U.S. Borax, Inc.

J Elmo Bloodworth

Donald G Turner

John H Chapman

Samuel M Pickering, Jr

Sam M Pickering, Jr

Michael A Linkous

A method for producing a delaminated kaolin clay having a G.E. brightness of at least 85, a solids content of at least 67 percent by weight, and a viscosity below 500 cps is disclosed. An aqueous slurry of kaolin clay is subjected to agitation in the presence of a hard grinding media. The slurry is then subjected to agitation in the presence of a soft grinding media. The result is that at least 80 percent of the delaminated kaolin has an equivalent spherical diameter of less than or equal to 2 microns.

Two-stage process for delaminating kaolin

The present invention provides a process for whitening kaolin contaminated with chlorite/biotite micas. The process comprises the steps of contacting the kaolin contaminated with chlorite/biotite micas with an aqueous acid solution to convert the chlorite/biotite micas into kaolin and one or more dissolved metal salts, and separating the kaolin from the dissolved metal salts. The present invention also provided an overall system for whitening kaolin contaminated with chlorite/biotite micas. The process comprises blunging the kaolin contaminated with chlorite/biotite micas to provide a 20 to 70 percent solid slurry, degritting the slurry, delaminating the degritted slurry, fractionating the degritted slurry, subjecting the slurry to a magnetic field to remove iron or iron-titanium oxides, reductive leaching the slurry, contacting the slurry with an aqueous acid solution to convert the chlorite/biotite micas into kaolin or a kaolin-like clay and one or more dissolved metal salts (e.g., iron, magnesium, and potassium salts), and separating the kaolin or kaolin-like clay from the dissolved metal salts.

Growing community of inventors

Milledgeville, GA, United States of America

J Elmo Bloodworth