Pyrophyllite - a potential material for application in tri-axial porcelain systems

Pyrophyllite is largely an overlooked raw material available in huge quantities in nature. This is mainly due to the fact that other comparable aluminosilicate raw materials like china clay are available in much purer form. However, fast depleting reserves of standard raw materials necessitated renewed attention on so far sparingly used raw materials like pyrophyllite. Investigative work on pyrophyllite is also insignificant in comparison to other ceramic raw materials. Available information are scattered and it is felt that a comprehensive review is needed for effective dissemination of the information already generated and available in the public domain. In the present article salient points on the material including structure, chemistry of heating and possibility of future applications particularly in triaxial ceramic system is discussed. In a case study one Indian pyrophyllite was incorporated (15%) in a triaxial body composition replacing both china clay and quartz. The changes in fired properties was tried to correlate with phase development and microstructure.