Mullite can withstand very high temperatures and will not deform or crack when repeatedly exposed to temperature fluctuations. Add it to slurries to create crucibles, ladles, and other parts by casting it. Mullite powder is common in furnaces, heaters, thermocouples, electrical insulation, and glass- and steel-industry refractories. When exposed to chemicals that are used to make steel, such as acid, it will not corrode. Due to fused fabrication, it has higher purity and more uniformity which leads to better thermal shock resistance and low thermal expansion.

Choose a particle size based on the application of your finished piece. Finer powders can be processed into finished pieces that will be harder, stronger, and more wear-resistant than those made with coarse grains. They may also have a finer finish. Parts made with coarse grain powders can be processed into pieces that are more porous and thermally shock-resistant than pieces made with finer grains. Mixing sizes can combine these properties.