Abstract: A method of treating a kaolin particulate material to improve its properties by removal of impurities which includes the steps of: (a) producing a dispersed aqueous suspension of a kaolin particulate material containing at least 0.1% by weight, based on the dry weight of the kaolin particulate material, of separable impurity by adding a dispersing agent to the kaolin particulate material to deflocculate solid particles of the material in the suspension; (b) conditioning the suspension prior to adding selective flocculation polymer thereto by allowing the suspension to age for a period of at least 30 minutes and optionally by adding one or more conditioning chemicals thereto; (c) adjusting the pH of the suspension to be at least about 9.5; (d) adding to the suspension at a pH of at least about 9.

Abstract: An improvement is disclosed applicable to the method for producing a calcined kaolin by the steps of wet beneficiating a crude kaolin to form a slurry of the beneficiated kaolin; dewatering the slurry to form a substantially dry calciner feed; and calcining the feed at a temperature of at least 1450.degree. F. by passing a stream of hot gases through a calciner in which the kaolin feed is resident, whereby an exhaust stream of hot gases is generated which entrains quantities of partially calcined and hydrous kaolin pigment fines. The improvement, enabling useful application of the kaolin pigment fines, comprises recovering the kaolin pigment fines from the exhaust stream for use in papermaking. The fines can be recovered at a wet scrubber, and after being partially dewatered, shipped directly as a product slurry to the paper maker.