Processes
Cordierite is a magnesium alumina silicate with chemical formula 2MgO.2Al2O3.5SiO2 from sedimentary rocks. It can also be synthesised in solid form by mixing stoichiometric amounts of oxides, using soft chemistry with salts or by devitrification of glass. After forming the powders, the products are sintered between 1,000 and 1,300°C.
Properties
Cordierite has many qualities suitable for industrial applications: low thermal conductivity and low expansion coefficient, resistance to heat, low dielectric loss, resistance to corrosion compared to smelted metals, and excellent high vacuum resistance.
In addition, as it is machinable using standard tools, it is used to create prototypes and its low thermal expansion lends itself to parts with tight tolerances.
Applications
Taking advantage of its good resistance to thermal shocks, cordierite is used in the field of electrical insulation, burner pipes or kiln furniture in the ceramics industry. This refractory material is also used as raw material in stoneware oven dishes or glass-ceramic cooker hobs. The automotive industry uses it in catalytic converters to convert pollutants such as CO, HC and NOx.