Kaolin in south Africa

摘要

KAOLIN IS A soft,white plastic clay consisting of a loose aggregation of randomly oriented stacks of kaolinite flakes.Kaolin deposits are classified as either primary or secondary.Primary kaolins result from residual weathering or hydrothermal alteration (or kaolinisation) of alkali feldspar-rich rocks such as granite or gneiss,whilst secondary kaolins are of sedimentary origin.