Refractory product, coating composition for preventing redox reaction, and method for producing refractory product

Abstract

Refractory articles, anti-redox coating compositions, and methods of making refractory articles are provided. A refractory article includes a platinum (Pt)-based substrate and a coating layer for preventing a redox reaction on a surface of the Pt-based substrate, in which the coating layer for preventing the redox reaction includes, in terms of oxide, SiO2 in an amount of about 40 wt% to about 70 wt%, Al2O3 in an amount of about 20 wt% to about 52 wt%, B2O3 in an amount of about 3 wt% to about 6 wt%, and CaO in an amount of about 2.4 wt% to about 4.8 wt%; wherein the coating layer comprises whiskers distributed in a silica matrix, and wherein the whiskers comprise a polyaluminum andalusite crystalline phase.

Description

[0001] This application claims priority to Korean Patent Application Serial No. 10-2017-0077447, filed on June 19, 2017, which is the basis of this application and is incorporated herein by reference in its entirety, as detailed below. Technical Field

[0002] The present invention relates to refractory articles, coating compositions for preventing redox reactions, and methods for manufacturing refractory articles. More specifically, it relates to refractory articles capable of reducing defects caused by platinum particles and foaming effects, antioxidant coating compositions, and methods for manufacturing refractory articles. Background Technology

[0003] In the manufacturing process of glass products, once the manufacturing equipment is started, its operation typically remains stable for several years. Therefore, it is difficult to stop or pause operation to identify the cause or multiple causes of defects. In glass products, the formation of bubbles or mixtures of opaque substances can lead to defects; therefore, reducing or eliminating the formation of such defects is important. Summary of the Invention

[0004] According to embodiments of this disclosure, a refractory article is provided, comprising: a platinum (Pt)-based substrate and a coating layer (i.e., an anti-oxidation-reduction coating layer) on the surface of the Pt-based substrate for preventing redox reactions, wherein, based on oxides, the coating layer may contain: SiO2 in an amount of about 40% to about 70% by weight, Al2O3 in an amount of about 20% to about 52% by weight, B2O3 in an amount of about 3% to about 6% by weight, and CaO in an amount of about 2.4% to about 4.8% by weight. The coating layer may contain whiskers distributed in a silica matrix. In some embodiments, the whiskers may include a polyaluminum andalusite crystalline phase.

[0005] In some embodiments, the refractory article may be a mixing chamber, which includes an inner surface of a Pt-based substrate, wherein a coating layer is at least partially applied to the inner surface of the mixing chamber.

[0006] In some embodiments, the coating layer may contain, in terms of oxides, SiO2 in an amount of about 40% to about 60% by weight, Al2O3 in an amount of about 32% to about 52% by weight, B2O3 oxide in an amount of about 3% to about 6% by weight, and CaO in an amount of about 2.4% to about 4.8% by weight.

[0007] Refractory products may also include agitators, wherein a coating layer may be applied at least partially to the side surface of the agitator.

[0008] In some embodiments, the refractory article may be a tube comprising an inner surface of a Pt-based substrate, wherein a coating layer may be applied to at least a portion of the outer surface of the tube.

[0009] In some embodiments, the coating layer may contain, in terms of oxides, SiO2 in an amount of about 60% to about 70% by weight, Al2O3 in an amount of about 20% to about 30% by weight, B2O3 in an amount of about 3% to about 6% by weight, and CaO in an amount of about 2.4% to about 4.8% by weight.

[0010] The coating layer may also include a network modifier in an amount of about 1% to about 7% by weight.

[0011] According to the embodiments disclosed herein, an antioxidant coating composition is provided, comprising a first refractory material, which, based on oxides, comprises: SiO2 in an amount of about 55% to about 70% by weight, Al2O3 in an amount of about 12% to about 22% by weight, B2O3 in an amount of about 5% to about 15% by weight, and CaO in an amount of about 5% to about 10% by weight; a second refractory material containing SiO2 as a major component; and a third refractory material containing Al2O3 as a major component; wherein the second refractory material is in an amount of about 25 parts by weight to about 130 parts by weight, and the third refractory material is in an amount of about 20 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the first refractory material.

[0012] The coating composition can be used to coat the inner surface of the mixing chamber, and the amount of the second refractory material can be from about 25 parts by weight to about 115 parts by weight, and the amount of the third refractory material is from about 45 parts by weight to about 150 parts by weight, relative to the amount of the first refractory material being 100 parts by weight.

[0013] The coating composition can be used to coat the outer surface of the pipe, and the amount of the second refractory material can be from about 33 parts by weight to about 90 parts by weight, and the amount of the third refractory material is from about 20 parts by weight to about 45 parts by weight, relative to the amount of the first refractory material being 100 parts by weight.

[0014] According to an embodiment of this disclosure, a method for manufacturing a refractory article is provided. The method includes: applying a slurry coating layer onto an article comprising a platinum (Pt)-based substrate, the slurry comprising a first refractory material, a second refractory material, and a third refractory material, wherein the first refractory material contains SiO2 in an amount of about 55% to about 70% by weight, Al2O3 in an amount of about 12% to about 22% by weight, B2O3 in an amount of about 5% to about 15% by weight, and CaO in an amount of about 5% to about 10% by weight; the second refractory material contains SiO2 as a main component; and the third refractory material contains Al2O3 as a main component; and heat-treating the slurry coating layer to form the refractory article.

[0015] In some implementations, the slurry can be applied by spraying. For example, the spraying method can be performed while the slurry is being homogenized at the slurry supply source.

[0016] It can be found at approximately 1350 C to approximately 1550 Heat treatment is performed at a temperature range of C for a time range of approximately 30 hours to approximately 100 hours.

[0017] After heat treatment, a microstructure consisting of particles of polyaluminum andalusite crystals dispersed in a silica matrix can be obtained from the slurry coating layer through heat treatment.

[0018] In some embodiments, the slurry may comprise: a second refractory material in an amount of about 25 parts by weight to about 130 parts by weight, and a third refractory material in an amount of about 20 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the first refractory material.

[0019] In some embodiments, the article may be a mixing chamber, and the slurry may comprise: a second refractory material in an amount of about 25 parts by weight to about 115 parts by weight, and a third refractory material in an amount of about 45 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the first refractory material.

[0020] In some embodiments, the article may be a tube, and the slurry may comprise: a second refractory material in an amount of about 33 parts by weight to about 90 parts by weight, and a third refractory material in an amount of about 20 parts by weight to about 45 parts by weight, relative to 100 parts by weight of the first refractory material. Attached Figure Description

[0021] Figure 1A The image is a structural image obtained according to the embodiment, wherein the whiskers are distributed on the surface of the silica matrix in the antioxidant coating layer; Figure 1BThe image is a cross-sectional structural image obtained according to the embodiment, wherein the whiskers are distributed in the silica matrix of the antioxidant coating layer; Figure 2 The process diagram conceptually shows a glass sheet manufacturing equipment that can be used with refractory products according to the embodiments; Figure 3 This is a conceptual diagram of a refractory article according to an embodiment, specifically showing... Figure 2 Mixing containers in manufacturing equipment; Figure 4 This is a concept diagram of a refractory article according to another embodiment, which shows... Figure 2 The inlet pipe in the manufacturing equipment; Figure 5 This is a graph showing the relationship between oxygen partial pressure and time for Experimental Example 10, Experimental Example 15, Experimental Example 16 and Comparative Example 10. Figure 6 This is a flowchart of a method for manufacturing refractory articles according to an embodiment. Detailed Implementation

[0022] This disclosure will be described more fully herein with reference to the accompanying drawings, in which exemplary embodiments are shown. However, the subject matter of this disclosure can be used in many different forms and should not be construed as limited to the exemplary embodiments described herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the subject matter to those skilled in the art. In the drawings, the thickness of layers and regions may be enlarged for clarity. Wherever possible, the same reference numerals will denote the same elements in the drawings. Therefore, this disclosure is not limited to the relative dimensions or spacing shown in the drawings.

[0023] Although terms such as "first" and "second" are used to describe various components, they are not limited by these terms. These terms are only used to distinguish one component from another. For example, the first component can refer to the second component, or the second component can refer to the first component; this does not create a contradiction.

[0024] In various exemplary embodiments, the terminology used herein is merely used to describe exemplary embodiments and should not be construed as limiting various other embodiments. Unless otherwise defined herein, singular expressions include plural expressions. In various exemplary embodiments, the terms "comprising" or "including" as used herein may indicate the presence of a corresponding function, operation, or component, and do not limit one or more other functions, operations, or components. It will also be understood that, when used in this specification, the terms "comprising" and / or "including" may be used to indicate the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0025] When a particular implementation can be carried out in different ways, the specific process sequence may differ from the stated sequence. For example, the two consecutive processes may be performed substantially simultaneously or in the reverse order.

[0026] Due to factors such as manufacturing techniques and / or tolerances, variations in the shape shown are expected. Therefore, embodiments of this disclosure should not be construed as limited to the specific shape of the areas shown herein, but should include, for example, shape deviations due to manufacturing processes. As used herein, the term "and / or" includes any combination of one or more of the related objects listed, as well as all combinations thereof. Furthermore, in this specification, "substrate" may refer to the substrate itself, or may include the substrate and a stacked structure of one or more coatings, layers, or films formed on the surface of the substrate. Additionally, in this specification, "surface of the substrate" may refer to the exposed surface of the substrate, or the outer surface of a coating, layer, or film formed on the substrate.

[0027] According to the embodiments disclosed herein, a refractory article is provided, comprising a platinum-based substrate and an antioxidant coating layer applied to the surface of the platinum-based substrate. The refractory article can be exposed to high-temperature environments (e.g., exposed to 1200°C). C to 1750 Any product of temperature C, for example, such as conduits, chambers, crucibles, etc. (or components thereof) used in the manufacture of glass products.

[0028] Platinum-based substrates can be substrates comprising platinum (Pt) as a major component. Platinum-based substrates can be pure Pt substrates or alloys of Pt with other metallic components (e.g., aluminum (Al), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), zirconium (Zr), molybdenum (Mo), ruthenium (Ru), palladium (Pd), tin (Sn), antimony (Sb), bismuth (Bi), and / or tungsten (W)). In this specification, "major component" defines a component that accounts for more than 50% by weight. For example, "Pt is the major component of a platinum-based substrate" can indicate that the amount of Pt in the platinum-based substrate exceeds 50% by weight.

[0029] The antioxidant coating layer may contain: SiO2 in an amount of about 40% to about 70% by weight, Al2O3 in an amount of about 20% to about 52% by weight, B2O3 in an amount of about 3% to about 6% by weight, and CaO in an amount of about 2.4% to about 4.8% by weight.

[0030] If the amount of SiO2 is too large, the coating layer may not be uniformly applied. On the other hand, if the amount of SiO2 is too small, the amount of Al2O3 will increase and the coating layer may be prone to delamination.

[0031] Antioxidant and reduction coating layers can have a structure in which whisker-like structures are distributed within a SiO2 matrix. Specifically, the whisker-like structures may include a polyaluminum andalusite crystalline phase.

[0032] Figure 1A The image is a photograph of such a structure according to the embodiment, wherein whiskers are distributed on the surface of the SiO2 matrix in the antioxidant coating layer.

[0033] Figure 1B It is a cross-sectional image of such a structure according to the embodiment, wherein the whiskers are distributed in the SiO2 matrix of the antioxidant coating layer.

[0034] See Figure 1A Fiber-like particles are concentrated at high density. See also Figure 1B The whisker-like particles can be distributed relatively evenly in the SiO2 matrix.

[0035] In addition, whisker-like particles containing polyaluminum andalusite crystal phases can be identified by energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis.

[0036] Figure 2 The process diagram shows the glass sheet manufacturing equipment 10 in a conceptual manner, which can be used with refractory articles according to embodiments of the present disclosure.

[0037] See Figure 2 The glass sheet manufacturing apparatus 10 may include a melting vessel 12 configured to receive batch material 37 supplied by a hopper 59. The batch material 57 can be introduced into the melting vessel 12 via a batch transfer device 11 driven by a motor 13. A controller 15 can control the motor 13 to introduce the required amount of batch material 57 into the melting vessel 12, as indicated by arrow 17. A glass level probe 19 is used to measure the level of the molten glass 21 within the riser 23, and the measured level information can be transmitted to the controller 15 via a communication line 25.

[0038] The glass sheet manufacturing apparatus 10 may include a refining vessel 27, such as a refining tube, which may be located downstream of the melting vessel 12 relative to the flow direction of the molten glass and is in fluid communication with the melting vessel 12 via a first connecting pipe 29. Furthermore, a mixing vessel 31 (e.g., a stirring chamber) may be located downstream of the refining vessel 27, and a transfer vessel 33 may be located downstream of the mixing vessel 31. As shown in the figures, a second connecting pipe 35 may connect the refining vessel 27 and the mixing vessel 31, and a third connecting pipe 37 may connect the mixing vessel 31 and the transfer vessel 33. A lower conduit 39 may be positioned to transfer the molten glass 21 from the transfer vessel 33 to the inlet pipe 41 of the molding apparatus 43.

[0039] At least a portion of the melting vessel 12 (e.g., at least a portion of the inner wall) may contain the refractory articles described above. The glass sheet manufacturing apparatus 10 may also include components that typically contain platinum or platinum-containing metals (e.g., platinum-rhodium, platinum-iridium, and combinations thereof), but may also contain molybdenum, palladium, rhenium, tantalum, titanium, tungsten, ruthenium, osmium, zirconium, and alloys thereof, and / or refractory metals such as zirconium dioxide. Platinum-containing components may include at least one of the following: a first connecting pipe, a settling vessel 27 (e.g., a settling tube), a second connecting pipe 35, a riser 23, a mixing vessel 31 (e.g., a stirring chamber), a third connecting pipe 37, a transfer vessel 33, a lower conduit 39, and an inlet pipe 41. Furthermore, at least a portion of the molding apparatus 43 may include the refractory articles described above and may be designed to form the glass strip 53.

[0040] Figure 3 This is a conceptual diagram of a refractory product according to an embodiment; specifically, it is... Figure 2 The mixing container 31 in the manufacturing equipment 10.

[0041] See Figure 3 The glass melt 21 can be uniformly stirred in the mixing vessel 31 by a stirrer 312. The mixing vessel 31 receives the supply of glass melt 21 from the clarifying vessel 27 (e.g., Figure 2 As shown, the glass melt 21 is mixed, and then the glass melt 21 is transferred to the transfer container 33. The temperature range in the mixing container 31 can be approximately 1400°C. C to approximately 1500 C. The agitator 312 may include a rod 312a and one or more impellers 312b attached to the rod 312a.

[0042] A collection tray 315 can be provided at rod 312a. The collection tray 315 can prevent impurities from falling through the gap between container cover 313 and rod 312a and being contained in the glass melt 21.

[0043] Specifically, the container body 311, the container cover 313, and the agitator 312 of the mixing container 31 may contain platinum or a platinum alloy entirely or at least partially, thereby producing a high-purity glass product with heat resistance relative to high-temperature processing conditions. Platinum may oxidize at high temperatures to form gaseous platinum oxide (PtO2(g)). However, in the relatively low-temperature region of the mixing container 31 or adjacent to the mixing container 31, the PtO2 gas may condense and / or chemically reduce, and may then be mixed into the glass melt 21, typically in the form of narrow, solid platinum needles. Due to the very high melting point of platinum (Pt(s)), the mixing of platinum (Pt(s)) into the glass melt 21 may lead to defects in the resulting glass product. The above reactions may be dependent on temperature, the flow rate of the gas phase, and the O2 concentration in the gas phase, and are expected to occur actively along the inner upper surface of the mixing container 31, which is not in contact with the glass melt 21.

[0044] Therefore, the inner wall surface of the container body 311 can be coated with the antioxidant epoxy coating layer 317a according to the embodiment. Specifically, the antioxidant reduction coating layer 317a can be applied to the wall surface of the container body 311 that is at a higher level than the upper surface (free surface) of the glass melt 21.

[0045] Furthermore, the antioxidant coating layer 317b according to the embodiment can be applied to the lower surface of the collection tray 315 and the outer surface of the rod 312a below the collection tray 315. The antioxidant coating layer 317b can be applied only to the portion higher than the upper interface of the glass melt 21.

[0046] Furthermore, the antioxidant coating layer 317c according to the embodiment can be applied to the lower surface (e.g., the inward-facing surface) of the container cover 313.

[0047] Each of the antioxidant coating layers 317a, 317b and 317c may contain: SiO2 in an amount of about 40% to about 60% by weight, Al2O3 in an amount of about 32% to about 52% by weight, B2O3 in an amount of about 3% to about 6% by weight, and CaO in an amount of about 2.4% to about 4.8% by weight.

[0048] If the amount of SiO2 is too high or the amount of Al2O3 is too low, the coating may not form uniformly. If the amount of SiO2 is too low or the amount of alumina is too high, the thermal shock resistance of the coating may deteriorate or the coating layer may be prone to delamination.

[0049] When the antioxidant coating layer 317 applied to the inner wall of the mixing container 31 or the like has a composition within the range described above, it can reduce the presence of platinum particles in the glass melt due to the oxidation and reduction of the platinum substrate and reduce the generation of defective products.

[0050] As a result of the analysis of defects, when it is assumed that the proportion of defects caused by platinum particles is 1.0 AU according to the prior art, when the antioxidant coating layer 317 is applied to the inner wall of the mixing container 31, the proportion of defects caused by platinum particles is reduced to 0.4 AU.

[0051] Figure 4 This is a concept diagram of a refractory article according to another embodiment, specifically showing... Figure 2 The inlet pipe 41 in the manufacturing equipment 10.

[0052] See Figure 4 , ( Figure 2 The glass melt 21 is transferred from the transfer container 33 to the inlet pipe 41 via the lower conduit 39. In addition, the glass melt 21 transferred to the inlet pipe 41 can be conveyed to the molding equipment 43 for forming glass ribbon 53.

[0053] While this disclosure should not be limited to any particular theory, it is believed that the surface bubbling effect of bubble formation in equipment employing platinum-containing components is a result of the formation of an oxygen-enriched layer near the platinum-glass melt interface. This oxygen-enriched layer in the glass is believed to result from a combination of electrochemical and chemical reactions. These include thermoelectric electrolysis of the melt, decomposition of multivalent oxides, and decomposition of OH groups and water dissolved in the glass. The latter effect is believed to have the greatest influence on the oxygen enrichment rate at the platinum-glass interface and the subsequent formation of surface bubbling (bubbles) at that interface. It is believed that at the temperature at which the glass is produced, some of the OH groups separate into neutral hydrogen and oxygen. When the hydrogen partial pressure at the platinum component-glass interface (within the component) is greater than the hydrogen partial pressure on the exterior of the platinum-containing component (i.e., the portion of the component not in contact with the glass), hydrogen will permeate out of the glass through the platinum skin. This loss of hydrogen leads to oxygen enrichment in the surface area of ​​the glass (the platinum contact area), which then forms bubbles if the solubility limit of the glass is exceeded.

[0054] The outer surface of the inlet pipe 41 can be coated with an antioxidant coating layer 411 according to the embodiment. Applying a suitable coating to the outer surface of the platinum-containing component (e.g., the inlet pipe 41) can reduce the rate of hydrogen permeation through the platinum-containing metal. This, in turn, can reduce or eliminate bubble formation. The antioxidant coating layer should have minimal crystallization volume shrinkage even at high temperatures and should not react with the platinum-containing component, which could lead to exposure of the platinum metal in the platinum-containing component.

[0055] Each of the antioxidant coating layer 411 may contain: SiO2 in an amount of about 60% to about 70% by weight, Al2O3 in an amount of about 20% to about 30% by weight, B2O3 in an amount of about 3% to about 6% by weight, and CaO in an amount of about 2.4% to about 4.8% by weight.

[0056] When the antioxidant coating layer 411 coated on the outer wall of the inlet pipe 41 has a composition within the range described above, the coating layer can remain intact at high temperatures and effectively prevent exposure of the platinum-based substrate by preventing the reaction between the antioxidant coating layer 411 and the platinum-containing components, while maintaining excellent coating quality. Therefore, bubbling of the glass melt passing through the inlet pipe 41, where the bubbling is caused by an oxidation-reduction (redox) reaction of hydroxyl groups, can be prevented.

[0057] If the amount of SiO2 is too high or the amount of Al2O3 is too low, an uneven coating may be formed. In addition, if the amount of SiO2 is too low or the amount of Al2O3 is too high, the durability of the coating layer and its ability to limit (e.g., eliminate) hydrogen permeation may deteriorate, or the coating layer may be prone to delamination.

[0058] Each of the antioxidant coating layers 411 may also contain a network modifier. The network modifier may be, for example, an alkali metal oxide or an alkaline earth metal oxide, but is not limited thereto. For example, the network modifier may be SrO or a glass frit. The amount of the network modifier contained in the antioxidant coating layer may be from about 1% by weight to about 7% by weight, but is not limited thereto.

[0059] If the amount of network modifier is too low, the effect of improving coating quality (e.g., preventing delamination) may be insufficient. If the amount of network modifier is too high, durability and the ability to limit (e.g., eliminate) hydrogen permeation may deteriorate.

[0060] The structure and effects of the embodiments disclosed herein will be described in detail below with reference to experimental examples and comparative examples. However, the experimental examples provided are intended to make this disclosure complete and comprehensive, and therefore the scope of this disclosure is not limited to the experimental examples.

[0061] <Experimental Example 1>

[0062] A first refractory material is prepared, comprising: 63 wt% SiO2, 17 wt% Al2O3, 10 wt% B2O3, 8 wt% CaO, and 2 wt% SrO. Furthermore, SiO2 is prepared as a second refractory material, and Al2O3 is prepared as a third refractory material.

[0063] The first refractory material is mixed in an amount of 43% by weight, the second refractory material is mixed in an amount of 26% by weight, and the third refractory material is mixed in an amount of 31% by weight, by ball milling. This translates to approximately 60.5 parts by weight of the second refractory material and approximately 72.1 parts by weight of the third refractory material, relative to 100 parts by weight of the first refractory material. Deionized (DI) water was used as the solvent, and approximately 2% methylcellulose by weight of the total weight was added to adjust the viscosity.

[0064] The antioxidant-reduction coating composition prepared above was applied to a platinum sample by spraying, with continuous agitation of the composition during spraying to prevent phase separation. The thickness of the coating composition was adjusted to achieve approximately 80% thickness after drying. The thickness is m.

[0065] Then, in 1450 The coated sample was heat-treated at temperature C for 72 hours, and images of the surface and cross-section of the coating layer were taken, as shown in... Figure 1A and 1B As shown.

[0066] <Experimental Examples 2 to 9>

[0067] An antioxidant coating layer was formed on the platinum sample in the same manner as in Experimental Example 1 above, except that the proportions of the mixture of the first to third refractory materials are shown in Table 1 below.

[0068] <Comparative Examples 1 to 7>

[0069] An antioxidant coating layer was formed on the platinum sample in the same manner as in Experimental Example 1 above, except that the proportions of the mixture of the first to third refractory materials are shown in Table 1 below.

[0070] Table 1 below shows the proportions of the refractory materials used in Experimental Examples 1 to 9 and Comparative Examples 1 to 7, and the composition of the resulting coating layers.

[0071] [Table 1]

[0072] (Unit: weight %)

[0073] In Table 1 above, D1 represents the first refractory material, D2 represents the second refractory material, and D3 represents the third refractory material.

[0074] For the samples of Experimental Examples 1 to 9 and Comparative Examples 1 to 7, at 1450 The coating layer was subjected to a heat treatment at a temperature of C for 14 days (336 hours) to assess its durability. The coating layer was then inspected to determine for any changes in its microstructure.

[0075] In addition, Figure 3 During the process, when the container cover 313 or the stirrer 312 is replaced, the mixing container 31 receives a thermal shock due to a drastic temperature change. For example, when the container cover 313 is replaced, the mixing container 31 is detected to receive approximately 100... C thermal shock, and when the stirrer 312 was replaced, approximately 300 was received. Thermal shock at 400°C. To assess tolerance to thermal shock, [the following parameters were used]. Temperature changes at C and 20 The thermal shock test was repeated three times under the condition of temperature change rate of C / min.

[0076] If no delamination and no cracking occur, the result is evaluated as ◎; if no delamination occurs but local cracking occurs, the result is evaluated as ○; if delamination occurs but the coated sample surface is not exposed, the result is evaluated as △; and if delamination occurs and the coated sample surface is exposed, the result is evaluated as X.

[0077] Table 2 below shows the changes in microstructure observed relative to Experimental Examples 1 to 9 and Comparative Examples 1 to 9, as well as the results of thermal shock tests.

[0078] [Table 2]

[0079] As shown in Tables 1 and 2 above, when the amount of SiO2 is less than 40% by weight or when the amount of Al2O3 exceeds 52% by weight, microstructure changes are observed and thermal shock resistance becomes insufficient or deteriorates (Comparative Examples 2, 3 and 7).

[0080] Furthermore, when the amount of SiO2 exceeds 70% by weight or when the amount of Al2O3 is less than 20% by weight, the thermal shock properties are acceptable in some cases (Comparative Examples 1 and 4), but poor or insufficient in others (Comparative Examples 5 and 6). In addition, microstructural changes were observed in these cases, suggesting the potential for additional cracking depending on variations in processing and operating conditions.

[0081] <Experimental Example 10>

[0082] A first refractory material is prepared, comprising: 63 wt% SiO2, 17 wt% Al2O3, 10 wt% B2O3, 8 wt% CaO, and 2 wt% SrO. Furthermore, SiO2 is prepared as a second refractory material, and alumina is prepared as a third refractory material.

[0083] The first refractory material is mixed in an amount of 55% by weight, the second refractory material is mixed in an amount of 33% by weight, and the third refractory material is mixed in an amount of 12% by weight, by ball milling. This translates to approximately 60 parts by weight of the second refractory material and approximately 21.8 parts by weight of the third refractory material, relative to 100 parts by weight of the first refractory material. DI water is used as a solvent, and approximately 2% methylcellulose by weight of the total weight is added to adjust the viscosity.

[0084] The antioxidant-reduction coating composition prepared as described above is applied to the outer surface of an inlet pipe (e.g., inlet pipe 41). Coating is performed by spraying, with continuous agitation of the composition during spraying to prevent phase separation. The thickness of the coating composition is adjusted to achieve approximately 60 mm after drying. A thickness of m. Then, at 1400 The process involves heat treatment at temperature C for two hours. The spraying, drying, and heat treatment processes described above are repeated three times.

[0085] <Experimental Examples 11 to 20>

[0086] An antioxidant coating layer was formed on the outer surface of the inlet pipe in the same manner as in Experimental Example 10 above, except that the proportions of the mixture of the first to third refractory materials are shown in Table 3 below.

[0087] Specifically, in Experimental Examples 15 and 16, the amounts of network modifier (RO) added were 2% by weight and 5% by weight, respectively. In Experimental Example 15, SrO was added as a network modifier, while in Experimental Example 16, glass frit was added as a network modifier. To add SrO as a network modifier in Experimental Example 15, an appropriate amount of strontium nitrate (Sr(NO3)2) was added to the DI water to be contained in the antioxidant-reduction coating composition. In Experimental Example 15, the additional amount of strontium oxide added as a network modifier was 2% by weight, while the amount of strontium oxide derived from the first refractory material was 1.08% by weight, thus the total amount of strontium oxide was 3.08% by weight.

[0088] Furthermore, the mixing ratios of the first to third refractory materials in Experimental Examples 17 to 20 were the same as those in Experimental Examples 6 to 9.

[0089] <Comparative Examples 8 to 14>

[0090] An antioxidant coating layer was formed on the outer surface of the inlet pipe in the same manner as in Experimental Example 10 above, except that the mixing ratio of the first to third refractory materials was different. The mixing ratio of the first to third refractory materials in Comparative Examples 8 to 14 was the same as that in Comparative Examples 1 to 7.

[0091] Table 3 below shows the proportions of the refractory materials used in Experimental Examples 10 to 20 and Comparative Examples 8 to 14, and the composition of the resulting coating layers.

[0092] [Table 3]

[0093] (Unit: weight %)

[0094] To assess the durability of the coating layer, at 1200 The platinum surface is then heat-treated at temperature C for 14 days (336 hours). It is then examined for exposure due to volume shrinkage or reaction with the refractory. An evaluation result of ◎ is given if the coating has a flat surface and the platinum surface is completely unexposed; ○ is given if the coating has a locally uneven surface and the platinum surface is completely unexposed; △ is given if the coating has a completely uneven surface even though the platinum surface is unexposed; and X is given if the platinum surface is at least partially exposed.

[0095] The coating quality is evaluated based on delamination, cracking, and thickness. If the coating is transparent, free of delamination or cracking, and has a uniform thickness, the evaluation result is ◎; if the coating has low transparency, free of delamination or cracking, and has a uniform thickness, the evaluation result is ○; if the coating layer delaminates or cracks, the evaluation result is △; and if delamination occurs, exposing the platinum surface, the evaluation result is X.

[0096] Hydrogen permeability is assessed by measuring the concentration of oxygen ions in the glass melt. An oxygen partial pressure equal to or greater than 1 atmosphere (atm) is assessed as X; an oxygen partial pressure equal to or greater than 0.1 atm but less than 1 atm is assessed as △; an oxygen partial pressure equal to or greater than 0.01 atm but less than 0.1 atm is assessed as ○; and an oxygen partial pressure less than 0.01 atm is assessed as ◎.

[0097] Table 4 below shows the evaluation results of coating quality, durability and hydrogen permeation properties examined relative to Experimental Examples 10 to 20 and Comparative Examples 8 to 14.

[0098] [Table 4]

[0099] As shown in Tables 3 and 4 above, when the amount of SiO2 is less than 40% by weight or when the amount of Al2O3 exceeds 52% by weight, degradation of durability and deterioration of hydrogen permeation barrier properties were identified (Comparative Examples 9, 10, and 14). Furthermore, when the amount of SiO2 exceeds 70% by weight or when the amount of Al2O3 is less than 20% by weight, deterioration of coating quality was identified (Comparative Examples 8 and 11 to 13).

[0100] like Figure 5 The figure shows the evolution of oxygen partial pressure over time relative to experimental Examples 10, 15, and 16, and Comparative Example 10. Figure 5 As shown, the oxygen partial pressure in Comparative Example 10 exceeded 1 atm, but in Experimental Examples 10, 15, and 16, the measured oxygen partial pressure was less than 0.01 atm. This indicates that hydrogen permeation was minimal in Experimental Examples 10, 15, and 16.

[0101] The antioxidant-reduction coating composition described above will be described in detail below.

[0102] The antioxidant coating composition may comprise a first refractory material, a second refractory material, and a third refractory material, wherein the amount of the second refractory material may be from about 25 parts by weight to about 130 parts by weight, and the amount of the third refractory material may be from about 20 parts by weight to about 150 parts by weight, relative to the amount of the first refractory material being 100 parts by weight.

[0103] Here, based on oxides, the first refractory material may comprise: SiO2 in an amount of about 55% to about 70% by weight, Al2O3 in an amount of about 12% to about 22% by weight, B2O3 in an amount of about 5% to about 15% by weight, and CaO in an amount of about 5% to about 10% by weight. Furthermore, the second refractory material may be a mixture containing SiO2 as a major component, or SiO2 alone. Furthermore, the third refractory material may be a mixture containing Al2O3 as a major component, such as alumina. As mentioned above, in this specification, "major component" defines a component with a composition percentage exceeding 50% by weight. For example, "the major component of the second refractory material is SiO2" means that the amount of silicon dioxide in the second refractory material exceeds 50% by weight.

[0104] In some embodiments, the antioxidant coating composition may be a composition for coating the inner surface of a mixing chamber. In this case, the antioxidant coating composition may comprise: a second refractory material in an amount of about 25 parts by weight to about 115 parts by weight, and a third refractory material in an amount of about 45 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the first refractory material.

[0105] In some other embodiments, the antioxidant coating composition may be a composition for coating the outer surface of a pipe. In this case, the antioxidant coating composition may comprise: a second refractory material in an amount of about 33 parts by weight to about 90 parts by weight, and a third refractory material in an amount of about 20 parts by weight to about 45 parts by weight, relative to 100 parts by weight of the first refractory material.

[0106] If the amount of the third refractory material relative to the amount of the first refractory material is too large, or the amount of the second refractory material is too small, the durability and hydrogen permeation barrier properties of the coating layer may deteriorate, or the coating layer may be prone to delamination. If the amount of the second refractory material relative to the amount of the first refractory material is too large, or the amount of the third refractory material is too small, the resulting coating may be uneven.

[0107] The first, second, and third refractory materials can be dispersed in a dispersion medium as powder. The dispersion medium can be a hydrophilic liquid, such as water, a solvent based on C1-C5 alcohols, a solvent based on C2-C8 diols, etc. Here, such a liquid as described above can be called a "solvent," but since the liquid actually disperses the first, second, and third refractory materials without dissolving them, the liquid may actually be a "dispersion medium" (dispersant).

[0108] The antioxidant coating composition may also contain an alkali metal salt or an alkaline earth metal salt as a source material for forming a network modifier. The alkali metal salt or alkaline earth metal salt may be, for example, strontium nitrate (Sr(NO3)2), but is not limited thereto. The alkali metal salt or alkaline earth metal salt may be soluble in a solvent. The antioxidant coating composition may include a source material for forming a network modifier in an amount of about 1% to about 7% by weight.

[0109] The manufacturing method of refractory products will be described below. Figure 6 This is a flowchart of a method for manufacturing refractory materials according to an embodiment.

[0110] See Figure 6 An antioxidant coating slurry is formed on the article (e.g., including articles containing a platinum substrate) (S100). The antioxidant coating slurry may contain a first refractory material, a second refractory material, and a third refractory material. The first to third refractory materials have been described in detail above, so their description is omitted here.

[0111] The antioxidant-reduction coating slurry may comprise: a second refractory material, in an amount of about 25 parts by weight to about 130 parts by weight, and a third refractory material, in an amount of about 20 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the first refractory material. The platinum-based substrate has been described in detail above, therefore its description is omitted here. The antioxidant-reduction coating slurry may be the antioxidant-reduction coating composition described above.

[0112] Antioxidant-reduction coating slurry layers can be formed by spraying, brushing, scalpel scraping, or other suitable methods, and are not limited to these methods.

[0113] It can adjust the layer of redox-resistant coating slurry, thereby achieving approximately 10% oxidative strength after heat treatment. m to approximately 500 The thickness is approximately 1 m. Therefore, the layer of the antioxidant coating slurry prior to the heat treatment step can be appropriately adjusted to achieve a thickness of approximately 15 m. m to approximately 700 The thickness of the coating layer is crucial. If the layer thickness is too small, the coating may not adequately limit (e.g., eliminate) hydrogen permeation. On the other hand, if the layer thickness is too large, it is economically unsuitable, and portions of the coating layer may peel off, resulting in defective products. Considering the above factors, those skilled in the art can appropriately select the layer thickness of the antioxidant coating slurry.

[0114] Depending on its composition, phase separation may easily occur in antioxidant coating compositions. Therefore, continuous homogenization of the antioxidant coating composition is required using methods such as agitation to form a uniform coating layer.

[0115] In addition, heat treatment (S200) can be performed on the antioxidant-reduction coating slurry. This can be done at approximately 1350°C. C to approximately 1550 The heat treatment is performed within a temperature range of approximately 30 to 100 hours. If the heat treatment temperature is too low or the duration is too short, the coating layer may have low strength and may not adequately prevent hydrogen permeation. On the other hand, if the heat treatment temperature is too high or the duration is too long, the coating layer may delaminate and may increase the number of defective products. Taking these factors into account, those skilled in the art will appropriately select the temperature and duration of the heat treatment.

[0116] Through heat treatment, a structure in which polyaluminum andalusite crystal particles are distributed in a silica matrix can be obtained.

[0117] The application of the slurry (S100) and the heat treatment (S200) can be repeated two or more times as a cycle. The number of cycles can be, for example, 2 to 10.

[0118] In some embodiments, the antioxidant coating slurry may comprise: a second refractory material in an amount of about 25 parts by weight to about 115 parts by weight, and a third refractory material in an amount of about 45 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the first refractory material. In this case, the slurry can be used to coat the inner wall surface of the stirring chamber for agitating the glass melt, the side surface of the agitator, and / or the inner surface of the covering of the stirring chamber.

[0119] In some embodiments, the antioxidant coating slurry may comprise: a second refractory material in an amount of about 33 parts by weight to about 90 parts by weight, and a third refractory material in an amount of about 20 parts by weight to about 45 parts by weight, relative to 100 parts by weight of the first refractory material. In this case, the slurry can be used to coat the outer surface of a pipe for transporting molten glass.

[0120] Although this disclosure has been specifically shown and described with reference to exemplary embodiments, it will be understood that various changes in form and detail may be made within the spirit and scope of the appended claims.

Claims

1. A refractory product comprising: Platinum (Pt) based substrate; and The coating layer disposed on a Pt-based substrate, based on oxides, comprises: SiO2 in an amount of about 40 wt% to about 70 wt%, Al2O3 in an amount of about 20 wt% to about 52 wt%, B2O3 in an amount of about 3 wt% to about 6 wt%, and CaO in an amount of about 2.4 wt% to about 4.8 wt%. The coating layer includes whiskers distributed in a silica matrix, wherein the whiskers include a polyaluminum andalusite crystal phase.

2. The refractory product as described in claim 1, wherein, The refractory product is a mixing chamber, which includes an inner surface of a Pt-based substrate and the coating layer applied to at least a portion of the inner surface of the mixing chamber.

3. The refractory product as described in claim 2, wherein, Based on oxides, the coating layer comprises: SiO2 in an amount of about 40% to about 60% by weight, Al2O3 in an amount of about 32% to about 52% by weight, B2O3 in an amount of about 3% to about 6% by weight, and CaO in an amount of about 2.4% to about 4.8% by weight.

4. The refractory product as described in claim 2, further comprising a stirrer, wherein, The coating layer is applied to at least a portion of the outer surface of the agitator.

5. The refractory product as described in claim 1, wherein, The refractory product is a tube having a Pt-based substrate surface, wherein the coating layer is applied to at least a portion of the outer surface of the tube.

6. The refractory product as described in claim 5, wherein, Based on oxides, the coating layer comprises: SiO2 in an amount of about 60% to about 70% by weight, Al2O3 in an amount of about 20% to about 30% by weight, B2O3 in an amount of about 3% to about 6% by weight, and CaO in an amount of about 2.4% to about 4.8% by weight.

7. The refractory article of claim 1, further comprising a network modifier in an amount of about 1% to about 7% by weight.

8. An antioxidant coating composition comprising: The first refractory material, based on oxides, comprises: SiO2 in an amount of about 55% to about 70% by weight, Al2O3 in an amount of about 12% to about 22% by weight, B2O3 in an amount of about 5% to about 15% by weight, and CaO in an amount of about 5% to about 10% by weight; The second refractory material contains SiO2 as its main component; and The third type of refractory material contains Al2O3 as its main component. in, The amount of the second refractory material is from about 25 parts by weight to about 130 parts by weight, and the amount of the third refractory material is from about 20 parts by weight to about 150 parts by weight, relative to the amount of the first refractory material being 100 parts by weight.

9. The antioxidant-reduction coating composition of claim 8, wherein, The composition is used to coat the inner surface of a mixing chamber, and the amount of the second refractory material is from about 25 parts by weight to about 115 parts by weight, and the amount of the third refractory material is from about 45 parts by weight to about 150 parts by weight, relative to the amount of the first refractory material being 100 parts by weight.

10. The antioxidant-reduction coating composition of claim 8, wherein, The composition is used to coat the outer surface of a tube, and the amount of the second refractory material is from about 33 parts by weight to about 90 parts by weight, and the amount of the third refractory material is from about 20 parts by weight to about 45 parts by weight, relative to the amount of the first refractory material being 100 parts by weight.

11. A method for manufacturing refractory articles, the method comprising: A slurry coating layer is applied to an article comprising a platinum (Pt)-based substrate, the slurry coating layer comprising a first refractory material, a second refractory material, and a third refractory material, wherein, based on oxides, the first refractory material comprises SiO2 in an amount of about 55% to about 70% by weight, Al2O3 in an amount of about 12% to about 22% by weight, B2O3 in an amount of about 5% to about 15% by weight, and CaO in an amount of about 5% to about 10% by weight; the second refractory material contains SiO2 as a major component; and the third refractory material contains Al2O3 as a major component. as well as The slurry coating is heat-treated to form refractory products; Of these, approximately 1350 C to approximately 1550 Heat treatment is performed at a temperature range of C for a time range of approximately 30 hours to approximately 100 hours.

12. The method of claim 11, wherein, The slurry coating layer is applied by spraying.

13. The method of claim 12, wherein, The spraying method involves homogenizing the slurry at the slurry supply source.

14. The method of claim 11, wherein, After heat treatment, a microstructure consisting of particles of polyaluminous andalusite crystals dispersed in a silica matrix is ​​obtained from the slurry coating layer through heat treatment.

15. The method of claim 11, wherein, The slurry coating comprises: a second refractory material in an amount of about 25 parts by weight to about 130 parts by weight, and a third refractory material in an amount of about 20 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the first refractory material.

16. The method of claim 15, wherein, The product is a mixing chamber, and the slurry coating layer comprises: a second refractory material in an amount of about 25 parts by weight to about 115 parts by weight, and a third refractory material in an amount of about 45 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the first refractory material.

17. The method of claim 15, wherein, The product is a pipe, and the slurry coating layer comprises: a second refractory material in an amount of about 33 parts by weight to about 90 parts by weight, and a third refractory material in an amount of about 20 parts by weight to about 45 parts by weight, relative to 100 parts by weight of the first refractory material.

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