Mullite Powders

(Aluminum Oxide – Silicon Dioxide)

≥ 99.5% pure

Particle Size Range:   < 45 microns (-325 Mesh)

Formula            3Al₂O₃-2SiO₂

CAS#                1302-93-8

Density              3.03 gram/cm³

Appearance     White to light grey powder

Form                  Free flowing, non-sticking powder

Applications: By far the largest use of mullite based products is in refractories.  The glass and steel industries are two main markets.

The steel industry is the largest user, where refractoriness, high creep resistance and thermal shock resistance are important.  The main use of high-mullite based products is in hot blast stove checker bricks.  Many refractories in use in the steel industry have varying amounts of mullite based aggregates in them.  Steel ladles, lances, reheat furnaces and slide gates are examples of mullite aggregate based products with various alumina contents.

The glass industry uses mullite based refractories in burner blocks, ports and in checker bricks as well as in the upper structure of the tanks where the glass is melted and in the drawing chambers.  Thermal shock resistance, chemical attack resistance, high hot strength and creep resistance are the primary properties valued by the industry.

Mullite based products are also resistant to particulate carryover into the glass melt.  This is particularly important in flat glass production, where contamination by low levels of Al₂O₃ is undesirable.

The next largest user of mullite is the ceramic industry mostly in kiln furniture items such as kiln setter slabs and posts for supporting ceramic ware during firing.

The aluminum and petrochemical industries also use mullite-based aggregates for applications requiring chemical attack resistance, thermal shock resistance and hot-load strength.

The good mechanical properties at high temperatures of high purity mullites have made them potential high temperature engineering ceramics, for example in turbine engine components.

Mullite is also a leading candidate material for high-strength infrared transmitting windows.

Other applications include electronic substrates and protective coatings.