Kyanite & Mullite

Description

KYANITE IS AN ESSENTIAL RAW MATERIAL IN MANY REFRACTORY AND CERAMIC PRODUCTS
In its raw form, kyanite is a blue crystal unlike any other mineral. Kyanite has the unique property of expanding irreversibly when heated. The degree of volume expansion is dependent upon the mesh size of the kyanite product selected. This predictable expansion helps in offsetting the shrinkage of other raw materials and binders employed in the mix and this makes it an important ingredient in the manufacture of refractories.
Kyanite Mining Corporation has perfected the process of refining kyanite to remove impurities. The result is Virginia Kyanite™, a dependable, high-quality end product that is 92-96% kyanite.

VIRGINIA MULLITE™ IS VERY LOW IN IMPURITIES COMPARED TO OTHER TRADITIONALLY SINTERED MULLITE
Mullite rarely occurs as a mineral in nature. The word mullite is derived from the Isle of Mull off the Scottish coast, where the only naturally occurring deposits of mullite have ever been found.
Mullite is a mineral with a very high melting temperature of 1840° Centigrade.  It is a premier acidic refractory mineral; it has no polymorphic inversions and possesses a low thermal expansion coefficient of 5.3 x 10 -6°C. When mullite re-crystallizes in a ceramic or a refractory it forms as small lenticular crystals which promote high strength, even at very high temperatures. 
Virginia Mullite™ produced by Kyanite Mining Corporation is purer than most sintered mullite and is very volume-stable. Virginia Mullite™ contains about 80% mullite, 11% finely dispersed amorphous silica, 3 -6% quartz, and about 2% cristobalite.  It is also different in particle shape and impurities than mullite formed by calcining clay minerals.