Method for forming aggregated kaolin pigment

摘要

A method for forming a hydrothermally aggregated kaolin clay pigment, comprising preparing an aqueous slurry of particulate kaolin clay and sodium aluminate, having a total solids concentration of from about 2 to 25% by weight, the weight ratio between kaolin and aluminate being greater than 1; and hydrothermally treating the slurry in a closed system to form aggregates of adherent kaolin platelets.