Metakaolin pigment with high brightness and low abrasion and manufacture thereof from soft kaolin clays

摘要

The invention relates to novel metakaolin pigments which are characterized by a unique combination of exceptionally high brightness and exceptionally low abrasion along with the excellent hiding power equal to that achieved by premium conventional calcined kaolin pigments. The invention relates also to a method of producing such metakaolin pigments by subjecting relatively coarse high purity and high crystallinity kaolin booklets to highly intensive media grinding to generate fine kaolin particles of reduced crystallinity, and calcining the ground particles while limiting calcination temperature and time such as to form metakaolin.