Zirconium-based amorphous material for the bottom sealing layer of glass melting furnace and its preparation method

Abstract

The present invention discloses a zirconium-based amorphous material for the bottom sealing layer of a glass melting furnace and a preparation method thereof, which relates to the technical field of bottom sealing materials for melting furnaces. The technical solution is as follows: it includes the following components in parts by weight: 18-52 parts of fused white corundum particles, 3-15 parts of alumina, 8-35 parts of zircon sand, 22-47 parts of zircon powder, 3-10 parts of clay fine powder, and 4-8 parts of binder; the crystal form of alumina is α-Al2O3, including alumina I and alumina II, 2000 mesh < particle size of alumina I ≤ 325 mesh, particle size of alumina II ≤ 2000 mesh, and the mass ratio of alumina I to alumina II is (2-5):1. The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace of the present invention is in a zero-expansion or slightly expanding state during the drying and sintering processes, will not crack and will not delaminate from the paving bricks, and has a better sealing effect; after sintering, it has a high bulk density and high resistance to glass melt erosion and glass melt permeability.

Description

Technical Field

[0001] The present invention relates to the technical field of bottom sealing materials for melting furnaces, and particularly to a zirconium-based amorphous material for the bottom sealing layer of a glass melting furnace and a preparation method thereof. Background Art

[0002] The bottom sealing layer of a glass melting furnace is a crucial part of the glass furnace. Its main functions are to prevent the leakage of molten glass, reduce heat loss, protect the furnace body structure, and extend the service life of the melting furnace, etc. With the continuous development of glass manufacturing technology, the performance requirements for the bottom sealing layer are getting higher and higher. It is required to be volume-stable, non-expanding, non-shrinking, and non-cracking during the heating process and under long-term high temperatures, and be able to resist the erosion of high-temperature molten glass and metal; and be able to withstand high temperatures above 1400 °C for a long time, have sufficient compressive strength and flexural strength to bear the pressure of molten glass; at the same time, this material must have good plasticity and adhesiveness to facilitate ramming construction.

[0003] Electrofused zirconia corundum brick is one of the important refractory raw materials containing zirconia. It is prepared by adding zircon sand, zirconia or desilicated zircon and alkali powder to alumina and melting in an electric arc furnace. The main crystal phase of electrofused zirconia corundum is α-Al2O3, the secondary crystal phase is baddeleyite, and there is a small amount of glass phase. Its appearance is generally yellowish-brown and very dense. According to the different ZrO2 contents, electrofused zirconia corundum can be divided into low electrofused zirconia corundum (ZrO2 content is about 10 - 15 wt.%), medium electrofused zirconia corundum (ZrO2 content is about 25 wt.%) and high electrofused zirconia corundum (ZrO2 content is about 40 wt.%). Due to its excellent resistance to glass erosion, electrofused zirconia corundum bricks are widely used in the bottom and walls of glass melting furnaces. The zirconium-based amorphous material for the sealing layer used in combination with electrofused zirconia corundum bottom paving bricks also plays a crucial role in the safety of the furnace structure. Only when the electrofused zirconia corundum bottom paving bricks, joints and sealing layer are combined into a closed and inseparable whole can the leakage of the melting furnace be effectively prevented and the service life of the melting furnace be extended.

[0004] Chinese invention patent CN106810282A discloses a method for producing ramming material by using waste electrofused zirconia corundum bricks. This method uses waste electrofused zirconia corundum bricks recovered from a glass furnace, which are sorted, quenched, crushed and screened to obtain electrofused zirconia corundum aggregates, and then the electrofused zirconia corundum aggregates are mixed evenly with zircon powder, binder and additives to obtain ramming material. Although this method realizes the recycling of waste electrofused zirconia corundum bricks from glass furnaces, in order to remove the glass and alkaline substances attached to the recycled waste electrofused zirconia corundum bricks, a large amount of carboxylic acid or organic acid, etc. needs to be introduced into the powder, and the dosage of additives is relatively large; during construction, the alkaline substances attached to the recycled material will react with the used binder phosphate to generate heat due to neutralization reaction, resulting in abnormal construction; in addition, due to the too high impurity content of the recycled material, the high-temperature performance of the final product is not good and it will pollute the glass.

[0005] Chinese Invention Patent CN119390446A discloses a preparation method of zirconia ramming material for glass furnaces. This patent uses zircon as refractory aggregate, fused cast zircon corundum micropowder as refractory powder, alumina as additive, and silica sol-alumina composite binder to replace traditional silicate as binder, and prepares the ramming material for glass furnaces through batching, mixing, forming, drying and sintering. In this patent, the zircon aggregate needs to be manually formed, sintered and crushed into required particles for the second time, and the fused cast zircon corundum micropowder even needs to be electrically fused, crushed and ground into powder, with complex preparation process and easy introduction of impurities. Moreover, this patent uses ramming material with different crystal phases from the paving bricks and relatively high impurity content such as Fe2O3. Due to its inability to sinter with the paving bricks into an integral composite layer at high temperature and high foaming rate, its resistance to upward drilling erosion of glass liquid is poor.

[0006] In summary, the commonly used zirconium-based bottom sealing materials for glass furnaces have the following problems: The bottom sealing materials generally use fused cast zircon corundum materials, recycled fused cast zircon corundum brick crushed materials, zircon brick crushed materials, etc. as main raw materials for preparation. Due to relatively high content of R2O, Fe2O3 and other impurities in the products, the crystal phases are inconsistent with the paving bricks, and they cannot sinter with the paving bricks into an integral composite layer at high temperature and have high foaming rate, so their resistance to upward drilling erosion of glass liquid is poor; during the furnace baking stage, the ramming material sealing layer has large firing shrinkage after being heated, and the sealing layer is subjected to compressive stress from the upper paving bricks and firing shrinkage stress of the ramming material, resulting in cracking of the sealing layer and loss of sealing function of the bottom sealing material; during the operation stage of the furnace, after the high-temperature glass liquid invades the sealing layer from the gaps of the paving bricks, the sealing layer reacts with the glass liquid, easily generating bubbles, resulting in bubble defects in the glass products, and even the glass liquid reacts violently with the sealing layer, causing the upper fused cast zircon corundum bottom paving bricks to arch upward, leading to furnace safety accidents.

[0007] Therefore, it is necessary to develop new zirconium-based amorphous materials for the bottom sealing layer of glass melting furnaces to solve the above problems. Summary of the Invention

[0008] The technical problem to be solved by the present invention is: To overcome the deficiencies of the prior art, to provide a zirconium-based amorphous material for the bottom sealing layer of glass melting furnaces and its preparation method, in which the zirconium-based amorphous material is in a zero-expansion or slightly expanding state during the drying and sintering processes, the sealing layer itself will not crack and will not delaminate from the paving bricks, with better sealing effect; and after sintering, it has a high bulk density, and has high resistance to glass liquid erosion and high resistance to glass liquid permeability.

[0009] The technical solution of the present invention is as follows:

[0010] On the one hand, the present invention provides a zirconium-based amorphous material for the bottom sealing layer of a glass melting furnace, comprising the following components in parts by weight: 18-52 parts of fused white corundum particles, 3-15 parts of alumina, 8-35 parts of zircon sand, 22-47 parts of zircon powder, 3-10 parts of clay fine powder, and 4-8 parts of binder; wherein, the crystal form of alumina is α-Al2O3, including alumina I and alumina II, the particle size of alumina I is 2000 mesh < alumina I particle size ≤ 325 mesh, the particle size of alumina II is ≤ 2000 mesh, and the mass ratio of alumina I to alumina II is (2-5):1.

[0011] Preferably, in the fused white corundum particles, Al2O3 > 99 wt.%, Fe2O3 < 0.1 wt.%, and 1 mm ≤ particle size ≤ 5 mm.

[0012] Preferably, in the alumina, Al2O3 > 99 wt.%, Fe2O3 < 0.05 wt.%.

[0013] Preferably, in the zircon sand, ZrO2 > 63 wt.%, Fe2O3 < 1 wt.%, TiO2 < 1.5 wt.%, and 120 mesh ≤ particle size ≤ 80 mesh.

[0014] Preferably, in the zircon powder, ZrO2 > 63 wt.%, Fe2O3 < 1 wt.%, TiO2 < 1.5 wt.%, and the particle size ≤ 325 mesh.

[0015] Preferably, the clay fine powder is Suzhou clay, Al2O3 > 36 wt.%, Fe2O3 < 1.2 wt.%, and the particle size ≤ 325 mesh.

[0016] Preferably, the binder is aluminum dihydrogen phosphate powder with a particle size ≤ 0.1 mm.

[0017] On the other hand, the present invention provides a preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace, comprising the following steps:

[0018] S1 Raw material mixing: Put each component into a mixer for dry mixing, and add 3-5 wt.% of water for mixing.

[0019] S2 Ramming construction: Pour the mixed mud into a mold and ram it until the surface is smooth.

[0020] S3 Curing and hardening: After construction, cure naturally for 24-48 h to harden, and a sample blank is obtained after demolding.

[0021] S4 Drying and sintering: Dry the sample blank, and then sinter it to obtain the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace.

[0022] Preferably, in step S4, the drying temperature is 100-120°C and the drying time is more than 12 hours; the sintering temperature is 1200-1400°C and the heat preservation time is more than 3 hours.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace of the present invention uses electrofused white corundum particles with high-purity raw materials as the aggregate, and specific proportions of alumina I, alumina II, zircon powder, zircon sand, etc. as the matrix. During long-term use, zircon sand and zircon powder in the matrix gradually react with specific proportions of alumina I and alumina II to form mullite, etc. The volume expansion generated just offsets the firing shrinkage of the sealing layer, making the overall volume of the material always in a zero-expansion or micro-expansion state. The sealing layer itself will not crack, and it will not delaminate from the paving bricks. It can be sintered with the paving bricks into an integral composite layer, and the sealing effect is good.

[0025] 2. The raw materials and their ratios used in the present invention make the main crystal phase of the sintered particles basically the same as that of the electrofused zirconium corundum paving bricks, and the main crystal phase of the matrix part is also the same as that of the electrofused zirconium corundum paving bricks. The matrix part is composed of corundum, zirconia, and mullite phases, with almost no glass phase and low impurity content. It has the advantages of good resistance to glass liquid erosion, low foaming property, and low permeability. At the same time, after sintering, it has a high volume density, high strength, small permanent linear change on heating, and good volume stability at high temperatures, and can withstand high temperatures above 1400°C for a long time.

[0026] 3. The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace of the present invention has good plasticity and adhesiveness, which is convenient for ramming construction. Detailed implementation manners

[0027] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention.

[0028] The raw materials in the following examples and comparative examples are all commercially available raw materials, and the chemical composition detection results and particle sizes of each raw material are shown in Tables 1-2:

[0029] Table 1 Chemical composition detection results of each raw material

[0030]

[0031] Table 2 Particle sizes of each raw material

[0032]

[0033] Example 1

[0034] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this embodiment comprises the following components in parts by weight: 42 parts of fused white corundum particles, 8 parts of alumina, 20 parts of zircon sand, 25 parts of zircon powder, 5 parts of Suzhou clay, and 6 parts of dihydrogen aluminum phosphate powder; wherein, the crystal form of alumina is α-Al2O3, and the mass ratio of alumina I to alumina II is 3:1; the particle size of the dihydrogen aluminum phosphate powder is ≤0.1 mm.

[0035] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this embodiment comprises the following steps:

[0036] S1 Raw material mixing: Put each component into a kneader and dry mix for 3 min, then add 3.5 wt.% water and knead for 10 min;

[0037] S2 Ramming construction: Pour the kneaded mud into a mold of 230 mm × 65 mm × 65 mm, and use a vibrator to ram until the surface is smooth;

[0038] S3 Curing and hardening: After construction, cure naturally for 24 h to harden, and obtain a sample blank after demolding;

[0039] S4 Drying and sintering: Put the sample blank into a drying oven and dry at 100 °C for 48 h, then put the dried blank into a furnace for sintering, the sintering temperature is 1400 °C, and keep warm for 3 h.

[0040] Example 2

[0041] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this embodiment comprises the following components in parts by weight: 30 parts of fused white corundum particles, 10 parts of alumina, 10 parts of zircon sand, 47 parts of zircon powder, 3 parts of Suzhou clay, and 7 parts of dihydrogen aluminum phosphate powder; wherein, the crystal form of alumina is α-Al2O3, and the mass ratio of alumina I to alumina II is 7:3; the particle size of the dihydrogen aluminum phosphate powder is ≤0.1 mm.

[0042] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this embodiment comprises the following steps:

[0043] S1 Raw material mixing: Put each component into a kneader and dry mix for 3 min, then add 3 wt.% water and knead for 10 min;

[0044] S2 Ramming construction: Pour the kneaded mud into a mold of 230 mm × 65 mm × 65 mm, and use a vibrator to ram until the surface is smooth;

[0045] S3 Curing and hardening: After construction, cure naturally for 30 h to harden, and obtain a sample blank after demolding;

[0046] S4 Drying and Sintering: Put the sample green body into a drying oven and dry it at 120 °C for 12 h. Then put the dried green body into a kiln for sintering. The sintering temperature is 1350 °C and hold for 5 h.

[0047] Example 3

[0048] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this example comprises the following components in parts by weight: 37 parts of fused white corundum particles, 8 parts of alumina, 25 parts of zircon sand, 27 parts of zircon powder, 3 parts of Suzhou clay, and 6 parts of dihydrogen aluminum phosphate powder; wherein, the crystal form of alumina is α-Al2O3, and the mass ratio of alumina I to alumina II is 3:1; the particle size of the dihydrogen aluminum phosphate powder is ≤ 0.1 mm.

[0049] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this example comprises the following steps:

[0050] S1 Raw Material Mixing: Put each component into a mixer and dry mix for 3 min, then add 5 wt.% water and mix for 10 min;

[0051] S2 Ramming Construction: Pour the mixed mud into a mold of 230 mm × 65 mm × 65 mm, and use a vibrator to ram until the surface is smooth;

[0052] S3 Curing and Hardening: After construction, cure naturally for 48 h to harden, and obtain a sample green body after demolding;

[0053] S4 Drying and Sintering: Put the sample green body into a drying oven and dry it at 110 °C for 18 h. Then put the dried green body into a kiln for sintering. The sintering temperature is 1200 °C and hold for 12 h.

[0054] Example 4

[0055] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this example comprises the following components in parts by weight: 18 parts of fused white corundum particles, 15 parts of alumina, 35 parts of zircon sand, 27 parts of zircon powder, 5 parts of Suzhou clay, and 8 parts of dihydrogen aluminum phosphate powder; wherein, the crystal form of alumina is α-Al2O3, and the mass ratio of alumina I to alumina II is 5:1; the particle size of the dihydrogen aluminum phosphate powder is ≤ 0.1 mm.

[0056] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this example is the same as that of Example 1.

[0057] Example 5

[0058] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this embodiment comprises the following components in parts by weight: 45 parts of fused white corundum particles, 5 parts of alumina, 20 parts of zircon sand, 22 parts of zircon powder, 8 parts of Suzhou clay, and 5 parts of dihydrogen aluminum phosphate powder; wherein, the crystal form of alumina is α-Al2O3, and the mass ratio of alumina I to alumina II is 4:1; the particle size of the dihydrogen aluminum phosphate powder is ≤0.1 mm.

[0059] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this embodiment is the same as that in Example 1.

[0060] Example 6

[0061] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this embodiment comprises the following components in parts by weight: 52 parts of fused white corundum particles, 3 parts of alumina, 8 parts of zircon sand, 27 parts of zircon powder, 10 parts of Suzhou clay, and 4 parts of dihydrogen aluminum phosphate powder; wherein, the crystal form of alumina is α-Al2O3, and the mass ratio of alumina I to alumina II is 2:1; the particle size of the dihydrogen aluminum phosphate powder is ≤0.1 mm.

[0062] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in this embodiment is the same as that in Example 4.

[0063] Comparative Example 1

[0064] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in Comparative Example 1 comprises the following components in parts by weight: 95 parts of fused zircon corundum brick particles and fine powder, 5 parts of Suzhou clay, and 6 parts of dihydrogen aluminum phosphate powder, and the particle size of the dihydrogen aluminum phosphate powder is ≤0.1 mm.

[0065] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in Comparative Example 1 is the same as that in Example 1.

[0066] Comparative Example 2

[0067] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in Comparative Example 2 comprises the following components in parts by weight: 95 parts of recycled fused zircon corundum brick particles and fine powder, 5 parts of Suzhou clay, and 6 parts of dihydrogen aluminum phosphate powder, and the particle size of the dihydrogen aluminum phosphate powder is ≤0.1 mm.

[0068] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in Comparative Example 2 is the same as that in Example 1.

[0069] Comparative Example 3

[0070] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in Comparative Example 3 comprises the following components in parts by weight: 95 parts of zircon stone brick particles and fine powder, 5 parts of Suzhou clay, and 6 parts of dihydrogen aluminum phosphate powder, and the particle size of the dihydrogen aluminum phosphate powder is ≤0.1 mm.

[0071] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in Comparative Example 3 is the same as that in Example 1.

[0072] Comparative Example 4

[0073] The difference from Example 1 is that fused zirconia corundum brick particles are used instead of fused white corundum particles in Example 1.

[0074] Comparative Example 5

[0075] The difference from Example 1 is that zircon sand brick particles are used instead of fused white corundum particles in Example 1.

[0076] Comparative Example 6

[0077] The difference from Example 1 is that the mass ratio of Alumina Ⅰ to Alumina Ⅱ is 7:1.

[0078] Comparative Example 7

[0079] The difference from Example 1 is that the mass ratio of Alumina Ⅰ to Alumina Ⅱ is 1:1.

[0080] Comparative Example 8

[0081] The difference from Example 1 is that Alumina Ⅰ is used instead of Alumina Ⅱ.

[0082] Comparative Example 9

[0083] The difference from Example 1 is that Alumina Ⅱ is used instead of Alumina Ⅰ.

[0084] Comparative Example 10

[0085] The difference from Example 1 is that activated alumina with a crystal form of γ-Al2O3 is used instead of alumina with a crystal form of α-Al2O3 in Example 1.

[0086] Comparative Example 11

[0087] The zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in Comparative Example 11 comprises the following components in parts by weight: 42 parts of fused white corundum particles, 20 parts of zircon sand, 33 parts of zircon powder, 5 parts of Suzhou clay, and 6 parts of aluminum dihydrogen phosphate powder, and the particle size of the aluminum dihydrogen phosphate powder ≤ 0.1 mm.

[0088] The preparation method of the zirconium-based amorphous material for the bottom sealing layer of the glass melting furnace in Comparative Example 11 is the same as that in Example 1.

[0089] The performance tests were carried out on the zirconium-based amorphous materials for the bottom sealing layer of the glass melting furnace prepared in Examples 1-6 and Comparative Examples 1-11. The apparent porosity and bulk density were tested according to the "Test Methods for Bulk Density, Apparent Porosity and True Porosity of Dense Shaped Refractory Products (GB / T 2997-2015)"; the cold crushing strength was tested according to the "Test Method for Cold Crushing Strength of Refractory Materials (GB / T 5072-2023)"; the compressive creep rate was tested according to the "Test Method for Compressive Creep of Refractory Materials (GB / T 5073-2005)"; the erosion rate was tested according to the "Test Method for Static Glass Erosion Resistance of Refractory Materials for Glass Melting Furnaces (JC / T 806-2017)"; the thickness of the penetration layer was directly measured from the discolored layer of the cut surface of the test bar after the erosion test; the foaming index was measured by using the test block sintered at 1200 °C for 3 h, cutting out a test block of 70 mm × 70 mm × 65 mm, drilling a hole with a diameter of 30 mm and a depth of 30 mm in the middle, putting glass and covering it with a cover plate of the same material, heating it to the test temperature at a heating rate of 200 °C / h, keeping it warm for 12 h, then cooling the sample in the furnace to room temperature, cutting a 10-mm-thick slice from the middle of the crucible, and observing the number of bubbles in the glass under a microscope; the linear change rate was tested according to the "Test Method for Linear Change Rate of Dense Refractory Castables (YBT 5203-1993)". The test results are shown in Table 3-4:

[0090] Table 3 Performance Test Results of Zirconium-based Amorphous Materials for the Bottom Sealing Layer of the Glass Melting Furnace in Examples 1-6

[0091]

[0092] Table 4 Performance Test Results of Zirconium-based Amorphous Materials for the Bottom Sealing Layer of the Glass Melting Furnace in Comparative Examples 1-11

[0093]

[0094] As can be seen from Table 3, for the zirconium-based amorphous materials for the bottom sealing layer of the glass melting furnace prepared in Examples 1-6, the linear change rates at 100 °C × 24 h and 800 °C × 24 h are both positive, that is, they are in a slightly expanded state during the drying stage, and the linear change rate at 1200 °C × 3 h is between 0.08 - 0.36%, and the volume expands slightly after sintering; the apparent porosity after firing at 1200 °C × 3 h is 14.3 - 15.1%, and the bulk density is 3.01 - 3.05 g / cm 3, the compressive strength is 80 - 99 MPa; the creep rate under 1300°C × 0.2 MPa is 0.06 - 0.46%; the erosion rate under 1350°C × 48 h is 0.97 - 1.5 mm / 24 h; the penetration layer thickness under 1350°C × 48 h is 1.24 - 1.66 mm; the foaming index under 1200°C × 12 h is 1 - 2. Comparing Example 1 with Examples 2 - 6 in Table 3, it can be seen that within the scope defined by the present invention, by appropriately adjusting the ratio of components such as fused white corundum particles, the performance differences of the prepared zirconium-based amorphous materials are not significant.

[0095] Comparing Examples 1 - 6 with Comparative Examples 1 - 3 in Table 4, it can be seen that for the zirconium-based amorphous material used for the bottom sealing layer of the glass melting furnace pool prepared by using the particles and fine powders obtained by crushing fused zirconia corundum bricks, recycled fused zirconia corundum bricks, and zircon sand bricks as aggregates and matrix, the linear change rates at 100°C × 24 h, 800°C × 24 h, and 1200°C × 3 h are positive or slightly shrinking, but the apparent porosity after sintering at 1200°C × 3 h is 20.5 - 24.2%, and the bulk density is only 2.56 - 3.01 g / cm 3 , the compressive strength is only 30 - 48 MPa, and the creep rate under 1300°C × 0.2 MPa is negative, ranging from -1.48% to -1.24%; the erosion rate under 1350°C × 48 h is 2.18 - 3.1 mm / 24 h, the penetration layer thickness reaches 3.52 - 4.66 mm, and the foaming index under 1200°C × 12 h is 3 - 5. Although the main crystal phases before sintering in Comparative Example 1 and Comparative Example 2 are similar to those of the fused zirconia corundum bottom paving bricks, the contents of R2O, Fe2O3, and other impurities in them are relatively high, and the sintering activity is poor. After sintering, they show poor erosion resistance, high foaming rate, and poor stability at high temperatures. The main crystal phase before sintering in Comparative Example 3 is quite different from that of the fused zirconia corundum bottom paving bricks. The decomposition phenomenon of zircon sand particles when encountering alkaline components results in poor overall erosion resistance, poor stability at high temperatures, high foaming rate, and it is difficult to sinter with the paving bricks into a composite layer as a whole after firing.

[0096] Comparing Example 1 with Comparative Examples 4 - 5, it can be seen that for the zirconium-based amorphous material used for the bottom sealing layer of the glass melting furnace pool prepared by using fused zirconia corundum brick particles and zircon sand brick particles instead of fused white corundum particles, the linear change rates at 100°C × 24 h, 800°C × 24 h, and 1200°C × 3 h are all positive, showing a slight expansion. The apparent porosity, bulk density, and compressive strength after sintering at 1200°C × 3 h are comparable to those of Example 1, but the creep rate under 1300°C × 0.2 MPa is negative, indicating that its volume is unstable under high temperature and high pressure. Further comparing Example 1 with Comparative Examples 4 - 5, the erosion rate, penetration layer thickness, and foaming index at 1350°C × 48 h in Comparative Examples 4 - 5 are all significantly increased, indicating that the present invention uses fused white corundum particles matching the matrix fine powder, which has obvious advantages in volume stability and low foaming property at high temperatures.

[0097] Comparing Comparative Example 1 with Comparative Examples 6-9, it can be seen that when the ratio of Alumina I to Alumina II exceeds the defined range of the present invention, the mullitization reaction weakens, and the volume expansion during phase change is not sufficient to offset the firing shrinkage of the material. After sintering, the volume shrinkage is large, and the creep rate under 1300°C × 0.2 MPa is negative. Although its apparent porosity, bulk density, compressive strength, erosion resistance and foaming property after sintering at 1200°C × 3 h are comparable to those of Example 1, its high-temperature volume stability is poor, and it is difficult to form a stable composite layer with the fused zirconia corundum bottom paving bricks.

[0098] Comparative Example 10 is a zirconium-based amorphous material for the bottom sealing layer of a glass melting furnace prepared from activated alumina of the γ-Al2O3 crystal form, which burst when dried to 652°C. The main reason is that the activated alumina adsorbs moisture during the batching and construction processes. During the drying and calcination processes, the crystal form transforms into α-Al2O3, and a large amount of bound water is discharged. The rapid drying heating rate causes the water in the brick to be discharged untimely, resulting in bursting.

[0099] Comparing Example 1 with Comparative Example 11, it can be seen that in Comparative Example 11, alumina of the α-Al2O3 crystal form is not used as the matrix, and the matrix is entirely composed of zircon sand powder and clay fine powder. Its linear change rates at 100°C × 24 h, 800°C × 24 h, and 1200°C × 3 h are all negative, and the volume shrinks during the firing process. Only the Al2O3 provided in the clay fine powder reacts with zircon sand and zircon sand powder, the mullitization reaction weakens, and the volume expansion during phase change is not sufficient to offset the firing shrinkage of the material. After sintering, the volume shrinkage is large; and the erosion rate, penetration layer thickness, and foaming index at 1350°C × 48 h are all significantly increased compared with Example 1.

Claims

1. Zirconium amorphous material for the bottom sealing layer of a glass melting furnace, characterized in that: The invention comprises the following components in parts by weight: 18-52 parts of fused white corundum particles, 3-15 parts of alumina, 8-35 parts of zircon sand, 22-47 parts of zircon powder, 3-10 parts of clay fine powder, and 4-8 parts of a binder; wherein the alumina crystal form is α-Al2O3, comprising alumina I and alumina II, 2000 mesh < alumina I particle size ≤ 325 mesh, alumina II particle size ≤ 2000 mesh, and a mass ratio of alumina I to alumina II is (2-5):1; in the fused white corundum particles, Al2O3> 99wt.%, Fe2O3< 0.1wt.%, and a particle size of 1mm≤≤5mm.

2. The zirconium amorphous material for the glass melting furnace bottom sealing layer according to claim 1, characterized in that: In the alumina, Al2O3>99wt.%, Fe2O3<0.05wt.%.

3. The zirconium amorphous material for the glass melting furnace bottom sealing layer according to claim 1, characterized in that: In the zircon sand, ZrO2>63wt.%, Fe2O3<1wt.%, TiO2<1.5wt.%, and particle size of 120 mesh≤≤80 mesh.

4. The zirconium amorphous material for the glass melting furnace bottom sealing layer according to claim 1, characterized in that: In the zircon powder, ZrO2>63wt.%, Fe2O3<1wt.%, TiO2<1.5wt.%, and particle size ≤325 mesh.

5. The zirconium amorphous material for the glass melting furnace bottom sealing layer according to claim 1, characterized in that: The clay fine powder is Suzhou clay, Al2O3>36wt.%, Fe2O3<1.2wt.%, and particle size ≤325 mesh.

6. The zirconium amorphous material for the glass melting furnace bottom sealing layer according to claim 1, characterized in that: The binder is aluminum dihydrogen phosphate powder with a particle size of ≤0.1 mm.

7. The method for preparing the zirconium amorphous material for the glass melting furnace bottom sealing layer according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1 Raw material mixing: put all components into a mixer and dry mix them, then add 3-5wt.% water and mix them; S2 Ramming construction: Pour the mixed mud into the mold and ram it until the surface is smooth; S3 curing and hardening: After the construction is completed, it is naturally cured for 24-48 hours to harden, and the sample body is obtained after demoulding; S4 drying and sintering: drying the sample body and then sintering it to obtain the zirconium amorphous material for the bottom sealing layer of the glass melting furnace.

8. The method for preparing the zirconium amorphous material for the glass melting furnace bottom sealing layer according to claim 7, characterized in that: In step S4, the drying temperature is 100-120°C, and the drying time is more than 12 hours; the sintering temperature is 1200-1400°C, and the heat preservation time is more than 3 hours.

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