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.

Abstract: A method is provided for reducing the abrasiveness of calcined clay, e.g. kaolin clay. The method comprises contacting the clay prior to calcination with an aliphatic diol, preferably ethylene glycol, in an amount sufficient to reduce the abrasiveness of the calcined product.

Abstract: A method for increasing the bulk density and decreasing the time of wetting with water of a substantially anhydrous kaolin clay powder, comprising dry milling said powder in a media mill wherein the media is at least +5 mesh, and using work inputs of from about 5 to about 40 HP-hrs/ton of dry clay. The process enables improved handling characteristics for the treated clay with respect to bulk material handling systems.

Abstract: A method for increasing the bulk density and decreasing the time of wetting with water of a substantially anhydrous kaolin clay powder, comprising dry ball-milling said powder using work inputs of from about 5 to about 40 HP-hrs/ton of dry clay. The milling may be effected by grinding the clay with ceramic balls of less than 5 inches diameter. The process enables improved handling characteristics for the treated clay with respect to bulk material handling systems.

Abstract: A method for increasing the bulk density and decreasing the time of wetting with water of a substantially anhydrous kaolin clay powder, comprising dry ball-milling the said powder using work inputs of from about 5 to about 40 HP-hrs/ton of dry clay, followed by pulverization in a high energy impact mill and classification to eliminate undesirable larger particles. The ball-milling may be effected by grinding the clay with ceramic balls of less than 5 inches diameter. The process enables improved handling characteristics for the treated clay with respect to bulk material handling systems.

Abstract: A method for continuously processing a kaolin clay which has relatively poor high-shear viscosity when prepared as a high-solids suspension, so as to obtain therefrom a fraction having a value of high-shear viscosity in high-solids suspension which is low relative to the starting clay, thereby being desirable for use in coating of paper. The method comprises the steps of forming the kaolin clay into a dilute aqueous suspension having from 10% to 20% solids by weight and forming said suspension into a continuous flow stream; mixing the stream of flowing suspension at a given point with from about 0.001% to 0.

Abstract: A method is disclosed for beneficiating a kaolin clay pigment to improve the rheological properties of a high solids suspension subsequently formed therefrom. According to the method, a 10 to 20% solids aqueous suspension of a kaolin clay is subjected to a selective rheological separation, by mixing the suspension with from about 0.001% to 0.1% by weight of dry clay, of a high molecular weight anionic polymer, and allowing the thereby treated suspension to separate into a sedimented phase, and a supernatant phase which is substantially free of aggregates; and separating the supernatant phase containing the beneficiated kaolin pigment in suspension. The suspended product of the process can then be conventionally processed, as by reductive bleaching, floccing, filtering, washing, dispersing, and drying.