Low-ablation refractory concrete and method of making same

Abstract

The application provides a low-ablation refractory concrete and a preparation method thereof. The low-ablation refractory concrete is prepared by taking recycled tabular corundum aggregate and sodium alumina ultrafine powder as main components and adding YJ type polycarboxylic admixture, wherein the sodium alumina ultrafine powder is used as a binding agent to replace a traditional aluminate cement binding system, and the Ca 2+ ion content, so that the fire resistance and ablation resistance of the material can be greatly improved, and the launching demand of a large-thrust rocket can be met. The low-ablation refractory concrete can be used in a serious-ablation part such as a flow guide groove of a rocket launching platform, and the fire resistance and ablation resistance of the low-ablation refractory concrete are obviously improved compared with those of previous materials.

Description

Technical Field

[0001] This invention relates to the field of aerospace materials, and in particular to a low-ablation refractory concrete and its preparation method. Background Technology

[0002] The rocket launch platform's duct is a crucial component of the launch tower, its primary function being to expel the high-temperature gas and flames generated during rocket launch, ensuring the tower's long-term safe operation. Therefore, the refractory concrete used in the duct must not only possess high density and strength, but also exhibit high refractoriness, resistance to flame impact, and ablation resistance. National military standards specify clear requirements for the ablation resistance of low-ablation refractory concrete, and it must also possess high strength and ease of construction.

[0003] Currently, low-ablation refractory concrete mainly uses waste refractory bricks as aggregate, with a bonding system of 18-20% aluminate cement, introducing a relatively large amount of Ca. 2+ Ions, more Ca 2+ Ions reduce the fire resistance and ablation resistance of materials, making it impossible for them to meet the requirements of national military standards in ablation rate testing, and also unable to meet the needs of increasingly high-thrust, high-frequency space launches. Summary of the Invention

[0004] In view of this, the present invention aims to propose a low-ablation refractory concrete and its preparation method. The low-ablation refractory concrete is formulated using solid waste as the main raw material, and a sodium aluminum oxide ultrafine powder binding system is used to replace the calcium aluminate cement binder, significantly reducing the calcium oxide emissions introduced by the use of large amounts of cement. 2+ Ions improve the fire resistance and ablation resistance of refractory concrete, enabling it to meet the national military standard for ablation resistance testing and achieve a high strength of over 100 MPa.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A low-ablation refractory concrete, wherein, by weight, 0.1-0.5 parts by weight of YJ-type polycarboxylate admixture and 4-5 parts by weight of water are added to every 100 parts by weight of dry material; every 100 parts by weight of dry material includes 68-80 parts by weight of recycled tabular corundum aggregate and 20-32 parts by weight of sodium aluminum oxide ultrafine powder; the sodium aluminum oxide ultrafine powder is obtained by calcining substandard industrial alumina with excessive Na2O content to form sodium aluminum oxide with cementing properties, and then grinding the sodium aluminum oxide through ultrafine grinding; YJ-type polycarboxylate additive is prepared from raw materials including a bottom mixture and a dropper. The dropper is added at a ratio of 30-35 wt% of the bottom mixture. By mass fraction, the bottom mixture includes 38-54% polyether, 45-60% deionized water, and 0.5-2% hydrogen peroxide. The dropper includes 9-19% acrylic acid, 0.3-0.9% sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, 0.3-0.6% vitamin C, 0.3-0.9% mercaptoethanol, and 81-90% deionized water.

[0006] According to the national standard GB / T 24487-2022 "Alumina", the Na2O content in industrial alumina is required to be divided into three grades according to the grade: AO-G grade, the Na2O content shall not exceed 0.35%; AO-1 grade, the content shall not exceed 0.45%; and AO-2 grade, the content shall not exceed 0.55%. Products with a Na2O content exceeding 0.55% are considered unqualified.

[0007] Furthermore, the sodium aluminum oxide ultrafine powder uses industrial alumina with a Na2O mass fraction exceeding 0.55%, and is calcined at a temperature of 815-1400℃ for 4-6 hours.

[0008] Furthermore, the D of sodium aluminum oxide ultrafine powder 50 The particle size is 0.5-3μm, and the Al2O3 content in the sodium aluminum oxide ultrafine powder is greater than 90wt%.

[0009] Furthermore, pure calcium aluminate was added as an activator during the ultrafine grinding process. The mass ratio of pure calcium aluminate to sodium aluminum oxide was (3-20):(80-97). Pure calcium aluminate and sodium aluminum oxide were ground together to a median particle size D. 50 It is an ultrafine powder with a particle size of 0.5-3μm. The ultrafine powder size of 0.5-3μm is conducive to achieving close packing.

[0010] The main mineral composition of sodium aluminum oxide ultrafine powder is sodium aluminum oxide (ideal chemical formula is NaAl). l1 O 17 Sodium aluminum oxide ultrafine powder itself has high activity, and by adding 3-20wt% pure calcium aluminate micro powder as an activator, a sodium aluminum oxide ultrafine powder gelation system with Al2O3≥90% can be prepared.

[0011] Furthermore, recycled tabular corundum aggregate is a recycled industrial raw material obtained by removing the metamorphic layer from solid waste discarded in the metallurgical industry, removing magnetic materials through strong magnetic separation, and then washing, drying, crushing, and screening processes; solid waste includes electric furnace covers and white corundum bricks.

[0012] Furthermore, the chemical composition of the recycled tabular corundum aggregate, by mass fraction, includes Al2O3: 94%, CaO: 1.2%, Na2O: 0.1%, SiO2: 4.0%, TiO2: 0.12%, MgO: 0.3%, Fe2O3: 0.10%, with the balance being impurities.

[0013] Typical physical properties of recycled tabular corundum aggregate: specific gravity 3.5 g / cm³ 3 Melting point: 2173K; raw materials can be in granular or fine powder form. Regenerated tabular corundum has high chemical purity, low impurity content, and a unique crystal structure. After a period of use, it exhibits extremely high refractoriness, good thermal shock resistance, uniform particle size, high bulk density, low porosity, and no false particles.

[0014] Furthermore, the preparation method of YJ-type polycarboxylate admixture is as follows: a. Dissolve polyether and hydrogen peroxide in deionized water and stir magnetically to form a homogeneous mixture at the bottom of the vessel; b. Add acrylic acid, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, vitamin C and mercaptoethanol sequentially to deionized water and stir thoroughly to obtain a uniformly dispersed drop solution. c. Subsequently, while stirring, the liquid is gradually added dropwise to the mixture at the bottom of the vessel. After the addition is complete, the reaction system is kept at the current temperature for 2 hours. The final product is YJ type polycarboxylate additive.

[0015] Acrylic acid is one of the core monomers in the preparation of polycarboxylate superplasticizers. After polymerization, it introduces a large number of carboxyl groups (-COOH) into the molecular chain. These carboxyl groups adsorb onto the surface of cementitious particles, giving the particles a negative charge. Based on electrostatic repulsion, the cementitious particles repel each other, breaking the flocculation structure between particles and releasing the trapped free water, thus achieving water reduction and dispersion effects. The sulfonic acid groups in sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, as functional monomers of polycarboxylate superplasticizers, have a much higher charge density (-SO3H) than carboxyl groups in their molecular structure. After adsorption onto the surface of cementitious particles, they enhance the electrostatic repulsion between particles, further improving dispersion efficiency. Furthermore, the sulfonic acid groups are less affected by cement hydration products and can maintain stable adsorption in highly alkaline environments, improving slump loss over time. Vitamin C is an organic retarder; its hydroxyl and carbonyl groups can react with the Ca2+ of hydrated products. 2+Complexation forms an adsorption film on the surface of hydrated particles, hindering the hydration reaction and delaying setting time. Simultaneously, by regulating the hydration rate, it prevents premature thickening of the slurry, significantly improving slump retention. Mercaptoethanol acts as a highly efficient chain transfer agent in the polymerization synthesis of polycarboxylate superplasticizers. It controls the polymerization process of monomers such as acrylic acid, adjusts the length and molecular weight distribution of the superplasticizer molecular chains, and makes the molecular chain structure more regular—ensuring sufficient adsorption sites and suitable expansion space for the molecular chains, ultimately optimizing the dispersion and slump retention performance of the superplasticizer.

[0016] Furthermore, in step a, the magnetic stirring speed is 80-300 r / min; In step c, the stirring speed is 400-1500 r / min.

[0017] Corundum is a "lean material" that is not easily wetted by mixing water, has a high specific gravity, and is prone to settling and segregation. The binder used is sodium aluminum oxide ultrafine powder, which has a short initial setting time of only 30-40 minutes, insufficient for on-site construction. Therefore, suitable admixtures are needed to reduce water consumption, extend the initial setting time, and improve the material's anti-segregation properties. Because sodium aluminum oxide ultrafine powder is a completely different binder from cement, there are no suitable admixtures available on the market; specially formulated admixtures are required.

[0018] Calculations show that adding this YJ-type polycarboxylate additive can achieve a water reduction rate of ≥35%, a water-to-binder ratio of 0.157, and improve the density of the material.

[0019] The present invention also provides a method for preparing low-ablation refractory concrete as described above, wherein dry materials, YJ-type polycarboxylate admixture and water are mixed and stirred in proportion to form concrete.

[0020] The present invention also provides an application of the low-ablation refractory concrete as described above in the guide channel of a rocket launch platform. The low-ablation refractory concrete is poured into the construction site and vibrated and molded with a vibrator to make it dense, thereby forming an ablation-resistant protective layer for the guide channel of the rocket launch platform.

[0021] Compared with existing technologies, the low-ablation refractory concrete and its preparation method described in this invention have the following advantages: (1) The low-ablation refractory concrete of the present invention contains sodium aluminum oxide ultrafine powder with an alumina content of more than 90%, which can make the prepared low-ablation refractory concrete reach a strength of more than 100 MPa at room temperature after 7 days, and the ablation resistance test meets the national military standard requirement of ≤1 mm / s.

[0022] (2) The low-ablation refractory concrete of the present invention forms an ablation-resistant, high-strength protective layer by being poured into the guide channel of the rocket launch platform, thereby ensuring the safe operation of the rocket launch platform. The low-ablation refractory concrete can be poured and constructed at room temperature, and its hydration hardening produces high strength and good ablation resistance. With the extension of service time and the increase of service temperature, the strength of the low-ablation refractory concrete will be further improved.

[0023] (3) The low-ablation refractory concrete of the present invention has a simple composition and utilizes recycled tabular corundum and substandard alumina to prepare sodium aluminum oxide ultrafine powder, thus practicing the green development strategy and promoting the dual carbon target. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1 A low-ablation refractory concrete, wherein, by weight, 0.25 parts by weight of YJ-type polycarboxylate admixture and 4.8 parts by weight of water are added to every 100 parts by weight of dry material; every 100 parts by weight of dry material includes 71.5 parts by weight of recycled tabular corundum aggregate and 28.5 parts by weight of sodium aluminum oxide ultrafine powder.

[0027] The sodium aluminum oxide ultrafine powder is formed by calcining industrial alumina with a Na2O content of more than 0.55% at 1380℃ for 5 hours to form sodium aluminum oxide with gelling properties. The sodium aluminum oxide is then ultrafine ground to 0.5-1μm. At the same time, pure calcium aluminate micro powder is added as an activator during the ultrafine grinding process. The mass ratio of pure calcium aluminate to sodium aluminum oxide is 15:85. The Al2O3 content in the obtained sodium aluminum oxide ultrafine powder is greater than 90wt%.

[0028] Recycled tabular corundum aggregate is a recycled industrial raw material obtained from solid waste discarded in the metallurgical industry after removing the metamorphic layer, removing magnetic materials through strong magnetic separation, and then undergoing washing, drying, crushing, and screening processes. Solid waste includes electric furnace covers and white corundum bricks. The chemical composition of recycled tabular corundum aggregate, by mass fraction, includes Al2O3: 94%, CaO: 1.2%, Na2O: 0.1%, SiO2: 4.0%, TiO2: 0.12%, MgO: 0.3%, Fe2O3: 0.10%, with the balance being impurities.

[0029] YJ-type polycarboxylate additives are prepared by the following method: a. Preparation of the mixture at the bottom of the vessel: 40% polyether and 1% hydrogen peroxide were dissolved in 59% deionized water and magnetically stirred at 200 r / min to form a homogeneous mixture at the bottom of the vessel. b. Add 15% acrylic acid, 0.6% sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, 0.5% vitamin C and 0.7% mercaptoethanol sequentially to 83.2% deionized water and stir thoroughly to obtain a uniformly dispersed drop solution; c. Subsequently, while stirring, the droplet is gradually added dropwise to the mixture at the bottom of the vessel. The addition ratio of the droplet is 33 wt% of the mixture at the bottom of the vessel. After the droplet addition is completed, the reaction system is kept at the current temperature for 2 hours. The final product is YJ type polycarboxylate additive.

[0030] Preparation of low-ablation refractory concrete: Mix the dry materials, YJ-type polycarboxylate additive, and water in the specified proportions, and stir them into a plastic body with certain thixotropic properties using a vertical shaft planetary forced mixer. Then, vibrate and pour the mixture onto the construction site.

[0031] Example 2 A low-ablation refractory concrete, wherein, by weight, 0.25 parts by weight of YJ-type polycarboxylate admixture and 5 parts by weight of water are added to every 100 parts by weight of dry material; every 100 parts by weight of dry material includes 69.5 parts by weight of recycled tabular corundum aggregate and 30.5 parts by weight of sodium aluminum oxide ultrafine powder.

[0032] Among them, sodium aluminum oxide ultrafine powder is formed by calcining industrial alumina with Na2O content exceeding 0.55% at 1380℃ for 5 hours to form sodium aluminum oxide with gelling properties. The sodium aluminum oxide is then ultrafine ground to 1-2μm. At the same time, pure calcium aluminate micro powder is added as an activator during the ultrafine grinding process. The mass ratio of pure calcium aluminate to sodium aluminum oxide is 20:80. The Al2O3 content in the obtained sodium aluminum oxide ultrafine powder is greater than 90wt%.

[0033] YJ-type polycarboxylate additives are prepared by the following method: a. Preparation of the mixture at the bottom of the vessel: 45% polyether and 2% hydrogen peroxide were dissolved in 53% deionized water and magnetically stirred at 220 r / min to form a homogeneous mixture at the bottom of the vessel. b. Add 15% acrylic acid, 0.6% sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, 0.5% vitamin C and 0.7% mercaptoethanol sequentially to 83.2% deionized water and stir thoroughly to obtain a uniformly dispersed drop solution; c. Subsequently, while stirring, the droplet is gradually added dropwise to the mixture at the bottom of the vessel. The addition ratio of the droplet is 33 wt% of the mixture at the bottom of the vessel. After the droplet is added, the reaction system is kept at the current temperature for 2 hours. The final product obtained is YJ type polycarboxylate additive.

[0034] The preparation of low-ablation refractory concrete is the same as in Example 1.

[0035] The national military standard has made clear requirements for the ablation resistance of low-ablation refractory concrete, with an index of ≤1mm / s.

[0036] The operating parameters for the test were as follows: fuel: aviation kerosene and oxygen, mass flow ratio: 2.23; combustion chamber pressure: 1.1 ± 0.05 MPa; combustion chamber temperature: 3250 K; nozzle outlet pressure: 0.07 MPa; nozzle outlet gas velocity: 2350 m / s; nozzle outlet gas temperature: 2030 K; nozzle outlet inner diameter: 65 mm. The distance from the nozzle to the specimen was 150 mm, and the angle between the injection axis and the specimen was 30°.

[0037] The test indicators for Examples 1-2 are shown in Table 1 below: Table 1 Test Indicators for Examples 1-2 The maximum ablation rate of the impact zone in Example 1 was 0.380 mm / s, and the maximum ablation rate of the impact zone in Example 2 was 0.395 mm / s, both less than 1 mm / s.

[0038] Comparative Example 1 The difference from Example 1 is that the YJ type polycarboxylate additive is replaced with a common water-reducing agent, otherwise it is the same as Example 1.

[0039] The test metrics are shown in Table 2 below: Table 2 Test Indicators for Example 1 and Comparative Example 1 The maximum ablation rate of the impact zone in Comparative Example 1 was 0.474 mm / s.

[0040] It is evident that the common water-reducing agent used in Comparative Example 1 is not suitable for the system of this invention, resulting in a decrease in bulk density, flexural strength, compressive strength, and maximum ablation rate.

[0041] Comparative Example 2 The difference from Example 1 is that the sodium aluminum oxide ultrafine powder is replaced with CA65 pure calcium aluminate cement, otherwise it is the same as Example 1.

[0042] The test metrics are shown in Table 3 below: Table 3 Test Indicators for Example 1 and Comparative Example 2 The maximum ablation rate of the impact zone in Comparative Example 2 was 1.265 mm / s, which is greater than 1 mm / s and therefore unqualified.

[0043] It is evident that the conventional binder CA65 pure calcium aluminate cement used in Comparative Example 2 is not suitable for the system of this invention, and its bulk density, flexural strength, and compressive strength all decreased, especially the maximum ablation rate, which could not meet the standard.

[0044] Comparative Example 3 The difference from Example 1 is that the sodium aluminum oxide ultrafine powder is replaced with ordinary alumina micro powder, otherwise it is the same as Example 1.

[0045] The test metrics are shown in Table 4 below: Table 4 Test Indicators of Example 1 and Comparative Example 3 The maximum ablation rate of the impact zone in Comparative Example 3 was 0.567 mm / s.

[0046] It is evident that when ordinary alumina micro powder is used instead, the bulk density, compressive strength, and maximum ablation rate are all inferior to those of the embodiments of the present invention.

[0047] Comparative Example 4 The difference from Example 1 is that the sodium aluminum oxide ultrafine powder uses industrial alumina with a Na2O mass fraction of no more than 0.35%, while the rest is the same as in Example 1.

[0048] The test metrics are shown in Table 5 below: Table 5 Test Indicators of Example 1 and Comparative Example 4 The maximum ablation rate of the impact zone in Comparative Example 4 was 0.609 mm / s.

[0049] It is evident that the mass fraction of Na2O in the raw materials used for sodium aluminum oxide ultrafine powder also affects the performance of concrete, with a significant impact on compressive strength and maximum ablation rate.

[0050] Comparative Example 5 The difference from Example 1 is that the amount of sodium aluminum oxide ultrafine powder used is 15 parts by weight, while the rest is the same as in Example 1.

[0051] The test metrics are shown in Table 6 below: Table 6 Test Indicators of Example 1 and Comparative Example 5 The maximum ablation rate of the impact zone in Comparative Example 5 was 0.540 mm / s.

[0052] It is evident that reducing the amount of sodium aluminum oxide ultrafine powder can also affect the performance of concrete, with a greater impact on compressive strength and maximum ablation rate.

[0053] Comparative Example 6 The difference from Example 1 is that the amount of sodium aluminum oxide ultrafine powder used is 38 parts by weight, while the rest is the same as in Example 1.

[0054] The test metrics are shown in Table 7 below: Table 7 Test Indicators for Example 1 and Comparative Example 6 The maximum ablation rate of the impact zone in Comparative Example 6 was 0.590 mm / s.

[0055] It is evident that excessive use of sodium aluminum oxide ultrafine powder can also affect the performance of concrete, having varying degrees of impact on bulk density, compressive strength, and maximum ablation rate.

[0056] Comparative Example 7 The difference from Example 1 is that the YJ type polycarboxylic acid additive does not contain sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, while the rest is the same as in Example 1.

[0057] The test metrics are shown in Table 8 below: Table 8 Test Indicators of Example 1 and Comparative Example 7 Comparative Example 7, due to the absence of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate in the water-reducing agent, exhibited poor slump retention, with an initial setting time of only 3 minutes. This insufficient setting time resulted in numerous honeycomb and pitted surfaces on the test blocks, indicating poor density. The maximum ablation rate in the impact zone was 1.322 mm / s, which is unacceptable.

[0058] Comparative Example 8 The difference from Example 1 is that the YJ type polycarboxylic acid additive is prepared without the addition of mercaptoethanol, otherwise it is the same as Example 1.

[0059] The test metrics are shown in Table 9 below: Table 9 Test Indicators for Example 1 and Comparative Example 8 Mercaptoethanol acts as a chain transfer agent in water-reducing agents, controlling the polymerization process of monomers such as acrylic acid and adjusting the length and molecular weight distribution of the water-reducing agent's molecular chains to achieve a more regular molecular chain structure and optimal water-reducing effect. Because mercaptoethanol was not added to the water-reducing agent in Comparative Example 8, the water-reducing agent effect was poor, resulting in a material with low bulk density and poor strength. The maximum ablation rate in the impact zone was 1.495 mm / s, which is unacceptable.

[0060] The data above shows that the present invention uses recycled plate-shaped corundum aggregate and sodium aluminum oxide ultrafine powder as the main components, and adds YJ type polycarboxylate admixture to formulate low-ablation refractory concrete. The low-ablation refractory concrete can achieve a strength of more than 100MPa at room temperature after 7 days, and the ablation resistance test meets the national military standard requirement of ≤1mm / s.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-ember refractory concrete, characterized in that: The low-ablation refractory concrete, by weight, comprises 0.1-0.5 parts by weight of YJ-type polycarboxylate admixture and 4-5 parts by weight of water per 100 parts by weight of dry material; each 100 parts by weight of dry material includes 68-80 parts by weight of recycled tabular corundum aggregate and 20-32 parts by weight of sodium aluminum oxide ultrafine powder; the sodium aluminum oxide ultrafine powder is obtained by calcining substandard industrial alumina with excessive Na2O content to form sodium aluminum oxide with gelling properties, and then grinding the sodium aluminum oxide through ultrafine grinding. YJ-type polycarboxylate additive is prepared from raw materials including a bottom mixture and a dropper. The dropper is added at a ratio of 30-35 wt% of the bottom mixture. By mass fraction, the bottom mixture includes 38-54% polyether, 45-60% deionized water, and 0.5-2% hydrogen peroxide. The dropper includes 9-19% acrylic acid, 0.3-0.9% sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, 0.3-0.6% vitamin C, 0.3-0.9% mercaptoethanol, and 81-90% deionized water.

2. The low-ablation refractory concrete according to claim 1, characterized in that: The sodium aluminum oxide ultrafine powder uses industrial alumina with a Na2O mass fraction exceeding 0.55%, and is calcined at a temperature of 815-1400℃ for 4-6 hours.

3. The low-ember refractory concrete according to claim 1, characterized in that: D of sodium aluminum oxide ultrafine powder 50 The particle size is 0.5-3μm, and the Al2O3 content in the sodium aluminum oxide ultrafine powder is greater than 90wt%.

4. The low-ember refractory concrete according to claim 1, characterized in that: Pure calcium aluminate is added as an activator during the ultrafine grinding process. The mass ratio of pure calcium aluminate to sodium aluminum oxide is 3-20:80-97. Pure calcium aluminate and sodium aluminum oxide are ground together to a median particle size D. 50 It is an ultrafine powder with a particle size of 0.5-3μm.

5. The low-ember refractory concrete according to claim 1, characterized in that: Recycled tabular corundum aggregate is a recycled industrial raw material obtained from solid waste discarded in the metallurgical industry after removing the metamorphic layer, removing magnetic materials through strong magnetic separation, and then undergoing washing, drying, crushing, and screening processes; solid waste includes electric furnace covers and white corundum bricks.

6. The low-ember refractory concrete according to claim 5, characterized in that: The chemical composition of recycled tabular corundum aggregate, by mass fraction, includes Al2O3: 94%, CaO: 1.2%, Na2O: 0.1%, SiO2: 4.0%, TiO2: 0.12%, MgO: 0.3%, Fe2O3: 0.10%, with the balance being impurities.

7. The low-ablation refractory concrete according to claim 1, characterized in that: The preparation method of YJ type polycarboxylate additive is as follows: a. Dissolve polyether and hydrogen peroxide in deionized water and stir magnetically to form a homogeneous mixture at the bottom of the vessel; b. Add acrylic acid, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, vitamin C and mercaptoethanol sequentially to deionized water and stir thoroughly to obtain a uniformly dispersed drop solution. c. Subsequently, while stirring, the liquid is gradually added dropwise to the mixture at the bottom of the vessel. After the addition is complete, the reaction system is kept at the current temperature for 2 hours. The final product is YJ type polycarboxylic acid additive.

8. A method for preparing low-ablation refractory concrete as described in any one of claims 1-7, characterized in that: The dry materials, YJ-type polycarboxylate admixture, and water are mixed in a certain proportion to form concrete.

9. The application of low-ablation refractory concrete as described in any one of claims 1-7 in the guide channel of a rocket launch platform, characterized in that: The low-ablation refractory concrete is poured into the construction area and vibrated to form a dense structure, thus constituting an ablation-resistant protective layer for the rocket launch platform's guide channel.

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