Method for improving the rheology of calcined kaolin clay products

摘要

A method for preparing a calcined kaolin clay powder having good high shear rheology in high solids aqueous slurries. A kaolin clay powder of fine particle size is calcined at a sufficient temperature and for a sufficient period to destroy the crystallinity thereof; and the calcined product is dry milled in a media mill, using a work input of from 100 to 160 hp-hr/ton of dry clay.