Refractory Kiln Posts Sanitary Ware Use Heat Stability Wear Resistance

Refractory high temperature Cordierite kiln post used for sanitary ware

1. Description

Cordierite makes the ceramic manufacture of products like catalytic converters possible. They constantly heat up and cool down quickly and must not crack because of the shock. These converters get their thermal shock resistance properties from a bonded matrix of low-expansion cordierite crystals. These crystals form during firing between 1300 to 1400C (interestingly, cordierite crystals have a lesser thermal expansion along one axis than another). Thus, the better the density of the precursor mix and controlled the firing the better the properties of the cordierite material are.
The ideal chemistry to produce the crystals is 13.8% MgO, 34.8% Al₂O₃ and 51.4% SiO₂ (2MgO, 2Al₂O₃, 5SiO₂). Talc, kaolin and raw alumina powder can be blended to produce this chemistry (other materials are also used e.g. aluminum hydroxide, steatite and other MgO minerals). Compound materials (like kaolin and talc) react better than pure oxide materials (like MgO, Al₂O₃, SiO₂). Materials of finer particle size react better.
A simple firing to 1300C (about cone 11 and within the reach of many ordinary kilns) and soaked may produce some crystal development. However firing (actually sintering) at 1400C+ with significant soaking time is needed for the best results. Thermal expansion measuring equipment is needed to determine if your firing is actually developing the crystal matrix or not.

2. Specification

3. Pacakge