Method for separating mixture of finely divided minerals and product thereof

US6068693A · kind A · utility

Assignee

• ECC International Limited · GB

Inventors

• William L. Garforth · Sandersville, US
• Robert J. Pruett · Milledgeville, US
• Dona L. Archer · Sandersville, US
• Jun Yuan · San Diego, US
• Michael J. Garska · Sandersville, US
• H. Vince Brown · Sandersville, US

Key dates

• Filing date: Jun 16, 1997
• Grant date: May 30, 2000
• Expiry date: Jun 16, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B33/10
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A method of enhancing the brightness and increasing the yield of a kaolin clay by optimizing the removal of the titania and mica impurities in the clay and the amount of clay remaining in the slurry is disclosed. The method is a selective flocculation process wherein the clay is blunged, dispersed, and conditioned before flocculation. In the flocculation step, a high molecular weight anionic polymer and a low molecular weight anionic polymer, such as sodium polyacrylate, are added to the slurry after the conditioning process, whereby the titania-mica enriched flocs are separated from the suspension which is enriched with kaolin. This final kaolin product has titania levels ranging from 0.1% to 0.5%, a reduced mica level, a high usable product yield, and a brightness greater than 89.5 and at least 91.5.