Calcined China Clay Powder is an anhydrous aluminium silicate produced by heating ultrafine natural kaolin to high temperatures in a kiln. The calcination process increases whiteness and hardness, improves electrical properties, and alters the size and shape of the kaolin particles.

Production :
Calcination occurs in two steps.

• At 700^oC, the de-hydroxylation of kaolin occurs forming a poorly crystalline metakaolin. Products produced at this temperature can improve the dielectric properties of PVC cable insulation.
• At 980^oC an amorphous defect spinel is formed which undergoes a transformation, with mullite recrystallizing in an amorphous glass at temperatures above 1100^oC. Products produced within this temperature range provide excellent properties in rubber compounds, improving mechanical properties and chemical resistance. It enhances rigidity, toughness, and dimensional stability.