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CN-122011813-A - High-temperature-resistant coating for graphite crucible, and preparation method and application thereof

CN122011813ACN 122011813 ACN122011813 ACN 122011813ACN-122011813-A

Abstract

The application provides a high-temperature-resistant coating for a graphite crucible, a preparation method and application thereof, and belongs to the field of high-temperature-resistant coatings. The high-temperature-resistant coating is an isolation layer covering the inner wall of the graphite crucible, and comprises the following raw materials of 90% -98% of alumina powder and 2% -10% of high-temperature-resistant adhesive. The high temperature resistant adhesive comprises one or more of phosphate adhesive, dextrin and silica sol. According to the application, an effective isolation barrier is introduced between the inner wall of the graphite base and the high-temperature slag, so that the adhesion effect of the slag and the graphite matrix is obviously reduced or eliminated, and the slag can be rapidly and effectively stripped from the inner wall of the graphite matrix, thereby realizing the recycling of the graphite base and finally achieving the purposes of reducing the detection cost and reducing the resource consumption.

Inventors

  • YANG TIANWU
  • ZHANG XIAOCHUANG
  • WANG JUN
  • Qin Zhuofan
  • ZHENG MINGYUE
  • BAI XU

Assignees

  • 首钢京唐钢铁联合有限责任公司

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. The high-temperature-resistant coating for the graphite crucible is characterized by being an isolating layer covering the inner wall of the graphite crucible, and comprises, by mass, 90% -98% of alumina powder and 2% -10% of high-temperature-resistant adhesive; wherein the high temperature resistant adhesive comprises one or more of phosphate adhesive, dextrin and silica sol.
  2. 2. The high temperature resistant coating of claim 1, wherein the high temperature resistant coating has a thickness of 0.1mm to 0.5 mm.
  3. 3. The high temperature resistant coating of claim 1, wherein the high temperature resistant coating has a melting point >2050 ℃.
  4. 4. The high temperature resistant coating according to claim 1, wherein the alumina powder has a purity of 99% or more.
  5. 5. The high temperature resistant coating of claim 1, wherein the phosphate-based binder is aluminum dihydrogen phosphate.
  6. 6. A method of producing a high temperature resistant coating according to any one of claims 1to 5, characterized in that the method comprises: Mixing alumina powder, a high-temperature-resistant adhesive and a solvent to obtain coating slurry; coating the coating slurry on the inner wall surface of the pretreated graphite crucible to form a wet film; And (3) drying and heat-treating the graphite crucible coated with the wet film to obtain the graphite crucible with the high-temperature-resistant coating.
  7. 7. The method according to claim 6, wherein the temperature of the drying treatment is 80 ℃ to 150 ℃, and the heat preservation time of the drying treatment is 1h to 3h.
  8. 8. The method according to claim 6, wherein the temperature of the heat treatment is 450 ℃ to 600 ℃, and the heat preservation time of the heat treatment is 1h to 2h.
  9. 9. Use of a refractory coating according to any one of claims 1 to 5, characterized in that a graphite crucible with the refractory coating is used for iron ore high temperature load reduction reflow drip test.
  10. 10. The use according to claim 9, wherein the graphite crucible with the high temperature resistant coating is reusable for a number of times greater than or equal to 9 when used in a high temperature load reduction reflow drip test of iron ore.

Description

High-temperature-resistant coating for graphite crucible, and preparation method and application thereof Technical Field The application relates to the technical field of high-temperature resistant coatings, in particular to a high-temperature resistant coating for a graphite crucible, a preparation method and application thereof. Background In the iron ore high-temperature load reduction soft melting drop test, a graphite crucible is generally adopted as a container for containing high-temperature slag, and the excellent high-temperature resistance and thermal shock resistance of the graphite material are mainly utilized. However, the high temperature slag generated during the test has very strong chemical activity and adhesion. When the slag directly contacts the inner wall of the graphite crucible, complex physicochemical reactions occur at high temperature, resulting in the slag forming an extremely tight and firm adhesion layer with the inner wall of the graphite after cooling solidification. The adhesion layer is difficult to clean effectively by conventional mechanical or chemical methods, so that the graphite crucible is scrapped after a single test because the graphite crucible cannot be cleaned, and the graphite crucible becomes a disposable consumable product. This not only significantly increases the detection cost of a single test, but also causes serious resource waste. Therefore, how to effectively increase the use times of the graphite crucible for the iron ore high-temperature load reduction soft melting drop test, thereby reducing the test cost and saving the resources, and becoming the technical problem to be solved in the field. Disclosure of Invention The application provides a high-temperature-resistant coating for a graphite crucible, a preparation method and application thereof, and aims to solve the technical problem of how to improve the use times of the graphite crucible for a high-temperature load reduction soft melting drop test of iron ore. In a first aspect, the embodiment of the application provides a high-temperature-resistant coating for a graphite crucible, which is an isolation layer covering the inner wall of the graphite crucible, and comprises, by mass, 90% -98% of alumina powder and 2% -10% of a high-temperature-resistant adhesive; wherein the high temperature resistant adhesive comprises one or more of phosphate adhesive, dextrin and silica sol. Optionally, the thickness of the high-temperature-resistant coating is 0.1 mm-0.5 mm. Optionally, the high temperature resistant coating has a melting point >2050 ℃. Optionally, the purity of the alumina powder is more than or equal to 99 percent. Optionally, the phosphate-based binder is aluminum dihydrogen phosphate. In a second aspect, an embodiment of the present application provides a method for preparing the high temperature resistant coating according to any one of the first aspects, where the method includes: Mixing alumina powder, a high-temperature-resistant adhesive and a solvent to obtain coating slurry; coating the coating slurry on the inner wall surface of the pretreated graphite crucible to form a wet film; And (3) drying and heat-treating the graphite crucible coated with the wet film to obtain the graphite crucible with the high-temperature-resistant coating. Optionally, the temperature of the drying treatment is 80-150 ℃, and the heat preservation time of the drying treatment is 1-3 h. Optionally, the temperature of the heat treatment is 450-600 ℃, and the heat preservation time of the heat treatment is 1-2 h. In a third aspect, an embodiment of the present application provides an application of the high temperature resistant coating according to any one of the first aspect, where a graphite crucible with the high temperature resistant coating is used for a high temperature load reduction reflow dripping test of iron ore. Optionally, the graphite crucible with the high-temperature resistant coating can be reused for more than or equal to 9 times when being used for a soft melting drop test of high-temperature load reduction of iron ore. Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages: the embodiment of the application provides a high-temperature-resistant coating for a graphite crucible, which is formed by arranging a high-temperature-resistant coating formed by specific raw materials on the inner wall of the graphite crucible, so that the use times of the high-temperature-resistant coating in an iron ore high-temperature load reduction reflow dripping test are remarkably improved. The core principle is that the coating forms an efficient physical and chemical isolation barrier between slag and graphite matrix. Specifically, the high-temperature-resistant coating takes alumina powder as a main component (90% -98%). The inherent extremely high melting point and excellent chemical inertness of alumina allows the coating to not soften