Kaolinite Products – Sector EPD

Kaolinite is a mineral belonging to the group of aluminosilicates. The term kaolin is used to describe a mineral dominated by kaolinite and derived primarily from thealteration of alkali feldspar and micas. Kaolin is commonly referred to as"China Clay" because it was first discovered at Kao-Ling, in China. As an industrial mineral, customers combine it with other raw materials in a wide variety of applications.

Kaolin is a white, soft, plastic mineral mainly composed of fine-grained plate-like particles. Kaolin is formed when the anhydrous aluminium silicates which are found in feldsparrich rocks, like granite, are altered by weathering or hydrothermal processes. The process which converted the hard granite into the soft matrix found in kaolin pits is known as "kaolinisation". The quartz and mica of the graniteremain relatively unchanged whilst the feldspar is transformed into kaolinite.Smectite may also form in small quantities in some deposits. The refining andprocessing of the fine fraction of the kaolinised granite yields predominantlykaolinite with minor amounts of mica, feldspar, traces of quartz and, dependingon the origin, organic substances and/or heavy minerals.

Individual kaolins vary in many physical aspects, which in turn influence their end use. Of particular commercial interest is the degree of crystallinity which influences the brightness, whiteness, opacity, gloss, film strength, and viscosity.