Process for producing a kaolin clay product

A process for producing a high brightness kaolin clay product of beneficiated kaolin clay particles in a high solids aqueous slurry, comprising:

• a. forming an aqueous suspension of crude kaolin clay at a relatively low solids content of less than about 70% by weight of kaolin particles;
• b. degritting the aqueous suspension of crude kaolin clay to remove kaolin clay particles having a particle size greater than about 325 mesh to form a degritted aqueous suspension;
• c. fractionating the degritted aqueous suspension of crude kaolin clay to produce a finer fraction having a particle size distribution wherein at least about 80% by weight of the particles have a particle size less than 2 micrometers equivalent spherical diameter;
• d. acidifying the aqueous suspension of relatively fine-particle size kaolin clay particles to a pH at least less than 5.0 to produce an acid flocculated suspension;
• e. contacting the acid flocculated aqueous suspension of relatively fine-particle size kaolin clay particles with a bleaching agent to reduce ferric ion impurities contained therein to ferrous ion impurities;
• f. adding a ferrous ion chelating agent to the bleached acid flocculated aqueous suspension of relatively fine-particle size kaolin clay particles whereby the ferrous ions are chelated;
• g. admixing an alkaline agent with the bleached acid flocculated aqueous suspension of relatively fine-particle size kaolin clay particles to raise the pH to a level greater than 5.0 to form a dispersed aqueous suspension of beneficiated kaolin clay particles;
• h. subjecting the dispersed aqueous suspension of beneficiated kaolin clay particles to membrane filtration to partially dewater the dispersed aqueous suspension of beneficiated kaolin clay particles;
• and
• i. thermally evaporating additional water from the partially dewatered dispersed aqueous suspension of beneficiated kaolin clay particles to produce a high solids product suspension of beneficiated kaolin clay particles.