Pyrophyllite

Specifications Products : Pyrophyllite Use : Industrial Use Color : Off White to White Form : Lumps,Powder, Grains & Calcined Packing Type : Pastic Bags Packing Size : 25kgs /50kgs Calcined Pyrophyllite Lumps Pyrophyllite is a member of phyllosilicate mineral spices, or Leaf silicates, which have sheet-like structure. It belongs to the clay family and composed of aluminium silicate hydroxide : AlSi2O5OH. The phyllosilicates from stacks of silicate layers that are composed to SiO4 tetrahedrons and the sheets are not directly linked above or below to the next silicate sheets. In pyrophyllite, two silicate layers are sandwitched in between the so called gibbsite layer. Gibsite Al(OH)3, is its own mineral and is composed or octahedrally coordinated aluminiums surrounded by six hydroxides. The Gibsite layer (G) in pyrophyllite is identical to gibsiteâ??s structure except that four of the hydroxides are replaces by four oxygens from the silicate layer (S). The overall pyrophyllite can be imagined as stacked S-G-S sandwitches. The bonding between these sand witche is nearly nonexistent and gives rise to pyrophyllite's softness and perfect cleavage. Pyrophyllite is also identical in physical properties to a quite distinct mineral called talc. The two are isomorphous, meaning they share the same monoclinic structure but have different chemistries. Talc has magnesiums instead of aluminums and is basically indistinguishable from pyrophyllite without a chemical test for aluminum. The test for aluminum involves applying a slight amount of cobalt nitrate solution on the specimen and then igniting the solution. The specimen should change color; a blue color confirms pyrophyllite, a violet color confirms talc. Pyrophyllite is a mild mineral (hardness of 1.0 to 1.5 on Mohs scale) with pearly luster. It has lower the firing temperature, reduces shrinking and cracking, and improves thermal shock resistance. Major application of pyrophyllite is in ceramics as talc counterpart, particularly in the manufacture of white ceramic products such as floor tile, wall tile, and electrical porcelain. Because of its PCE of 30 to 32 (moderate to high duty), pyrophyllite is used as refractory in brick form or monolith, other applications of pyrophyllite are as insecticide carrier and extender in paint, Filler in plastics, paper, rubber, and vinyl tiles. Pyrophyllite when calcined are used in Engineering Ceramic products. While refined Pyrophyllite after calcination is suitable for paint application as an extender. At the same time It is most suitable as an active filler in Thermoplastics when micronized and surface modified.