CN116986897A - Sintered high-zirconium brick and preparation method thereof - Google Patents

Abstract

The application relates to a sintered high-zirconium brick and a preparation method thereof, wherein the sintered high-zirconium brick for the liquid surface line position of a glass melting tank is prepared from the following raw materials in percentage by weight ₂ 76-88wt%; ZA eutectic 5-10wt%; y is Y ₂ O ₃ 2‑8wt％；MgO 2‑6wt％；CaO 2‑4wt％；CeO ₂ 0.4-1.2wt%; srO0.3-1wt%. The sintered high-zirconium brick of the application has good crystal development due to the long-time high-temperature sintering of the product because of the introduction of the main component zirconium dioxide resisting glass erosion. As the corundum baddeleyite plate-shaped eutectic is introduced into the system ingredients, the eutectic belongs to a plate-shaped structure and has the property of buffering thermal stress, so that the product has excellent thermal shock resistance, and the sintered high-zirconium brick has excellent glass erosion resistance and ideal useThe service life is significant for improving the product quality, reducing the cost and improving the enterprise and social benefits of glass enterprises.

Description

Sintered high zirconium brick and preparation method thereof

Technical field

The invention belongs to the field of high-temperature inorganic new materials, and particularly relates to high-zirconium bricks sintered at the liquid level line of a glass melting tank and a preparation method thereof.

Background technique

At present, the walls of domestic glass furnace melting pools use fused zirconium corundum bricks (fused AZS for short). According to the zirconium dioxide content contained in the fused zirconium corundum bricks, there are AZS33#, AZS36#, and AZS41#, which respectively represent the ZrO2 content. 33%, 36%, 41%.

Fused zirconium corundum pool wall tiles are made of industrial alumina and zircon sand (containing ZrO ₂ : about 65%, SiO ₂ : about 34%), plus some soda ash Na ₂ CO ₃ , and are melted and cast in an electric arc furnace. The physical phase composition of this brick is: corundum, baddeleyite, corundum baddeleyite eutectic, and glass phase. Since about 15% of the low-melting glass phase exists in the brick, under high-temperature working conditions, the glass phase in the brick continues to precipitate to the surface of the brick, and is continuously physically washed away by the flowing high-temperature glass liquid, causing the brick to crack. There are holes in the internal structure of the brick, and then the high-temperature glass liquid gradually penetrates and erodes into the interior along the surface of the brick body. After the permeable layer gradually becomes a metamorphic layer, it falls off and is lost in the glass liquid. Under the dual effects of physical erosion and chemical erosion of the bricks by the glass liquid, the thickness of the pool wall bricks continues to become thinner. When the thickness of the pool wall bricks is reduced to 60-80mm, the outer wall of the melting pool has to be added with additional bricks or the furnace must be shut down for maintenance. , thus causing maintenance or production shutdown losses and increasing the production costs of glass enterprises.

At present, according to the conventional design of the liquid level line of the domestic glass furnace melting pool, the liquid level line position is set 50mm downward from the top of the pool wall brick, see attached figure 2. By observing the corrosion status of the electro-fused AZS pool wall bricks, we can see that the most serious areas of erosion and erosion of the pool wall bricks are at the liquid level line of the glass molten pool. The erosion depth at the liquid level line of the same AZS pool wall brick is 3-5 times that of other parts. times, the reason is: the liquid level line of the glass melting pool is at the junction of the three phases of solid, liquid and gas. In addition, the temperature of the glass feed liquid is high and the flow rate is fast, which leads to the erosion rate of the fused AZS bricks at the liquid level line far exceeding Other parts of fused AZS bricks. Therefore, how to optimize and improve the corrosion resistance of the wall bricks at the liquid level line of the glass melting pool, increase the life of the furnace, and reduce the cost of furnace maintenance is of great significance.

Contents of the invention

The object of the present invention is to overcome the deficiencies in the prior art and provide a sintered high zirconium brick used at the liquid level position of the glass melting tank and a preparation method thereof.

The technical idea of the present invention to solve the above technical problems is as follows: improve the corrosion resistance of the liquid level line position of the wall bricks of the glass kiln melting pool from the following aspects: first, ensure that the ZrO ₂ component content is within a reasonable range; second, The first is to add corundum baddeleyite plate-like eutectic (referred to as ZA eutectic) to further optimize the thermal shock resistance of the product on the premise of meeting the corrosion resistance of the product; the third is to add a rare earth oxide group with a high melting point that inhibits the erosion of the glass liquid. The fourth is to maximize the goal of achieving zero glass phase content in products; the fifth is to adopt a special manufacturing process of vacuum high-pressure molding and high-temperature sintering. Therefore, using sintered high zirconium bricks at the liquid level of the glass furnace melting pool will not significantly increase the construction cost of the glass furnace, but can also significantly increase the overall service life of the glass furnace and has excellent cost performance.

The invention is realized through the following technical solutions: a sintered high zirconium brick used at the liquid level position of the glass melting tank is made of the following raw materials in weight percentages: ZrO ₂ 76-88wt%; ZA eutectic 5-10wt% ; Y ₂ O ₃ 2-8wt%; MgO 2-6wt%; CaO 2-4wt%; CeO ₂ 0.4-1.2wt%; SrO 0.3-1wt%.

Further, the ZrO ₂ purity is not less than 99%, and the particle size is 1um-30um.

Further, the content of ZrO ₂ and Al ₂ O ₃ in the ZA eutectic is not less than 99%, and the particle size is 2um-44um.

Further, the purity of the Y ₂ O ₃ is not less than 99%, and the particle size is 1um-10um.

Further, the purity of the MgO is not less than 99%, and the particle size is 2um-10um.

Further, the CaO purity is not less than 99%, and the particle size is 2um-10um.

Further, the CeO ₂ purity is not less than 99%, and the particle size is 0.2um-8um.

Further, the purity of the SrO is not less than 99%, and the particle size is 0.2um-8um.

The preparation method of a sintered high zirconium brick for the liquid level position of a glass melting tank includes the following steps:

Step 1: Materials are mixed and granulated. According to the above-mentioned raw material types and proportions, the raw materials are put into a three-dimensional mixer and mixed for 24 hours; the mixed raw materials are then put into a granulator for granulation, screening, and granulation. The particle size is controlled to 20-180 mesh to obtain a blank.

Step 2: Molding and blanking. Put the granulated raw materials into the mold cavity of a high-tonnage vacuum press for pressure molding. The absolute value of the vacuum degree is not less than 0.09MPa, and the molding pressure is not less than 800MPa to obtain a dense semi-finished product. body.

Step 3: Firing, raising the temperature to 1700-1750°C, and sintering at a constant temperature for 25-36 hours. After cooling, a sintered high zirconium brick for the liquid level position of the glass melting pool is obtained.

The beneficial effects of the present invention: the sintered high zirconium bricks used at the liquid level position of the glass melting pool are resistant to glass erosion and have a long service life. The main mechanism is:

1. The sintered high zirconium brick of this application introduces 76-88wt% of zirconium dioxide, the main component that is resistant to glass erosion. Since the product is sintered at high temperature for a long time, the crystal develops well. If the ZrO ₂ component content is less than 76%, the corrosion resistance of the product will be attenuated; if the ZrO ₂ component content is >88%, the corrosion resistance will not be significantly improved, but it will cause the thermal shock resistance of the product to deteriorate.

2. The sintered high zirconium bricks of this application incorporate corundum baddeleyite plate-like eutectic into the system ingredients. This eutectic has a plate-like structure and has the property of buffering thermal stress, so that the product has excellent thermal shock resistance.

3. The sintered high zirconium bricks of this application introduce high melting point and anti-erosion components into the system ingredients - rare earth oxides cerium oxide CeO ₂ and strontium oxide SrO. CeO ₂ has the effect of further stabilizing the ZrO ₂ crystal lattice, making the product Zirconium oxide does not produce volume changes during phase transformation due to temperature changes; SrO can effectively prevent the SiO ₂ in the glass liquid from reacting with the stabilizers (MgO, CaO) in the zirconia crystal lattice, and has the ability to prevent the destabilization of zirconia. Function, the introduction of rare earth raw materials further optimizes the corrosion resistance and thermal shock resistance of the product.

4. The three oxide components of Y ₂ O ₃ , MgO, and CaO introduced into the sintered high zirconium bricks of this application are composite stabilizers for zirconium oxide. Since the ionic radii of these three oxide components are similar to those of zirconium oxide, they can form a solid solution with zirconium oxide, prompting zirconium oxide to become a stable tetragonal or cubic phase, and avoiding volume expansion and contraction caused by the phase transformation of zirconium oxide. Product cracking defects caused by stress.

5. Since the sintered high zirconium bricks of this application do not contain silica and sodium oxide in the system ingredients, the harmful glass phase in the product is almost zero.

6. The sintered high zirconium bricks of this application are pressed by a high-tonnage vacuum press in the molding process, and the sintering process uses long-term high-temperature sintering, so that the products have high density, low porosity, and excellent structural properties, making it difficult for the glass liquid to Products produce penetrating erosion.

Therefore, the sintered high zirconium bricks of the present application have excellent glass corrosion resistance and ideal service life, and are of great significance for glass companies to improve product quality, reduce costs, and improve corporate and social benefits.

Description of drawings

Figure 1 is a comparative view of the samples cut along the center line of the sintered high zirconium bricks prepared in Example 2 of the present application and the AZS brick 33# after corrosion.

Figure 2 is a comparison chart of samples before and after dynamic corrosion resistance of sintered high zirconium bricks and AZS brick 33# prepared in Example 2 of the present application.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In the following embodiments,

The purity of _ZrO2 is not less than 99%, and the particle size is 1um-30um.

The content of ZrO ₂ and AI ₂ O ₃ in ZA eutectic is not less than 99%, and the particle size is 2um-44um.

The purity of Y ₂ O ₃ is not less than 99%, and the particle size is 1um-10um.

The purity of MgO is not less than 99%, and the particle size is 2um-10um.

The purity of CaO is not less than 99%, and the particle size is 2um-10um.

The purity of _CeO2 is not less than 99%, and the particle size is 0.2um-8um.

The purity of SrO is not less than 99%, and the particle size is 0.2um-8um.

The preparation method of the sintered high zirconium brick used for the liquid level position of the glass melting tank includes the following steps:

Step 1: Materials are mixed and granulated. According to the raw material ratio, the relevant raw materials are put into the three-dimensional mixer and mixed for 24 hours; the mixed raw materials are then put into the granulator for granulation, screening, and granulation particle size control. 20-180 mesh to obtain the blank.

Step 2: Forming and blanking. Put the granulated raw materials into the mold cavity of a high-tonnage vacuum press for pressure molding. The absolute value of the vacuum degree is not less than 0.09MPa, and the molding pressure is not less than 800MPa to obtain a semi-finished green body. .

Step 3: Firing, raising the temperature to 1680-1750°C, sintering at a high temperature for 20-26 hours at a constant temperature, and cooling to obtain sintered high zirconium bricks for the liquid level position of the glass melting pool.

Example 1

A sintered high zirconium brick used at the liquid level position of the glass melting tank, including the following raw materials in terms of mass percentage

Zirconium dioxide material: 88%;

ZA eutectic material: 6%

Yttrium oxide material: 2%;

Magnesium oxide material: 2%;

Calcium oxide material: 1%;

Cerium oxide material: 0.6%;

Strontium oxide material: 0.4%

Example 2

A sintered high zirconium brick used at the liquid level position of the glass melting tank, including the following raw materials in terms of mass percentage

Zirconia material: 83%;

ZA eutectic material: 7%

Yttrium oxide material: 5%;

Magnesium oxide material: 2%;

Calcium oxide material: 2%;

Cerium oxide material: 0.7%;

Strontium oxide material: 0.3%

Example 3

A sintered high zirconium brick used at the liquid level position of the glass melting tank, including the following raw materials in terms of mass percentage

Zirconia material: 76%;

ZA eutectic material: 10%

Yttrium oxide material: 4%;

Magnesium oxide material: 4.5%;

Calcium oxide material: 4%;

Cerium oxide material: 0.8%;

Strontium oxide material: 0.7%

Performance parameter characterization:

1. Test the relevant properties of the above-mentioned Examples 1-3 and Comparative Example AZS33# bricks. The testing standards involved are as follows:

The implementation standard for load softening temperature detection is GB/T5989-1998;

The implementation standard for apparent porosity testing is GB/T2997-2000;

The implementation standard for volume density testing is GB/T2997-2000;

The implementation standard for compressive strength testing is GB/T50081-2002;

The implementation standard for thermal shock stability testing is YB/T376.1-1995.

The relevant performance test results are as follows:

It can be seen from the above table that the various performance indicators of the sintered high zirconium brick invented by the present application are better than the 33# fused AZS brick.

2. Glass liquid corrosion resistance test

The sintered high zirconium bricks prepared in Example 2 of the present application and the 33# fused AZS bricks were subjected to a glass liquid corrosion resistance comparative test. The comparative test conditions are as follows:

erosion medium High silicate glass Test temperature 1600℃ Keeping time 48h Sample speed 50 rpm

The comparative test results are as follows:

From the test data of resistance to glass liquid erosion and pictures of samples after erosion described in the table above, it can be concluded that the sintered high zirconium bricks of the present invention have very excellent resistance to glass liquid erosion. At the position of the glass liquid level line, the high zirconium bricks The erosion amount and erosion rate index are only 1.7% of that of 33# fused AZS bricks, which is of great significance for greatly extending the life of glass furnaces and reducing furnace maintenance costs.

Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still The technical solutions described in the foregoing embodiments may be modified, or equivalent substitutions may be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in protection scope of the present invention.

Claims (10)

1. A sintered high zirconium brick, characterized by: including the following raw materials: ZrO ₂ , ZA eutectic, Y ₂ O ₃ , MgO, CaO, CeO ₂ , SrO. 2. A sintered high zirconium brick according to claim 1, characterized in that: the weight percentage content of the raw materials is: ZrO ₂ 76-88wt%, ZA eutectic 5-10wt%, Y ₂ O ₃ 2- 8wt%, MgO 2-6wt%, CaO 2-4wt%, CeO ₂ 0.4-1.2wt%, SrO 0.3-1wt%. 3. A sintered high-zirconium brick according to claim 1, characterized in that: the weight percentage content of the raw materials is: zirconia 83wt%, ZA eutectic 7wt%, Y ₂ O ₃ 5wt%, MgO 2wt% , CaO 2wt%, CeO ₂ 0.7wt%, SrO0.3wt%. 4. A sintered high zirconium brick according to claim 1, characterized in that the content of ZrO ₂ and Al ₂ O ₃ in the ZA eutectic is not less than 99%, and the particle size is 2um-44um. 5. A sintered high zirconium brick according to claim 1, characterized in that the _ZrO2 purity is not less than 99%, and the particle size is 1um-30um. 6. A method for preparing the sintered high zirconium brick according to any one of claims 1 to 5, characterized by comprising the following steps: Step 1: Mix and granulate the materials. According to the raw material ratio, put the raw materials into the three-dimensional mixer and mix for 24 hours; the mixed raw materials are then put into the granulator for granulation and screening, and the granulation particle size is controlled for 20 -180 mesh, get the blank; Step 2: Forming and blanking. The granulated raw materials are put into the mold cavity of a high-tonnage vacuum press for pressure molding to obtain a dense semi-finished product blank; Step 3: Firing, heating to a certain temperature, constant temperature sintering for a certain period of time, and obtaining sintered high zirconium bricks after cooling. 7. The preparation method according to claim 6, characterized in that the absolute value of the vacuum degree in step two is not less than 0.09MPa. 8. The preparation method according to claim 6, characterized in that the molding pressure in step two is not less than 800MPa. 9. The preparation method according to claim 6, characterized in that the heating temperature in step three is 1700-1750°C, and the constant temperature sintering time in step three is 25-36 hours. 10. Application of the sintered high zirconium brick according to any one of claims 1 to 5 at the liquid level line of the glass melting pool.