After natural cooling to room temperature, the sample was obtained. Then, the thermal conductivity was tested in accordance with the cross-shaped hot wire method in GB / T 5990-2021.

[0102] Table 1 Performance Test Data

[0103]

[0104] As can be seen from the data in Table 1, the high-strength energy-saving refractory castables prepared in Examples 6-8 of this application have low thermal conductivity, excellent flexural strength, and exhibit good mechanical properties and slag resistance.

[0105] The binder added to the components of the refractory castable prepared in this application (6-8) contains benzene rings, quaternary ammonium salts, borate esters, siloxanes, and phosphate esters. Among these, the positive charge of the quaternary ammonium salt structure forms electrostatic attraction and hydrogen bonds with the hydroxyl groups on the surface of the refractory castable; the boric acid generated from the hydrolysis of the borate ester forms coordination bonds with metal oxides in the matrix materials such as magnesium aluminate spinel and white corundum; the silanol groups generated from the hydrolysis of the siloxane condense with the hydroxyl groups on the surface of silica micropowder to form a covalent bond network; and the acidic groups of the phosphate ester react with the basic components (such as magnesium aluminate spinel) to generate a stable phosphate-bound phase. These multiple structures synergistically construct a strong interfacial bond through chemical adsorption and chemical bonding, improving the room temperature resistance of the refractory castable. The flexural properties are improved; at the same time, the organic segments (carbon chains, benzene rings) in the molecule can relieve thermal stress. Siloxanes, borate esters, and phosphate esters are transformed into a SiO2, B2O3, P2O5 composite glass phase at high temperatures, filling the gaps between particles and promoting sintering, thereby improving the high-temperature flexural properties of refractory castables. In addition, the chemical inertness of benzene rings and siloxane chains can reduce slag erosion, the low-viscosity glass phase forms a dense glaze layer that hinders slag penetration, and the surface activity of quaternary ammonium salts optimizes the compactness of particle packing, thus comprehensively improving the mechanical properties and slag resistance of refractory castables.

[0106] The dispersant added to the components of the refractory castable prepared in this application (6-8) contains long-chain alkyl groups, long flexible ether chains, imidazolium cations, and Schiff base structures. Among these, the imidazolium cation structure can strongly adsorb onto oxide particles, the Schiff base structure can complex metal ions in the system, and inhibit particle agglomeration; the long-chain alkyl groups provide hydrophobic steric hindrance effects, hindering particle agglomeration; and the long flexible ether chains, through hydrophilicity and flexibility, regulate molecular extensibility, preventing hydrophobic aggregation. At high temperatures, the nitrogen-containing structures remaining after the decomposition of imidazolium and Schiff bases can react with Al2O3 in the system to generate an AlN reinforcing phase, thereby improving the post-firing mechanical properties and slag erosion resistance of the refractory castable.

[0107] In Comparative Example 2, the binder used had a reduced number of hydrolyzable methoxy groups in its siloxane structure, resulting in a lower number of silanol groups generated after hydrolysis. This reduced the number of covalent bonding sites between the binder and the hydroxyl groups on the refractory castable surface, leading to a smaller covalent bond network and a decrease in the amount of SiO2 glass phase formed at high temperatures. Consequently, the mechanical properties and slag resistance of the refractory castable decreased. In Comparative Example 6, the dispersant used had a shorter alkyl chain, which failed to provide sufficient steric hindrance, resulting in poor particle dispersibility and a reduction in the mechanical properties and slag erosion resistance of the refractory castable.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A high-strength, energy-saving refractory castable, characterized in that, The ingredients include the following parts by weight: 35-40 parts magnesium aluminum spinel, 25-30 parts millimeter-sized white fused alumina, 8-10 parts silica micro powder, 12-15 parts micron-sized white fused alumina micro powder, 5-7 parts binder, 0.3-0.4 parts dispersant, 4-5 parts stainless steel fiber, 0.3-0.4 parts water-reducing agent, and 3.5-4.5 parts deionized water; The binder is prepared by the following method: S1: Dimethyl(3-aminophenyl)phosphonate reacts with 4-(ethylene oxide-2-ylmethoxy)phenylboronic acid pinacol ester to generate intermediate 1, the chemical structural formula of which is as follows: ； S2: Intermediate 1 reacts with 3-chloropropyltrimethoxysilane to generate intermediate 2, whose chemical structural formula is as follows: ； S3: Intermediate 2 and N 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 -The reaction of bis(3-carboxypropyl)octane-1,8-diammonium bromide produces a binder, the chemical structure of which is as follows: ； The chemical structural formula of the dispersant is as follows: 。 2. The high-strength, energy-saving refractory castable according to claim 1, characterized in that, In step S1, the molar ratio of dimethyl (3-aminophenyl)phosphonate to 4-(ethylene oxide-2-ylmethoxy)phenylboronic acid pinacol ester is 1:(1.05-1.1).

3. The high-strength, energy-saving refractory castable according to claim 1, characterized in that, In step S2, the molar ratio of intermediate 1 to 3-chloropropyltrimethoxysilane is 1:(1.03-1.05).

4. The high-strength, energy-saving refractory castable according to claim 1, characterized in that, In step S3, the intermediate 2 and N 1 N 1 N 8 N 8 -Tetrabenzyl-N 1 N 8 The molar ratio of bis(3-carboxypropyl)octane-1,8-diammonium bromide to the feed is (2.1-2.2):

1.

5. The high-strength, energy-saving refractory castable according to claim 1, characterized in that, The dispersant is prepared by the following method: N1: 1-Decylimidazole reacts with dibromonepentyl glycol to generate intermediate A, the chemical structural formula of which is as follows: ； N2: Intermediate A reacts with 12-oxododecanoic acid to generate intermediate B, whose chemical structural formula is as follows: ； N3: Intermediate B reacts with aminopentaethylene monomethyl ether to form a dispersant.

6. The high-strength, energy-saving refractory castable according to claim 5, characterized in that, In step N1, the molar ratio of 1-decylimidazole to dibromoneopentyl glycol is 2.05:

1.

7. The high-strength, energy-saving refractory castable according to claim 5, characterized in that, In step N2, the molar ratio of intermediate A to 12-oxododecanoic acid is 1:2.

1.

8. The high-strength, energy-saving refractory castable according to claim 5, characterized in that, In step N3, the molar ratio of intermediate B to aminopentaethylene monomethyl ether is 1:2.

05.

9. The high-strength, energy-saving refractory castable according to claim 1, characterized in that, The water-reducing agent is a polycarboxylate high-performance water-reducing agent.

10. A method for preparing the high-strength, energy-saving refractory castable according to any one of claims 1-9, characterized in that, Includes the following steps: (1) Weigh the following by weight: 35-40 parts magnesium aluminum spinel, 25-30 parts millimeter-sized white fused alumina, 8-10 parts silica powder, 12-15 parts micron-sized white fused alumina powder, 5-7 parts binder, 0.3-0.4 parts dispersant, 4-5 parts stainless steel fiber, 0.3-0.4 parts water-reducing agent, and 3.5-4.5 parts deionized water; (2) Mix magnesium aluminum spinel, millimeter-sized white fused alumina, silica powder, micron-sized white fused alumina powder, binder, dispersant, stainless steel fiber, water-reducing agent and deionized water to obtain high-strength energy-saving refractory castable.

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