阅读说明：本技术 转炉挡渣滑板用氧化锆陶瓷及其制备方法 (Zirconia ceramic for converter slag stopping sliding plate and preparation method thereof ) 是由 方斌祥 赵义 罗明 施岳明 汤忠达 尹明强 徐亮 邬晓滢 于 2020-11-13 设计创作，主要内容包括：本申请提供了转炉挡渣滑板用氧化锆陶瓷及其制备方法,其原料的重量份组成为：电熔镁部分稳定氧化锆细粉10～20；电熔单斜氧化锆微粉50～60；化学法单斜氧化锆微粉10～20；化学法氧化镁微粉1～3；钙部分稳定氧化锆喷雾造粒粉10～20；结合剂8～14。本申请的转炉挡渣滑板用氧化锆陶瓷具有优异的抗冲刷性能和抗剥落性能等。(The application provides a zirconia ceramic for a converter slag stopping sliding plate and a preparation method thereof, wherein the zirconia ceramic comprises the following raw materials in parts by weight: 10-20 parts of fused magnesia partially stabilized zirconia fine powder; 50-60 parts of electric melting monoclinic zirconia micro powder; 10-20 parts of monoclinic zirconia micropowder by a chemical method; 1-3 parts of chemical method magnesium oxide micro powder; 10-20 parts of calcium-part-stabilized zirconia spray granulation powder; 8-14 of a binder. The zirconia ceramic for the converter slag stopping sliding plate has excellent anti-scouring performance, anti-stripping performance and the like.)

1. The zirconia ceramic for the converter slag stopping sliding plate is characterized by comprising the following raw materials in parts by weight:

2. the zirconia ceramic for a converter slag stopper slide plate according to claim 1, wherein the fused magnesia partially stabilized zirconia fine powder has a particle size of-325 mesh, ZrO, or the like₂+HfO₂The content of the MgO is more than or equal to 99 wt%, and the stable phase is 50-70 vol%.

3. The zirconia ceramic for a converter slag stopper slide plate according to claim 1, wherein the fused monoclinic zirconia micropowder has a particle size D₅₀≤2μm，ZrO₂+HfO₂The content is more than or equal to 99.0 wt%.

4. The zirconia ceramic for a converter slag stopper slide plate according to claim 1, wherein the chemical monoclinic zirconia micropowder has a particle size D₅₀≤4μm，ZrO₂+HfO₂The content is more than or equal to 99.0 wt%.

5. The zirconia ceramic for a converter slag stopper slide plate according to claim 1, wherein the chemical process magnesia micropowder has a particle size D₅₀Less than or equal to 6 mu m, and the MgO content is more than or equal to 98.5wt percent.

6. The zirconia ceramic for a converter slag stopper slide plate according to claim 1, wherein the particle size of the calcium partially stabilized zirconia spray granulated powder is 90 to 100 mesh, and ZrO is present₂+HfO₂The content of CaO is more than or equal to 99 wt%, and the stable phase is 70-85 vol%.

7. The zirconia ceramic for the converter slag stopping sliding plate according to claim 1, wherein the bonding agent comprises the following raw materials in parts by weight:

8. the preparation method of the zirconia ceramic for the converter slag-stopping sliding plate according to any one of claims 1 to 7, which is characterized by comprising the following steps:

(1) uniformly mixing the fused magnesium partially-stabilized zirconia fine powder, the fused monoclinic zirconia micro powder, the chemical monoclinic zirconia micro powder and the chemical magnesia to obtain a mixture A;

(2) uniformly mixing the mixture A, the calcium partially-stabilized zirconia spray granulation powder and the binding agent, and sieving to obtain spherical granulation materials;

(3) dehydrating the spherical granulation material;

(4) pressing and molding the dehydrated spherical granulating material to obtain a ceramic blank;

(5) drying the ceramic body;

(6) sintering the dried ceramic blank at 1700-1750 ℃ for 6-8 h to prepare zirconia ceramic;

(7) and packaging the zirconia ceramics after the zirconia ceramics are qualified.

9. The method for preparing the zirconia ceramic for the converter slag-stopping sliding plate according to claim 8, wherein the particle size of the spherical granulated material is 0.1-1.5 mm; the volume density of the ceramic body is 4.2-4.4 g/cm³。

10. The method for preparing the zirconia ceramic for the converter slag-stopping sliding plate according to claim 8, wherein the volume density of the zirconia ceramic is 5.25-5.40 g/cm³The compressive strength is 300-450 MPa, the monoclinic phase is 65-75 vol%, and the stable phase is 25-35 vol%.

Technical Field

The application relates to the technical field of zirconia ceramics, in particular to zirconia ceramics for a converter slag stopping sliding plate and a preparation method thereof.

Background

At present, in the process of producing clean steel in steel enterprises, the sliding plate technology is widely applied to the flow control of molten steel. The sliding plate is generally made of aluminum carbon, aluminum zirconium carbon, carbon magnesium, magnesium spinel carbon and the like, but the problems of hole expansion, cast hole pull-off, plate surface oxidation, galling, steel clamping and the like exist in the using process, particularly the converter slag-blocking sliding plate has severe working conditions, the using temperature is over 1600 ℃, and the service life is far longer than that of a steel ladle and a tundish sliding plate, so that the sliding plate has higher requirements on the scouring resistance and the thermal shock resistance.

In order to prolong the service life of the sliding plate, a high-melting-point zirconia material can be embedded in the plate surface and the cast hole of the sliding plate, but most of the zirconia for the sliding plate has the problems of complex preparation process, lower density, incapability of considering compressive strength, anti-stripping performance and anti-scouring performance, short service life and the like.

Disclosure of Invention

The application aims to provide the zirconia ceramic for the converter slag stopping sliding plate, and the zirconia ceramic has excellent compressive strength, scouring resistance, stripping resistance and the like so as to solve the problems in the prior art.

The zirconia ceramic for the converter slag stopping sliding plate comprises the following raw materials in parts by weight:

the zirconia ceramic for the converter slag-stopping sliding plate takes the electric melting monoclinic zirconia micro powder as a main material, part of stable zirconia components are introduced, the ratio of monoclinic phase to stable phase is optimized, and high-activity chemical method zirconia and chemical method magnesia are introduced simultaneously, so that the components of the raw materials can be fully mixed and sintered, and the density and the strength of the zirconia ceramic are improved.

In order to optimize the matrix structure of the zirconia ceramic, calcium part-stabilized zirconia spray granulation powder which is calcium part with solid content of 60 percent is also introduced into the raw materialsThe stabilized zirconia slurry is atomized and sprayed out and dried in a spray granulation tower under high pressure to prepare-80-mesh spherical granulation material, and then presintering is carried out at 1000-1300 ℃ to obtain certain strength, the volume shrinkage after presintering is about 10%, the granularity is changed into 90-100 meshes, and ZrO is obtained₂+HfO₂The content of CaO is more than or equal to 99 wt%, and the stable phase is 70-85 vol%. In the subsequent stirring and pressing processes, the granulation structure of the pre-sintered partially calcium stabilized zirconia spray granulation powder cannot be damaged, the granulation powder still remains in a spherical structure in a finished product, and the shrinkage rate of the powder is close to that of other components in the high-temperature sintering process.

Optionally, the particle size of the fused magnesia partially stabilized zirconia fine powder is-325 meshes, and ZrO in the fused magnesia partially stabilized zirconia fine powder₂+HfO₂The content of the MgO is more than or equal to 99 wt%, and the stable phase is 50-70 vol%.

Optionally, the particle size D of the fused monoclinic zirconia micro powder₅₀≤2μm，ZrO₂+HfO₂The content is more than or equal to 99.0 wt%.

Optionally, the particle size D of the monoclinic zirconia micropowder prepared by the chemical method₅₀≤4μm，ZrO₂+HfO₂The content is more than or equal to 99.0 wt%.

Optionally, the particle size D of the chemical method magnesium oxide micro powder₅₀Less than or equal to 6 microns, and the MgO content is more than or equal to 98.5 percent.

Optionally, the binder comprises the following raw materials in parts by weight:

wherein, the environment-friendly glue is used as a binder of the raw material, and the main component is polyvinyl alcohol.

Magnesium acetate and calcium acetate are introduced into the binder solution, and Mg is used as the Mg²⁺And Ca²⁺As a stabilizer of monoclinic zirconia, the stabilizer can be used for realizing the homogenization of a small dose of the stabilizer in the ingredients more easily, so that the stabilized zirconia generated in situ can be uniformly distributed in a microscopic state, and the sintering qualification rate and the quality stability of the invention are improved. The acetate ions can be CO in the subsequent heating and firing process₂The form escapes, and the furnace lining of the furnace is not damaged, and the environment is not polluted.

The application also provides a preparation method of the zirconia ceramic for the converter slag stopping sliding plate, which comprises the following steps:

(1) uniformly mixing the fused magnesium partially-stabilized zirconia fine powder, the fused monoclinic zirconia micro powder, the chemical monoclinic zirconia micro powder and the chemical magnesia to obtain a mixture A;

(2) uniformly mixing the mixture A, the calcium partially-stabilized zirconia spray granulation powder and the binding agent, and sieving to obtain spherical granulation materials;

(3) dehydrating the spherical granulation material;

(4) pressing and molding the dehydrated spherical granulating material to obtain a ceramic blank;

(5) drying the ceramic body;

(6) and sintering the dried ceramic blank at 1700-1750 ℃ for 6-8 h to obtain the zirconia ceramic.

(7) And packaging the zirconia ceramics after the zirconia ceramics are qualified.

In the step (2), inclined high-speed granulation equipment can be adopted for mixing materials, on one hand, all components of the raw materials are effectively and uniformly mixed, on the other hand, spherical granulation materials with the particle size of 0.1-1.5 mm compact can be rapidly prepared in a short time, the later-stage compression molding is facilitated, the microstructure of a blank body is optimized, a plurality of particles are in point contact, the occlusion type contact among the traditional crushing granulation materials is replaced, the release of thermal stress of the zirconia ceramic under cold and hot impact is facilitated, and the anti-stripping performance of the zirconia ceramic is improved.

The spherical granulating material in the step (3) can be dehydrated in a high-efficiency boiling dryer until the water content is less than or equal to 3.5 wt%, so that the water content is reduced, and the forming and sintering of a green body are facilitated.

In the step (4), the spherical granulating material can be pressed and molded in a hydraulic mode, the pressure is required to be 170-200 MPa, and the bulk density of the prepared ceramic blank is 4.2-4.4 g/cm³The forming process does not damage the spherical particle structure in the ceramic blank, and the percent of pass of the zirconia ceramic finished product after high-temperature sintering>95％。

In the step (5), the ceramic body needs to be spread in the drying process to avoid damage or deformation, and the ceramic body can be sintered at high temperature after being dried until the water content is less than or equal to 0.5 percent.

The volume density of the zirconia ceramic prepared by the method is 5.25-5.40 g/cm³The compressive strength is 300-450 MPa, the monoclinic phase is 75-65 vol%, and the stable phase is 25-35 vol%.

The zirconia ceramic for the converter slag stopping sliding plate prepared by the application has a uniform spherical granulating material point contact microstructure, a reasonable monoclinic phase and a stable phase proportion, very high density and strength, a lower volume change rate under cold and hot impact, excellent anti-scouring performance and anti-stripping performance, and is suitable for serving as an inlaid refractory material of a sliding plate surface and a cast hole.

Drawings

FIG. 1 is a scanning electron microscope photograph of a zirconia ceramic for a converter slag stopper slide plate.

Detailed Description

The technical solutions described in the present application will be further described with reference to the following embodiments, but the present application is not limited thereto.

Example 1

15 parts by weight of fused magnesia partially stabilized zirconia fine powder of 325 meshes and 59 parts by weight of fused monoclinic zirconia (D)₅₀2 μm), 10 parts of chemical monoclinic zirconia fine powder (D)₅₀4 μm), 1 part of chemical magnesium oxide fine powder (D)₅₀6 μm) was mixed in a ball mill for 2h to obtain a mixture a; mixing the mixture A, 15 parts of calcium partially-stabilized zirconia spray granulation powder and 10 parts of binding agent (3 parts of environment-friendly glue, 2 parts of magnesium acetate, 1 part of calcium acetate and 4 parts of water) in an inclined high-speed granulation device, stirring at a high speed, uniformly mixing, granulating, sieving to obtain spherical granulation materials, and dehydrating in a high-efficiency fluidized drying machine until the water content is 2.5 wt%; forming the dehydrated spherical granulation material on a hydraulic press under the pressure of 170MPa to obtain a ceramic blank, and testing that the volume density of the ceramic blank is 4.2g/cm³(ii) a Spreading the raw material green body on the surface of a commercially available tile, putting the tile into an oven to be dried until the water content is 0.5 percent to prepare a ceramic green body, then putting the ceramic green body into a kiln, and heating to 1730 ℃ to sinter for 6 hours; the zirconia ceramics sintered and discharged from the kiln are inspectedAnd then packaging.

The internal structure of the zirconia ceramic was examined using a scanning electron microscope, and as shown in fig. 1, the zirconia ceramic had a uniform spherical pellet point contact microstructure.

The volume density of the zirconia ceramic is tested to be 5.25g/cm³The compressive strength was 320MPa, the monoclinic phase was 75 vol%, and the stationary phase was 25 vol%.

The zirconia ceramic has no crack after being subjected to a 1100 ℃ water cooling thermal shock resistance test for 8 times, is used as an inlaid material for a 100-ton converter slag-stopping sliding plate in a steel mill, has 25 times of service life, has a melting loss rate of 1mm per furnace, and has no abnormal stripping phenomenon.

Example 2

According to the weight portion, 12 portions of fused magnesia partially stabilized zirconia fine powder with the mesh of 800 meshes and 60 portions of fused monoclinic zirconia (D)₅₀1.5 μm), 13 parts of chemical monoclinic zirconia fine powder (D)₅₀2.5 μm) and 1.5 parts of chemical magnesium oxide fine powder (D)₅₀4 μm) in a ball mill for 3h to obtain a mixture a; mixing the mixture A, 13.5 parts of calcium partially-stabilized zirconia spray granulation powder and 11 parts of binding agent (3 parts of environment-friendly glue, 2 parts of magnesium acetate, 2 parts of calcium acetate and 4 parts of water) in an inclined high-speed granulation device, stirring at a high speed, uniformly mixing, granulating, sieving to obtain spherical granulation materials, and dehydrating in a high-efficiency fluidized drying machine until the water content is 3.0 wt%; forming the dehydrated spherical granulating material on a hydraulic press at the maximum pressure of 185MPa to obtain a ceramic blank with the bulk density of 4.3g/cm³(ii) a And then, spreading the raw material green body on the surface of a commercially available tile, putting the tile into an oven for drying until the water content is 0.4 percent to prepare a ceramic green body, then putting the ceramic green body into a kiln, heating to 1750 ℃, sintering for 8 hours, and packaging the zirconia ceramic sintered out of the kiln after inspection.

The volume density of the zirconia ceramic is tested to be 5.32g/cm³The compressive strength was 380MPa, the monoclinic phase was 70 vol%, and the stationary phase was 30 vol%.

The zirconia ceramic has no crack after being subjected to a 1100 ℃ water cooling thermal shock resistance test for 8 times, is used as an inlaid material for a 250-ton converter slag-stopping sliding plate in a steel mill, has 21 service lives, has a melting loss rate of 1.4 mm/furnace, and has no abnormal stripping phenomenon.

Example 3

According to the weight portion, 10 portions to 1000 meshes of fused magnesia partially stabilized zirconia fine powder and 62 portions of fused monoclinic zirconia (D)₅₀1.0 μm), 12 parts of chemical monoclinic zirconia fine powder (D)₅₀1.5 μm) and 2 parts of chemical magnesium oxide micropowder (D)₅₀3 μm) was mixed in a ball mill for 4h to obtain a mixture a; mixing the mixture A, 14 parts of calcium partially-stabilized zirconia spray granulation powder and 12 parts of binding agent (4 parts of environment-friendly glue, 1.5 parts of magnesium acetate, 1.5 parts of calcium acetate and 5 parts of water) in an inclined high-speed granulation device at a high speed, uniformly stirring, granulating, sieving to obtain spherical granulation materials, and dehydrating in a high-efficiency boiling dryer until the water content is 3.5%; forming the dehydrated spherical granulating material on a hydraulic press at the maximum pressure of 200MPa to obtain a ceramic blank with the bulk density of 4.4g/cm³(ii) a Spreading the raw material blank on the surface of a commercially available tile, putting the tile into an oven for drying until the water content is 0.3 percent to prepare a ceramic blank, then putting the ceramic blank into a kiln, and heating to 1740 ℃ for sintering for 7 hours; and packaging the zirconia ceramics fired and discharged from the kiln after inspection.

The volume density of the zirconia ceramic is tested to be 5.40g/cm³Compressive strength 430MPa, monoclinic phase 65 vol%, stationary phase 35 vol%.

The zirconia ceramic has no crack after being subjected to a 1100 ℃ water cooling thermal shock resistance test for 8 times, is used as an inlaid material for a 350-ton converter slag-stopping sliding plate in a certain steel mill, has 18 service lives, has a melting loss rate of 1.5 mm/furnace, and has no abnormal stripping phenomenon.

Appropriate changes and modifications to the embodiments described above will become apparent to those skilled in the art from the disclosure and teachings of the foregoing description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.