A rare earth-containing ceramic grinding ball and preparation method thereof

Abstract

The invention discloses a rare earth-containing ceramic grinding ball and a preparation method thereof, belonging to the technical field of grinding ball production. The preparation method of the ceramic grinding ball comprises the following steps: calcined kaolin, aluminum oxide, zirconium silicate, zirconium oxide, composite rare earth oxide and a binder are mixed and stirred, pure water is added thereto according to a mass ratio of 1:1, and ultrafine slurry is obtained by wet rough grinding and fine grinding, and the ultrafine slurry is dehydrated by filter pressing, flash evaporated at high temperature and broken up to obtain ultrafine powder, and the ultrafine powder is rolled into a shape, and then dried, pre-sintered, sintered and polished to obtain a ceramic grinding ball. The ceramic grinding ball prepared by the invention is added with a composite rare earth oxide composed of yttrium oxide and cerium oxide. After detection, the addition of the composite rare earth oxide helps to improve the wear resistance of the prepared ceramic grinding ball.

Description

Technical Field

[0001] The invention belongs to the technical field of grinding ball production, and in particular relates to a rare earth-containing ceramic grinding ball and a preparation method thereof. Background Art

[0002] Ball milling is an efficient material processing technology that achieves material refinement and mixing through the mechanical action between the grinding media and the material in the ball mill. Planetary ball mills, stirred mills, vibrating mills and other equipment can achieve micron-level fineness, while sand mills can achieve submicron and nanometer-level fineness. In order to achieve high fineness of powder, in addition to advanced grinding machinery, the selection of grinding media is also very critical. The ball milling media is mainly grinding balls, and the materials of the grinding balls include stainless steel, cemented carbide or ceramics. Among them, ceramics have the advantages of light weight, acid and alkali corrosion resistance and high temperature resistance compared to stainless steel and cemented carbide, and have better wear resistance.

[0003] At present, the commonly used ceramic grinding balls on the market are mainly alumina balls and zirconia balls. In comparison, pure zirconia balls have better toughness, strength and density, but are more expensive. Pure alumina balls have better hardness and wear resistance. Therefore, mixing zirconia and alumina should be able to obtain ceramic grinding balls with stronger comprehensive performance. However, zirconia powder is a lean material with relatively poor plasticity and fluidity. In the process of mixing with other components such as alumina, it is easy to produce problems such as loose internal structure and many holes, which affects the strength, hardness and wear resistance of the final prepared ceramic grinding balls. Therefore, it is necessary to improve the formula and preparation method of ceramic grinding balls. Summary of the invention

[0004] The invention provides a rare earth-containing ceramic grinding ball and a preparation method thereof, and aims to improve the strength, hardness and wear resistance of the ceramic grinding ball by improving the formula and preparation method of the ceramic grinding ball.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A method for preparing a rare earth-containing ceramic grinding ball comprises the following steps:

[0007] Ingredient homogenization: calcined kaolin, alumina, zirconium silicate, zirconium oxide, composite rare earth oxide and binder are mixed and stirred to obtain a mixture;

[0008] Ultrafine wet grinding: adding pure water to the mixture in a mass ratio of 1:1, rough grinding by wet method to obtain a coarse slurry of 600-800 mesh, and then fine grinding by wet method to obtain an ultrafine slurry of 8000-10000 mesh;

[0009] Drying and breaking up: the ultrafine slurry is filtered and dehydrated to obtain ultrafine slurry, and then the ultrafine slurry is flash evaporated at high temperature to obtain ultrafine powder cake, and then broken up to obtain ultrafine powder;

[0010] Molding: rolling the ultrafine powder into a shape to obtain a grinding ball blank;

[0011] Sintering: drying, pre-sintering and sintering the grinding ball blank to obtain a grinding ball;

[0012] Polishing: The grinding balls are polished to obtain ceramic grinding balls.

[0013] Furthermore, the mass ratio of the calcined kaolin, alumina, zirconium silicate, zirconium oxide, composite rare earth oxide and binder is 5-7.5:7.5-10:4-5:67.5-70.5:4-5:1-2.

[0014] Furthermore, the composite rare earth oxide is formed by mixing yttrium oxide and cerium oxide in a mass ratio of 1.4 to 1.5:1.

[0015] Furthermore, the binding agent is prepared by the following steps:

[0016] Phenolic resin was added to KH-560, and the mixture was stirred at a speed of 300 to 500 r / min for 40 to 50 min. Carbon black was then added thereto, the system was heated to 45 to 50° C., stirred at a constant temperature for 1 to 2 h, and cooled to room temperature to obtain a binder.

[0017] Furthermore, the usage ratio of KH-560, phenolic resin and carbon black is 100mL:10g:1-2g.

[0018] Furthermore, the temperature of the high-temperature flash evaporation is 320-350° C., and the time is 12-15 seconds.

[0019] Furthermore, the roll-forming process:

[0020] Take 10% of the total mass of ultrafine powder, add 0.5wt% of polyvinyl alcohol-water solution at a mass ratio of 5:1, stir and mix for 30 minutes, and then roll at a speed of 20-30r / min to obtain balls, and then spray pure water on the surface of the balls in the form of mist, add the remaining ultrafine powder, and then roll at a speed of 35-40r / min to obtain grinding ball blanks.

[0021] Furthermore, the pre-firing includes the following process:

[0022] The temperature is increased to 450-500°C at a heating rate of 1-2°C / min, and kept at this temperature for 3-4 hours. The temperature is then increased to 870-900°C at a heating rate of 1-1.5°C / min, and kept at this temperature for 3-4 hours. After the holding is completed, the furnace is cooled to room temperature to complete the pre-firing process.

[0023] Furthermore, the sintering includes the following process:

[0024] The temperature is increased to 1150-1200°C at a heating rate of 1°C / min, and kept at this temperature for 1-1.5 hours. The temperature is then increased to 1500-1550°C at a heating rate of 1°C / min, and kept at this temperature for 3-4 hours. After the holding is completed, the furnace is cooled to room temperature, and the material is discharged to complete the sintering process.

[0025] Furthermore, the rare earth-containing ceramic grinding ball is prepared by the above preparation method.

[0026] Beneficial effects of the present invention:

[0027] The present invention provides a rare earth-containing ceramic grinding ball and a preparation method thereof. Specifically, a composite rare earth oxide composed of yttrium oxide and cerium oxide is added to the ceramic grinding ball prepared by the present invention. After testing, it is found that the addition of the composite rare earth oxide helps to improve the wear resistance of the prepared ceramic grinding ball. The specific analysis is as follows: first, the main raw material in the ultrafine powder is zirconium oxide powder, but zirconium oxide powder belongs to a lean material, and the plasticity and fluidity of the lean material are relatively poor, while rare earth oxide is a good surfactant, which can improve the wetting performance of the material. The addition of rare earth oxide can promote the material between particles to fill the pores, reduce the porosity of the material, improve the density, and thus help to improve the wear resistance; then, the addition of yttrium oxide helps to reduce the sintering temperature of the ceramic grinding ball, thereby improving the density between the ingredients, thereby improving the wear resistance; finally, the porosity of the ceramic grinding ball can be further reduced by compounding yttrium oxide and cerium oxide, that is, the density is improved, thereby improving the wear resistance of the ceramic grinding ball.

[0028] At the same time, the ceramic grinding balls prepared by the present invention are added with calcined kaolin, which is rich in silicon dioxide. Silicon dioxide and aluminum oxide are synthesized into mullite under high temperature conditions. The synthesis of mullite will produce volume expansion, which is used to offset the internal stress generated by the volume contraction during the sintering process of the grinding balls, thereby improving the strength of the finally prepared ceramic grinding balls.

[0029] Next, a self-made binder is added to the ceramic grinding ball prepared by the present invention, and the binder is prepared by KH-560 modified phenolic resin and then doped with filler graphite. The present invention introduces silicon oxygen bonds into the phenolic resin, which helps to improve the thermal stability and mechanical properties of the phenolic resin, and at the same time, improves the wetting ability and adhesion between the phenolic resin and the remaining grinding ball ingredient powders, thereby improving the compactness of the grinding ball, and finally achieving the purpose of improving the strength of the ceramic grinding ball.

[0030] Finally, the binder prepared by the present invention contains graphite, and the silicon dioxide and aluminum oxide in the graphite and calcined kaolin will form a high-hardness composite during the high-temperature sintering process. ,at the same time, Able to form dense and high hardness during high temperature oxidation process layer, by converting the alumina powder into a dense layer, which improves the dispersibility of alumina in the ceramic grinding balls, thereby helping to improve the hardness of the finally prepared ceramic grinding balls. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] A method for preparing a rare earth-containing ceramic grinding ball comprises the following steps:

[0034] Ingredients: Calcined kaolin, alumina, zirconium silicate, zirconium oxide, composite rare earth oxide and binder were weighed in a mass ratio of 5:7.5:4:67.5:4:1, wherein the composite rare earth oxide was prepared by mixing yttrium oxide and cerium oxide in a mass ratio of 1.4:1, and the binder was prepared by the following steps: 10 g of phenolic resin was added to 100 mL of KH-560, stirred and mixed at a speed of 300 r / min for 40 min, and then 1 g of carbon black was added thereto. The temperature was raised to 45°C, stirred at a constant temperature for 1 hour, and cooled to room temperature to obtain a binder, wherein calcined kaolin was purchased from Inner Mongolia Sanxin Kaolin Co., Ltd.; alumina was purchased from Hunan Jiutai Metallurgical Technology Co., Ltd.; zirconium silicate and zirconium oxide were both purchased from Inner Mongolia Minghai Zirconium Industry Co., Ltd.; yttrium oxide and cerium oxide were both purchased from Ningbo Jinlei Nanomaterial Technology Co., Ltd.; KH-560 and phenolic resin (solid content 70%) were both purchased from Sinopharm Chemical Reagent Co., Ltd.; carbon black was purchased from Wuhai Black Cat Carbon Black Co., Ltd.

[0035] Homogenization: The calcined kaolin, alumina, zirconium silicate, zirconium oxide and auxiliary materials are mixed and stirred for 1 hour to ensure that the various raw material components are evenly distributed to avoid differences in ceramic properties caused by uneven components. After mixing and stirring, a mixture is obtained.

[0036] Ultrafine wet grinding: add pure water to the above mixture at a mass ratio of 1:1, and then place it in a QM-3SP04 planetary ball mill for wet coarse grinding to obtain a 600-mesh coarse slurry, and then place the coarse slurry in a RWM-1 horizontal sand mill for wet fine grinding to obtain an 8000-mesh ultrafine slurry. The process of coarse grinding first and then fine grinding ensures that the slurry reaches the target particle size and increases the plasticity of the slurry.

[0037] Drying: Place the above-mentioned ultrafine slurry in a filter press for filtration and dehydration to obtain ultrafine slurry, and then subject the ultrafine slurry to high-temperature flash evaporation. The temperature is set to 320°C and the time is set to 12s. The ultrafine slurry is transformed into a dry powder state suitable for molding through high-temperature flash evaporation, that is, an ultrafine powder cake is obtained.

[0038] Break up: The ultrafine powder cake after drying has lumps and needs to improve fluidity. Therefore, the ultrafine powder cake needs to be stirred and broken up. The stirring time is 1 hour. After stirring, ultrafine powder is obtained.

[0039] Molding: The above-mentioned ultrafine powder is roll-molded. The rolling molding process is as follows: 10% of the total mass of the ultrafine powder is taken, and a polyvinyl alcohol-water solution with a mass fraction of 0.5wt% is added thereto at a mass ratio of 5:1, and the mixture is stirred for 30 minutes, and then rolled at a speed of 20r / min to obtain a ball, and then pure water is sprayed on the surface of the ball in the form of mist, and the remaining ultrafine powder is added, and then rolled at a speed of 35r / min to allow the ultrafine powder to wrap the ball, and finally rolled into a spherical shape to obtain a grinding ball blank, wherein polyvinyl alcohol (Mw9000-10000) was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0040] Sintering: The above-mentioned grinding ball blank is placed at 180°C and dried for 12 hours, taken out, and then pre-burned: the temperature is increased to 450°C at a heating rate of 2°C / min, kept warm for 3 hours, and then the temperature is increased to 870°C at a heating rate of 1.5°C / min, kept warm for 3 hours. After the insulation is completed, it is cooled to room temperature with the furnace to complete the pre-burning process. The pre-burning is used to remove free water and part of the bound water in the grinding ball blank, and at the same time remove part of the organic matter and gas. The internal structure of the grinding ball blank is made more uniform and defects are reduced through pre-burning; after the pre-burning is completed, sintering is carried out, and the sintering process is as follows: the temperature is increased to 1150°C at a heating rate of 1°C / min, kept warm for 1 hour, and then the temperature is increased to 1500°C at a heating rate of 1°C / min, kept warm for 3 hours. After the insulation is completed, it is cooled to room temperature with the furnace, discharged, and the grinding ball is obtained.

[0041] Polishing: The above grinding balls are polished to obtain ceramic grinding balls.

[0042] Screening: The ceramic grinding balls are screened according to particle size and then packaged and stored separately.

[0043] Example 2

[0044] A method for preparing a rare earth-containing ceramic grinding ball comprises the following steps:

[0045] Ingredients: Calcined kaolin, alumina, zirconium silicate, zirconium oxide, composite rare earth oxide and binder were weighed in a mass ratio of 6:8:4.5:70:5:1, wherein the composite rare earth oxide was prepared by mixing yttrium oxide and cerium oxide in a mass ratio of 1.5:1, and the binder was prepared by the following steps: 10 g of phenolic resin was added to 100 mL of KH-560, stirred and mixed at a speed of 500 r / min for 50 min, and then 2 g of carbon black was added thereto, and the system was heated to 400 °C. The mixture was heated to 50°C and stirred at a constant temperature for 2 hours. The mixture was cooled to room temperature to obtain a binder, wherein calcined kaolin was purchased from Inner Mongolia Sanxin Kaolin Co., Ltd.; alumina was purchased from Hunan Jiutai Metallurgical Technology Co., Ltd.; zirconium silicate and zirconium oxide were both purchased from Inner Mongolia Minghai Zirconium Industry Co., Ltd.; yttrium oxide and cerium oxide were both purchased from Ningbo Jinlei Nanomaterial Technology Co., Ltd.; KH-560 and phenolic resin (solid content 70%) were both purchased from Sinopharm Chemical Reagent Co., Ltd.; carbon black was purchased from Wuhai Black Cat Carbon Black Co., Ltd.

[0046] Homogenization: The calcined kaolin, alumina, zirconium silicate, zirconium oxide and auxiliary materials are mixed and stirred for 2 hours to ensure that the various raw material components are evenly distributed to avoid differences in ceramic properties caused by uneven components. After mixing and stirring, a mixture is obtained.

[0047] Ultrafine wet grinding: add pure water to the above mixture at a mass ratio of 1:1, and then place it in a QM-3SP04 planetary ball mill for wet coarse grinding to obtain a 700-mesh coarse slurry, and then place the coarse slurry in a RWM-1 horizontal sand mill for wet fine grinding to obtain a 10,000-mesh ultrafine slurry. The process of coarse grinding first and then fine grinding ensures that the slurry reaches the target particle size and increases the plasticity of the slurry.

[0048] Drying: Place the above-mentioned ultrafine slurry in a filter press for filtration and dehydration to obtain ultrafine slurry, and then subject the ultrafine slurry to high-temperature flash evaporation. The temperature is set to 340°C and the time is set to 15s. The ultrafine slurry is transformed into a dry powder state suitable for molding through high-temperature flash evaporation, that is, an ultrafine powder cake is obtained.

[0049] Break up: The ultrafine powder cake after drying has lumps and needs to improve fluidity. Therefore, the ultrafine powder cake needs to be stirred and broken up. The stirring time is 2 hours. After stirring, ultrafine powder is obtained.

[0050] Molding: The above-mentioned ultrafine powder is roll-molded. The rolling molding process is as follows: 10% of the total mass of the ultrafine powder is taken, and a polyvinyl alcohol-water solution with a mass fraction of 0.5wt% is added thereto at a mass ratio of 5:1, and the mixture is stirred for 30 minutes, and then rolled at a speed of 30r / min to obtain a ball, and then pure water is sprayed on the surface of the ball in the form of mist, and the remaining ultrafine powder is added, and then rolled at a speed of 40r / min to allow the ultrafine powder to wrap the ball, and finally rolled into a spherical shape to obtain a grinding ball blank, wherein polyvinyl alcohol (Mw9000-10000) was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0051] Sintering: The above-mentioned grinding ball blank is placed at 200°C and dried for 12 hours, taken out, and then pre-burned: the temperature is increased to 480°C at a heating rate of 1°C / min, and the temperature is kept for 4 hours. The temperature is then increased to 880°C at a heating rate of 1°C / min, and the temperature is kept for 4 hours. After the temperature is kept, the blank is cooled to room temperature with the furnace to complete the pre-burning process. The pre-burning is used to remove free water and part of the bound water in the grinding ball blank, and at the same time remove part of the organic matter and gas. The internal structure of the grinding ball blank is made more uniform and defects are reduced through pre-burning. After the pre-burning is completed, sintering is carried out. The sintering process is as follows: the temperature is increased to 1170°C at a heating rate of 1°C / min, and the temperature is kept for 1.5 hours. The temperature is then increased to 1530°C at a heating rate of 1°C / min, and the temperature is kept for 4 hours. After the temperature is kept, the blank is cooled to room temperature with the furnace, and the material is discharged to obtain the grinding ball.

[0052] Polishing: The above grinding balls are polished to obtain ceramic grinding balls.

[0053] Screening: The ceramic grinding balls are screened according to particle size and then packaged and stored separately.

[0054] Example 3

[0055] A method for preparing a rare earth-containing ceramic grinding ball comprises the following steps:

[0056] Ingredients: Calcined kaolin, alumina, zirconium silicate, zirconium oxide, composite rare earth oxide and binder were weighed in a mass ratio of 7.5:10:5:70.5:5:2, wherein the composite rare earth oxide was prepared by mixing yttrium oxide and cerium oxide in a mass ratio of 1.5:1, and the binder was prepared by the following steps: 10 g of phenolic resin was added to 100 mL of KH-560, stirred and mixed at a speed of 500 r / min for 50 min, and then 2 g of carbon black was added thereto. The temperature was raised to 50°C, stirred at a constant temperature for 2 hours, and cooled to room temperature to obtain a binder, wherein calcined kaolin was purchased from Inner Mongolia Sanxin Kaolin Co., Ltd.; alumina was purchased from Hunan Jiutai Metallurgical Technology Co., Ltd.; zirconium silicate and zirconium oxide were both purchased from Inner Mongolia Minghai Zirconium Industry Co., Ltd.; yttrium oxide and cerium oxide were both purchased from Ningbo Jinlei Nanomaterial Technology Co., Ltd.; KH-560 and phenolic resin (solid content 70%) were both purchased from Sinopharm Chemical Reagent Co., Ltd.; carbon black was purchased from Wuhai Black Cat Carbon Black Co., Ltd.

[0057] Homogenization: The calcined kaolin, alumina, zirconium silicate, zirconium oxide and auxiliary materials are mixed and stirred for 2 hours to ensure that the various raw material components are evenly distributed to avoid differences in ceramic properties caused by uneven components. After mixing and stirring, a mixture is obtained.

[0058] Ultrafine wet grinding: add pure water to the above mixture at a mass ratio of 1:1, and then place it in a QM-3SP04 planetary ball mill for wet coarse grinding to obtain 800 mesh coarse slurry, and then place the coarse slurry in a RWM-1 horizontal sand mill for wet fine grinding to obtain 10000 mesh ultrafine slurry. The process of coarse grinding first and then fine grinding ensures that the slurry reaches the target particle size and increases the plasticity of the slurry.

[0059] Drying: Place the above-mentioned ultrafine slurry in a filter press for filtration and dehydration to obtain ultrafine slurry, and then subject the ultrafine slurry to high-temperature flash evaporation. The temperature is set to 350°C and the time is set to 15s. The ultrafine slurry is transformed into a dry powder state suitable for molding through high-temperature flash evaporation, that is, an ultrafine powder cake is obtained.

[0060] Break up: The ultrafine powder cake after drying has lumps and needs to improve fluidity. Therefore, the ultrafine powder cake needs to be stirred and broken up. The stirring time is 2 hours. After stirring, ultrafine powder is obtained.

[0061] Molding: The above-mentioned ultrafine powder is roll-molded. The rolling molding process is as follows: 10% of the total mass of the ultrafine powder is taken, and a polyvinyl alcohol-water solution with a mass fraction of 0.5wt% is added thereto at a mass ratio of 5:1, and the mixture is stirred for 30 minutes, and then rolled at a speed of 30r / min to obtain a ball, and then pure water is sprayed on the surface of the ball in the form of mist, and the remaining ultrafine powder is added, and then rolled at a speed of 40r / min to allow the ultrafine powder to wrap the ball, and finally rolled into a spherical shape to obtain a grinding ball blank, wherein polyvinyl alcohol (Mw9000-10000) was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0062] Sintering: The above-mentioned grinding ball blank is placed at 200°C and dried for 12 hours, taken out, and then pre-burned: the temperature is increased to 500°C at a heating rate of 1.5°C / min, kept for 4 hours, and then the temperature is increased to 900°C at a heating rate of 1°C / min, kept for 4 hours. After the insulation is completed, it is cooled to room temperature with the furnace to complete the pre-burning process. The pre-burning is used to remove free water and part of the bound water in the grinding ball blank, and at the same time remove part of the organic matter and gas. The pre-burning makes the internal structure of the grinding ball blank more uniform and reduces defects; after the pre-burning is completed, sintering is carried out, and the sintering process is as follows: the temperature is increased to 1200°C at a heating rate of 1°C / min, kept for 1.5 hours, and then the temperature is increased to 1550°C at a heating rate of 1°C / min, kept for 4 hours. After the insulation is completed, it is cooled to room temperature with the furnace, and the material is discharged to obtain the grinding ball.

[0063] Polishing: The above grinding balls are polished to obtain ceramic grinding balls.

[0064] Screening: The ceramic grinding balls are screened according to particle size and then packaged and stored separately.

[0065] Comparative Example 1

[0066] Comparative Example 1 is the control group of Example 2, in which the composite rare earth oxide in Example 2 is replaced by yttrium oxide, and the other ingredient types, ingredient amounts and preparation methods remain unchanged to obtain ceramic grinding balls.

[0067] Comparative Example 2

[0068] Comparative Example 2 is the control group of Example 2, in which the composite rare earth oxide in Example 2 is replaced with cerium oxide, and the other ingredient types, ingredient amounts and preparation methods remain unchanged to obtain ceramic grinding balls.

[0069] Comparative Example 3

[0070] Comparative Example 3 is the control group of Example 2, in which the composite rare earth oxide in Example 2 is removed, and the other ingredient types, ingredient amounts and preparation methods remain unchanged, thereby obtaining ceramic grinding balls.

[0071] Comparative Example 4

[0072] Comparative Example 4 is the control group of Example 2, in which the binder in Example 2 is replaced with phenolic resin, and the other ingredient types, ingredient amounts and preparation methods remain unchanged to obtain ceramic grinding balls.

[0073] The ceramic grinding balls prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were subjected to performance tests. The performance test process is as follows, and the performance test results are shown in Table 1:

[0074] Density: The density of the ceramic grinding balls was tested using a DX-6000 density tester; Mohs hardness. The density of the ceramic grinding balls was tested using the American Mineralab Mohs hardness tester. Strength: The compressive strength of the ceramic grinding balls was tested using a CMT6104 electronic universal testing machine. Self-wear rate: The self-wear rate of the ceramic grinding balls was tested using a QM-3SP04 planetary ball mill at a speed of 300r / min in a nylon ball mill with an inner diameter of 110mm.

[0075] Table 1 Performance test results

[0076]

[0077] It can be seen from Table 1 that the ceramic grinding balls prepared in Examples 1 to 3 of the present invention have more excellent density, hardness, strength and wear resistance. Specifically, by comparing the data of Example 2 with Comparative Examples 1 to 3, it can be seen that the addition of composite rare earth oxides in the present invention can significantly improve the wear resistance of the ceramic grinding balls finally prepared; by comparing the data of Example 2 with Comparative Example 4, it can be seen that the use of KH-560 modified phenolic resin in the present invention, and then doping with filler graphite, can significantly improve the hardness and strength of the ceramics finally prepared.

[0078] It should be noted that, in this article, terms such as "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or equipment that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment.

[0079] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a rare earth-containing ceramic grinding ball, characterized in that: The following steps are involved: Ingredient homogenization: calcined kaolin, alumina, zirconium silicate, zirconium oxide, composite rare earth oxide and binder are mixed and stirred to obtain a mixture; Ultrafine wet grinding: adding pure water to the mixture in a mass ratio of 1:1, rough grinding by wet method to obtain a coarse slurry of 600-800 mesh, and then fine grinding by wet method to obtain an ultrafine slurry of 8000-10000 mesh; Drying and breaking up: the ultrafine slurry is filtered and dehydrated to obtain ultrafine slurry, and then the ultrafine slurry is flash evaporated at high temperature to obtain ultrafine powder cake, and then broken up to obtain ultrafine powder; Molding: rolling the ultrafine powder into a shape to obtain a grinding ball blank; Sintering: drying, pre-sintering and sintering the grinding ball blank to obtain a grinding ball; Polishing: polishing the grinding balls to obtain ceramic grinding balls; The mass ratio of the calcined kaolin, alumina, zirconium silicate, zirconium oxide, composite rare earth oxide and binder is 5-7.5:7.5-10:4-5:67.5-70.5:4-5:1-2; The composite rare earth oxide is prepared by mixing yttrium oxide and cerium oxide in a mass ratio of 1.4 to 1.5:1; The binding agent is prepared by the following steps: Phenolic resin was added to KH-560, and the mixture was stirred at a speed of 300 to 500 r / min for 40 to 50 min. Carbon black was then added thereto, the system was heated to 45 to 50° C., stirred at a constant temperature for 1 to 2 h, and cooled to room temperature to obtain a binder.

2. The method for preparing a rare earth-containing ceramic grinding ball according to claim 1, characterized in that: The dosage ratio of the KH-560, phenolic resin and carbon black is 100 mL: 10 g: 1-2 g.

3. The method for preparing a rare earth-containing ceramic grinding ball according to claim 1, characterized in that: The temperature of the high-temperature flash evaporation is 320-350° C., and the time is 12-15 seconds.

4. The method for preparing a rare earth-containing ceramic grinding ball according to claim 1, characterized in that: The roll-forming process: Take 10% of the total mass of ultrafine powder, add 0.5wt% of polyvinyl alcohol-water solution at a mass ratio of 5:1, stir and mix for 30 minutes, and then roll at a speed of 20-30r / min to obtain balls, and then spray pure water on the surface of the balls in the form of mist, add the remaining ultrafine powder, and then roll at a speed of 35-40r / min to obtain grinding ball blanks.

5. The method for preparing a rare earth-containing ceramic grinding ball according to claim 1, characterized in that: The pre-firing process includes the following steps: The temperature is increased to 450-500°C at a heating rate of 1-2°C / min, and kept at this temperature for 3-4 hours. The temperature is then increased to 870-900°C at a heating rate of 1-1.5°C / min, and kept at this temperature for 3-4 hours. After the holding is completed, the furnace is cooled to room temperature to complete the pre-firing process.

6. The method for preparing a rare earth-containing ceramic grinding ball according to claim 1, characterized in that: The sintering process includes the following steps: The temperature is increased to 1150-1200°C at a heating rate of 1°C / min, and kept at this temperature for 1-1.5 hours. The temperature is then increased to 1500-1550°C at a heating rate of 1°C / min, and kept at this temperature for 3-4 hours. After the holding is completed, the furnace is cooled to room temperature, and the material is discharged to complete the sintering process.

7. A rare earth-containing ceramic grinding ball, characterized in that: The invention is prepared by the preparation method described in any one of claims 1 to 6.

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