usually contain about 55% to 80% aluminum oxide (Al2O3), but the specific aluminum content may vary depending on the manufacturing method, raw material quality and process parameters.

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Electric Fusion: This is a method that uses electrical energy to heat materials to melting temperature. In the electrofusion process, a large amount of heat energy is generated by passing an electric current through a resistance in the material, causing the material to melt. This method is often used to prepare high-purity, high-performance materials because it allows greater control over the material's chemical composition and structure. Fused mullite bricks are mainly made of high-alumina bauxite or industrial alumina, clay or silica, melted in an electric arc furnace, then cast and annealed to make refractory bricks. The main mineral component is mullite.