Other names: : Kyanite concentrate, OR Grade Sillimanite, Q Grade Sillimanite, Orissa Sillimanite, Chavara Sillimanite
Colour and appearance: cream colour, off white colour, greyish white colour
Uses:
1. Sillimanite is used in manufacturing refractories.
2. Sillimanite is used in manufacturing Kiln Furniture
3. Sillimanite powder is used to manufacture foundry paints
4. Sillimanite is used in primary and secondary coating in investment casting
5. Sillimanite is used in manufacturing of high-alumina refractories
6. Sillimanite is also used in metal, glass, ceramic and cement industries
About Sillimanite:
Andalusite, kyanite and sillimanite are the structural polymorphs of Al2SiO5. All the three forms are sillimanite group of minerals. India is one of the dominant supply in world in terms of best quality sillimanite. For Kyanite decomposition begins at 1100°C; Kyanite complete decomposition is at 1410°C; Kyanite Peak on thermal curve is at 1420°C For Andalusite decomposition begins at 1410°C; Andalusite complete decomposition is at 1500°C; Andalusite Peak on thermal curve is at 1510°C For Sillimanite decomposition begins at 1550°C; Sillimanite complete decomposition is at 1625°C; Sillimanite Peak on thermal curve is at 1560°C Sillimanite is also called as naturally form mullite. But its mullite level increase during the calcination in a rotary kiln. Performance of mullite increases with increase in alumina content in mineral. How sillimanite used in refractories?
Refractories is one of most important use of mullite (hence it is sillimanite mineral). Mullite consist of interlocking needle shaped crystals which provides good creep resistance and stable at 1800°C. It provides good refractories and high loading at high temperature. Refractory lining for blast, copper roasting, glass furnace, gunning mixes, plastic, kiln furniture, cement Kiln, combustion chambers, ladle and nozzles. How Sillimanite is used in ceramics? Sillimanite or Andalusite or Kyanite is used as the source of alumina and silica in manufacturing of ceramics like sanitaryware, cookware, dinnerware, ceramic tiles and electric porcelain. Mullite is used in ceramics to counter balance the shrinkage caused by clays during manufacturing. How sillimanite is used in metallurgy? Sillimanite minerals is used as high temperature sand in forming casting molds. Sillimanite is also used in powder form in manufacturing foundry paints/ mold sprays to facilitate removal of metal casting from mold. Sillimanite is also used as in kiln lining and kiln furniture to reduce thermal cracking during the manufacturing process by formation of mullite during the process.