Mullite insulation bricks are high-alumina refractory materials with mullite (Al₂O₃·2SiO₂) as the primary crystalline phase. The alumina content generally ranges from 50% to 60%. In addition to mullite, those with lower alumina content also contain small amounts of glass and cristobalite; those with higher alumina content also contain small amounts of corundum. They have a high refractoriness, reaching temperatures exceeding 1790°C.
Mullite insulation bricks are primarily divided into two categories: lightweight mullite bricks and heavy mullite bricks. These bricks are further subdivided into JM23 mullite insulation bricks, JM26 mullite insulation bricks, and JM28 mullite bricks, depending on the temperature they can withstand.
The names of lightweight mullite insulation bricks, such as JM23, JM26, and JM28, actually convey their refractory grade. The “JM” serial number serves as a visual indicator of their refractory performance. These numbers not only help professionals quickly identify brick grades but also provide users with a clear basis for purchasing.
It’s worth noting that the alumina content of lightweight mullite insulation bricks is a key quality indicator. For example, JM23, JM26, JM28, and JM30 have alumina contents ranging from 38-44%, 50-58%, 65-70%, and 70-73%, respectively. As the alumina content increases, the brick’s insulation performance and refractoriness also improve. This means higher-grade bricks offer greater stability and durability in high-temperature environments.
So, what are the refractory temperatures of these bricks? Lightweight mullite insulation bricks such as JM23, JM26, JM28, JM30, and JM32 have refractory temperatures of 1250°C, 1350°C, 1450°C, 1550°C, and 1650°C, respectively. These data not only demonstrate the exceptional performance of mullite insulation bricks but also provide solid support for their application in various high-temperature environments.
As a high-quality refractory material, mullite insulation bricks are widely used as refractory linings or insulation layers for hot surfaces in various thermal equipment. Mullite insulation bricks can be found in the production of materials like ceramics and glass, as well as in heat treatment equipment in metallurgy and chemical industries. Their outstanding refractory properties and thermal insulation performance provide crucial support and assurance for industrial production.