Zirconium oxide powder and processing method thereof

Abstract

The invention belongs to the field of ceramic powder processing, and discloses a zirconium oxide powder processing method, which comprises the following steps: adding deionized water, a first dispersant and zirconium oxide powder into a vertical ball mill, mixing, and carrying out primary grinding to obtain slurry I; adding the slurry I, deionized water and a second dispersing agent into the sand mill for mixing, and performing secondary grinding to obtain slurry II; then filtering the slurry II, and performing spray granulation to obtain processed zirconium oxide powder; by controlling the particle size of the zirconium oxide powder, the diameter of zirconium beads during grinding, the addition amount of the dispersing agent and the concentration of zirconium oxide in the slurry, the zirconium oxide powder with the D90 particle size of 0.6-0.7 mu m and the specific surface area of 10.5-11.5 m < 2 > / g can be obtained; in addition, the invention also discloses the zirconium oxide powder which is prepared by the processing method of the zirconium oxide powder.

Description

Technical Field

[0001] The invention relates to the field of ceramic powder processing, and in particular to zirconium oxide powder and a processing method thereof. Background Art

[0002] Zirconia has high melting point, high hardness and excellent wear resistance, so it has been widely used in various fields, especially in high-temperature ceramics. When making high-temperature ceramic materials, the particle size and specific surface area of ​​zirconia powder will affect the performance of high-temperature ceramic materials. Therefore, the particle size and specific surface area of ​​zirconia are strictly controlled during the production process of zirconia.

[0003] There are a lot of existing technologies disclosed for controlling the particle size and specific surface area of ​​zirconia powder, such as:

[0004] Chinese patent application 202010112534.9 discloses a zirconium oxide powder and an ultrafine grinding method thereof, and Chinese patent application 201910767179.6 discloses a composite zirconium oxide powder method, and its preparation method and use.

[0005] In the above-mentioned prior art, the particle size of the obtained zirconium oxide powder can be controlled within a certain range.

[0006] The present application has found through research that, in the process of multiple grindings, by adjusting the concentration of the sizing material and grinding with zirconium beads of different particle sizes, the particle size and specific surface area of ​​the ground zirconium oxide powder can also be controlled within a certain range.

[0007] The problem that this solution needs to solve is: how to control the particle size and specific surface area of ​​the ground zirconium oxide powder. Summary of the invention

[0008] The present invention aims to provide a zirconium oxide powder and a processing method thereof, wherein a zirconium oxide powder having an initial particle size of 30 to 50 μm is added, and the concentration of zirconium oxide in the slurry of the first grinding and the second grinding is controlled for grinding, so that a zirconium oxide powder having a D90 particle size of 0.6 to 0.7 μm and a specific surface area of ​​10.5 to 11.5 m can be obtained. 2 / g of zirconium oxide powder.

[0009] To achieve the above object, the present application discloses a method for processing zirconium oxide powder, comprising the following steps:

[0010] Step 1: Weigh zirconium oxide powder, deionized water, and a first dispersant, add them into a vertical ball mill, mix them, add zirconium beads, grind them once, and obtain slurry 1;

[0011] Step 2: Add slurry 1, deionized water, and the second dispersant into a sand mill, mix, and add zirconium beads for secondary grinding to obtain slurry 2;

[0012] Step 3: filtering and spray granulating the slurry 2 to obtain processed zirconium oxide powder;

[0013] Wherein, the particle size of the zirconium oxide powder is 30 to 50 μm;

[0014] In one grinding, the diameter of the zirconium beads is 4-6 mm, the grinding speed is 500-600 rpm, and the grinding time is 1.5-2 h;

[0015] In the secondary grinding, the diameter of the zirconium beads is 0.3-0.5 mm, the grinding speed is 400-700 rpm, and the grinding time is 70-110 min;

[0016] The mass ratio of zirconium oxide powder to deionized water in slurry 1 is 50-55:45-50, and the mass ratio of zirconium oxide powder to deionized water in slurry 2 is 30-35:65-70;

[0017] The total mass of the first dispersant and the second dispersant is 0.2-0.3% of the mass of the zirconium oxide powder, and the mass ratio of the first dispersant to the second dispersant is 1.8-2.2:2.8-3.2.

[0018] When grinding zirconium oxide powder with an initial particle size of 30 to 50 μm, zirconium beads of different particle sizes are used for the first grinding and the second grinding. If the concentration of the slurry does not change, the zirconium beads with smaller particle sizes are directly replaced for grinding. Since the fluidity of the slurry during grinding is poor, the grinding effect of the powder will be reduced; and changing the concentration of the slurry will inevitably lead to an unstable slurry system and easy grain agglomeration. Therefore, dispersant needs to be added simultaneously during the water replenishment process to stabilize the dispersion system, thereby effectively improving the uniformity of the zirconia powder and reducing the powder particle size.

[0019] Preferably, the specific operation of the secondary grinding is: first grinding at a rotation speed of 400-500 rpm for 20-40 min, and then grinding at a rotation speed of 500-700 rpm for 50-70 min.

[0020] Preferably, the amount of zirconium beads added in the first grinding is 430-470 kg, and the amount of zirconium beads added in the second grinding is 65-75 kg.

[0021] Preferably, the first dispersant and the second dispersant are both polycarboxylate D305 or polycarboxylate AD8098.

[0022] Preferably, the filtration screen in step 3 has a mesh size of 1200;

[0023] During spray granulation, the inlet temperature was 240°C, the outlet temperature was 100°C, the atomizer speed was 14000rpm, and the pump speed was 0.2MPa.

[0024] In addition, a zirconium oxide powder is also disclosed, which is prepared by the above-mentioned zirconium oxide powder processing method.

[0025] Preferably, the D90 particle size of the zirconium oxide powder is 0.6 to 0.7 μm, and the BET specific surface area is 10.5 to 11.5 m 2 / g.

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

[0027] The present invention provides a zirconium oxide powder and a processing method thereof. The zirconium oxide powder with a particle size of 30 to 50 μm is ground in two steps, the slurry concentration of the first grinding and the second grinding is controlled, and a dispersant is added to stabilize the dispersion system while controlling the slurry, so that after grinding zirconium beads with different particle sizes, a D90 particle size of 0.6 to 0.7 μm and a specific surface area BET of 10.5 to 11.5 m 2 / g of zirconium oxide powder. 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: 100 kg of zirconium oxide powder with a particle size of 40 μm and deionized water were weighed in a mass ratio of 52.5:47.5, and then added into a vertical ball mill together with the first dispersant, mixed, and 450 kg of zirconium beads with a diameter of 5 mm were added and ground at a speed of 550 rpm for 1.8 hours to obtain slurry 1;

[0031] Step 2: Add slurry 1, deionized water, and the second dispersant into a sand mill, mix, add 70 kg of zirconium beads with a diameter of 0.4 mm, grind at 450 rpm for 30 min, and then grind at 600 rpm for 60 min to obtain slurry 2 with a mass ratio of zirconium oxide powder to deionized water of 32.5:67.5;

[0032] Step 3: Filter the slurry 2 through a 1200 mesh filter, and then spray granulate it under the conditions of an inlet temperature of 240°C, an outlet temperature of 100°C, an atomizer speed of 14000rpm, and a pump speed of 0.2MPa to obtain processed zirconium oxide powder.

[0033] Wherein, the first dispersant and the second dispersant are both polycarboxylate D305, and the total mass of polycarboxylate D305 is 0.25% of the zirconium oxide powder;

[0034] The mass ratio of the first dispersant to the second dispersant is 2:3.

[0035] Example 2

[0036] Step 1: 100 kg of zirconium oxide powder with a particle size of 30 μm and deionized water were weighed in a mass ratio of 52.5:47.5, and then added into a vertical ball mill together with the first dispersant for mixing, and 450 kg of zirconium beads with a diameter of 5 mm were added and ground at a speed of 500 rpm for 2 hours to obtain slurry 1;

[0037] Step 2: Add slurry 1, deionized water, and the second dispersant into a sand mill, mix, add 70 kg of zirconium beads with a diameter of 0.4 mm, grind at 400 rpm for 40 minutes, and then grind at 500 rpm for 70 minutes to obtain slurry 2 with a mass ratio of zirconium oxide powder to deionized water of 32.5:67.5;

[0038] Step 3: Filter the slurry 2 through a 1200 mesh filter, and then spray granulate it under the conditions of an inlet temperature of 240°C, an outlet temperature of 100°C, an atomizer speed of 14000rpm, and a pump speed of 0.2MPa to obtain processed zirconium oxide powder.

[0039] Wherein, the first dispersant and the second dispersant are both polycarboxylate D305, and the total mass of polycarboxylate D305 is 0.25% of the zirconium oxide powder;

[0040] The mass ratio of the first dispersant to the second dispersant is 2:3.

[0041] Example 3

[0042] Step 1: 100 kg of zirconium oxide powder with a particle size of 50 μm and deionized water were weighed in a mass ratio of 52.5:47.5, and then added into a vertical ball mill together with the first dispersant for mixing, and 450 kg of zirconium beads with a diameter of 5 mm were added and ground at a speed of 600 rpm for 1.5 hours to obtain slurry 1;

[0043] Step 2: Add slurry 1, deionized water, and the second dispersant into a sand mill, mix, add 70 kg of zirconium beads with a diameter of 0.4 mm, grind at 500 rpm for 20 min, and then grind at 700 rpm for 50 min to obtain slurry 2 with a mass ratio of zirconium oxide powder to deionized water of 32.5:67.5;

[0044] Step 3: Filter the slurry 2 through a 1200 mesh filter, and then spray granulate it under the conditions of an inlet temperature of 240°C, an outlet temperature of 100°C, an atomizer speed of 14000rpm, and a pump speed of 0.2MPa to obtain processed zirconium oxide powder.

[0045] Wherein, the first dispersant and the second dispersant are both polycarboxylate D305, and the total mass of polycarboxylate D305 is 0.25% of the zirconium oxide powder;

[0046] The mass ratio of the first dispersant to the second dispersant is 2:3.

[0047] Example 4

[0048] It is basically the same as Example 1, except that the diameter of the zirconium beads ground once is 4 mm, and the diameter of the zirconium beads ground twice is 0.5 mm.

[0049] Example 5

[0050] It is basically the same as Example 1, except that the diameter of the zirconium beads ground once is 6 mm, and the diameter of the zirconium beads ground twice is 0.3 mm.

[0051] Example 6

[0052] It is basically the same as Example 1, except that the mass ratio of zirconium oxide powder to deionized water in slurry one is 50:50, and the mass ratio of zirconium oxide powder to deionized water in slurry two is 30:70.

[0053] Example 7

[0054] It is basically the same as Example 1, except that the mass ratio of zirconium oxide powder to deionized water in slurry one is 55:45, and the mass ratio of zirconium oxide powder to deionized water in slurry two is 35:65.

[0055] Example 8

[0056] The method is basically the same as Example 1, except that the total mass of the first dispersant and the second dispersant is 0.2% of the mass of the zirconium oxide powder.

[0057] Example 9

[0058] The method is basically the same as Example 1, except that the total mass of the first dispersant and the second dispersant is 0.3% of the mass of the zirconium oxide powder.

[0059] Example 10

[0060] It is basically the same as Example 1, except that the amount of zirconium beads added in the first grinding is 430 kg, and the amount of zirconium beads added in the second grinding is 75 kg.

[0061] Embodiment 11

[0062] It is basically the same as Example 1, except that the amount of zirconium beads added in the first grinding is 470 kg, and the amount of zirconium beads added in the second grinding is 65 kg.

[0063] Comparative Example 1

[0064] Step 1: 100 kg of zirconium oxide powder with a particle size of 50 μm and deionized water were weighed in a mass ratio of 52.5:47.5, and then added into a vertical ball mill together with the first dispersant, mixed, and 450 kg of zirconium beads with a diameter of 5 mm were added and ground at a speed of 550 rpm for 1.8 hours to obtain slurry 1;

[0065] Step 2: Add slurry 1 into a sand mill, add 70 kg of zirconium beads with a diameter of 0.4 mm, grind at 450 rpm for 30 min, and then grind at 600 rpm for 60 min to obtain slurry 2 with a mass ratio of zirconium oxide powder to deionized water of 52.5:47.5;

[0066] Step 3: Filter the slurry 2 through a 1200 mesh filter, and then spray granulate it under the conditions of an inlet temperature of 240°C, an outlet temperature of 100°C, an atomizer speed of 14000rpm, and a pump speed of 0.2MPa to obtain processed zirconium oxide powder.

[0067] The first dispersant is polycarboxylate D305, and the mass of the polycarboxylate D305 is 0.15% of the zirconium oxide powder.

[0068] Comparative Example 2

[0069] It is basically the same as Example 1, except that the particle size of the zirconium oxide powder in step 1 is 20 μm.

[0070] Comparative Example 3

[0071] It is basically the same as Example 1, except that the particle size of the zirconium oxide powder in step 1 is 60 μm.

[0072] Comparative Example 4

[0073] It is basically the same as Example 1, except that the diameter of the zirconium beads in the first grinding is 7 mm, and the diameter of the zirconium beads in the second grinding is 0.2 mm.

[0074] Comparative Example 5

[0075] It is basically the same as Example 1, except that the diameter of the zirconium beads in the first grinding is 3 mm, and the diameter of the zirconium beads in the second grinding is 0.6 mm.

[0076] Comparative Example 6

[0077] It is basically the same as Example 1, except that the mass ratio of zirconium oxide powder to deionized water in slurry one is 60:40, and the mass ratio of zirconium oxide powder to deionized water in slurry two is 40:60.

[0078] Comparative Example 7

[0079] It is basically the same as Example 1, except that the mass ratio of zirconium oxide powder to deionized water in slurry one is 45:55, and the mass ratio of zirconium oxide powder to deionized water in slurry two is 25:75.

[0080] Performance Test:

[0081] Zirconia powder specific surface area: Use a Micromeritics 3020 nitrogen adsorption specific surface area tester for automatic testing. Weigh a certain amount of the sample prepared in the above Examples 1-11 or Comparative Examples 1-7 and put it into a sample tube. Degas it in a degassing station. After degassing, place the sample tube on the above instrument to automatically complete the test to obtain the powder specific surface area.

[0082] The performance test results are shown in Table 1:

[0083] Table 1

[0084]

[0085]

[0086] Result analysis:

[0087] 1. It can be seen from Examples 1-11 that when the initial particle size of the zirconium oxide powder, the grinding speed and time of the zirconium oxide powder, the diameter and addition amount of the zirconium beads in the first grinding or the second grinding, the concentration of the zirconium oxide powder in the slurry 1 and the slurry 2, and the addition amount of the first dispersant and the second dispersant are changed within a certain range, the D90 particle size of the zirconium oxide powder obtained after processing is in the range of 0.6-0.7 μm and the specific surface area is in the range of 10.5-11.5 m 2 / g.

[0088] 2. It can be seen from Example 1 and Comparative Example 1 that after the zirconium oxide powder slurry is ground once, the concentration of zirconium oxide in the slurry is not changed, and zirconium beads with smaller particle size are directly used for secondary grinding. Due to the poor fluidity of the slurry during grinding with small-particle-size zirconium beads, and thus the grinding effect of the slurry is reduced, the D90 particle size of the obtained zirconium oxide powder increases, and the specific surface area of ​​the powder decreases.

[0089] 3. It can be seen from Example 1 and Comparative Examples 2-3 that when zirconium oxide powder with smaller or larger particle size is used as raw material for grinding, due to the change in powder particle size, under the same grinding process parameters, the interaction force between particles of the powder with larger particle size is weaker during the grinding process, resulting in insufficient grinding; while the interaction force between particles of the powder with smaller particle size is stronger, and agglomeration is easily caused, which in turn affects the further reduction of the particle size.

[0090] 4. It can be seen from Example 1 and Comparative Examples 4-5 that during the grinding process, when the initial particle size of the ground zirconia powder is the same, zirconium beads with larger or smaller particle sizes are replaced for grinding during the first grinding and the second grinding. Since zirconium beads with different particle sizes collide with the zirconia powder for different times in the same time, the D90 particle size of the obtained zirconia powder is affected. Although zirconium beads with larger particle sizes are used in the first grinding and zirconium beads with smaller particle sizes are used in the second grinding, the zirconia powder with the expected particle size and specific surface area cannot be achieved.

[0091] 5. It can be seen from Example 1 and Comparative Examples 6-7 that when the concentration of the zirconium oxide powder in the grinding slurry of the primary grinding or secondary grinding process is further increased or decreased, the number of particles per unit volume increases when the slurry concentration is high, and the collision frequency between particles increases, resulting in an increase in the grinding probability between particles, thereby reducing the particle size of the powder. On the contrary, when the slurry concentration is low, the collision frequency between particles decreases, the grinding effect of the powder is weakened, and the particle size increases.

[0092] 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 processing zirconium oxide powder, characterized in that: The following steps are involved: Step 1: Weigh zirconium oxide powder, deionized water, and a first dispersant, add them into a vertical ball mill, mix them, add zirconium beads, grind them once, and obtain slurry 1; Step 2: Add slurry 1, deionized water, and the second dispersant into a sand mill, mix, and add zirconium beads for secondary grinding to obtain slurry 2; Step 3: filtering and spray granulating the slurry 2 to obtain processed zirconium oxide powder; Wherein, the particle size of the zirconium oxide powder is 30 to 50 μm; In the first grinding, the diameter of the zirconium beads is 4 to 6 mm, the grinding speed is 500 to 600 rpm, and the grinding time is 1.5 to 2 hours; In the secondary grinding, the diameter of the zirconium beads is 0.3-0.5 mm, the grinding speed is 400-700 rpm, and the grinding time is 70-110 min; The mass ratio of zirconium oxide powder to deionized water in the first slurry is 50-55:45-50, and the mass ratio of zirconium oxide powder to deionized water in the second slurry is 30-35:65-70; The total mass of the first dispersant and the second dispersant is 0.2-0.3% of the mass of the zirconium oxide powder, and the mass ratio of the first dispersant to the second dispersant is 1.8-2.2:2.8-3.

2.

2. The method for processing zirconium oxide powder according to claim 1, characterized in that: The specific operation of the secondary grinding is: first grinding at a rotation speed of 400-500 rpm for 20-40 min, and then grinding at a rotation speed of 500-700 rpm for 50-70 min.

3. The method for processing zirconium oxide powder according to claim 1, characterized in that: The amount of zirconium beads added in the first grinding is 430-470 kg, and the amount of zirconium beads added in the second grinding is 65-75 kg.

4. The method for processing zirconium oxide powder according to claim 1, characterized in that: The first dispersant and the second dispersant are both polycarboxylate D305 or polycarboxylate AD8098.

5. The method for processing zirconium oxide powder according to claim 1, characterized in that: The mesh number of the filtration screen in step 3 is 1200 mesh; During spray granulation, the inlet temperature was 240°C, the outlet temperature was 100°C, the atomizer speed was 14000rpm, and the pump speed was 0.2MPa.

6. A zirconium oxide powder, characterized in that: The invention is prepared by the zirconium oxide powder processing method according to any one of claims 1 to 5.

7. The zirconium oxide powder according to claim 6, characterized in that: The zirconium oxide powder has a D90 particle size of 0.6 to 0.7 μm and a BET specific surface area of ​​10.5 to 11.5 m 2 / g.

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