Patent ID: 7494541

Claim:
A method of processing kaolin, comprising sequentially: providing a kaolin crude comprising higher amount of gray kaolin and a lower amount of white kaolin; degritting the kaolin crude; subject the degritted kaolin crude to flotation to provide a kaolin having reduced titania content; ozonating the kaolin having reduced titania content; centrifuging the kaolin at high speeds to provide a coarse stream and fine stream, the course stream comprising kaolin wherein at least about 70% by weight has a size of 2 microns or less, the fine stream comprising kaolin wherein at least about 80% by weight has a size of 1 micron or less; refining the coarse stream into a coarse engineered kaolin pigment, wherein the coarse engineered kaolin pigment has a surface area from about 15 to about 19 m 2 /g and about 0.75% by weight or less of titania; and refining the fine stream into a fine glossing kaolin pigment; with the proviso that the method does not comprise fractioning the kaolin.