EP-4741364-A1 - HIGH ZIRCONIA BRICK, AND PREPARATION PROCESS AND USE THEREOF

EP4741364A1EP 4741364 A1EP4741364 A1EP 4741364A1EP-4741364-A1

Abstract

The present application discloses a high zirconia brick and a preparation process and use thereof. The high zirconia brick can include the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of alumina, and 0.1-40% of yttria, iron oxide, titania, magnesia, calcia, and silica in total. In the present application, heating and annealing cooling are controlled by means of curved temperature control, and a high zirconia brick prepared has uniform and segregation-free distribution of all elements and consistent overall density, without defects such as needle-like pores, bubble retention, and surface cavities. The high zirconia brick prepared by the technological method has features of short delivery cycles of products and customizable production

Inventors

LIANG, Xinxing
FAN, Chongfang
LIU, XIAOGANG
LIANG, Qixing
BA, Yali
ZHANG, NING
LIU, YALONG
SHEN, WEIFENG
GE, Mengzhen
WU, YAHUI

Assignees

Zhengzhou Fangming High-Temperature Ceramic New Material Co., Ltd.

Dates

Publication Date: 20260513
Application Date: 20251111

Claims (10)

A high zirconia brick, wherein the high zirconia brick comprises the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of alumina, and 0.1-40% of yttria, iron oxide, titania, magnesia, calcia, and silica in total; or the high zirconia brick comprises the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of magnesia, and 0.1-40% of yttria, iron oxide, titania, calcia, and silica in total; or the high zirconia brick comprises the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of calcia, and 0.1-40% of magnesia, yttria, iron oxide, titania, and silica in total; or the high zirconia brick comprises the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of chromia, and 0.1-40% of calcia, magnesia, yttria, iron oxide, titania, and silica in total; or the high zirconia brick comprises the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of beryllia, and 0.1-40% of calcia, magnesia, yttria, iron oxide, titania, and silica in total.
A process for preparing the high zirconia brick according to claim 1, wherein the preparation process comprises the following steps: step 1: weighing and evenly mixing components, and allowing the components to react at 1,800-3,000°C for at least 45 min to form a molten liquid or a solid phase structure that is cooled to obtain a solid solution raw material; step 2: grinding the solid solution raw material obtained in step 1 into a powder having a D50 value of 0.2-100 microns; step 3: adding 0.1-5% of an organic binder or an inorganic binder to the powder obtained in step 2 and mixing the powder evenly; step 4: placing the powder obtained in step 3 in a mold and pressing the powder for at least 15 s under a pressure of not less than 500 tons to form an initial blank; step 5: heating the initial blank obtained in step 4 from room temperature to 1,600-1,950°C in at least 5 h by a temperature-controlled heating device, keeping the temperature at not lower than 1,600°C for at least 1 h, and then, lowering the temperature to room temperature in at least 5 h to obtain a high zirconia brick blank; and step 6: grinding and trimming the brick blank obtained in step 5 to obtain the high zirconia brick.
The preparation process according to claim 2, wherein the mixed components in step 1 are melted at 1,800-3,000°C for at least 45 min and cooled to obtain a solid solution raw material containing evenly distributed elements; or, the mixed components are subjected to high-temperature liquid-phase reaction sintering at 1,800-3,000°C for at least 60 min and cooled to obtain a solid solution raw material containing evenly distributed elements.
The preparation process according to claim 2, wherein the organic binder in step 3 is selected from at least one of polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyacrylamide (PAM), polyimide adhesive, epoxy adhesive, phenolic resin adhesive, and urea formaldehyde resin adhesive; and the inorganic binder comprises, but is not limited to paraffin wax and plant ash.
The preparation process according to claim 2, wherein the powder obtained in step 3 is placed in a mold, and formed by cold isostatic pressing at a pressure of 500-10,000 tons or pressed at a pressure not less than 500 tons for at least 15 s to form an initial blank.
The preparation process according to claim 2, wherein the mold comprises, but is not limited to a rubber mold, a polyurethane mold, and a metal mold.
The preparation process according to claim 2, wherein the temperature-controlled heating device in step 5 uses a programmable temperature controller, and is set with a starting temperature of room temperature, a heating rate of 320-390°C/h, a heating time of at least 5 h, a final temperature of 1,600-1,950°C, and a holding time of at least 1 h.
The preparation process according to claim 7, wherein the temperature-controlled heating device comprises, but is not limited to an electric heating device, an electromagnetic induction heating device, a vacuum heating device, a protective atmosphere heating device, a gas heating device, a plasma heating device, and a microwave heating device.
The preparation process according to claim 2, wherein a programmable temperature controller is used for cooling and annealing in step 5, and is set with a starting temperature of a furnace temperature, a cooling rate of 390-320°C/h, a cooling time of at least 5 h, and a final temperature of room temperature.
A use of the high zirconia brick according to any one of claim 1, for producing key ceramic products used in glass kilns, the ceramic products comprising, but are not limited to crucibles for special glass, high zirconia ceramic stirring paddles, high zirconia ceramic bricks, high zirconia wire-drawing crucibles, high zirconia shaped parts, and quartz furnaces.

Description

TECHNICAL FIELD The present disclosure relates to materials used in glass kilns, and specifically relates to a high zirconia brick and a preparation process and use thereof. BACKGROUND Materials used in glass kilns roughly include sintered materials and fused-cast materials. Although a preparation process of sintered materials is relatively simple, the porosity is generally high (about 10-30%), which can easily cause problems such as bubbles and detachment of aggregates when used in glass kilns, resulting in defects such as bubbles and sand grains in glass products. Therefore, sintered materials are not suitable for critical parts to be in contact with high-temperature molten glass in glass kilns. Specifically, for high zirconia sintered materials with stabilizers such as Y2O3, MgO, and CaO added to prevent monoclinic crystal and regular crystal phase transition of zirconia at 900-1,200°C, the thermal expansion coefficient is relatively high, and is likely to cause thermal stress cracking in a heating process. Also, stabilizers may dissolve in molten glass in a high-temperature environment of glass kilns, causing stable zirconia to transform to an unstable state and continue phase transition, making a material structure fragile, and also causing defects such as sand grains in glass. Therefore, such type of material is not suitable for glass kilns. Relatively speaking, fused-cast refractory materials are melted and fully homogenized in an electric furnace before being cast, cooled and solidified, and the obtained product has a dense structure and well-developed crystallization and is more suitable for use in glass kilns. Fused-cast materials having a high zirconia content have become preferred materials in glass melting kilns due to excellent corrosion resistance. Such materials are mainly divided into two types: Al2O3-ZrO2-SiO2 series fused cast refractory materials having a zirconia content of 33-41%; and high zirconia content series fused cast refractory materials having a high zirconia content of 80-95%. The latter has been widely used in high-quality glass kilns in recent years due to better corrosion resistance and low pollution to molten glass. However, existing high zirconia series refractory materials still have some defects, such as a lower glass phase content compared to electrocast zirconia corundum (AZS), and due to a difference in a cooling rate during a casting process, part materials may exhibit a growth ring-like structure with high porosity, which may lead to problems such as foaming. In addition, large-scale application of the high zirconia series fused cast refractory materials is hindered by low yield, long delivery cycle, and high price. Also, significant differences in application results are caused due to poor thermal shock performance and industry quality control capabilities of fused cast high zirconia products. Therefore, the research and application of refractory materials used in glass kilns still require continuous exploration and innovation to meet the demand of the glass industry for high-quality and high-performance refractory materials. SUMMARY An objective of the present disclosure is to provide a high zirconia brick and a preparation process and use thereof, to solve problems such as high manufacturing cost and poor thermal shock performance of existing high zirconia series fused cast refractory materials. To achieve the objective, the present disclosure provides the following technical solutions: According to a first aspect, the present disclosure provides a high zirconia brick, the high zirconia brick includes the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of alumina, and 0.1-40% of yttria, iron oxide, titania, magnesia, calcia, and silica in total;or the high zirconia brick includes the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of magnesia, and 0.1-40% of yttria, iron oxide, titania, calcia, and silica in total;or the high zirconia brick includes the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of calcia, and 0.1-40% of magnesia, yttria, iron oxide, titania, and silica in total;or the high zirconia brick includes the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of chromia, and 0.1-40% of calcia, magnesia, yttria, iron oxide, titania, and silica in total;or the high zirconia brick includes the following components in percentage by weight: 40-99% of zirconia, 0.1-60% of beryllia, and 0.1-40% of calcia, magnesia, yttria, iron oxide, titania, and silica in total. According to a second aspect, the present disclosure provides a process for preparing a high zirconia brick, the preparation process including the following steps: step 1: weighing and evenly mixing components, and allowing the components to react at 1,800-3,000°C for at least 45 min to form a molten liquid or a solid phase structure that is cooled to obtain a solid solution raw material;step 2: