Abstract: A method of dispersing a solid particulate material in an aqueous medium by addition to the aqueous medium of a dispersing agent wherein the solid particulate material is to be used as a filler or pigment in a sheet material which is required to come into contact with foodstuffs, wherein the dispersing agent is a composition comprising:

Abstract: A method of dispersing a solid particulate material in an aqueous medium by addition to the aqueous medium of a dispersing agent wherein the solid particulate material is to be used as a filler or pigment in a sheet material which is required to come into contact with foodstuffs, wherein the dispersing agent is a composition comprising: (1) up to 0.25% by weight, based on the dry weight of the particulate solid material, of a water-soluble salt of a poly(acrylic acid) having a weight average molecular weight not greater than 20,000, and (2) from 0.02% to 1.5% by weight, based on the dry weight of the particulate solid material, of either (a) an anionic polyelectrolyte which comprises a water-soluble salt of a copolymer of acrylic acid with acrylamide; or (b) a water-soluble condensed phosphate salt.

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.