Patent ID: 6068693
Filing Date: 2000-05-30
Classification: B03B,B03D,C04B

Abstract:
A method for a selective flocculation of finely divided kaolin clay particles from a kaolin crude containing impurity particles, comprising:(a) forming said crude clay containing kaolin clay particles and said impurity particles into a dispersed aqueous slurry by adding at least one dispersant to said crude;(b) adding one conditioning agent to said dispersed aqueous slurry to condition said slurry, said conditioning agent being a source of inorganic monovalent cation;(c) flocculating said conditioned slurry by adding to said conditioned slurry a low molecular weight anionic polymer having a molecular weight ranging from about 1000 to about 20,000 and a high molecular weight anionic polymer having a molecular weight ranging from about 10 to about 15 million to flocculate said impurity particles, which flocs settle as a dense lower layer; and(d) removing said settled dense lower layer from said aqueous slurry; andwherein the use of said low molecular weight anionic polymer and said high molecular weight anionic polymer in step (c) increases the yield of said kaolin clay particles without aging in step (b).