| 摘要 |
<p>A method for reducing the viscosity and for refining crude kaolin clays is disclosed. The inherent viscosities of crude kaolin clay ores, particularly those having acceptable optical and purity properties for use in preparing paper coating pigments, but normally rejected because of their high inherent viscosities, are significantly reduced by contacting an aqueous slurry of the crude clay with an inorganic polymeric complex having the general formula ¢AI(OH)yA3-y!x wherein x = 6 to 24, y = 1.0 to 2.75 and A is selected from the group consisting of Cl?, (SO?)0.5 and NO?. In a preferred embodiment the above treated clay is also subjected to a high shear mixing action or kneading prior to further conventional processing procedures, such as fractionation, leaching, etc. The treatment of the clay with the above polymer complex and high shear mixing or kneading have a synergistic effect in providing a refined clay product having significantly lower viscosity when dispersed or slurried. The refined products produced in accordance with the method thus have particular use as paper coating pigments. -I-</p> |
