What are the main uses of corundum in refractory materials

Due to the abundant raw materials used and convenient supply of corundum materials, they can be used in the production process of traditional refractory materials to produce corundum refractory materials, as well as in the production of special refractory materials, namely high-temperature ceramics, using methods derived from traditional ceramics. Therefore, after more than half a century of research and production, the process has become increasingly mature and the variety has continued to increase, becoming the most widely used refractory material. Its uses are as follows:

Corundum refractory products, especially special corundum refractory products, namely high-temperature ceramics, are not only produced in the refractory materials industry, but also in the building materials, electronics, chemical, machinery and other industries. Corundum refractory materials are high-quality and efficient products, and developed industrial countries abroad are seeking high-purity raw materials, among which high-purity corundum raw materials are one of the key development products.

(1) Due to its high temperature resistance, corrosion resistance, and high strength, it is used as a sliding nozzle for pouring steel, smelting rare and precious metals, special alloys, high-purity metals, glass wire drawing, and making crucibles and vessels for laser glass; Various high-temperature furnaces, such as refractory materials, ceramic ironmaking, and lining (walls and pipes) of blast furnaces; Physical and chemical vessels, spark plugs, heat-resistant and anti-oxidation coatings. Low silicon sintered corundum bricks with SiO2 less than 0.5% are specialized lining materials for carbon black, boron chemical, fertilizer, synthetic ammonia reactors, and gasifiers.

(2) Due to its high hardness, good wear resistance, and high strength, it is used as a component for various reaction vessels, pipelines, and chemical pumps in chemical systems; Make mechanical components and various grinding tools, such as wire drawing dies, pencil lead molds, etc; Make cutting tools, grinding materials, bulletproof materials, human joints, sealing grinding rings, etc.

(3) Due to its high temperature insulation properties, it is used as a sheath and protective tube for thermocouples, insulating ceramics, and various other high-temperature insulation components.

(4) Al2O3 is an ionic crystal with a very stable structure. When used at high frequencies, high voltages, and high temperatures, its insulation performance is still excellent, and the loss is not large, and the dielectric constant is also not large. It is widely used in the electronics industry for solid integrated circuit substrate sockets, housings, ceramic frames, microwave windows, etc.

(5) Corundum products have good air tightness and are airtight even at high temperatures, so they are widely used in vacuum electronics, such as using corundum to make various large electronic tube shells and dual in-line packaging shells in solid microcircuits.

(6) Corundum insulation materials, such as lightweight corundum bricks, hollow corundum balls, and fiber products, are widely used in the walls and roofs of various high-temperature kilns, which are both heat-resistant and insulated.

(7) Transparent corundum products can be used to make light tubes and microwave fairings. In addition, Na - β - Al2O3 type products are used as the dielectric material for manufacturing sodium sulfur batteries.