Slip casting process of ceramic part for ceramic pump

Abstract

The invention discloses a slip casting process of a ceramic part for a ceramic pump. The slip casting process comprises the following steps: adding argil and water into a ball mill for grinding and filtering to obtain slurry; the slurry is taken and injected into the porous resin mold in three stages, high-pressure grouting is carried out in the last stage, the pressure in the porous resin mold is increased to 1.4-3 MPa, the high-pressure grouting time is 30-60 min, and the slurry is cured and formed to obtain a ceramic body; and the ceramic body is taken to be air-dried, so that the water content in the ceramic body is smaller than 10%, and then the ceramic body is sintered, ground and polished in sequence to obtain the ceramic part for the ceramic pump. The method can be used for producing the ceramic part with the thickness of more than 20mm for the ceramic pump, and the performance (such as hardness and compressive strength) of the ceramic part can meet the use standard of the ceramic pump.

Description

Technical Field

[0001] The invention belongs to the technical field of ceramic pump production, and in particular relates to a slip injection molding process for ceramic components used in ceramic pumps. Background Art

[0002] Ceramic pumps are industrial pumps that utilize ceramic materials for key components (such as the ceramic liner and pump cover). They are primarily used for conveying corrosive, highly abrasive, or high-purity media. Ceramic materials (such as alumina, zirconium oxide, or silicon carbide) are resistant to strong acids (hydrochloric acid, sulfuric acid), strong bases, and organic solvents, offering excellent corrosion resistance, wear resistance, high-temperature resistance, thermal stability, and low production and maintenance costs. They are suitable for applications in highly corrosive and abrasive environments, such as nonferrous metallurgy, chemical engineering, environmental protection engineering, and new energy (lithium battery slurry, polysilicon pickling).

[0003] The production process of key ceramic components for ceramic pumps mainly includes raw material proportioning, slurry mixing, slurry injection, green compacting, curing, moisture separation, sintering, processing, and quality inspection. The slurry injection process is the process of filling the mold with ceramic slurry to form a complex structure green body. It is the core process of ceramic component production and has a significant impact on the performance of the resulting component. Since the ceramic components used in ceramic pumps have different requirements from conventional ceramic parts, the requirements for the slurry injection process are also more stringent. For example, the ceramic liner or pump cover used in ceramic pumps requires a thickness of 20 to 40 mm. However, the conventional slurry injection molding process cannot produce ceramic parts with a thickness of more than 20 mm, which cannot meet the production requirements of ceramic pump ceramic components. Therefore, the slurry injection molding process needs to be optimized and improved. Summary of the Invention

[0004] In response to the above-mentioned shortcomings, the present invention discloses a grouting molding process for ceramic components for ceramic pumps, which can produce ceramic components for ceramic pumps with a thickness of 20 to 40 mm, and the performance of the ceramic components (such as hardness and compressive strength) can meet the use standards of ceramic pumps.

[0005] The present invention is achieved by adopting the following technical solutions: A slip casting process for ceramic components for ceramic pumps, comprising the following steps: (1) adding clay and water into a ball mill and grinding them to obtain a grinding material, and filtering the grinding material to obtain a slurry; the viscosity of the slurry is 1000 to 5000 mPa·s, and the solid content of the slurry is 70 to 85%; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to be 0.5-0.7 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 0.8-1.3 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 1.4-2 MPa. The high-pressure injection time is 30-60 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; (3) The ceramic blank obtained in step (2) is air-dried to reduce the water content in the ceramic blank to less than 10%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0006] Furthermore, the weight ratio of the clay to water in step (1) is (2-2.5):1.

[0007] Furthermore, in the clay of step (1), the content of aluminum oxide is 15-20%, and the content of silicon dioxide is 65-70%.

[0008] Furthermore, in step (1), clay, auxiliary materials and water are added to a ball mill for grinding to obtain a grinding material, wherein the amount of the auxiliary materials is 30-40% of the weight of the clay, and the auxiliary materials include any one or more combinations of feldspar powder, pyrochlore powder, wood clay and kaolin.

[0009] Furthermore, in step (1), an additive is added to the clay, wherein the additive comprises any one or more of water glass, soda ash, yttrium nitrate, cobalt nitrate, and ammonium polyacrylate, and the amount of the additive added is 0.5-1% of the weight of the clay. The addition of the additive not only regulates the rheological properties and stability of the slurry, which is beneficial to the subsequent grouting process, but also has the functions of fluxing, promoting sintering, stabilizing the crystal phase structure, etc., effectively improving the mechanical strength and density of the ceramic component.

[0010] Furthermore, the additive comprises the following components by weight: 10-20 parts water glass, 5-8 parts soda ash, 1-4 parts yttrium nitrate, 1-3 parts cobalt nitrate, and 2-5 parts ammonium polyacrylate, with the amount of cobalt nitrate being lower than that of yttrium nitrate. The composite additive consisting of yttrium nitrate, cobalt nitrate, and ammonium polyacrylate not only regulates the rheological properties and stability of the slurry but also improves the sintering properties of the ceramic component after slurry injection, thereby enhancing the quality of the ceramic component.

[0011] Furthermore, in step (1), the proportion of particles with a particle size of less than 1 μm in the slurry is less than 5%. By controlling the particle size in the slurry after grinding, not only can a good sintering density be ensured, but also the slurry can have good fluidity.

[0012] Furthermore, the average pore diameter of the porous resin mold in step (2) is 1 to 10 μm, and the clamping pressure is maintained at 4 to 5 MPa. Selecting a suitable average pore diameter of the porous resin mold allows for timely drainage and exhaust during the high-pressure grouting process, which is beneficial to improving the molding effect of the ceramic blank.

[0013] Furthermore, during the grouting process in step (2), the temperature of the slurry is maintained within the range of 20-30° C. By controlling the slurry temperature, the slurry can be guaranteed to have stable fluidity, and a flow region can be provided to ensure the density of the solidified green body, thereby improving the quality of the ceramic component.

[0014] Compared with the existing technology, this technical solution has the following beneficial effects: The present invention regulates parameters such as the viscosity and solid content of the clay slurry to ensure that the clay slurry has good fluidity. The clay slurry is then injected into a porous resin mold using high-pressure grouting and solidified to obtain a ceramic blank for a ceramic pump component. Finally, the ceramic blank is air-dried to further remove moisture and then sintered, ground, and polished to obtain a ceramic pump component. The obtained ceramic pump component has excellent hardness and compressive strength, can meet the use requirements of the ceramic pump, and solves the technical problem that the existing grouting molding process cannot produce ceramic components (pump cover, pump body liner) with a thickness of 20 to 40 mm. DETAILED DESCRIPTION

[0015] The present invention is further illustrated by the following examples, which are not intended to limit the present invention. Specific experimental conditions and methods not specified in the following examples are conventional methods well known to those skilled in the art.

[0016] Example 1: A slip casting process for a ceramic component for a ceramic pump, comprising the following steps: (1) According to the weight ratio of clay to water being 2.3:1, clay, auxiliary materials and water are added to a ball mill for grinding to obtain a grinding material, and the grinding material is filtered to obtain a slurry; the viscosity of the slurry is 2000mPa·s, and the solid content of the slurry is 80%; the proportion of particles with a particle size of less than 1μm in the slurry is 4.5%; the content of aluminum oxide in the clay is 18.3%, and the content of silicon dioxide is 68.2%; the amount of the auxiliary materials is 35% of the weight of the clay, and the auxiliary materials are a combination of feldspar powder, jiaobao powder, wood clay and kaolin; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to 0.6 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 0.9 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 1.8 MPa. The high-pressure injection time is 25 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; the average diameter of the pores of the porous resin mold is 5 μm, and the clamping pressure is maintained at 5 MPa; the temperature of the slurry is maintained at 25°C during the injection process; (3) The ceramic blank obtained in step (2) is air-dried to make the water content in the ceramic blank 8%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0017] Example 2: A slip casting process for a ceramic component for a ceramic pump, comprising the following steps: (1) According to the weight ratio of clay to water being 2:1, clay, auxiliary materials and water are added to a ball mill for grinding to obtain a grinding material, and the grinding material is filtered to obtain a slurry; the viscosity of the slurry is 1000 mPa·s, and the solid content of the slurry is 70%; the proportion of particles with a particle size of less than 1 μm in the slurry is 5%; the content of aluminum oxide in the clay accounts for 15%, and the content of silicon dioxide accounts for 65%; the amount of the auxiliary materials used is 30% of the weight of the clay, and the auxiliary materials are a combination of feldspar powder, jiaobao powder, wood clay and kaolin; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to 0.5 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 0.8 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 1.4 MPa. The high-pressure injection time is 30 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; the average diameter of the holes in the porous resin mold is 10 μm, and the clamping pressure is maintained at 4 MPa; during the injection process, the temperature of the slurry is maintained at 20°C; (3) The ceramic blank obtained in step (2) is air-dried to reduce the water content in the ceramic blank to 10%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0018] Example 3: A slip casting process for a ceramic component for a ceramic pump, comprising the following steps: (1) Clay, auxiliary materials and water are added to a ball mill in a clay to water weight ratio of 2.5:1, and ground to obtain a grinding material, which is then filtered to obtain a slurry; the viscosity of the slurry is 5000 mPa·s, and the solid content of the slurry is 85%; the proportion of particles with a particle size of less than 1 μm in the slurry is 1%; the content of aluminum oxide in the clay is 20%, and the content of silicon dioxide is 70%; the amount of the auxiliary materials used is 40% of the weight of the clay, and the auxiliary materials are a combination of feldspar powder and kaolin; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to 0.7 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 1 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 2 MPa. The high-pressure injection time is 20 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; the average diameter of the pores of the porous resin mold is 1 μm, and the clamping pressure is maintained at 5 MPa; the temperature of the slurry is maintained at 30°C during the injection process; (3) The ceramic blank obtained in step (2) is air-dried to make the water content in the ceramic blank 8%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0019] Example 4: A slip casting process for a ceramic component for a ceramic pump, comprising the following steps: (1) According to the weight ratio of clay to water of 2.3:1, clay, auxiliary materials and water are added to a ball mill for grinding to obtain a grinding material, and the grinding material is filtered to obtain a slurry; the viscosity of the slurry is 2000mPa·s, and the solid content of the slurry is 80%; the proportion of particles with a particle size of less than 1μm in the slurry is 4.5%; the content of aluminum oxide in the clay is 18.4%, and the content of silicon dioxide is 68.1%; the amount of the auxiliary materials is 35% of the weight of the clay, and the auxiliary materials are a combination of feldspar powder, coke powder, wood clay and kaolin; auxiliary agents are added to the clay, and the amount of the auxiliary agents added is 0.8% of the weight of the clay; the auxiliary agents include the following components in parts by weight: 15 parts of water glass, 6 parts of soda ash, 3 parts of yttrium nitrate, 2 parts of cobalt nitrate and 4 parts of ammonium polyacrylate; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to 0.6 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 0.9 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 1.8 MPa. The high-pressure injection time is 25 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; the average diameter of the pores of the porous resin mold is 5 μm, and the clamping pressure is maintained at 5 MPa; the temperature of the slurry is maintained at 25°C during the injection process; (3) The ceramic blank obtained in step (2) is air-dried to make the water content in the ceramic blank 8%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0020] Example 5: A slip casting process for a ceramic component for a ceramic pump, comprising the following steps: (1) According to the weight ratio of clay to water being 2:1, clay, auxiliary materials and water are added to a ball mill for grinding to obtain a grinding material, and the grinding material is filtered to obtain a slurry; the viscosity of the slurry is 1000mPa·s, and the solid content of the slurry is 70%; the proportion of particles with a particle size of less than 1μm in the slurry is 5%; the content of aluminum oxide in the clay is 18.2%, and the content of silicon dioxide is 68.2%; the amount of the auxiliary materials is 30% of the weight of the clay, and the auxiliary materials are a combination of feldspar powder, coke powder, wood clay and kaolin; auxiliary agents are added to the clay, and the amount of the auxiliary agents added is 0.5% of the weight of the clay; the auxiliary agents include the following components in parts by weight: 10 parts of water glass, 5 parts of soda ash, 1 part of yttrium nitrate, 1 part of cobalt nitrate and 2 parts of ammonium polyacrylate; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to 0.5 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 0.8 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 1.4 MPa. The high-pressure injection time is 30 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; the average diameter of the holes in the porous resin mold is 10 μm, and the clamping pressure is maintained at 4 MPa; during the injection process, the temperature of the slurry is maintained at 20°C; (3) The ceramic blank obtained in step (2) is air-dried to reduce the water content in the ceramic blank to 10%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0021] Example 6: A slip casting process for a ceramic component for a ceramic pump, comprising the following steps: (1) According to the weight ratio of clay to water being 2.5:1, clay, auxiliary materials and water are added to a ball mill for grinding to obtain a grinding material, and the grinding material is filtered to obtain a slurry; the viscosity of the slurry is 5000mPa·s, and the solid content of the slurry is 85%; the proportion of particles with a particle size of less than 1μm in the slurry is 1%; the content of aluminum oxide in the clay is 18.2%, and the content of silicon dioxide is 68.1%; the amount of the auxiliary materials is 40% of the weight of the clay, and the auxiliary materials are a combination of feldspar powder, coke powder, wood clay and kaolin; auxiliary agents are added to the clay, and the amount of the auxiliary agents added is 1% of the weight of the clay; the auxiliary agents include the following components in parts by weight: 20 parts of water glass, 8 parts of soda ash, 4 parts of yttrium nitrate, 3 parts of cobalt nitrate and 5 parts of ammonium polyacrylate; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to 0.7 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 1 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 2 MPa. The high-pressure injection time is 20 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; the average diameter of the pores of the porous resin mold is 1 μm, and the clamping pressure is maintained at 5 MPa; the temperature of the slurry is maintained at 30°C during the injection process; (3) The ceramic blank obtained in step (2) is air-dried to make the water content in the ceramic blank 8%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0022] Example 7: A slip casting process for a ceramic component for a ceramic pump, comprising the following steps: (1) According to the weight ratio of clay to water of 2.2:1, clay, auxiliary materials and water are added to a ball mill for grinding to obtain a grinding material, and the grinding material is filtered to obtain a slurry; the viscosity of the slurry is 3000mPa·s, and the solid content of the slurry is 82%; the proportion of particles with a particle size of less than 1μm in the slurry is 3.5%; the content of aluminum oxide in the clay accounts for 18.2%, and the content of silicon dioxide accounts for 68.2%; the amount of the auxiliary materials is 32% of the weight of the clay, and the auxiliary materials are a combination of feldspar powder, coke powder, wood clay and kaolin; auxiliary agents are added to the clay, and the amount of the auxiliary agents added is 0.6% of the weight of the clay; the auxiliary agents include the following components in parts by weight: 18 parts of water glass, 7 parts of soda ash, 3 parts of yttrium nitrate, 2 parts of cobalt nitrate and 3 parts of ammonium polyacrylate; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to 0.6 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 0.8 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 2 MPa. The high-pressure injection time is 25 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; the average diameter of the pores of the porous resin mold is 5 μm, and the clamping pressure is maintained at 5 MPa; the temperature of the slurry is maintained at 28°C during the injection process; (3) The ceramic blank obtained in step (2) is air-dried to reduce the water content in the ceramic blank to 9%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0023] Comparative Example 1: A slip casting process for a ceramic component for a ceramic pump, comprising the following steps: (1) According to the weight ratio of clay to water being 2.3:1, clay, auxiliary materials and water are added to a ball mill for grinding to obtain a grinding material, and the grinding material is filtered to obtain a slurry; the viscosity of the slurry is 2000mPa·s, and the solid content of the slurry is 80%; the proportion of particles with a particle size of less than 1μm in the slurry is 4.5%; the content of aluminum oxide in the clay is 18.3%, and the content of silicon dioxide is 68.2%; the amount of the auxiliary materials is 35% of the weight of the clay, and the auxiliary materials are a combination of feldspar powder, jiaobao powder, wood clay and kaolin; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following two stages: in the first stage, the pressure of the delivery pump is controlled to 0.6 MPa and the slurry is slowly injected into the porous resin mold until the slurry fills the cavity of the porous resin mold; in the second stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 1.8 MPa. The high-pressure injection time is 25 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge the water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; the average diameter of the pores of the porous resin mold is 5 μm, and the clamping pressure is maintained at 5 MPa; during the injection process, the temperature of the slurry is maintained at 25°C; (3) The ceramic blank obtained in step (2) is air-dried to make the water content in the ceramic blank 8%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

[0024] Experimental Example 1: A ceramic pump body liner for a ceramic pump was prepared according to the methods described in Examples 1 to 7 and Comparative Example 1, and then the performance of the ceramic pump body liner was tested. The test results are shown in Table 1.

[0025] Table 1 Ceramic pump body performance test results

[0026] As can be seen from the above table, the ceramic components produced according to the present invention have good hardness, flexural strength and acid resistance, and can improve the compressive strength after soaking in acid for a period of time, indicating that the ceramic components produced by the present invention have long-term acid resistance. Moreover, after soaking in acid, surface microcracks, pores or low-strength impurities on the surface of the components can be further removed, stress concentration points can be reduced, and the remaining parts can be made denser, thereby improving the compressive strength.

[0027] Experimental Example 2: A ceramic pump cover for a ceramic pump was prepared according to the method described in Example 4, wherein the viscosity of the slurry in step (1) was controlled to be 500 mPa·s, 1000 mPa·s, 2000 mPa·s, 3000 mPa·s, 5000 mPa·s, 6000 mPa·s, and 8000 mPa·s. The performance of the ceramic pump cover was then tested, and the test results are shown in Table 2.

[0028] Table 2 Performance test results of ceramic pump covers prepared with different slurry viscosities

[0029] As can be seen from the table above, the slurry viscosity adjusted according to the present invention promotes uniform slurry distribution, reduces porosity and microcracks, and improves density after sintering, thereby achieving good hardness, flexural strength, and acid resistance. However, excessively high or low viscosity can easily lead to internal unevenness in the green body, easily forming pores and defects, and thus affecting the performance of the ceramic component.

[0030] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A slip casting process for ceramic components for ceramic pumps, characterized in that: The following steps are involved: (1) adding clay and water into a ball mill and grinding them to obtain a grinding material, and filtering the grinding material to obtain a slurry; the viscosity of the slurry is 1000 to 5000 mPa·s, and the solid content of the slurry is 70 to 85%; (2) The slurry obtained in step (1) is injected into a porous resin mold through a delivery pump. The injection is divided into the following three stages: in the first stage, the pressure of the delivery pump is controlled to be 0.2-0.7 MPa and the slurry is slowly injected into the porous resin mold; in the second stage, the pressure of the delivery pump is increased to 0.8-1.3 MPa and the slurry is continuously injected into the porous resin mold until the cavity of the porous resin mold is filled with the slurry; in the third stage, high-pressure injection is performed into the porous resin mold to increase the pressure in the porous resin mold to 1.4-3 MPa. The high-pressure injection time is 30-60 minutes. During the high-pressure injection process, the water and air outlet holes of the porous resin mold are kept open to discharge water and air in the porous resin mold, so that the slurry in the porous resin mold is solidified and formed to obtain a ceramic blank; (3) The ceramic blank obtained in step (2) is air-dried to reduce the water content in the ceramic blank to less than 10%, and then the ceramic blank is sintered, ground, and polished in sequence to obtain a ceramic component for a ceramic pump.

2. The slip casting process for ceramic components for ceramic pumps according to claim 1, characterized in that: The weight ratio of clay to water in step (1) is (2-2.5):

1.

3. The slip casting process for ceramic components for ceramic pumps according to claim 1, characterized in that: In step (1), the content of aluminum oxide in the clay is 15-20%, and the content of silicon dioxide is 65-70%.

4. The slip casting process for ceramic components for ceramic pumps according to claim 1, characterized in that: In step (1), clay, auxiliary materials and water are added into a ball mill for grinding to obtain a grinding material, wherein the amount of the auxiliary materials is 30-40% of the weight of the clay, and the auxiliary materials include any one or more combinations of feldspar powder, charcoal powder, wood clay and kaolin.

5. The slip casting process for ceramic components for ceramic pumps according to claim 1, characterized in that: The clay in step (1) is added with an auxiliary agent, which includes any one or more combinations of water glass, soda ash, yttrium nitrate, cobalt nitrate, and ammonium polyacrylate, and the amount of the auxiliary agent added is 0.5-1% of the weight of the clay.

6. The slip casting process for ceramic components for ceramic pumps according to claim 3, characterized in that: The auxiliary agent comprises the following components in parts by weight: 10-20 parts of water glass, 5-8 parts of soda ash, 1-4 parts of yttrium nitrate, 1-3 parts of cobalt nitrate, and 2-5 parts of ammonium polyacrylate, and the amount of cobalt nitrate is lower than that of yttrium nitrate.

7. The slip casting process for ceramic components for ceramic pumps according to claim 1, characterized in that: In the slurry in step (1), the proportion of particles with a particle size of less than 1 μm is less than 5%.

8. The slip casting process for ceramic components for ceramic pumps according to claim 1, characterized in that: The pores of the porous resin mold in step (2) have an average diameter of 1 to 10 μm, and the clamping pressure is maintained at 4 to 5 MPa.

9. The slip casting process for ceramic components for ceramic pumps according to claim 1, characterized in that: During the grouting process in step (2), the temperature of the slurry is maintained in the range of 20 to 30°C.

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