Isostatic pressing clay crucible and preparation method thereof

Abstract

The invention relates to the technical field of crucible preparation, in particular to an isostatic pressing clay crucible and a preparation method thereof. Comprising the following components in percentage by mass: 25-35% of graphite; 35%-45% of low-moisture clay; 5%-15% of high bauxite; 2%-10% of metal silicon; 1%-5% of boron carbide; and 1%-10% of an additive. The preparation method of the isostatic pressing clay crucible comprises the following steps: S1, taking a proper amount of raw materials, and uniformly mixing the raw materials in a mixer; s2, sealing and storing the uniformly mixed materials for a period of time; s3, performing compression molding by adopting a cold isostatic pressing process; s4, performing staged drying treatment on the formed green body; and S5, roasting the blank in the step S4 at high temperature for a period of time. The formed crucible is uniform and compact in structure, high in structural strength, resistant to high temperature and long in service life. And in addition, the production efficiency is effectively improved through a short-period isostatic pressing technology. The method is suitable for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of crucible preparation, and particularly relates to an isostatic pressing clay crucible and a preparation method thereof. Background Art

[0002] Clay crucibles are commonly used melting containers in the metallurgical industry, mainly used for melting non-ferrous metals (such as aluminum, copper, zinc, lead, precious metals, etc.) and their alloys. Their core advantages are high temperature resistance, thermal shock resistance, and low cost, but the performance of crucibles with different formulations and processes varies significantly.

[0003] The traditional production process route of large graphite clay crucibles is: mixing, aging, milling, crushing, pressing into lumps, forming, drying, and roasting. Mixing: Put raw materials such as graphite, clay, and bauxite into a mixer and add sufficient water to mix into a material with a relatively high water content; Aging: Put the mixed material into an extrusion machine to extrude it into mud strips, and then stack the mud strips into piles for sealing and placement; Milling: Take out the mud strips that have been placed for a long enough time and put them into a large mill for rolling with water added. It takes about one to two hours of rolling, and water needs to be added multiple times in the middle until the mud is rolled to the standard; Crushing: Put the rolled mud into a crusher to crush it into mud particles with relatively uniform size; Pressing into lumps: Put the crushed mud particles into a pressing machine to be compacted and preliminarily extruded into mud blanks; Forming: Move the mud blanks to a mold, and the mold is shaped by means of extrusion force during rotation to finally form the shape of the crucible, and the forming stage ends; Drying: The strength of the just-formed crucible is extremely poor and can barely maintain its shape unchanged. It needs to be slowly moved to a shady place and wait for the crucible to slowly lose water and harden; Roasting: Coat the hardened crucible with an anti-oxidation coating and then put it into a kiln for roasting to finally make a finished product.

[0004] From the perspective of the entire process flow, the production cycle is very long. Among them, aging requires one to two months, from milling to forming takes one to two days, the drying stage requires at least half a month, and drying too quickly is likely to cause the crucible to crack. Roasting takes two to three days. Therefore, it takes about two months from the start of material preparation to the finished product. Secondly, it is difficult to control the product quality. Limited by such a long production cycle, changes in weather and even air humidity will have a great impact on the aging, forming, and drying stages, and ultimately lead to deviations in product quality. Third, the production efficiency is low. The entire production process depends highly on labor, and the degree of automation of production equipment is very low. Therefore, the production of products is very slow. Fourth, the product performance is poor. Since the traditional rotational molding method is still used in the production method, rotational molding requires the raw material to be mud for operation, and the mud itself determines its poor compressibility. Its high water content will cause more pores to be generated in the crucible during drying and roasting, thus seriously affecting the performance of the product.

[0005] Furthermore, traditional binders are phenolic resins or bitumen, which will release certain harmful gases such as formaldehyde during the drying stage or roasting stage, causing certain pollution to the environment. Summary of the Invention

[0006] The present invention provides an isostatic pressing clay crucible and a preparation method thereof to solve the technical problems of long production cycle and poor quality stability in the traditional crucible process in the prior art.

[0007] To solve the above problems, an isostatic pressing clay crucible and a preparation method thereof provided by the present invention adopt the following technical solutions:

[0008] The isostatic pressing clay crucible comprises the following components in mass percentage:

[0009] Graphite: 25%-35%;

[0010] Low-moisture clay: 35%-45%;

[0011] High-alumina bauxite: 5%-15%;

[0012] Metallic silicon: 2%-10%;

[0013] Boron carbide: 1%-5%;

[0014] Additive: 1%-10%;

[0015] Among them, the additive is hydrogel or lignin.

[0016] Furthermore, the water content of the low-moisture clay is less than 5%.

[0017] Furthermore, the particle size of the graphite is 100-120 mesh; the particle size of the low-moisture clay is 325-350 mesh; the particle size of the high-alumina bauxite is 200-325 mesh; the particle size of the metallic silicon is 280-300 mesh; the particle size of the boron carbide is 280-300 mesh.

[0018] The preparation method of the above isostatic pressing clay crucible comprises the following steps:

[0019] S1. Take appropriate amounts of graphite, low-moisture clay, metallic silicon, boron carbide, and additive and mix them evenly in a mixer;

[0020] S2. Store the evenly mixed materials in a sealed manner for a period of time to make the moisture distribution of the materials more uniform;

[0021] S3. Use the cold isostatic pressing process to press and form, where the pressing pressure is 30 Mpa - 60 Mpa, and keep the pressure for 1-5 minutes before demolding.

[0022] S4. Dry the formed green body in stages until the water content is less than 3%;

[0023] S5. Bake the embryo body in step S4 at high temperature for a period of time.

[0024] Further, in S2, the time for sealed storage is 24 h.

[0025] Further, in S4, when drying:

[0026] The first stage is to dry at 80 °C for 12 h;

[0027] The second stage is to dry at 120 °C for 12 h;

[0028] The second stage is to dry at 200 °C for 24 h.

[0029] Further, the high-temperature baking temperature of the embryo body is 1100 °C - 1300 °C, and the baking time is 3 - 4 h.

[0030] Further, the density of the crucible after firing and forming is 2.1 - 2.3 g / cm 3 , the flexural strength is 5 - 6 MPa, the porosity is 5% - 10%, and the porosity difference between the upper and lower surfaces of the crucible bottom is less than 2%.

[0031] The beneficial effects of the graphite small crucible and its preparation method provided by the present invention are as follows:

[0032] 1. In the present invention, through the close packing of graphite with a suitable particle size and fine-grained low-moisture clay, metal silicon, and boron carbide, among which the low-moisture clay has the finest particle size and is effectively filled between the graphite particles, improving the overall strength. The binder uses an environmentally friendly binder, hydrogel or lignin. To avoid the release of blocked gases during roasting. In addition, the combination of metal silicon (Si) and boron carbide (B4C) is not a simple superposition, but realizes synergistic enhancement through high-temperature chemical reactions and microstructure optimization, improving the erosion resistance and extending the service life.

[0033] The hydrogel in the present invention can adsorb a large amount of water and form a three-dimensional network structure, enabling the mixture to uniformly transmit pressure during the isostatic pressing process, reducing the density gradient of the green body (porosity difference < 2%); inhibiting particle segregation and preventing the stratification of coarse graphite (100 - 120 mesh) and fine particles (clay / B4C).

[0034] 2. In the present invention, through the short-cycle isostatic pressing forming technology, the production efficiency is effectively improved. Suitable for large-scale production. Brief Description of the Drawings

[0035] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present invention will become readily understandable. In the drawings, several embodiments of the present invention are shown by way of example and not limitation, and the same or corresponding reference numerals denote the same or corresponding parts, wherein:

[0036] Figure 1 It is a physical diagram of the finished crucible in Example 1 of the present invention;

[0037] Figure 2 It is a physical diagram of the finished crucible in Comparative Example 1 of the present invention. Detailed Embodiments

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0039] The number of any element in the drawings is for illustration rather than limitation, and any naming is only for distinction and does not have any limiting meaning.

[0040] Next, with reference to several representative embodiments of the present invention, the principles and spirit of the present invention will be elaborated in detail.

[0041] Example 1:

[0042] The isostatic pressing clay crucible provided in this embodiment includes the following components in mass percentage:

[0043] Graphite: 35%;

[0044] Low-moisture clay: 35%;

[0045] High-alumina bauxite: 5%;

[0046] Metallic silicon: 10%;

[0047] Boron carbide: 5%;

[0048] Additive: 10%;

[0049] Among them, the additive is a hydrogel.

[0050] The hydrogel in this embodiment is an environmentally friendly binder produced by Binxia New Materials Co., Ltd. in Zouping City.

[0051] Furthermore, the water content of the low-moisture clay is less than 5%.

[0052] Further, the particle size of the graphite is 100 - 120 mesh; the particle size of the low - moisture clay is 325 - 350 mesh; the particle size of the high - alumina bauxite is 200 - 325 mesh; the particle size of the metallic silicon is 280 - 300 mesh; the particle size of the boron carbide is 280 - 300 mesh.

[0053] The preparation method of the isostatic pressing clay crucible described above includes the following steps:

[0054] S1. Take appropriate amounts of graphite, low - moisture clay, metallic silicon, boron carbide, and additives and mix them evenly in a mixer.

[0055] S2. Store the evenly - mixed material sealed for a period of time to make the moisture distribution of the material more uniform. Specifically, the sealing storage time is 24 h.

[0056] S3. Use the cold isostatic pressing process to press into shape, where the pressing pressure is 50 Mpa, and keep the pressure for 3 min before demolding.

[0057] S4. Dry the formed green body in stages until the water content is less than 3%.

[0058] Specifically, during drying:

[0059] The first stage is to dry at 80 °C for 12 h;

[0060] The second stage is to dry at 120 °C for 12 h;

[0061] The third stage is to dry at 200 °C for 24 h.

[0062] S5. High - temperature roast the green body in S4 for a period of time. The high - temperature roasting temperature of the green body is 1100 °C - 1300 °C, and the roasting time is 48 h.

[0063] Example 2:

[0064] The isostatic pressing clay crucible provided in this example includes the following components by mass percentage:

[0065] Graphite: 30%;

[0066] Low - moisture clay: 45%;

[0067] High - alumina bauxite: 5%

[0068] Metallic silicon: 5%;

[0069] Boron carbide: 5%;

[0070] Additive: 10%;

[0071] Among them, the additive is hydrogel.

[0072] The hydrogel in this embodiment is an environmentally friendly binder produced by Binxia New Materials Co., Ltd. in Zouping City.

[0073] Furthermore, the water content of the low-moisture clay is less than 5%.

[0074] Furthermore, the particle size of the graphite is 100 - 120 mesh; the particle size of the low-moisture clay is 325 - 350 mesh; the particle size of the bauxite is 200 - 325 mesh; the particle size of the metallic silicon is 280 - 300 mesh; the particle size of the boron carbide is 280 - 300 mesh.

[0075] The preparation method of the isostatic pressing clay crucible described above includes the following steps:

[0076] S1. Take appropriate amounts of graphite, low-moisture clay, metallic silicon, boron carbide, and additives and mix them evenly in a mixer.

[0077] S2. Seal and store the evenly mixed materials for a period of time to make the moisture distribution of the materials more uniform. Specifically, the sealing storage time is 24h.

[0078] S3. Use the cold isostatic pressing process to press into shape, where the pressing pressure is 30Mpa - 60Mpa, and keep the pressure for 1 - 5min before demolding.

[0079] S4. Dry the formed green body in stages until the water content is less than 3%.

[0080] Specifically, when drying:

[0081] The first stage is to dry at 80°C for 12h;

[0082] The second stage is to dry at 120°C for 12h;

[0083] The third stage is to dry at 200°C for 24h.

[0084] S5. High-temperature roast the green body in S4 for a period of time. The high-temperature roasting temperature of the green body is 1100°C - 1300°C, and the roasting time is 48h.

[0085] Example 3:

[0086] The isostatic pressing clay crucible provided in this embodiment includes the following components by mass percentage:

[0087] Graphite: 25%;

[0088] Low-moisture clay: 40%;

[0089] Bauxite: 10%;

[0090] Metallic silicon: 10%;

[0091] Boron carbide: 5%;

[0092] Additive: 10%;

[0093] Among them, the additive is a hydrogel.

[0094] The hydrogel in this example is an environmentally friendly binder produced by Binxia New Materials Co., Ltd. in Zouping City.

[0095] Further, the water content of the low-moisture clay is less than 5%.

[0096] Further, the particle size of the graphite is 100 - 120 mesh; the particle size of the low-moisture clay is 325 - 350 mesh; the particle size of the bauxite is 200 - 325 mesh; the particle size of the metallurgical silicon is 280 - 300 mesh; the particle size of the boron carbide is 280 - 300 mesh.

[0097] The preparation method of the above isostatic pressing clay crucible includes the following steps:

[0098] S1. Take appropriate amounts of graphite, low-moisture clay, metallurgical silicon, boron carbide, and additive and mix them evenly in a mixer;

[0099] S2. Store the evenly mixed materials sealed for a period of time to make the moisture distribution of the materials more uniform. Specifically, the sealing storage time is 24h.

[0100] S3. Use the cold isostatic pressing process to press and form, where the pressing pressure is 30 Mpa - 60 Mpa, and keep the pressure for 1 - 5 min before demolding.

[0101] S4. Dry the formed green body in stages until the water content is less than 3%.

[0102] Specifically, during drying:

[0103] The first stage is to dry at 80°C for 12h;

[0104] The second stage is to dry at 120°C for 12h;

[0105] The third stage is to dry at 200°C for 24h.

[0106] S5. High-temperature roast the green body in S4 for a period of time. The high-temperature roasting temperature of the green body is 1100°C - 1300°C, and the roasting time is 48h.

[0107] Example 4:

[0108] The isostatic pressing clay crucible provided in this example includes the following components in mass percentage:

[0109] Graphite: 35%;

[0110] Low-moisture clay: 45%;

[0111] High-aluminum bauxite: 5%;

[0112] Metallic silicon: 4%;

[0113] Boron carbide: 1%;

[0114] Additive: 10%;

[0115] Among them, the additive is a hydrogel.

[0116] The hydrogel in this example is an environmentally friendly binder produced by Binxia New Materials Co., Ltd. in Zouping City.

[0117] Furthermore, the water content of the low-moisture clay is less than 5%.

[0118] Furthermore, the particle size of the graphite is 100 - 120 mesh; the particle size of the low-moisture clay is 325 - 350 mesh; the particle size of the high-aluminum bauxite is 200 - 325 mesh; the particle size of the metallic silicon is 280 - 300 mesh; the particle size of the boron carbide is 280 - 300 mesh.

[0119] The preparation method of the above isostatic pressing clay crucible includes the following steps:

[0120] S1. Take appropriate amounts of graphite, low-moisture clay, metallic silicon, boron carbide, and additive and mix them evenly in a mixer;

[0121] S2. Store the evenly mixed materials sealed for a period of time to make the moisture distribution of the materials more uniform. Specifically, the sealing storage time is 24h.

[0122] S3. Use the cold isostatic pressing process to press into shape, where the pressing pressure is 30 Mpa - 60 Mpa, and keep the pressure for 1 - 5 min before demolding.

[0123] S4. Dry the formed green body in stages until the water content is less than 3%.

[0124] Specifically, when drying:

[0125] The first stage is to dry at 80°C for 12h;

[0126] The second stage is to dry at 120°C for 12h;

[0127] The second stage is to dry at 200°C for 24h.

[0128] S5. High-temperature roast the green body in S4 for a period of time. The high-temperature roasting temperature of the green body is 1100°C - 1300°C, and the roasting time is 48h.

[0129] Example 5:

[0130] The isostatic pressing clay crucible provided by this embodiment includes components with the following mass percentages:

[0131] Graphite: 28%;

[0132] Low-moisture clay: 38%;

[0133] High-aluminum bauxite: 9%;

[0134] Metallic silicon: 10%;

[0135] Boron carbide: 5%;

[0136] Additive: 10%;

[0137] Among them, the additive is a hydrogel.

[0138] The hydrogel in this embodiment is an environmental protection binder produced by Zouping Binxia New Materials Co., Ltd.

[0139] Furthermore, the water content of the low-moisture clay is less than 5%.

[0140] Furthermore, the particle size of the graphite is 100 - 120 mesh; the particle size of the low-moisture clay is 325 - 350 mesh; the particle size of the high-aluminum bauxite is 200 - 325 mesh; the particle size of the metallic silicon is 280 - 300 mesh; the particle size of the boron carbide is 280 - 300 mesh.

[0141] The preparation method of the above isostatic pressing clay crucible includes the following steps:

[0142] S1. Take appropriate amounts of graphite, low-moisture clay, metallic silicon, boron carbide, and additive and mix them evenly in a mixer;

[0143] S2. Store the evenly mixed materials in a sealed manner for a period of time to make the moisture distribution of the materials more uniform. Specifically, the sealed storage time is 24 h.

[0144] S3. Use the cold isostatic pressing process to press into shape, where the pressing pressure is 50 Mpa, and keep the pressure for 3 min before demolding.

[0145] S4. Dry the formed green body in stages until the water content is less than 3%.

[0146] Specifically, during drying:

[0147] The first stage is to dry at 80 °C for 12 h;

[0148] The second stage is to dry at 120 °C for 12 h;

[0149] The third stage is to dry at 200 °C for 24 h.

[0150] S5. Bake the embryo body at a high temperature for a period of time. The temperature for baking the embryo body at a high temperature is 1100°C - 1300°C, and the baking time is 48 hours.

[0151] Example 6:

[0152] The isostatic pressing clay crucible provided in this example includes components with the following mass percentages:

[0153] Graphite: 30%;

[0154] Low-moisture clay: 40%;

[0155] Bauxite: 15%;

[0156] Metallic silicon: 2%;

[0157] Boron carbide: 3%;

[0158] Additive: 10%;

[0159] Among them, the additive is hydrogel.

[0160] The hydrogel in this example is an environmentally friendly binder produced by Binxia New Materials Co., Ltd. in Zouping City.

[0161] Furthermore, the water content of the low-moisture clay is less than 5%.

[0162] Furthermore, the particle size of the graphite is 100 - 120 mesh; the particle size of the low-moisture clay is 325 - 350 mesh; the particle size of the bauxite is 200 - 325 mesh; the particle size of the metallic silicon is 280 - 300 mesh; the particle size of the boron carbide is 280 - 300 mesh.

[0163] The preparation method of the above isostatic pressing clay crucible includes the following steps:

[0164] S1. Take appropriate amounts of graphite, low-moisture clay, metallic silicon, boron carbide, and additive and mix them evenly in a mixer.

[0165] S2. Store the evenly mixed materials sealed for a period of time to make the moisture distribution of the materials more uniform. Specifically, the sealed storage time is 24 hours.

[0166] S3. Use the cold isostatic pressing process to press into shape, where the pressing pressure is 50 Mpa, and keep the pressure for 3 minutes before demolding.

[0167] S4. Dry the formed green body in stages until the water content is less than 3%.

[0168] Specifically, during drying:

[0169] The first stage is to dry at 80°C for 12 hours;

[0170] The second stage is to dry at 120 °C for 12 h;

[0171] The second stage is to dry at 200 °C for 24 h.

[0172] S5. High-temperature roast the green body in S4 for a period of time. The high-temperature roasting temperature of the green body is 1100 °C - 1300 °C, and the roasting time is 48 h.

[0173] Example 7:

[0174] The isostatic pressing clay crucible provided in this example includes components with the following mass percentages:

[0175] Graphite: 35%;

[0176] Low-moisture clay: 45%;

[0177] High-aluminum bauxite: 5%;

[0178] Metallic silicon: 9%;

[0179] Boron carbide: 5%;

[0180] Additive: 1%;

[0181] Among them, the additive is lignin.

[0182] In this example, the lignin is the lignin liquid produced by Jinan Shengquan Group Co., Ltd. and the model is SQBS-1.

[0183] Furthermore, the water content of the low-moisture clay is less than 5%.

[0184] Furthermore, the particle size of the graphite is 100 - 120 mesh; the particle size of the low-moisture clay is 325 - 350 mesh; the particle size of the high-aluminum bauxite is 200 - 325 mesh; the particle size of the metallic silicon is 280 - 300 mesh; the particle size of the boron carbide is 280 - 300 mesh.

[0185] The preparation method of the above isostatic pressing clay crucible includes the following steps:

[0186] S1. Take appropriate amounts of graphite, low-moisture clay, metallic silicon, boron carbide, and additive and mix them evenly in a mixer;

[0187] S2. Store the evenly mixed materials sealed for a period of time to make the moisture distribution of the materials more uniform. Specifically, the sealed storage time is 24 h.

[0188] S3. Use the cold isostatic pressing process to press into shape, where the pressing pressure is 35 Mpa, and keep the pressure for 5 min before demolding.

[0189] S4. Dry the formed green embryos in stages until the water content is less than 3%.

[0190] Specifically, during drying:

[0191] The first stage is to dry at 80°C for 12 hours;

[0192] The second stage is to dry at 120°C for 12 hours;

[0193] The third stage is to dry at 200°C for 24 hours.

[0194] S5. High-temperature roast the embryos in S4 for a period of time. The high-temperature roasting temperature of the embryos is 1100°C - 1300°C, and the roasting time is 48 hours.

[0195] Comparative Example 1:

[0196] Prepare a small graphite crucible using the traditional process. Weigh 40% graphite, 50% clay, and 10% bauxite according to the proportion.

[0197] The preparation method includes the following steps:

[0198] S1. Add sufficient water to the materials in the above proportion and preliminarily knead until it becomes a uniform mud;

[0199] S2. Put the mixed mud into an extrusion machine and extrude a mud bar with a diameter of about 5 - 10 cm;

[0200] S3. Stack the mud bars, cover them with a plastic film and seal them for 1 month of aging to promote the uniform distribution of moisture and the decomposition of organic matter.

[0201] S4. Put the aged mud bars into a large mill, add water while rolling, and continue for 1 - 2 hours.

[0202] S5. Crush the rolled mud material through a crusher to form uniform mud particles;

[0203] S6. The mud particles are the raw materials for crucible pressing. The forming method is rotational molding, that is, the worker uses a rotational tank machine to drive the plastic mold to rotate and uses an internal knife to extrude the mud material to complete the crucible shaping;

[0204] S7. Place the green embryos for one week to allow the embryos to gradually lose moisture, and then enter the kiln for firing at a temperature of 1200 and a time of 50 - 60 hours.

[0205] Experimental Example:

[0206] Take the crucibles prepared in Examples 1 - 7 and Comparative Example 1 for measurement. The results are shown in the following table.

[0207]

[0208]

[0209] The finished crucible in Example 1 and the crucible in Comparative Example 1 were subjected to a high temperature resistance test, and the temperature was raised to 1600° C. The finished crucible in Example 1 heated up quickly and had a good appearance without cracks. The crucible in Comparative Example 1 heated up slowly and had a damaged appearance with cracks.

[0210] Comparative analysis shows that in Examples 1-7, the density is 2.1–2.3 g / cm 3 , indicating that the material structure is relatively dense and the particles are reasonably stacked, while the density of comparative example 1 is only 1.8 g / cm 3 , indicating that there are more pores inside the material and the structure is loose. High density means that the crucible is more resistant to high temperature, better in thermal shock resistance, and longer in service life.

[0211] In Examples 1-7, the flexural strength is 5-6 MPa, indicating that the crucible is not easy to break when subjected to stress, and the flexural strength of the comparative example is low. Higher flexural strength makes the crucible less likely to break during transportation, loading and high-temperature use.

[0212] In Examples 1-7, the porosity is 5-10%, with Example 1 being the lowest. Low porosity means that the crucible is denser, reduces molten metal penetration, improves corrosion resistance, reduces thermal stress concentration, reduces the risk of cracking during high-temperature use, and has better thermal shock resistance.

[0213] In Examples 1-7, the porosity difference between the upper and lower surfaces of the bottom is less than 2%, indicating that the internal structure of the material is uniform. The uniform pore distribution allows the crucible to be heated more evenly, reducing the risk of local overheating or cracking.

[0214] In addition, overall comparison shows that the overall production cycle of Examples 1-7 is significantly shortened, greatly improving production efficiency. The overall production cycle in Comparative Example 1 is 3-5 times that of the above.

[0215] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, and they should be covered by the protection scope of the present invention.

Claims

1. Isostatic pressing clay crucible, characterized in that, It comprises components with the following mass percentages: Graphite: 25% - 35%; Low - moisture clay: 35% - 45%; High - alumina bauxite: 5% - 15%; Metallic silicon: 2% - 10%; Boron carbide: 1% - 5%; Additive: 1% - 10%; Among them, the additive is hydrogel or lignin.

2. The isostatic pressing clay crucible according to claim 1, wherein The water content of the low - moisture clay is less than 5%.

3. The isostatic pressing clay crucible according to claim 1, wherein The particle size of the graphite is 100 - 120 mesh; the particle size of the low - moisture clay is 325 - 350 mesh; the particle size of the high - alumina bauxite is 200 - 325 mesh; the particle size of the metallic silicon is 280 - 300 mesh; the particle size of the boron carbide is 280 - 300 mesh.

4. The preparation method of the isostatic pressing clay crucible according to any one of claims 1-3, characterized in that, It comprises the following steps: S1. Take appropriate amounts of graphite, low - moisture clay, metallic silicon, boron carbide, and additive and mix them evenly in a mixer; S2. Store the evenly - mixed material sealed for a period of time to make the moisture distribution of the material more uniform; S3. Use the cold isostatic pressing process to press into shape, where the pressing pressure is 30 Mpa - 60 Mpa, and keep the pressure for 1 - 5 min before demolding. S4. Dry the formed green body in stages until the water content is less than 3%; S5. High - temperature roast the green body in S4 for a period of time.

5. The preparation method of the isostatic pressing clay crucible according to claim 4, wherein, In S2, the sealing storage time is 24 h.

6. The preparation method of the isostatic pressing clay crucible according to claim 4, characterized in that In S4, during drying: the first stage is drying at 80°C for 12 h; the second stage is drying at 120°C for 12 h; There is a mistake here, it should be the third stage is drying at 200°C for 24 h.

7. The preparation method of the isostatic pressing clay crucible according to claim 4, characterized in that, In S5, the high - temperature roasting temperature of the green body is 1100°C - 1300°C, and the roasting time is 48 h.

8. The preparation method of the isostatic pressing clay crucible according to claim 4, characterized in that, The density of the crucible after firing and shaping is 2.1-2.3 g / cm 3 , the flexural strength is 5-6 MPa, the porosity is 5%-10%, and the difference in porosity between the upper and lower surfaces of the bottom of the crucible is less than 2%.

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