HIGH WHITENESS METAKAOLIN AND HIGH WHITENESS FULLY CALCINED KAOLIN

摘要

The present invention relates to calcined kaolins having optimal whiteness and brightness properties. The calcined kaolins can comprise metakaolin, fully calcined kaolin, or flash calcined kaolin. The kaolin can be calcined from hydrous kaolin that has been subjected to enhanced magnetic separation. The resulting calcined kaolin can have a whiteness defined by a Hunter lab coordinate L value of at least about (96). The calcined kaolin can also have a brightness of at least about (90), as measured by a Technibrite TB-1C instrument. The present invention also relates to methods of preparing calcined kaolins. The present invention also relates to paints, polymers, coatings, ceramics, paper, and cementitious products comprising these calcined kaolins.