A castable and its preparation method and application

Abstract

The application relates to the technical field of materials, in particular to a castable and a preparation method and application thereof. The castable comprises, in parts by weight, organic silicon resin: 100 parts; first calcined filler: 40-220 parts; and second calcined filler: 0.5-2 parts. The material provided by the application has the advantages that after forming, the filling material is uniformly distributed, the internal stress is small at high temperature, the thermal expansion coefficient is low, the high-temperature resistance (300 DEG C long-term use) and the radiation resistance (gamma ray / 10000 kGy) are extremely high, and the comprehensive physical properties and processing performance are excellent.

Description

Technical Field

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

[0002] With the rapid development of my country's aviation, aerospace, and nuclear power industries, winding coils used in various equipment, from aero-engines, rocket engines, satellite ion thrusters, and various gas turbine sensors to nuclear power reactor core drives and induction devices, are facing bottlenecks in heat resistance. High-temperature resistant electromagnetic wire has developed rapidly in recent years, achieving long-term stable performance at temperatures of 400℃ and above. However, the supporting insulating impregnation and casting materials have consistently failed to overcome the technical bottleneck of 300℃, thus reducing the overall heat resistance of the winding coils. Some equipment uses electromagnetic wire winding without impregnation or casting to improve the coil's heat resistance.

[0003] This only guarantees short-term high-temperature use of the coil. Because the coil is not impregnated or cast, there are a lot of gaps inside the winding coil, the surface is uneven, and it can only rely on the less than 1mm insulation of the electromagnetic wire itself. Not only is the withstand voltage level low, but during long-term energized use, the microcurrent on the insulation surface in the gaps expands, causing the coil to fail in a short time.

[0004] Currently, high-temperature resistant insulating impregnating castables are divided into two types: pure organic materials and organic / inorganic composite materials. Pure organic high-temperature resistant insulating impregnating castables use heat-resistant epoxy, silicone, polyimide, polyetheretherketone, etc. Due to the inherent characteristics of organic materials, their long-term (over 20,000 hours) service temperature generally does not exceed 240℃. Organic / inorganic composite high-temperature resistant insulating impregnating castables are made by combining organic resins such as silicone and polysilazane with inorganic powders with certain insulating capabilities, such as silica, aluminum oxide, magnesium oxide, and calcium oxide. Their short-term (within 100 hours) service temperature can reach 300℃ or even higher, but their long-term (over 20,000 hours) service temperature generally does not exceed 260℃. The main reason lies in the fact that the high-temperature insulating impregnated castable material of organic / inorganic composite material is prepared by reducing the size of inorganic particles, adding dispersants, and grinding to extend the deposition time of inorganic particles, so as to make the spatial composition distribution of the impregnated castable as uniform as possible. However, in actual use, the impregnated castable needs to undergo a high-temperature curing process of at least 2 hours. At the beginning of this process, the impregnated castable is heated, and its viscosity drops sharply, and the inorganic particles are also deposited rapidly. This results in uneven distribution of inorganic particles in the molded impregnated castable, and even the absence of inorganic components on the upper surface. During high-temperature use, the impregnated castable has high internal stress and is prone to cracking. The parts with less inorganic content age and fail first, greatly reducing the high-temperature service life of the winding coil.

[0005] Currently, researchers mainly reduce the dielectric constant of silicon materials by foaming (physical foaming, chemical foaming, and supercritical foaming, etc.) or adding porous fillers (such as porous silica, molecular sieves, polyhedral oligomeric silsesquioxanes (POSS), etc.), and control the dielectric properties of materials by changing the porosity and pore size (CN109535729B, CN108129692 B, CN112778770B, CN109320964 A, US005785789 A, CN110551397A, CN101638505A, CN111187461A). However, on the one hand, the numerous micro- and nano-porous structures with uneven pore sizes not only lead to an excessive reduction in the mechanical properties and voltage resistance of silicone rubber, but also cause an increase in the water absorption rate of silicone rubber, resulting in fluctuations and deterioration in the dielectric properties of the material. On the other hand, during the material processing, small molecules can penetrate into the mesopores of the porous filler, making it impossible to effectively exert its low dielectric properties. Furthermore, the specific surface area of ​​substances such as aerogels is huge, and excessive addition will seriously affect the processing and molding of silicone rubber, and also interfere with the matching of foaming and vulcanization, thus affecting the cell density, size and overall material properties of the material. Summary of the Invention

[0006] To address the problems existing in the prior art, the first aspect of the present invention provides a castable refractory, comprising, by weight:

[0007] 100 parts of organosilicon resin

[0008] 40-220 parts of the first calcined packing

[0009] The second calcined filler is 0.5 to 2 parts.

[0010] Preferably, it comprises, by weight:

[0011] 100 parts of organosilicon resin

[0012] 100-170 parts of the first calcined packing

[0013] The second calcined filler is 0.8 to 1.5 parts.

[0014] This technology utilizes silicone resin to fill the voids in the castable "skeleton" with different gap gradients formed by the first and second calcined fillers, fundamentally solving the problem of stratification between silicone resin and inorganic fillers. Specifically, this technology employs a high-temperature calcination process after mixing silicone resin with inorganic fillers such as silica and alumina. The high temperature completely decomposes the silicone resin, and the residual material (mainly silica) grows a textured surface with a large specific surface area on the inorganic particles. Through different grinding and sieving processes, calcined filler particles with different specific surface areas and composition ratios are extracted. These are then re-proportioned to form the skeleton structure for the castable. This is then mixed with silicone resin, supplemented with dispersants and defoamers, allowing the silicone resin to impregnate and fill the calcined filler particles, thus preparing a high-temperature resistant castable. On the one hand, it solves the problems of sedimentation and stratification caused by inorganic particle agglomeration and the difference in surface polarity between organosilicon resin and inorganic particles in the preparation of castables by existing technologies, thereby improving the performance uniformity and heat resistance of castables. On the other hand, due to the pre-calcination, not only is the residue of small molecules in the castable reduced during high-temperature use, but the particles with a large surface area ratio can also form mutual anchoring and support, thereby improving the mechanical properties, electrical properties, and temperature shock resistance of the castable.

[0015] Preferably, the castable in A1) includes 0.2 to 1 part of a dispersant; more preferably, it is 0.3 to 0.6 parts;

[0016] Preferably, the castable in A2) includes 0.2 to 1 part of defoamer; more preferably, it is 0.3 to 0.6 parts;

[0017] Preferably, the silicone resin in A3) is selected from polyalkyl silicone resin, polyaryl silicone resin, or one or more of polyalkylaryl silicone resin; preferably, the silicone resin is selected from polyphenylmethyl vinyl hydrosiloxane; the silicone resin in this invention, at high temperatures, especially in an environment with oxygen, as the carbon-containing components are oxidized (forming carbon dioxide) and volatilized, the residue is mainly silicon dioxide. Silicon dioxide itself has high temperature resistance, thus ensuring that the casting material of this invention has good high temperature resistance. The above components have relatively excellent thermal stability, which meets the high temperature resistance requirements of this invention.

[0018] Preferably, A4) the first calcined filler comprises a first component and a second component;

[0019] Preferably, (A5) the preparation method of the second calcined filler is as follows: a first mixture of methyl organosilicon resin and filler is subjected to a first grinding, followed by a first calcination. After separating the calcination residue, the flocculent aggregate is subjected to a second calcination to obtain the second calcined filler. The second calcined filler is one of the high-temperature calcination residues of organosilicon resin and has a flocculent structure. It is produced by the decomposition of silicon-containing small molecules during the calcination process, suspended in the air and adsorbed on the inner surface of the calcination container. Its function is to increase the viscosity of the castable in the refractory, form an entangled morphology with the calcined filler, and further improve the anchoring effect between the fillers.

[0020] The main component of the methyl organosilicon resin in this invention is similar to that of polyphenylmethyl vinyl hydrosiloxane, and in particular, the residue after high-temperature calcination is similar to the high-temperature products of polyphenylmethyl vinyl hydrosiloxane, which is beneficial to the bonding of the organosilicon resin and the calcined filler in the subsequent castable. At the same time, the methyl organosilicon resin is more easily thermally decomposed, and the decomposition process leaves fewer small carbon molecules, reducing the impact on the dielectric properties of the castable.

[0021] Preferably, in feature A1), the dispersant is selected from one or more of polyvinylpyrrolidone (PVP), polystyrene alcohol, and hydroxyapatite;

[0022] Preferably, in feature A2), the defoamer is selected from one or more of silicone oil-based silicone defoamers and emulsion-based silicone defoamers; preferably, the defoamer is selected from silicone oil-based silicone defoamers; the defoamer is used to promote the elimination of micro-bubbles introduced into the casting material by stirring, so that the silicone resin can be fully integrated into the surface gaps of the calcined filler.

[0023] In feature A4), the castable comprises 30 to 150 parts by weight of the first component; preferably, it comprises 70 to 120 parts.

[0024] Preferably, in feature A4), the castable includes 10 to 70 parts by weight of the second component; more preferably, it is 30 to 50 parts.

[0025] More preferably, the castable refractories, by weight, comprise

[0026]

[0027] More preferably, the castable refractories, by weight, comprise

[0028]

[0029] Preferably, in feature A4), the preparation method of the first component and the second component is as follows: a second mixture of methyl silicone resin and filler is subjected to a second grinding, followed by a third calcination, the addition of a first solvent, separation of the precipitate, drying of the precipitate, further grinding, and the addition of a second solvent. The precipitate at the bottom is the first component, and the component suspended in the second solvent is the second component. The first component consists of inorganic particles, on which a layer of silicone calcination residue is formed. This residue is the main component responsible for the high-temperature resistance of the castable. Due to its relatively smaller specific surface area compared to the second component, it precipitates to the bottom in the solvent. The second component is mainly silicone resin calcination residue, which encapsulates or binds a small amount of inorganic particles. Due to its much larger specific surface area compared to the first component and its porous surface structure, it is suspended in the solvent. Its function is to anchor the calcined filler component one, forming a spatial network structure together with the first component, which is the "skeleton" of the castable.

[0030] Preferably, in feature A5), the first mixture comprises 100 parts by weight of methyl silicone resin and 150-500 parts by weight of filler; preferably, the first mixture comprises 220-420 parts by weight of filler.

[0031] Preferably, in feature A5), the methyl silicone resin is one or more polyalkyl silicone resins; more preferably, it is a polymethyl vinyl hydrosiloxane resin.

[0032] Preferably, in feature A5), the first mixture further comprises 2 to 20 parts by weight of zinc oxide powder; more preferably, 4 to 10 parts.

[0033] Preferably, in feature A5), the first mixture further comprises 2 to 20 parts by weight of calcium oxide powder; more preferably, 4 to 10 parts.

[0034] Preferably, in feature A5), the filler is selected from one or more of silica powder and alumina powder;

[0035] More preferably, the composition of the first mixture and the second mixture, by weight, includes

[0036]

[0037] More preferably, the composition of the first mixture and the second mixture, by weight, includes

[0038]

[0039] Preferably, in feature A5), the temperature of the first grinding is 50℃~90℃; for example, it can be 50℃~60℃, 60℃~70℃, 70℃~80℃, 80℃~90℃, etc.

[0040] Preferably, in feature A5), the first grinding time is 0.5h to 4h; for example, it can be: 0.5h to 1h, 1h to 1.5h, 1.5h to 2h, 2h to 2.5h, 2.5h to 3h, 3h to 3.5h, 3.5h to 4h, etc., preferably 2h to 3h;

[0041] Preferably, in feature A5), the first calcination equipment is a closed high-temperature furnace;

[0042] Preferably, in feature A5), the temperature of the first calcination is 350℃~500℃; more preferably, it is 400℃~450℃; for example, it can be 350℃~400℃, 400℃~450℃, 450℃~500℃, etc.

[0043] Preferably, in feature A5), the first calcination time is 1 hour to 96 hours; more preferably, it is 4 hours to 6 hours.

[0044] Preferably, in feature A5), the second calcination temperature is 500℃~650℃; more preferably, it is 550℃~600℃.

[0045] Preferably, in feature A5), the second calcination time is 1 hour to 6 hours; for example, it can be 1 hour to 2 hours, 2 hours to 3 hours, 4 hours to 5 hours, 5 hours to 6 hours, etc. Preferably, it is 3 hours to 4 hours.

[0046] Preferably, in feature A5), after the second calcination, cooling is also included.

[0047] Preferably, in characteristic A111), the dispersant is selected from a mixture of polyvinylpyrrolidone (PVP) and calcium hydroxyphosphate; preferably, the mass ratio of PVP to calcium hydroxyphosphate is (3:2) to (2:1).

[0048] 1) The castable is used to reduce the surface energy between different components of the castable and to promote the mutual wetting between different components of the castable.

[0049] Preferably, in feature A53), the zinc oxide powder has a purity > 99% and a fineness ≥ 500 mesh; more preferably, the purity is greater than 99.5% and the fineness is ≥ 2000 mesh.

[0050] Preferably, in feature A54), the calcium oxide powder has a purity greater than 99% and a fineness ≥ 500 mesh; more preferably, the purity is greater than 99.5% and the fineness is ≥ 2000 mesh.

[0051] Preferably, in feature A55), the silica powder and alumina powder have a purity greater than 99% and a fineness ≥ 500 mesh; alternatively, the purity is greater than 99.5% and the fineness is ≥ 2500 mesh.

[0052] Preferably, in feature 511) of A5111), the settling time is 0.5h to 4h; for example, it can be 0.5h to 1h, 1h to 1.5h, 2h to 2.5h, 2.5h to 3h, 3h to 3.5h, 3.5h to 4h, etc. Preferably, it is 2h to 3h;

[0053] Preferably, in feature A43), the second mixture comprises, by weight, 100 parts of methyl silicone resin and 150-500 parts of filler; more preferably, it comprises 220-420 parts of filler.

[0054] Preferably, in feature A43), the first mixture further comprises 2 to 20 parts by weight of zinc oxide powder; more preferably, it comprises 4 to 10 parts.

[0055] Preferably, in feature A433), the first mixture further comprises 2 to 20 parts by weight of calcium oxide powder; more preferably, it comprises 4 to 10 parts.

[0056] Preferably, in feature A43), the filler is selected from one or more of silica powder and alumina powder;

[0057] Preferably, in feature A43), the temperature of the second grinding is 50°C to 90°C; for example, it can be 50°C to 60°C, 60°C to 70°C, 70°C to 80°C, 80°C to 90°C, etc.

[0058] Preferably, in feature A43), the second grinding time is 0.5h to 4h; for example, it can be 0.5h to 1h, 1h to 1.5h, 1.5h to 2h, 2h to 2.5h, 2.5h to 3h, 3h to 3.5h, 3.5h to 4h, etc. Preferably, it is 2h to 3h.

[0059] Preferably, in feature A43), the third calcination equipment is a closed high-temperature furnace;

[0060] Preferably, in feature A43), the temperature of the third calcination is 350℃~500℃; for example, it can be 350℃~400℃, 400℃~450℃, 450℃~500℃, etc.; preferably, it is 400℃~450℃.

[0061] Preferably, in feature A43), the third calcination time is 1 hour to 96 hours; more preferably, it is 4 hours to 6 hours.

[0062] In this invention, the temperature and time of the first, second, and third calcinations determine the final morphology and yield of the first component, the second component, and the second calcined filler. Higher calcination temperatures and longer times increase the yields of the first component, the second component, and the second calcined filler, but reduce the surface organosilicon calcination residue of the first component, resulting in poorer performance when prepared as a castable. Lower calcination temperatures and shorter times reduce the yields of the first component and the second calcined filler, or even prevent their production, particularly the second calcined filler, which may not be formed at all.

[0063] Preferably, in feature A43), the first solvent is selected from one or more of xylene, glycerol, and alcohol; preferably, it is glycerol.

[0064] Preferably, in feature A43), the separation and precipitation process further includes a settling period before precipitation; preferably, the settling time is 0.5h to 4h; for example, it can be 0.5h to 1h, 1h to 1.5h, 1.5h to 2h, 2h to 2.5h, 2.5h to 3h, 3h to 3.5h, 3.5h to 4h, etc., preferably 2h to 3h;

[0065] Preferably, in feature A43), the drying temperature is 200℃~350℃; for example, it can be 200℃~250℃, 250℃~300℃, 300℃~350℃, etc.; preferably, it is 270℃~320℃.

[0066] Preferably, in feature A43), the drying time is 12h to 24h; more preferably, it is 16h to 20h.

[0067] Preferably, in feature A43), the third grinding time is 0.5h to 4h; for example, it can be 0.5h to 1h, 1h to 1.5h, 2h to 2.5h, 2.5h to 3h, 3h to 3.5h, 3.5h to 4h, etc.; preferably, it is 2h to 3h.

[0068] Preferably, in feature A43), the third grinding to a fineness ≥ 500 mesh; preferably, the third grinding to a fineness ≥ 1500 mesh;

[0069] Preferably, in feature A43), the second solvent is selected from a mixture of glycerol and xylene, wherein the mass ratio of glycerol to xylene is (1:15) to (1:20).

[0070] Preferably, in feature A54), when the filler includes silica powder and aluminum oxide powder, the first mixture comprises 100-350 parts of silica powder and 50-150 parts of aluminum oxide powder by weight; preferably, the first mixture comprises 150-300 parts of silica powder and 70-120 parts of aluminum oxide powder.

[0071] The second aspect of the present invention provides a method for preparing the above-mentioned castable, comprising: firstly performing a first degassing treatment on an organosilicon resin, then adding a second calcined filler and performing a first mixing and stirring, then adding the first calcined filler and performing a second mixing and stirring, and performing a second degassing treatment to obtain the castable.

[0072] Preferably, in the first degassing treatment, the temperature is increased to 50℃~90℃; for example, it can be: 50℃~60℃, 60℃~70℃, 70℃~80℃, 80℃~90℃, etc.

[0073] Preferably, B2) the first degassing treatment is carried out under vacuum conditions, wherein the vacuum degree is ≤0.05MPa;

[0074] Preferably, B3) the time for the first degassing treatment is 60-120 min; for example, it can be 60-70 min, 70-80 min, 80-90 min, 90-100 min, 100-110 min, 110-120 min, etc.

[0075] Preferably, B4) the first mixing and stirring time is 30-60 min; for example, it can be 30-35 min, 35-40 min, 40-45 min, 45-50 min, 50-55 min, 55-60 min, etc. The rotation speed is 60-500 rpm, preferably 240-300 rpm.

[0076] Preferably, when adding the first calcined filler to B5) and performing the second mixing and stirring, the second component is added and stirred for 30-60 minutes, and then the first component is added and stirred for 30-60 minutes; for example, it can be 30-35 minutes, 35-40 minutes, 40-45 minutes, 45-50 minutes, 50-55 minutes, 55-60 minutes, etc.

[0077] Preferably, in B6), the second mixing and stirring time is 60–120 min; the rotation speed is 240–1200 rpm, preferably 800–1000 rpm.

[0078] Preferably, during the second degassing treatment (B7), the temperature is increased to 50°C to 90°C.

[0079] Preferably, B8) the second degassing treatment is carried out under vacuum conditions, wherein the vacuum degree is ≤0.05MPa;

[0080] Preferably, the second degassing treatment time (B9) is 120-240 min; for example, it can be 120-140 min, 140-160 min, 160-180 min, 180-200 min, 200-220 min, 220-240 min, etc.

[0081] Preferably, before the first defoaming treatment, a dispersant and an antifoaming agent are added to the silicone resin for a third mixing and stirring.

[0082] Preferably, the third mixing and stirring time in C1) is 10 to 30 minutes; for example, it can be 10 to 15 minutes, 15 to 20 minutes, 20 to 25 minutes, 25 to 30 minutes, etc.

[0083] Preferably, the rotation speed of the third mixing and stirring in C2) is 1200-2000 rpm, more preferably 1500-1800 rpm;

[0084] Preferably, during the third degassing treatment described in C3), the temperature is increased to 50℃~90℃; for example, it can be 50℃~60℃, 60℃~70℃, 70℃~80℃, 80℃~90℃, etc.

[0085] The third aspect of the present invention provides an application of the above-mentioned castable material, which is applied to winding coils for various equipment such as aero-engines, rocket engines, satellite ion thrusters, various gas turbine sensors, nuclear power core drives, and induction devices.

[0086] The present invention has the following beneficial effects:

[0087] 1) This invention provides an insulating castable with high dimensional stability after high-temperature and radiation-resistant curing and molding, and its preparation method. By premixing organosilicon resin and inorganic fillers, and employing low-temperature calcination, three new fillers with different properties are obtained. The first organic / inorganic calcined filler component is mainly composed of inorganic powder, and utilizes the calcination residue of organosilicon resin to form a coating layer with bumps, needle-like morphology on the surface of the inorganic particles. This not only increases the surface area of ​​the inorganic filler particles and reduces the surface energy between the inorganic particles and the organosilicon resin, prolonging the suspension time of the inorganic particles in the resin, but also allows for the early introduction of the effective components of the organosilicon resin at high temperatures, reducing the impact of substances decomposed and emitted by the organosilicon at high temperatures, such as carbon-containing particles, on the electrical and mechanical properties of the castable. The second organic / inorganic calcined filler component has smaller inorganic particle sizes and more calcination residue of organosilicon resin deposited on its surface. The third component, composed of organic / inorganic calcined filler, is an aerosol-like inorganic flocculent. It not only introduces extremely fine inorganic flocculent particles into the castable but also increases its viscosity and the settling resistance of larger inorganic particles. Through the combination of these three different forms of organic / inorganic calcined filler, the inorganic component becomes extremely stable in the insulating castable, with a settling time exceeding 100 hours at room temperature and exceeding 10 hours at 150℃. After curing, an insulating castable with high temperature resistance, radiation resistance, and high dimensional stability can be obtained.

[0088] 2) The material provided by this invention has uniform distribution of filler material after molding, low internal stress at high temperature, low coefficient of thermal expansion, extremely high high temperature resistance (long-term use at 300℃) and radiation resistance (γ-rays / 10000kGy), as well as excellent comprehensive physical properties and processing performance. Detailed Implementation

[0089] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0090] It should be understood that the content disclosed in this specification is for the understanding and reading of those skilled in the art, and is not intended to limit the conditions under which the present invention can be implemented. Therefore, it has no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives that the present invention can achieve, should still fall within the scope of the technical content disclosed in the present invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity of description and are not intended to limit the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0091] Example 1

[0092] A casting refractory compound, by weight, comprises the following components: 100 parts of polyphenylenemethyl vinyl hydrosiloxane resin, 105 parts of the first component in the first calcined filler, 37 parts of the second component in the first calcined filler, 1.2 parts of the second calcined filler, 0.45 parts of dispersant, and 0.47 parts of defoamer.

[0093] The preparation of the first and second calcined fillers, by mass parts, consists of 100 parts of methyl organosilicon resin, 255 parts of silica powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 950 parts of alumina powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 6.5 parts of zinc oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), and 5.5 parts of calcium oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh).

[0094] The preparation process of the first component in the first calcined packing is as follows:

[0095] 1) Grind a mixture of polymethyl vinyl hydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish and place it in a container. Add glycerol solvent, the amount of which is 1-3 times the mass of the calcination residue. Stir evenly and let stand for 2-3 hours. 4) Remove the precipitate from the bottom of the container after separation and dry it at 270℃-320℃ for 8-12 hours. 5) Grind the mixture for another 2-3 hours until the fineness is greater than or equal to 1500 mesh to obtain the first component of the first calcined filler.

[0096] The preparation process of the second component in the first calcined packing is as follows:

[0097] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) Remove the ceramic dish after cooling. 4) Place the calcination residue in the porcelain dish into a container, add glycerol solvent (the amount of glycerol solvent added is 1 to 3 times the amount of calcination residue), stir evenly, and let stand for 2 to 3 hours; 5) Take out the upper suspension in the container, filter out the suspended particles in the suspension using a filter sieve with a fineness of 2500 mesh or higher, and dry at 270℃ to 320℃ for 8 to 12 hours; 6) Grind again for 2 to 3 hours until the fineness is greater than or equal to 2000 mesh to obtain the second component in the first calcined filler.

[0098] The second calcined filler preparation process is as follows:

[0099] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then place it into a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish, retain the flocculent aggregate on the inner wall of the high-temperature furnace, and continue calcining at 550℃-600℃ for 3-4 hours. 5) After cooling, remove the flocculent aggregate on the inner wall of the high-temperature furnace to obtain the second calcined filler.

[0100] The dispersant is a mixture of polystyrene alcohol and calcium hydroxyphosphate in a mass ratio of 2:1.

[0101] The defoamer is a Wacker silicone oil-based silicone defoamer, brand name 885E.

[0102] The preparation method is as follows:

[0103] 1) Take the silicone resin, dispersant and defoamer according to the material ratio, stir with a high-speed mixer for 20 minutes for the first mixing, then heat to 70℃ and degas under vacuum conditions (vacuum degree to below 0.05MPa) for 60 to 120 minutes;

[0104] 2) Add the second calcined filler in 2-3 batches according to the material ratio, and mix thoroughly with a high-speed mixer for 45 minutes.

[0105] 3) Add the second component in 3 to 5 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0106] 4) Add the first component in 4 to 10 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0107] 5) Heat the material and degas it under vacuum conditions (vacuum degree below 0.05MPa) for 180 minutes to obtain an insulating castable with high dimensional stability after high temperature and radiation resistant curing.

[0108] Example 2 (With the total composition remaining unchanged, the proportion of the first component in the first calcined packing is increased, and the proportion of the second component in the first calcined packing is decreased.)

[0109] A casting refractory compound, by weight, comprises the following components: 100 parts of polyphenylenemethyl vinyl hydrosiloxane resin, 135 parts of the first component in the first calcined filler, 7 parts of the second component in the first calcined filler, 1.2 parts of the second calcined filler, 0.45 parts of dispersant, and 0.47 parts of defoamer.

[0110] The preparation of the first and second calcined fillers, by mass parts, consists of 100 parts of methyl organosilicon resin, 255 parts of silica powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 950 parts of alumina powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 6.5 parts of zinc oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), and 5.5 parts of calcium oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh).

[0111] The preparation process of the first component in the first calcined packing is as follows:

[0112] 1) Grind a mixture of polymethyl vinyl hydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish and place it in a container. Add glycerol solvent, the amount of which is 1-3 times the mass of the calcination residue. Stir evenly and let stand for 2-3 hours. 4) Remove the precipitate from the bottom of the container after separation and dry it at 270℃-320℃ for 8-12 hours. 5) Grind the mixture for another 2-3 hours until the fineness is greater than or equal to 1500 mesh to obtain the first component of the first calcined filler.

[0113] The preparation process of the second component in the first calcined packing is as follows:

[0114] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) Remove the ceramic dish after cooling. 4) Place the calcination residue in the porcelain dish into a container, add glycerol solvent (the amount of glycerol solvent added is 1 to 3 times the amount of calcination residue), stir evenly, and let stand for 2 to 3 hours; 5) Take out the upper suspension in the container, filter out the suspended particles in the suspension using a filter sieve with a fineness of 2500 mesh or higher, and dry at 270℃ to 320℃ for 8 to 12 hours; 6) Grind again for 2 to 3 hours until the fineness is greater than or equal to 2000 mesh to obtain the second component in the first calcined filler.

[0115] The second calcined filler preparation process is as follows:

[0116] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then place it into a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish, retain the flocculent aggregate on the inner wall of the high-temperature furnace, and continue calcining at 550℃-600℃ for 3-4 hours. 5) After cooling, remove the flocculent aggregate on the inner wall of the high-temperature furnace to obtain the second calcined filler.

[0117] The dispersant is a mixture of polystyrene alcohol and calcium hydroxyphosphate in a mass ratio of 2:1.

[0118] The defoamer is a Wacker silicone oil-based silicone defoamer, brand name 885E.

[0119] The preparation method is as follows:

[0120] 1) Take the silicone resin, dispersant and defoamer according to the material ratio, stir with a high-speed mixer for 30 minutes for the first mixing, then heat to 90℃ and degas under vacuum conditions (vacuum degree to below 0.05MPa) for 60 to 120 minutes;

[0121] 2) Add the second calcined filler in 2-3 batches according to the material ratio, and mix thoroughly with a high-speed mixer for 60 minutes.

[0122] 3) Add the second component in 3 to 5 batches according to the material ratio, and mix with a high-speed mixer for 60 minutes until evenly mixed;

[0123] 4) Add the first component in 4 to 10 batches according to the material ratio, and mix with a high-speed mixer for 60 minutes until evenly mixed;

[0124] 5) Heat the material and degas it under vacuum conditions (vacuum degree below 0.05MPa) for 240 minutes to obtain an insulating castable with high dimensional stability after high temperature and radiation resistant curing.

[0125] Example 3 (With the total composition remaining unchanged, the proportion of the first component in the first calcined packing is reduced, and the proportion of the second component in the first calcined packing is increased.)

[0126] A casting refractory compound, by weight, comprises the following components: 100 parts of polyphenylenemethyl vinyl hydrosiloxane resin, 5 parts of the first component in the first calcined filler, 137 parts of the second component in the first calcined filler, 1.2 parts of the second calcined filler, 0.45 parts of dispersant, and 0.47 parts of defoamer.

[0127] The preparation of the first and second calcined fillers, by mass parts, consists of 100 parts of methyl organosilicon resin, 255 parts of silica powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 950 parts of alumina powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 6.5 parts of zinc oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), and 5.5 parts of calcium oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh).

[0128] The preparation process of the first component in the first calcined packing is as follows:

[0129] 1) Grind a mixture of polymethyl vinyl hydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish and place it in a container. Add glycerol solvent, the amount of which is 1-3 times the mass of the calcination residue. Stir evenly and let stand for 2-3 hours. 4) Remove the precipitate from the bottom of the container after separation and dry it at 270℃-320℃ for 8-12 hours. 5) Grind the mixture for another 2-3 hours until the fineness is greater than or equal to 1500 mesh to obtain the first component of the first calcined filler.

[0130] The preparation process of the second component in the first calcined packing is as follows:

[0131] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) Remove the ceramic dish after cooling. 4) Place the calcination residue in the porcelain dish into a container, add glycerol solvent (the amount of glycerol solvent added is 1 to 3 times the amount of calcination residue), stir evenly, and let stand for 2 to 3 hours; 5) Take out the upper suspension in the container, filter out the suspended particles in the suspension using a filter sieve with a fineness of 2500 mesh or higher, and dry at 270℃ to 320℃ for 8 to 12 hours; 6) Grind again for 2 to 3 hours until the fineness is greater than or equal to 2000 mesh to obtain the second component in the first calcined filler.

[0132] The second calcined filler preparation process is as follows:

[0133] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then place it into a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish, retain the flocculent aggregate on the inner wall of the high-temperature furnace, and continue calcining at 550℃-600℃ for 3-4 hours. 5) After cooling, remove the flocculent aggregate on the inner wall of the high-temperature furnace to obtain the second calcined filler.

[0134] The dispersant is a mixture of polystyrene alcohol and calcium hydroxyphosphate in a mass ratio of 2:1.

[0135] The defoamer is a Wacker silicone oil-based silicone defoamer, brand name 885E.

[0136] The preparation method is as follows:

[0137] 1) Take the silicone resin, dispersant and defoamer according to the material ratio, stir with a high-speed mixer for 10 minutes for the first mixing, then heat to 50℃ and degas under vacuum conditions (vacuum degree to below 0.05MPa) for 60 to 120 minutes;

[0138] 2) Add the second calcined filler in 2-3 batches according to the material ratio, and mix thoroughly using a high-speed mixer for 30 minutes.

[0139] 3) Add the second component in 3 to 5 batches according to the material ratio, and mix thoroughly using a high-speed mixer for 30 minutes;

[0140] 4) Add the first component in 4 to 10 batches according to the material ratio, and mix thoroughly using a high-speed mixer for 30 minutes;

[0141] 5) Heat the material and degas it under vacuum conditions (vacuum degree below 0.05MPa) for 120 minutes to obtain an insulating castable with high dimensional stability after high temperature and radiation resistant curing.

[0142] Example 4 (without dispersant and defoamer)

[0143] A castable refractory, by weight, comprises the following components: 100 parts of polyphenylmethyl vinyl hydrosiloxane resin, 105 parts of the first component in the first calcined filler, 37 parts of the second component in the first calcined filler, 1.2 parts of the second calcined filler, and 0.47 parts of defoamer.

[0144] The preparation of the first and second calcined fillers, by mass parts, consists of 100 parts of methyl organosilicon resin, 255 parts of silica powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 950 parts of alumina powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 6.5 parts of zinc oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), and 5.5 parts of calcium oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh).

[0145] The preparation process of the first component in the first calcined packing is as follows:

[0146] 1) Grind a mixture of polymethyl vinyl hydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish and place it in a container. Add glycerol solvent, the amount of which is 1-3 times the mass of the calcination residue. Stir evenly and let stand for 2-3 hours. 4) Remove the precipitate from the bottom of the container after separation and dry it at 270℃-320℃ for 8-12 hours. 5) Grind the mixture for another 2-3 hours until the fineness is greater than or equal to 1500 mesh to obtain the first component of the first calcined filler.

[0147] The preparation process of the second component in the first calcined packing is as follows:

[0148] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) Remove the ceramic dish after cooling. 4) Place the calcination residue in the porcelain dish into a container, add glycerol solvent (the amount of glycerol solvent added is 1 to 3 times the amount of calcination residue), stir evenly, and let stand for 2 to 3 hours; 5) Take out the upper suspension in the container, filter out the suspended particles in the suspension using a filter sieve with a fineness of 2500 mesh or higher, and dry at 270℃ to 320℃ for 8 to 12 hours; 6) Grind again for 2 to 3 hours until the fineness is greater than or equal to 2000 mesh to obtain the second component in the first calcined filler.

[0149] The second calcined filler preparation process is as follows:

[0150] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then place it into a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish, retain the flocculent aggregate on the inner wall of the high-temperature furnace, and continue calcining at 550℃-600℃ for 3-4 hours. 5) After cooling, remove the flocculent aggregate on the inner wall of the high-temperature furnace to obtain the second calcined filler.

[0151] The defoamer is a Wacker silicone oil-based silicone defoamer, brand name 885E.

[0152] The preparation method is as follows:

[0153] 1) Take the silicone resin, dispersant and defoamer according to the material ratio, stir with a high-speed mixer for 20 minutes for the first mixing, then heat to 70℃ and degas under vacuum conditions (vacuum degree to below 0.05MPa) for 60 to 120 minutes;

[0154] 2) Add the second calcined filler in 2-3 batches according to the material ratio, and mix thoroughly with a high-speed mixer for 45 minutes.

[0155] 3) Add the second component in 3 to 5 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0156] 4) Add the first component in 4 to 10 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0157] 5) Heat the material and degas it under vacuum conditions (vacuum degree below 0.05MPa) for 180 minutes to obtain an insulating castable with high dimensional stability after high temperature and radiation resistant curing.

[0158] Example 5 (No zinc oxide or calcium oxide was added during the preparation of the first and second calcined packings)

[0159] A casting refractory compound, by weight, comprises the following components: 100 parts of polyphenylenemethyl vinyl hydrosiloxane resin, 105 parts of the first component in the first calcined filler, 37 parts of the second component in the first calcined filler, 1.2 parts of the second calcined filler, 0.45 parts of dispersant, and 0.47 parts of defoamer.

[0160] The preparation of the first and second calcined fillers, by mass, consists of 100 parts of methyl organosilicon resin, 255 parts of silica powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), and 950 parts of alumina powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh).

[0161] The preparation process of the first component in the first calcined packing is as follows:

[0162] 1) Grind a mixture of polymethyl vinyl hydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish and place it in a container. Add glycerol solvent, the amount of which is 1-3 times the mass of the calcination residue. Stir evenly and let stand for 2-3 hours. 4) Remove the precipitate from the bottom of the container after separation and dry it at 270℃-320℃ for 8-12 hours. 5) Grind the mixture for another 2-3 hours until the fineness is greater than or equal to 1500 mesh to obtain the first component of the first calcined filler.

[0163] The preparation process of the second component in the first calcined packing is as follows:

[0164] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 400℃-450℃ for 4-6 hours. 3) Remove the ceramic dish after cooling. 4) Place the calcination residue in the porcelain dish into a container, add glycerol solvent (the amount of glycerol solvent added is 1 to 3 times the amount of calcination residue), stir evenly, and let stand for 2 to 3 hours; 5) Take out the upper suspension in the container, filter out the suspended particles in the suspension using a filter sieve with a fineness of 2500 mesh or higher, and dry at 270℃ to 320℃ for 8 to 12 hours; 6) Grind again for 2 to 3 hours until the fineness is greater than or equal to 2000 mesh to obtain the second component in the first calcined filler.

[0165] The second calcined filler preparation process is as follows:

[0166] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then place it into a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at 400℃-450℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish, retain the flocculent aggregate on the inner wall of the high-temperature furnace, and continue calcining at 550℃-600℃ for 3-4 hours. 5) After cooling, remove the flocculent aggregate on the inner wall of the high-temperature furnace to obtain the second calcined filler.

[0167] The dispersant is a mixture of polystyrene alcohol and calcium hydroxyphosphate in a mass ratio of 2:1.

[0168] The defoamer is a Wacker silicone oil-based silicone defoamer, brand name 885E.

[0169] The preparation method is as follows:

[0170] 1) Take the silicone resin, dispersant and defoamer according to the material ratio, stir with a high-speed mixer for 20 minutes for the first mixing, then heat to 70℃ and degas under vacuum conditions (vacuum degree to below 0.05MPa) for 60 to 120 minutes;

[0171] 2) Add the second calcined filler in 2-3 batches according to the material ratio, and mix thoroughly with a high-speed mixer for 45 minutes.

[0172] 3) Add the second component in 3 to 5 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0173] 4) Add the first component in 4 to 10 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0174] 5) Heat the material and degas it under vacuum conditions (vacuum degree below 0.05MPa) for 180 minutes to obtain an insulating castable with high dimensional stability after high temperature and radiation resistant curing.

[0175] Example 6 (Lowering the calcination temperature when preparing the calcined component)

[0176] A casting refractory compound, by weight, comprises the following components: 100 parts of polyphenylenemethyl vinyl hydrosiloxane resin, 105 parts of the first component in the first calcined filler, 37 parts of the second component in the first calcined filler, 1.2 parts of the second calcined filler, 0.45 parts of dispersant, and 0.47 parts of defoamer.

[0177] The preparation of the first and second calcined fillers, by mass parts, consists of 100 parts of methyl organosilicon resin, 255 parts of silica powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 950 parts of alumina powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), 6.5 parts of zinc oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh), and 5.5 parts of calcium oxide powder (purity greater than 99.9%, fineness greater than or equal to 2500 mesh).

[0178] The preparation process of the first component in the first calcined packing is as follows:

[0179] 1) Grind a mixture of polymethyl vinyl hydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 300℃-350℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish and place it in a container. Add glycerol solvent, the amount of which is 1-3 times the mass of the calcination residue. Stir evenly and let stand for 2-3 hours. 4) Remove the precipitate from the bottom of the container after separation and dry it at 270℃-320℃ for 8-12 hours. 5) Grind the mixture for another 2-3 hours until the fineness is greater than or equal to 1500 mesh to obtain the first component of the first calcined filler.

[0180] The preparation process of the second component in the first calcined packing is as follows:

[0181] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then transfer it to a ceramic dish. The ball mill speed is 500-1000 rpm. 2) Calcine the mixture in a sealed high-temperature furnace at 300℃-350℃ for 4-6 hours. 3) Remove the ceramic dish after cooling. 4) Place the calcination residue in the porcelain dish into a container, add glycerol solvent (the amount of glycerol solvent added is 1 to 3 times the amount of calcination residue), stir evenly, and let stand for 2 to 3 hours; 5) Take out the upper suspension in the container, filter out the suspended particles in the suspension using a filter sieve with a fineness of 2500 mesh or higher, and dry at 270℃ to 320℃ for 8 to 12 hours; 6) Grind again for 2 to 3 hours until the fineness is greater than or equal to 2000 mesh to obtain the second component in the first calcined filler.

[0182] The second calcined filler preparation process is as follows:

[0183] 1) Grind a mixture of polymethylvinylhydrosiloxane resin, silica powder (SiO2), alumina powder (Al2O3), zinc oxide powder (ZnO), and calcium oxide powder (CaO) in a ball mill for 2-3 hours at 50℃-90℃, then place it into a ceramic dish. The ball mill speed is 500 rpm-1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at 300℃-350℃ for 4-6 hours. 3) After cooling, remove the calcination residue from the ceramic dish, retain the flocculent aggregate on the inner wall of the high-temperature furnace, and continue calcining at 550℃-600℃ for 3-4 hours. 5) After cooling, remove the flocculent aggregate on the inner wall of the high-temperature furnace to obtain the second calcined filler.

[0184] The dispersant is a mixture of polystyrene alcohol and calcium hydroxyphosphate in a mass ratio of 2:1.

[0185] The defoamer is a Wacker silicone oil-based silicone defoamer, brand name 885E.

[0186] The preparation method is as follows:

[0187] 1) Take the silicone resin, dispersant and defoamer according to the material ratio, stir with a high-speed mixer for 20 minutes for the first mixing, then heat to 70℃ and degas under vacuum conditions (vacuum degree to below 0.05MPa) for 60 to 120 minutes;

[0188] 2) Add the second calcined filler in 2-3 batches according to the material ratio, and mix thoroughly with a high-speed mixer for 45 minutes.

[0189] 3) Add the second component in 3 to 5 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0190] 4) Add the first component in 4 to 10 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0191] 5) Heat the material and degas it under vacuum conditions (vacuum degree below 0.05MPa) for 180 minutes to obtain an insulating castable with high dimensional stability after high temperature and radiation resistant curing.

[0192] Example 7 (Conventional method, physical mixing of all components)

[0193] A casting refractory, by weight, comprises the following components: 100 parts of polyphenylenemethyl vinyl hydrosiloxane resin, 105 parts of aluminum oxide powder (purity greater than 99.9%, fineness: greater than or equal to 2500 mesh), 37 parts of silicon dioxide (purity greater than 99.9%, fineness: greater than or equal to 2500 mesh), 0.6 parts of zinc oxide powder (purity greater than 99.9%, fineness: greater than or equal to 2500 mesh), 0.6 parts of calcium oxide powder (purity greater than 99.9%, fineness: greater than or equal to 2500 mesh), 0.45 parts of dispersant, and 0.47 parts of defoamer.

[0194] The dispersant is a mixture of polystyrene alcohol and calcium hydroxyphosphate in a mass ratio of 2:1.

[0195] The defoamer is a Wacker silicone oil-based silicone defoamer, brand name 885E.

[0196] The mixture is placed in a ball mill and ground for 2 to 3 hours at 50℃ to 90℃.

[0197] The preparation method is as follows:

[0198] 1) Take the silicone resin, dispersant and defoamer according to the material ratio, stir with a high-speed mixer for 20 minutes for the first mixing, then heat to 70℃ and degas under vacuum conditions (vacuum degree to below 0.05MPa) for 60 to 120 minutes;

[0199] 2) Add the second calcined filler in 2-3 batches according to the material ratio, and mix thoroughly with a high-speed mixer for 45 minutes.

[0200] 3) Add the second component in 3 to 5 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0201] 4) Add the first component in 4 to 10 batches according to the material ratio, and mix with a high-speed mixer for 45 minutes until evenly mixed;

[0202] 5) Heat the material and degas it under vacuum conditions (vacuum degree below 0.05MPa) for 180 minutes to obtain an insulating castable with high dimensional stability after high temperature and radiation resistant curing.

[0203] Performance test comparison of Examples 1-7:

[0204] Test standards: JB / T 3078 "Organic Silicone Impregnating Varnish"; GB / T1981 "Electrical Insulating Varnish". Specific results are shown in Table 1.

[0205] Table 1 Comparison of performance tests in Examples 1-7

[0206]

[0207] As shown in Table 1, Example 1 is the optimal example.

[0208] Example 2, while keeping the total amount of the first and second components in the first calcined filler constant, increased the relative proportion of the first component and decreased the relative proportion of the second component. Experimental data shows that the second component in the first calcined filler has a significant impact on the uniformity of the prepared castable. Reducing the amount of the second component leads to the separation of the prepared castable, and cracking at high temperatures after curing.

[0209] Example 3, while keeping the total amount of the first and second components in the first calcined filler constant, increased the relative proportion of the second component and decreased the relative proportion of the first component. Experimental data shows that the first component in the first calcined filler has a significant impact on the heat resistance of the prepared castable; reducing the amount of the first component leads to a significant decrease in the insulation performance of the prepared castable at high temperatures after curing.

[0210] Example 4 did not include dispersants or defoamers. The experimental data shows that dispersants and defoamers affect the dispersibility and air bubble elimination of the castable. The presence of air bubbles in the castable leads to performance degradation and cracking at 350°C.

[0211] In Example 5, zinc oxide and calcium oxide were not added during the preparation of the first and second calcined fillers. The main function of zinc oxide and calcium oxide is to improve the surface gloss and strength of the castable after curing. Experimental data shows that zinc oxide and calcium oxide have little effect on the heat resistance and insulation properties of the castable, but they do affect its gloss.

[0212] Example 6 reduced the calcination temperature during the preparation of the calcined packings, resulting in both calcined packings one and two failing to achieve the desired morphology. The experimental data shows that the effect was very poor.

[0213] Example 7 is a comparative example, ensuring all components are present without calcination. The experimental data shows that the results are very poor.

[0214] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A castable refractory, characterized in that, Included by weight: 100 parts of organosilicon resin; 40-220 parts of the first calcined filler; 0.5 to 2 parts of the second calcined filler; Dispersant 0.2–1 part; Defoamer 0.2-1 part; The organosilicon resin is selected from one or more of polyalkyl organosilicon resin, polyaryl organosilicon resin, and polyalkylaryl organosilicon resin. The dispersant is selected from a mixture of polyvinylpyrrolidone (PVP) and calcium hydroxyphosphate; wherein the mass ratio of polyvinylpyrrolidone (PVP) to calcium hydroxyphosphate is (3:2) to (2:1); The defoamer is selected from silicone oil-based silicone defoamers; The first calcined packing includes a first component and a second component; The preparation process of the first component in the first calcined packing is as follows: 1) At 50℃~90℃, the mixture of polymethyl vinyl hydrosiloxane resin, silica powder, alumina powder, zinc oxide powder and calcium oxide powder is put into a ball mill and ground for 2h~3h, and then loaded into a ceramic dish. The ball mill speed is 500 rpm~1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at a temperature of 400℃~450℃ for 4h~6h; 3) After cooling, remove the calcination residue from the ceramic dish, put it into a container, add glycerol solvent, the amount of glycerol solvent added is 1 to 3 times the amount of calcination residue, stir evenly and let stand for 2 to 3 hours. 4) Remove the sediment from the bottom of the container after stratification and dry it at 270℃~320℃ for 8h~12h; 5) Grind for another 2 to 3 hours until the fineness is greater than or equal to 1500 mesh to obtain the first component in the first calcined filler; The preparation process of the second component in the first calcined packing is as follows: 1) At 50℃~90℃, the mixture of polymethyl vinyl hydrosiloxane resin, silica powder, alumina powder, zinc oxide powder and calcium oxide powder is put into a ball mill and ground for 2h~3h, and then loaded into a ceramic dish. The ball mill speed is 500 rpm~1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at a temperature of 400℃~450℃ for 4h~6h; 3) After cooling, remove the calcination residue from the ceramic dish, put it into a container, add glycerol solvent, the amount of glycerol solvent added is 1 to 3 times the amount of calcination residue, stir evenly and let stand for 2 to 3 hours. 4) Remove the upper layer of suspension from the container, filter out the suspended particles in the suspension using a filter screen with a fineness of 2500 mesh or higher, and dry it at 270℃~320℃ for 8h~12h. 5) Grind for another 2 to 3 hours until the fineness is greater than or equal to 2000 mesh to obtain the second component in the first calcined filler; The second calcined filler preparation process is as follows: 1) At 50℃~90℃, the mixture of polymethyl vinyl hydrosiloxane resin, silica powder, alumina powder, zinc oxide powder and calcium oxide powder is put into a ball mill and ground for 2h~3h, and then loaded into a ceramic dish. The ball mill speed is 500 rpm~1000 rpm. 2) Then place it in a sealed high-temperature furnace for calcination at a temperature of 400℃~450℃ for 4h~6h; 3) After cooling, remove the calcination residue from the ceramic dish, retain the flocculent aggregate on the inner wall of the high-temperature furnace, and continue calcining at 550℃~600℃ for 3h~4h; 4) After cooling, remove the flocculent aggregates from the inner wall of the high-temperature furnace to obtain the second calcined packing; The preparation of the first and second calcined fillers, by mass fraction, consists of 100 parts of methyl organosilicon resin, 255 parts of silica powder, 950 parts of alumina powder, 6.5 parts of zinc oxide powder, and 5.5 parts of calcium oxide powder.

2. The castable refractory according to claim 1, characterized in that, The castable material comprises 70 to 120 parts of a first component and / or the castable material comprises 30 to 50 parts of a second component.

3. The castable refractory according to claim 1, characterized in that, Included by weight: 100 parts of organosilicon resin 100-170 parts of the first calcined packing The second calcined filler is 0.8 to 1.5 parts.

4. The method for preparing the castable according to any one of claims 1-3, characterized in that, include: First, the silicone resin undergoes a first degassing treatment, then a second calcined filler is added and mixed for a first mixing and stirring, followed by a second degassing treatment to obtain the castable.

5. The method for preparing the castable according to claim 4, characterized in that, Includes at least one of the following technical features: B1) During the first degassing treatment, the temperature is increased to 50°C to 90°C; B2) The first degassing treatment is carried out under vacuum conditions, with a vacuum degree ≤ 0.05 MPa; B3) The first degassing treatment time is 60–120 min; B4) The first mixing and stirring time is 30-60 min; the rotation speed is 60-500 rpm; B5) When adding the first calcined filler, during the second mixing and stirring, first add the second component and stir for 30-60 minutes, then add the first component and stir for 30-60 minutes. B6) The second mixing and stirring time is 60-120 min; the rotation speed is 240-1200 rpm; B7) During the second degassing treatment, the temperature is increased to 50-90°C; B8) The second degassing treatment is carried out under vacuum conditions, with a vacuum degree ≤ 0.05 MPa; B9) The second degassing treatment time is 120-240 min.

6. The method for preparing the castable according to claim 5, characterized in that, Includes at least one of the following technical features: (1) In B4), the rotational speed is 240-300 rpm; (2) In B6), the rotational speed is 800 to 1000 rpm.

7. The method for preparing the castable according to any one of claims 4-6, characterized in that, Before the first defoaming treatment, a dispersant and an antifoaming agent are added to the silicone resin for a third mixing and stirring.

8. The method for preparing the castable according to claim 7, characterized in that, Includes at least one of the following technical features: C1) The third mixing and stirring time is 10-30 minutes; C2) The third mixing and stirring speed is 1200-2000 rpm.

9. The method for preparing the castable according to claim 8, characterized in that, The third mixing and stirring speed is 1500-1800 rpm.

10. An application of a castable refractory, characterized in that, The castable material according to any one of claims 1-3 or the castable material prepared by the method according to any one of claims 4-9 is used in winding coils for various equipment such as aero engines, rocket engines, satellite ion thrusters, various gas turbine sensors, nuclear power core drives, and induction devices.

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