Ceramic powder and powder preparation method of ceramic sheet substrate

Abstract

The invention belongs to the technical field of waste ceramic sheet recycling, and discloses a ceramic sheet substrate powdering method, which comprises the following steps: sintering a ceramic sheet substrate waste material for at least three times to obtain an intermediate, crushing and ball-milling the prepared intermediate, mixing with a solvent and a dispersing agent, and sanding to obtain slurry, carrying out spray granulation on the prepared slurry to obtain ceramic powder; in the sintering process of intermediate preparation, the sintering temperature is 800-1400 DEG C, and the sintering time is 1.5-3 h. According to the preparation method, the ceramic sheet is sintered, so that unit cells of the ceramic sheet continuously grow in a high-temperature state, the number of grain boundaries of the ceramic sheet is further reduced, the brittleness of the ceramic sheet is increased, the ceramic sheet is easier to grind, and in addition, the preparation method has the advantages that the preparation process is simple, and the preparation cost is low. The invention also discloses the ceramic powder prepared by using the powder preparation method of the ceramic sheet substrate.

Description

Technical Field

[0001] The present application relates to the technical field of recycling ceramic waste sheets, and in particular to a method for preparing ceramic powder and a ceramic thin sheet substrate. Background Art

[0002] Nowadays, ceramic substrates are increasingly used in new energy and electronic chips. A variety of ceramic materials can be used in many different units, and zirconia ceramics are mainly used in high-tech and precision fields. The surface defect control is very strict, and no defects such as obvious patterns, scratches, holes, cracks, pits, etc. are allowed. This leads to a large number of defective samples in the production process. At the current level in the industry, the defect rate is as high as 40%, which is a very large number. Therefore, it is necessary to develop a process to recycle it and turn it back into raw materials, and try to keep various properties the same as the raw materials, including a specific surface area within a certain range and ultra-fine particle size distribution, and very few impurities introduced.

[0003] This type of ceramic sheet substrate is generally prepared using the tape casting sintering method. First, the powder raw material is dispersed through the ingredients, and mixed with the solvent additive to form a slurry. Then, the slurry is tape cast into a green sheet of precise specifications through a tape casting machine. Finally, the binder is removed and sintered into ceramic porcelain. After quality inspection, it is divided into defective samples and qualified samples. At this time, the defective samples are the raw materials that we need to turn into powder. The current mainstream method for processing defective samples is to recover the metal by acid dissolution precipitation and then re-powder. This method is highly polluting, takes a long time, and is costly.

[0004] At the same time, in the process of grinding ceramic sheets, grinding balls are often used for grinding to a finer particle size, and the grinding balls are mostly yttrium-stabilized zirconia balls. During the high-speed grinding process, this type of grinding ball can easily introduce the yttrium in the grinding ball into the ball-milled material, causing an increase in the yttrium impurity in the ball-milled material.

[0005] Chinese patent application 202110658713.7 discloses a method for recycling zirconia ceramic waste, comprising: cleaning zirconia ceramic waste; crushing the cleaned zirconia ceramic waste with a double roller mill to obtain crushed material; crushing the crushed material with a jet mill to obtain a crushed material; mixing the crushed material with water to obtain a slurry with a solid content of 15% to 30%, grinding the slurry with a grinder, standing after grinding, separating the clear liquid, and obtaining a slurry with a solid content of 30% to 45%; spray drying the slurry to obtain zirconia ceramic recycled powder; pressing the zirconia ceramic recycled powder, sintering and forming, and obtaining a regenerated zirconia ceramic device;

[0006] This scheme recycles zirconia ceramic waste through pure physical methods to obtain recycled powder with uniform particle size distribution, and prepares it into zirconia ceramic devices with excellent performance through pressing and sintering. The recycling process has low energy consumption, low cost, short process flow, easy implementation, and high efficiency, thus realizing the recycling and reuse of zirconia. However, this scheme does not use ball milling technology in the crushing process.

[0007] The problem that this solution needs to solve is: how to provide a method for powdering ceramic thin-sheet substrates that can recycle ceramic waste by ball milling technology without introducing too much yttrium as an impurity. Summary of the invention

[0008] The purpose of the present application is to provide a method for powdering a ceramic thin sheet substrate. By sintering the ceramic thin sheet, the crystal cells of the ceramic thin sheet continue to grow under high temperature conditions, thereby reducing the number of grain boundaries of the ceramic thin sheet, thereby increasing the brittleness of the ceramic thin sheet and making it easier to grind. In addition, the present application also discloses a ceramic powder.

[0009] To achieve the above object, the present application discloses a method for preparing a ceramic thin-sheet substrate, comprising the following steps:

[0010] Step 1: sintering the ceramic thin-sheet substrate waste at least three times to obtain an intermediate;

[0011] Step 2: crushing and ball-milling the intermediate obtained in step 1, mixing with a solvent and a dispersant, and sand-milling to obtain a slurry;

[0012] Step 3: spray granulating the slurry obtained in step 2 to obtain ceramic powder;

[0013] In the step 1, the temperature of the sintering process is 800-1400° C. and the time is 1.5-3 hours.

[0014] Preferably, the rotation speed of the sanding process in step 2 is 800-1200 r / min.

[0015] Preferably, in step 1, the sintering is performed three times;

[0016] During the first sintering process, the sintering temperature is 800-900°C and the time is 1.5-3h;

[0017] During the second sintering process, the sintering temperature is 900-1100°C (excluding 900°C), and the sintering time is 1.5-3h;

[0018] During the third sintering process, the sintering temperature is 1100 to 1400° C. (excluding 1400° C.), and the sintering time is 1.5 to 3 hours.

[0019] Preferably, the ceramic sheet substrate is a zirconia ceramic sheet substrate.

[0020] Preferably, during the ball milling process of step 2, the mass ratio of the grinding balls to the crushed intermediate is 4-6:4-6;

[0021] The grinding balls are composed of large-size grinding balls, medium-size grinding balls and small-size grinding balls, and the diameter of the large-size grinding balls is 15±2mm, the diameter of the medium-size grinding balls is 10±2mm, and the diameter of the small-size grinding balls is 5±2mm.

[0022] Preferably, the mass ratio of the large-diameter grinding balls, the medium-diameter grinding balls, and the small-diameter grinding balls is 4:4:2-3.

[0023] Preferably, during the spray granulation process, the air inlet temperature is 220-280° C., the outlet temperature is 100-140° C., and the atomizer speed is 10000-14000 r / min.

[0024] In addition, the present application also discloses a ceramic powder, which is prepared by the above-mentioned powder making method of the ceramic thin sheet substrate.

[0025] Preferably, the specific surface area of ​​the ceramic powder is 9.5 to 11.5 m 2 / g, and the impurity yttrium content is less than 100ppm.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a powder making method for a ceramic thin slice substrate. The method sinters the ceramic thin slice so that the crystal cells of the ceramic thin slice continue to grow under high temperature, thereby reducing the number of grain boundaries of the ceramic thin slice, thereby increasing the brittleness of the ceramic thin slice and making it easier to grind, thereby reducing the rotation speed of a ball mill and a grinder during subsequent ball milling and grinding, thereby reducing the amount of yttrium impurity introduced. DETAILED DESCRIPTION

[0028] In the description of the present invention, it should be noted that, if the specific conditions are not specified in the examples, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0029] Example 1

[0030] Step 1: Sintering the ceramic thin-sheet substrate waste once, twice, and three times to obtain an intermediate, wherein the temperature of the first sintering is 800° C. and the time is 3 h;

[0031] The secondary sintering temperature is 800°C and the time is 3h;

[0032] The temperature of the third sintering is 800℃ and the time is 3h;

[0033] Step 2: The intermediate prepared in step 1 is crushed into a block intermediate of about 0.5 cm×0.5 cm, and then the block intermediate is put into a ball mill at a mass ratio of grinding balls to intermediates of 4:6, wherein the grinding balls are yttrium-stabilized zirconia grinding balls with a particle size of 10±2 mm;

[0034] The powder obtained after ball milling is mixed with water and B1 dispersant in a mass ratio of 10:20:0.03 and put into a sand mill for sand milling at a speed of 800r / min for 4h. During the sand milling, an iron remover is connected to remove iron, and finally a slurry is obtained;

[0035] Step 3: Spray granulate the slurry obtained in step 2 to obtain ceramic powder. During the spray granulation process, the inlet air temperature is 220°C, the outlet temperature is 100°C, and the atomizer speed is 14000r / min.

[0036] Example 2

[0037] Step 1: Sintering the ceramic thin-sheet substrate waste once, twice, and three times to obtain an intermediate, wherein the temperature of the first sintering is 1400° C. and the time is 1.5 h;

[0038] The secondary sintering temperature is 1400°C and the time is 1.5h;

[0039] The temperature of the third sintering is 1400°C and the time is 1.5h;

[0040] Step 2: The intermediate prepared in step 1 is crushed into a block intermediate of about 0.5 cm×0.5 cm, and then the block intermediate is put into a ball mill at a mass ratio of grinding balls to intermediates of 6:4, wherein the grinding balls are yttrium-stabilized zirconia grinding balls with a particle size of 10±2 mm;

[0041] The powder obtained after ball milling is mixed with water and B1 dispersant in a mass ratio of 10:20:0.03 and put into a sand mill for sand milling at a speed of 1200r / min for 1.5h. During the sand milling, an iron remover is connected to remove iron, and finally a slurry is obtained;

[0042] Step 3: spray granulate the slurry obtained in step 2 to obtain ceramic powder. During the spray granulation process, the inlet air temperature is 280°C, the outlet temperature is 140°C, and the atomizer speed is 10000r / min.

[0043] Example 3

[0044] Step 1: sintering the ceramic thin-sheet substrate waste once, twice, and three times to obtain an intermediate, wherein the temperature of the first sintering is 1100° C. and the time is 2 h;

[0045] The secondary sintering temperature is 1100°C and the time is 2h;

[0046] The temperature of the third sintering is 1100°C and the time is 2h;

[0047] Step 2: The intermediate prepared in step 1 is crushed into a block intermediate of about 0.5 cm×0.5 cm, and then the block intermediate is put into a ball mill at a mass ratio of grinding balls to intermediates of 5:5, wherein the grinding balls are yttrium-stabilized zirconia grinding balls with a particle size of 10±2 mm;

[0048] The powder obtained after ball milling is mixed with water and B1 dispersant in a mass ratio of 10:20:0.03 and put into a sand mill for sand milling at a speed of 1000r / min for 2.5h. During the sand milling, an iron remover is connected to remove iron, and finally a slurry is obtained;

[0049] Step 3: spray granulate the slurry obtained in step 2 to obtain ceramic powder. During the spray granulation process, the inlet air temperature is 250°C, the outlet temperature is 120°C, and the atomizer speed is 12000r / min.

[0050] Example 4

[0051] The method is basically the same as Example 1, except that the primary sintering temperature is 850°C and the time is 3h;

[0052] The secondary sintering temperature is 1000°C and the time is 3h;

[0053] The temperature of the three sinterings is 1300℃ and the time is 3h.

[0054] Example 5

[0055] The method is basically the same as Example 1, except that the primary sintering temperature is 1300°C and the time is 3h;

[0056] The secondary sintering temperature is 1000°C and the time is 3h;

[0057] The temperature of the third sintering is 850℃ and the time is 3h.

[0058] Example 6

[0059] The method is basically the same as Example 1, except that the primary sintering temperature is 850°C and the time is 3h;

[0060] The secondary sintering temperature is 1300°C and the time is 3h;

[0061] The temperature of the three sinterings is 1000℃ and the time is 3h.

[0062] Example 7

[0063] The method is basically the same as Example 1, except that step 2 is specifically as follows:

[0064] Step 2: The intermediate prepared in step 1 is crushed into a block intermediate of about 0.5 cm×0.5 cm, and then the block intermediate is put into a ball mill at a mass ratio of grinding balls to intermediates of 4:6, wherein the grinding balls are yttrium-stabilized zirconia grinding balls with a particle size of 10±2 mm;

[0065] The powder obtained after ball milling is mixed with water and B1 dispersant in a mass ratio of 10:20:0.03 and put into a sand mill for sand milling at a speed of 800r / min for 4h. During the sand milling, an iron remover is connected to remove iron, and finally a slurry is obtained;

[0066] The grinding balls are composed of large-size grinding balls, medium-size grinding balls and small-size grinding balls. The diameter of the large-size grinding balls is 15±2mm, the diameter of the medium-size grinding balls is 10±2mm, the diameter of the small-size grinding balls is 5±2mm, and the mass ratio of the large-size grinding balls, the medium-size grinding balls and the small-size grinding balls is 4:4:2.

[0067] Example 8

[0068] The method is basically the same as Example 1, except that step 2 is specifically as follows:

[0069] Step 2: The intermediate prepared in step 1 is crushed into a block intermediate of about 0.5 cm×0.5 cm, and then the block intermediate is put into a ball mill at a mass ratio of grinding balls to intermediates of 4:6, wherein the grinding balls are yttrium-stabilized zirconia grinding balls with a particle size of 10±2 mm;

[0070] The powder obtained after ball milling is mixed with water and B1 dispersant in a mass ratio of 10:20:0.03 and put into a sand mill for sand milling at a speed of 800r / min for 4h. During the sand milling, an iron remover is connected to remove iron, and finally a slurry is obtained;

[0071] The grinding balls are composed of large-diameter grinding balls and small-diameter grinding balls, and the diameter of the large-diameter grinding balls is 15±2 mm, the diameter of the small-diameter grinding balls is 5±2 mm, and the mass ratio of the large-diameter grinding balls to the small-diameter grinding balls is 4:2.

[0072] Comparative Example 1

[0073] It is basically the same as Example 1, except that step 1 is specifically as follows:

[0074] Step 1: Sinter the ceramic thin-sheet substrate waste once to obtain an intermediate, and the sintering temperature is 800° C. and the time is 3 hours.

[0075] Comparative Example 2

[0076] It is basically the same as Example 1, except that step 1 is specifically as follows:

[0077] Step 1: Sintering the ceramic sheet substrate waste twice to obtain an intermediate, and the temperature of the first sintering is 800° C. and the time is 3 h;

[0078] The secondary sintering temperature is 800℃ and the time is 3h.

[0079] Comparative Example 3

[0080] It is basically the same as Example 1, except that step 1 is specifically as follows:

[0081] Step 1: sintering the ceramic sheet substrate waste three times to obtain an intermediate, and the temperature of the first sintering is 600° C. and the time is 3 hours;

[0082] The secondary sintering temperature is 600 °C and the time is 3 h;

[0083] The temperature of the three sinterings is 600℃ and the time is 3h.

[0084] Performance Test:

[0085] The specific surface area of ​​the ceramic powder was tested by a BET tester, and the content of yttrium impurity in the ceramic powder was tested by ICP-oes. The test results are shown in Table 1:

[0086] Table 1

[0087]

[0088]

[0089] Result analysis:

[0090] 1. Through implementation 1-3, it can be seen that when the relevant parameters in the ceramic powder production process are slightly modified, the yttrium content of Examples 1-3 and the specific surface area of ​​the obtained powders all show obvious fluctuations, but the above fluctuations are all within a reasonable range, and it can be seen that with the increase of the speed of the sand mill, the specific surface area of ​​the powder gradually increases. The reason is that with the increase of the speed of the sand mill and the sand milling time, the particle size of the powder gradually decreases, and with the decrease of the particle size, the specific surface area of ​​the powder shows a trend of gradually increasing;

[0091] It can also be seen from Examples 1-3 that, compared with the sanding time, the sanding speed has a more dramatic effect on the particle size and specific surface area;

[0092] 2. It can be seen from Example 1 and Example 4-6 that, on the one hand, since the sanding time and sanding speed of Example 4-6 are the same as those of Example 1, the impurity yttrium content of Example 4-6 is equivalent to that of Example 1. Further, by observing the specific surface area of ​​Example 4-6, it can be seen that Example 4 has a more significant improvement trend in the specific surface area of ​​the ceramic powder relative to Example 1 through three sinterings with gradually increasing temperatures. It can be seen that the sintering method of Example 4 is the most prominent in the growth of zirconium oxide grains, and the grain boundaries inside it are the most scarce, which leads to its higher brittleness, so that Example 4 obtains a finer ceramic powder with a larger specific surface area at the same sanding speed as Example 1;

[0093] The gradual cooling and large temperature changes in Example 5 and Example 6 caused partial fragmentation of the zirconia ceramic slices, which is one of the reasons for the relatively small specific surface area. On the other hand, it may also be due to the slightly drastic temperature fluctuations of the two, which led to a large difference in the size of the internal unit cells of the zirconia, resulting in a low uniformity of the grain boundary distribution, which resulted in some large-size powder residues in the subsequent ball milling, sand milling, etc.

[0094] 3. It can be seen from Examples 1 and 7-8 that when the size of the grinding balls is compounded, the specific surface area of ​​the obtained powder has a tendency to increase to a certain extent. The reason is that the grinding balls of various particle sizes increase the collision efficiency between the powder and the grinding balls during the ball milling process, thereby improving the ball milling efficiency of the powder;

[0095] 4. It can be seen from Example 1 and Comparative Examples 1-2 that when one sintering or two sinterings are used, the particle size of the powder of Comparative Examples 1-2 has a significant downward trend. It can be seen that under the same sanding state, the zirconium oxide of Comparative Examples 1-2 is more difficult to crush. The reason is that the crystal cell growth of Comparative Examples 1-2 is not sufficient compared with that of Example 1, which leads to excessive strength of the material and is difficult to crush;

[0096] Although Comparative Example 3 was sintered three times, the temperature was insufficient, so there was also a problem of insufficient cell growth.

[0097] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a powder of a ceramic thin-sheet substrate, characterized in that: The following steps are involved: Step 1: sintering the ceramic thin-sheet substrate waste at least three times to obtain an intermediate; Step 2: crushing and ball-milling the intermediate obtained in step 1, mixing with a solvent and a dispersant, and sand-milling to obtain a slurry; Step 3: spray granulating the slurry obtained in step 2 to obtain ceramic powder; In the step 1, the temperature of the sintering process is 800-1400° C. and the time is 1.5-3 hours.

2. The method for preparing a powder of a ceramic thin-sheet substrate according to claim 1, characterized in that: The rotation speed of the sand grinding process in step 2 is 800-1200 r / min, and the time is 1.5-4 h.

3. The method for preparing a powder of a ceramic thin-sheet substrate according to claim 1, characterized in that: In the step 1, the sintering is performed three times; During the first sintering process, the sintering temperature is 800-900°C and the time is 1.5-3h; During the second sintering process, the sintering temperature is 900-1100°C (excluding 900°C), and the sintering time is 1.5-3h; During the third sintering process, the sintering temperature is 1100-1400° C. (excluding 1100° C.), and the sintering time is 1.5-3 hours.

4. The method for preparing a powder of a ceramic thin-sheet substrate according to claim 1, characterized in that: The ceramic sheet substrate is a zirconia ceramic sheet substrate.

5. The method for preparing a powder of a ceramic thin-sheet substrate according to claim 1, characterized in that: During the ball milling process of step 2, the mass ratio of the grinding balls to the crushed intermediate is 4-6:4-6; The grinding balls are composed of large-size grinding balls, medium-size grinding balls and small-size grinding balls, and the diameter of the large-size grinding balls is 15±2mm, the diameter of the medium-size grinding balls is 10±2mm, and the diameter of the small-size grinding balls is 5±2mm.

6. The method for preparing a powder of a ceramic thin-sheet substrate according to claim 5, characterized in that: The mass ratio of the large-diameter grinding balls, the medium-diameter grinding balls and the small-diameter grinding balls is 4:4:2-3.

7. The method for preparing a powder of a ceramic thin-sheet substrate according to claim 1, characterized in that: During the spray granulation process, the inlet air temperature is 220-280°C, the outlet temperature is 100-140°C, and the atomizer speed is 10000-14000r / min.

8. A ceramic powder, characterized in that: The ceramic thin sheet substrate is prepared by the powder making method of any one of claims 1-7.

9. The ceramic powder according to claim 8, characterized in that: The specific surface area of ​​the ceramic powder is 9.5 to 11.5 m 2 / g, and the impurity yttrium content is less than 100ppm.

Images