A boron-containing carbon in-core structure for a high-temperature gas-cooled reactor and a preparation method thereof

Abstract

This invention discloses a boron-containing carbon reactor internal component for high-temperature gas-cooled reactors and its preparation method, belonging to the technical field of carbon reactor internal components. The boron-containing carbon reactor internal component for high-temperature gas-cooled reactors is prepared by uniformly dispersing boron carbide in phenolic resin to obtain a boron-containing phenolic resin binder, which is then added to calcined coke, mixed countercurrently, molded, and calcined at a controlled temperature. The boron-containing carbon reactor internal component for high-temperature gas-cooled reactors prepared by this invention has high strength, dense and uniform blank, and outstanding comprehensive mechanical properties. This invention is applicable to the preparation of boron-containing carbon reactor internal components for high-temperature gas-cooled reactors.

Description

Technical Field

[0001] This invention belongs to the technical field of carbon reactor internals, specifically a boron-containing carbon reactor internal for high-temperature gas-cooled reactors and its preparation method. Background Technology

[0002] The high-temperature gas-cooled reactor (HTGR) in fourth-generation nuclear reactors differs significantly from traditional pressurized water reactors. It uses helium as a coolant and employs a modular design. This design endows the HTGR with inherent safety characteristics and offers significant advantages such as no water source requirement at the construction site and a simple and easily controllable structure.

[0003] Boron-containing carbon reactor internals, as the core support structure of high-temperature gas-cooled reactors, undertake a dual critical function: on the one hand, as a thermal insulation layer, they effectively isolate the high temperatures generated by the reactor core, ensuring the safety of the surrounding structures; on the other hand, as a neutron shielding layer, the boron element added to the components absorbs leaked neutrons, preventing performance degradation of the metal reactor core support structure and pressure vessel due to neutron radiation. Since the design service life of the reactor core support structure is no less than 60 years, and it cannot be repaired or replaced during service, reactor shutdown is necessary in the event of damage. Therefore, extremely high requirements are placed on the performance indicators and quality uniformity of boron-containing carbon reactor internals.

[0004] However, existing preparation technologies still have many shortcomings and cannot meet the stringent requirements of high-temperature gas-cooled reactors for boron-containing carbon reactor internals, specifically in the following aspects:

[0005] First, the uniformity of boron carbide dispersion is difficult to guarantee. When boron carbide is directly mixed and kneaded with carbon materials and pitch, uneven dispersion of boron carbide is likely to occur, resulting in the inability to guarantee the quality uniformity of boron-containing carbon reactor internals. Although the "Manufacturing Method of Isotropic Carbon Reactor Internals for High-Temperature Gas-Cooled Reactors" published in CN108467269A improves the dispersion effect by performing secondary dispersion of boron carbide, which improves the quality uniformity of the components to a certain extent, this method increases the complexity of the process and consumes more time and energy, which is not conducive to industrial production.

[0006] Secondly, the use of asphalt binders presents multiple problems. Existing technologies commonly use asphalt as a binder, combined with mixing, extrusion, or vibration molding processes, such as the low-cost method for preparing boron-containing carbon bricks disclosed in CN108002837A. However, this method struggles to ensure the performance indicators and quality uniformity of boron-containing carbon brick internal components. On one hand, when asphalt is used as a binder, mixing and molding under heating conditions are difficult to control. Improper temperature control can easily lead to the formation of cold material lumps, directly resulting in substandard products. On the other hand, asphalt is a liquid-phase carbonization material, which softens and forms a liquid phase during firing, especially when using a vertical kiln, easily causing uneven quality between the upper and lower parts of the product. Furthermore, open pores are formed during asphalt carbonization, leading to reduced product strength and affecting the structural stability of the components.

[0007] Secondly, there are shortcomings in the kneading and molding processes. The kneading machines used in the existing technology have a low stirring speed, and the raw materials are prone to agglomerate and form clumps during the stirring process, resulting in uneven internal quality of the product. At the same time, the molding pressure of extrusion or vibration molding is relatively low, resulting in low product density, which in turn has an adverse effect on the performance indicators of the subsequent finished products.

[0008] Finally, subsequent processing is costly and risky. The impregnation and secondary calcination processes in the preparation of boron-containing carbon stack internals not only prolong the production cycle and increase production costs, but also pose a risk of generating defective products during operation, reducing the production qualification rate. Summary of the Invention

[0009] The purpose of this invention is to provide a boron-containing carbon reactor internal component for high-temperature gas-cooled reactors and its preparation method. By dispersing boron carbide in phenolic resin, the problem of uneven quality, low strength, and low pass rate of boron-containing carbon reactor internal components is solved, while achieving the goals of shortening the production cycle, reducing production costs, and simplifying the process.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A boron-containing carbon reactor internal component for a high-temperature gas-cooled reactor, the raw materials for which are made include, by weight, 70-80 parts of calcined coke, 5-10 parts of boron carbide and 22-26 parts of phenolic resin.

[0012] Phenolic resin is used as the dispersion medium for boron carbide.

[0013] The anisotropy ratio of the boron-containing carbon reactor internals used in the high-temperature gas-cooled reactor is ≤1.1, and the bulk density is 1.75~1.81 g·cm³. -3 The compressive strength is ≥90MPa and the tensile strength is ≥14MPa.

[0014] As another limitation, the proportion of calcined coke particles < 0.075 mm is 40~50 wt%, the proportion of calcined coke particles ≤ 0.075 mm and < 0.15 mm is 15~30 wt%, the proportion of calcined coke particles ≤ 0.15 mm and 0.15 mm and ≤ 0.5 mm is 20~35 wt%, and the proportion of calcined coke particles ≤ 1 mm and 0.5 mm and ≤ 1 mm is 15~30 wt%.

[0015] As a further limitation, the calcined coke has an ash content ≤0.5wt%, a moisture content ≤0.5wt%, a resistivity ≤400μΩ·m, and a true density ≥2.10g / cm³. 3 .

[0016] As a third limitation, the boron carbide has a particle size of <0.045 mm and a total boron content of >75 wt%.

[0017] As a fourth limitation, the phenolic resin is a thermosetting phenolic resin.

[0018] As a further limitation, the phenolic resin has a solid content of ≥80%, a viscosity of 25~35 Pa·s, and a carbon residue rate of ≥47%.

[0019] This invention also provides a method for preparing boron-containing carbon reactor internals for high-temperature gas-cooled reactors, comprising the following steps:

[0020] S1. Boron carbide is uniformly dispersed in phenolic resin to obtain a boron-containing phenolic resin binder;

[0021] S2. Add the boron-containing phenolic resin binder to the calcined coke, mix in a countercurrent manner, mold, and bake at a constant temperature to obtain the boron-containing carbon reactor internals for the high-temperature gas-cooled reactor.

[0022] As a limitation, a high-speed countercurrent mixer is used for countercurrent mixing;

[0023] The stirring blades and the cylinder of the high-speed countercurrent mixer rotate in opposite directions. The stirring blades rotate at a speed of 600~1200 r / min, and the cylinder rotates at a speed of 250 r / min.

[0024] As another limitation, the temperature for heat preservation and roasting is 1000~1200℃, and the time is 12~48h;

[0025] Before and during the molding process, a vacuum is drawn to a pressure of <-0.08MPa;

[0026] The pressure for compression molding is 20~35MPa.

[0027] By adopting the above technical solution, the technical progress achieved by this invention compared with the prior art is as follows:

[0028] ① This invention provides a boron-containing carbon reactor internal component for high-temperature gas-cooled reactors, which has more uniform quality and more stable performance. By uniformly dispersing boron carbide in phenolic resin, the dispersion method of boron carbide is improved, solving the problems of uneven boron carbide distribution caused by direct kneading in the prior art, and the complexity and energy consumption of secondary dispersion process, thus ensuring consistent component distribution inside the component. In addition, a high-speed countercurrent mixer is used to fully mix the binder phenolic resin and calcined coke. The high mixing speed ensures the uniformity of the mixing process, and the counter-rotation of the agitator and the cylinder also ensures that no material clumps are generated during the mixing process. The high uniformity of the product increases the compactness of the product, further ensuring the uniformity of the overall quality of the component.

[0029] ② The boron-containing carbon reactor internals for high-temperature gas-cooled reactors provided by this invention use phenolic resin as a binder. During the high-temperature carbonization process, it is solid-phase carbonization and does not form liquid-phase flow. It does not have the problem of uneven quality at the top and bottom of the product when using asphalt as a binder. In addition, the carbonization of phenolic resin forms closed pores, resulting in low apparent porosity and high strength of the product. It does not require impregnation and secondary baking treatment, which significantly improves production efficiency.

[0030] ③ The boron-containing carbon reactor internals for high-temperature gas-cooled reactors provided by this invention have a higher molding pressure compared to extrusion or vibration molding. Furthermore, vacuum treatment is performed throughout the molding process, resulting in a high-density, highly uniform, and high-yield preform. Testing shows an anisotropy ratio ≤1.1 and a bulk density of 1.75~1.81 g·cm³. -3 Compressive strength ≥90MPa, tensile strength ≥14MPa;

[0031] ④ The present invention provides a method for preparing boron-containing carbon reactor internals for high-temperature gas-cooled reactors. The preparation process is simple and suitable for industrial production. Detailed Implementation

[0032] The present invention will be further described in detail below through specific embodiments. It should be understood that the described embodiments are only for explaining the present invention and do not limit the present invention.

[0033] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0034] Example 1

[0035] This embodiment prepares a boron-containing carbon reactor internal component for a high-temperature gas-cooled reactor, specifically including the following steps performed sequentially:

[0036] S1. Place 25 kg of thermosetting phenolic resin with a solid content ≥80%, a viscosity of 25~35 Pa·s, and a carbon residue rate ≥47% into a storage tank equipped with a stirring device, turn on the stirring, and add 15 kg of boron carbide with a particle size <0.045 mm and a total boron content >75 wt% while stirring, so that the boron carbide is uniformly dispersed in the phenolic resin to obtain a boron-containing phenolic resin binder.

[0037] S2. Ash content ≤ 0.5wt%, moisture ≤ 0.5wt%, resistivity ≤ 400μΩ·m, true density ≥ 2.10g / cm³ 3 60 kg of calcined coke was placed in a high-speed countercurrent mixer and mixed at room temperature for 3 min. Boron-containing phenolic resin binder was added to the high-speed countercurrent mixer by pumping. The agitator of the high-speed countercurrent mixer was set to rotate clockwise at 600 r / min and the cylinder to rotate counterclockwise at 250 r / min. Mixing was carried out at room temperature for 20 min. After mixing, a vacuum was drawn for ≥60 s until the vacuum degree was <-0.08 MPa. The vacuum degree was maintained, and the molding pressure was set to 20~35 MPa for molding. The molding pressure was maintained for 60 s. After calcination at 1100℃ for 24 h, boron-containing carbon reactor internals for high-temperature gas-cooled reactors were obtained.

[0038] The gradation of the calcined coke used is as follows: 40-50 wt% of calcined coke with a particle size <0.075 mm, 15-30 wt% of calcined coke with a particle size ≤0.15 mm and a particle size ≤0.15 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm.

[0039] For the boron-containing carbon reactor internals prepared in this embodiment for use in high-temperature gas-cooled reactor linings of blast furnaces, the bulk density was tested according to the method in GB / T 24528, the compressive strength was tested according to the method in GB / T 1431, the tensile strength was tested according to the method in DIN 51914, and the coefficient of thermal expansion was tested according to the method in GB / T 7320. The anisotropy ratio was calculated accordingly. The test results showed that the anisotropy ratio was 1.1 and the bulk density was 1.81 g·cm³. -3 It has a compressive strength of 120MPa and a tensile strength of 16MPa.

[0040] Comparative Example 1

[0041] This comparative example verifies the effect of dispersing boron carbide in phenolic resin on the performance of boron-containing carbon reactor internals for high-temperature gas-cooled reactors by changing the dispersion medium relationship.

[0042] Specifically, the order of adding phenolic resin in the preparation method is changed: 15 kg of boron carbide with a particle size <0.045 mm and a total boron content >75 wt% is directly weighed, along with ash content ≤0.5 wt%, moisture content ≤0.5 wt%, resistivity ≤400 μΩ·m, and true density ≥2.10 g / cm³. 3 60 kg of calcined coke was placed in a high-speed countercurrent mixer and mixed at room temperature for 3 min. 25 kg of thermosetting phenolic resin with a solid content ≥80%, viscosity 25~35 Pa·s, and carbon residue ≥47% was added to the high-speed countercurrent mixer via pumping. The mixer's agitator was set to rotate clockwise at 600 r / min, and the cylinder counterclockwise at 250 r / min, and mixed at room temperature for 20 min. After mixing, a vacuum was applied for ≥60 s until the vacuum level was <-0.08 MPa. The vacuum level was maintained, and a molding pressure of 20~35 MPa was set for molding, maintaining the molding pressure for 60 s. The mixture was then calcined at 1100℃ for 24 h to obtain a boron-containing carbon stack internal component. The bulk density of the obtained boron-containing carbon stack internal component was tested according to the method in GB / T 24528, and the compressive strength was tested according to the method in GB / T 1431. The results were compared with DIN... The tensile strength was tested using the method described in 51914, and the results showed a bulk density of 1.8 g·cm³. -3 The compressive strength is 40 MPa and the tensile strength is 11 MPa. This indicates that the order in which phenolic resin is added as a dispersion medium affects the various properties of the boron-containing carbon stack internals prepared in this invention. Adding it after the calcined coke and boron carbide are mixed will reduce the compressive strength and tensile strength.

[0043] Comparative Example 2

[0044] In this comparative example, the phenolic resin in Example 1 was replaced with an equal amount of asphalt to prepare a boron-carbon stack internal component. Its bulk density was tested according to the method in GB / T 24528, its compressive strength according to the method in GB / T 1431, and its tensile strength according to the method in DIN 51914. The test results showed that the bulk density was 1.70 g·cm³. -3 Its pressure resistance is 60 MPa and its tensile strength is 10 MPa. All of its properties are inferior to the boron-containing carbon reactor internals for high-temperature gas-cooled reactors prepared in Examples 1-3.

[0045] Example 2

[0046] This embodiment prepares a boron-containing carbon reactor internal component for a high-temperature gas-cooled reactor, specifically including the following steps performed sequentially:

[0047] S1. Place 23 kg of thermosetting phenolic resin with a solid content ≥80%, a viscosity of 25~35 Pa·s, and a carbon residue rate ≥47% into a storage tank equipped with a stirring device, turn on the stirring, and add 12 kg of boron carbide with a particle size <0.045 mm and a total boron content >75 wt% while stirring, so that the boron carbide is uniformly dispersed in the phenolic resin to obtain a boron-containing phenolic resin binder.

[0048] S2. Ash content ≤ 0.5wt%, moisture ≤ 0.5wt%, resistivity ≤ 400μΩ·m, true density ≥ 2.10g / cm³ 3 65 kg of calcined coke was placed in a high-speed countercurrent mixer and mixed at room temperature for 4 min. Boron-containing phenolic resin binder was added to the high-speed countercurrent mixer by pumping. The agitator of the high-speed countercurrent mixer was set to rotate clockwise at 800 r / min and the cylinder to rotate counterclockwise at 250 r / min. Mixing was carried out at room temperature for 15 min. After mixing, a vacuum was drawn for ≥60 s until the vacuum degree was <-0.08 MPa. The vacuum degree was maintained, and the molding pressure was set to 20~35 MPa for molding. The molding pressure was maintained for 60 s. After calcination at 1200℃ for 48 h, boron-containing carbon reactor internals for high-temperature gas-cooled reactors were obtained.

[0049] The gradation of the calcined coke used is as follows: 40-50 wt% of calcined coke with a particle size <0.075 mm, 15-30 wt% of calcined coke with a particle size ≤0.15 mm and a particle size ≤0.15 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm.

[0050] For the boron-containing carbon reactor internals for high-temperature gas-cooled reactors used in blast furnace working linings prepared in this embodiment, the bulk density was tested according to the method in GB / T 24528, the compressive strength was tested according to the method in GB / T 1431, the tensile strength was tested according to the method in DIN 51914, and the coefficient of thermal expansion was tested according to the method in GB / T 7320. The anisotropy ratio was calculated accordingly. The test results showed that the anisotropy ratio was 1.0 and the bulk density was 1.78 g·cm³. -3 It has a compressive strength of 100MPa and a tensile strength of 15MPa.

[0051] Example 3

[0052] This embodiment prepares a boron-containing carbon reactor internal component for a high-temperature gas-cooled reactor, specifically including the following steps performed sequentially:

[0053] S1. Place 20 kg of thermosetting phenolic resin with a solid content ≥80%, a viscosity of 25~35 Pa·s, and a carbon residue rate ≥47% in a storage tank equipped with a stirring device, turn on the stirring, and add 10 kg of boron carbide with a particle size <0.045 mm and a total boron content >75 wt% while stirring, so that the boron carbide is evenly dispersed in the phenolic resin to obtain a boron-containing phenolic resin binder.

[0054] S2. Ash content ≤ 0.5wt%, moisture ≤ 0.5wt%, resistivity ≤ 400μΩ·m, true density ≥ 2.10g / cm³ 3 70 kg of calcined coke was placed in a high-speed countercurrent mixer and mixed at room temperature for 5 min. Boron-containing phenolic resin binder was added to the high-speed countercurrent mixer by pumping. The agitator of the high-speed countercurrent mixer was set to rotate clockwise at 1200 r / min and the cylinder to rotate counterclockwise at 250 r / min. Mixing was carried out at room temperature for 10 min. After mixing, a vacuum was drawn for ≥60 s until the vacuum degree was <-0.08 MPa. The vacuum degree was maintained, and the molding pressure was set to 20~35 MPa for molding. The molding pressure was maintained for 60 s. After calcination at 1000℃ for 12 h, boron-containing carbon reactor internals for high-temperature gas-cooled reactors were obtained.

[0055] The gradation of the calcined coke used is as follows: 40-50 wt% of calcined coke with a particle size <0.075 mm, 15-30 wt% of calcined coke with a particle size ≤0.15 mm and a particle size ≤0.15 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm.

[0056] For the boron-containing carbon reactor internals for high-temperature gas-cooled reactors used in blast furnace working linings prepared in this embodiment, the bulk density was tested according to the method in GB / T 24528, the compressive strength was tested according to the method in GB / T 1431, the tensile strength was tested according to the method in DIN 51914, and the coefficient of thermal expansion was tested according to the method in GB / T 7320. The anisotropy ratio was calculated accordingly. The test results showed that the anisotropy ratio was 0.9 and the bulk density was 1.75 g·cm³. -3 It has a compressive strength of 90 MPa and a tensile strength of 14 MPa.

[0057] Example 4

[0058] This embodiment prepares a boron-containing carbon reactor internal component for a high-temperature gas-cooled reactor, specifically including the following steps performed sequentially:

[0059] S1. Place 25 kg of thermosetting phenolic resin with a solid content ≥80%, a viscosity of 25~35 Pa·s, and a carbon residue rate ≥47% into a storage tank equipped with a stirring device, turn on the stirring, and add 14 kg of boron carbide with a particle size <0.045 mm and a total boron content >75 wt% while stirring, so that the boron carbide is uniformly dispersed in the phenolic resin to obtain a boron-containing phenolic resin binder.

[0060] S2. Ash content ≤ 0.5wt%, moisture ≤ 0.5wt%, resistivity ≤ 400μΩ·m, true density ≥ 2.10g / cm³ 3 67 kg of calcined coke was placed in a high-speed countercurrent mixer and mixed at room temperature for 3 min. Boron-containing phenolic resin binder was added to the high-speed countercurrent mixer by pumping. The agitator of the high-speed countercurrent mixer was set to rotate clockwise at 600 r / min and the cylinder to rotate counterclockwise at 250 r / min. Mixing was carried out at room temperature for 20 min. After mixing, a vacuum was drawn for ≥60 s until the vacuum degree was <-0.08 MPa. The vacuum degree was maintained, and the molding pressure was set to 20~35 MPa for molding. The molding pressure was maintained for 60 s. After calcination at 1100℃ for 24 h, boron-containing carbon reactor internals for high-temperature gas-cooled reactors were obtained.

[0061] The gradation of the calcined coke used is as follows: 40-50 wt% of calcined coke with a particle size <0.075 mm, 15-30 wt% of calcined coke with a particle size ≤0.15 mm and a particle size ≤0.15 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm.

[0062] Example 5

[0063] This embodiment prepares a boron-containing carbon reactor internal component for a high-temperature gas-cooled reactor, specifically including the following steps performed sequentially:

[0064] S1. Place 22 kg of thermosetting phenolic resin with a solid content ≥80%, a viscosity of 25~35 Pa·s, and a carbon residue rate ≥47% into a storage tank equipped with a stirring device, turn on the stirring, and add 11 kg of boron carbide with a particle size <0.045 mm and a total boron content >75 wt% while stirring, so that the boron carbide is uniformly dispersed in the phenolic resin to obtain a boron-containing phenolic resin binder.

[0065] S2. Ash content ≤ 0.5wt%, moisture ≤ 0.5wt%, resistivity ≤ 400μΩ·m, true density ≥ 2.10g / cm³ 360 kg of calcined coke was placed in a high-speed countercurrent mixer and mixed at room temperature for 3 min. Boron-containing phenolic resin binder was added to the high-speed countercurrent mixer by pumping. The agitator of the high-speed countercurrent mixer was set to rotate clockwise at 600 r / min and the cylinder to rotate counterclockwise at 250 r / min. Mixing was carried out at room temperature for 20 min. After mixing, a vacuum was drawn for ≥60 s until the vacuum degree was <-0.08 MPa. The vacuum degree was maintained, and the molding pressure was set to 20~35 MPa for molding. The molding pressure was maintained for 60 s. After calcination at 1100℃ for 24 h, boron-containing carbon reactor internals for high-temperature gas-cooled reactors were obtained.

[0066] The gradation of the calcined coke used is as follows: 40-50 wt% of calcined coke with a particle size <0.075 mm, 15-30 wt% of calcined coke with a particle size ≤0.15 mm and a particle size ≤0.15 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm.

[0067] Example 6

[0068] This embodiment prepares a boron-containing carbon reactor internal component for a high-temperature gas-cooled reactor, specifically including the following steps performed sequentially:

[0069] S1. Place 23 kg of thermosetting phenolic resin with a solid content ≥80%, a viscosity of 25~35 Pa·s, and a carbon residue rate ≥47% into a storage tank equipped with a stirring device, turn on the stirring, and add 15 kg of boron carbide with a particle size <0.045 mm and a total boron content >75 wt% while stirring, so that the boron carbide is evenly dispersed in the phenolic resin to obtain a boron-containing phenolic resin binder.

[0070] S2. Ash content ≤ 0.5wt%, moisture ≤ 0.5wt%, resistivity ≤ 400μΩ·m, true density ≥ 2.10g / cm³ 3 63 kg of calcined coke was placed in a high-speed countercurrent mixer and mixed at room temperature for 3 min. Boron-containing phenolic resin binder was added to the high-speed countercurrent mixer by pumping. The agitator of the high-speed countercurrent mixer was set to rotate clockwise at 600 r / min and the cylinder to rotate counterclockwise at 250 r / min. Mixing was carried out at room temperature for 20 min. After mixing, a vacuum was drawn for ≥60 s until the vacuum degree was <-0.08 MPa. The vacuum degree was maintained, and the molding pressure was set to 20~35 MPa for molding. The molding pressure was maintained for 60 s. After calcination at 1100℃ for 24 h, boron-containing carbon reactor internals for high-temperature gas-cooled reactors were obtained.

[0071] The gradation of the calcined coke used is as follows: 40-50 wt% of calcined coke with a particle size <0.075 mm, 15-30 wt% of calcined coke with a particle size ≤0.15 mm and a particle size ≤0.15 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm.

[0072] The boron-containing carbon reactor internals prepared in the above embodiments, which can be used in high-temperature gas-cooled reactors, were tested and found to have an anisotropy ratio ≤1.1 and a bulk density of 1.75~1.81 g·cm³. -3 The compressive strength is ≥90MPa, and the tensile strength is ≥14MPa. Therefore, the method of this invention and the resulting boron-containing carbon reactor internals for high-temperature gas-cooled reactors have high density, good uniformity, outstanding mechanical properties, and longer service life.

[0073] It should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing boron-containing carbon reactor internals for high-temperature gas-cooled reactors, characterized in that, The raw materials used to make it include, by weight, 70-80 parts of calcined coke, 5-10 parts of boron carbide, and 22-26 parts of phenolic resin; Phenolic resin is used as the dispersion medium for boron carbide. The gradation of the calcined coke is as follows: 40-50 wt% of calcined coke with a particle size <0.075 mm, 15-30 wt% of calcined coke with a particle size ≤0.15 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm and a particle size ≤1 mm and a particle size ≤0.5 mm. The calcined coke has an ash content ≤0.5wt%, a moisture content ≤0.5wt%, a resistivity ≤400μΩ·m, and a true density ≥2.10g / cm³. 3 ; Its preparation method includes the following steps: S1. Boron carbide is uniformly dispersed in phenolic resin to obtain a boron-containing phenolic resin binder; S2. Add the boron-containing phenolic resin binder to the calcined coke, mix in a countercurrent manner, mold, and bake at a constant temperature to obtain the boron-containing carbon reactor internals for the high-temperature gas-cooled reactor. The temperature for heat preservation and calcination is 1000~1200℃, and the time is 12~48h; Before and during compression molding, a vacuum level of <-0.08MPa is applied. The pressure for compression molding is 20~35MPa.

2. The method for preparing boron-containing carbon reactor internals for high-temperature gas-cooled reactors according to claim 1, characterized in that, The boron carbide has a particle size of <0.045 mm and a total boron content of >75 wt%.

3. The method for preparing boron-containing carbon reactor internals for high-temperature gas-cooled reactors according to claim 2, characterized in that, The phenolic resin is a thermosetting phenolic resin.

4. The method for preparing boron-containing carbon reactor internals for high-temperature gas-cooled reactors according to claim 3, characterized in that, The phenolic resin has a solid content of ≥80%, a viscosity of 25~35 Pa·s, and a carbon residue rate of ≥47%.

5. A method for preparing boron-containing carbon reactor internals for a high-temperature gas-cooled reactor according to any one of claims 1 to 4, characterized in that, Countercurrent mixing is performed using a high-speed countercurrent mixer; The stirring blades and the cylinder of the high-speed countercurrent mixer rotate in opposite directions. The stirring blades rotate at a speed of 600~1200 r / min, and the cylinder rotates at a speed of 250 r / min.