Abstract: A method of enhancing the brightness and increasing the yield of a kaolin clay by optimizing the removal of the titania and mica impurities in the clay and the amount of clay remaining in the slurry is disclosed. The method is a selective flocculation process wherein the clay is blunged, dispersed, and conditioned before flocculation. In the flocculation step, a high molecular weight anionic polymer and a low molecular weight anionic polymer, such as sodium polyacrylate, are added to the slurry after the conditioning process, whereby the titania-mica enriched flocs are separated from the suspension which is enriched with kaolin. This final kaolin product has titania levels ranging from 0.1% to 0.5%, a reduced mica level, a high usable product yield, and a brightness greater than 89.5 and at least 91.5.

Abstract: A method of producing a high opacifying kaolin pigment by separating from one or more iron-stained titania-containing crude kaolins having a titania content of from about 1 to 2 weight percent, one or more titania-enriched kaolin fractions which contain the titania in an amount of above 2 weight percent; subjecting the fraction(s) to media grinding; dewatering and drying the media ground fraction(s); blending the fraction(s) with a fine particle size unground kaolin having a titania content less than 2%, in proportions to provide a calciner feed having at least 2% titania; and calcining the feed at a temperature in the range of 1500.degree. to 2200.degree. F.