Abstract

Five kaolins and eight ball clays from the State of Santa Catarina used industrially for whitewares productíon and other applications were characterized in relation to their clay minerals, especially that related to the kaolin group. The following methods were used: XRD, DTA. TI M. SEM and EDS / TEM (elementals microanalysis by EDS). The main objective was to prove that the electrón óptical methods are necessary to detect small amounts of 7A°-halloysite in presence of kaolinite because they are masked in the XRD curves. In conclusión, five kaolins and three ball clays were found being mixtures of kaolinites (either well-crystallized or b-axis disordered) with different percentages of 7A-halloysite (either long or short lubes), while the other five ball clays are constituted only by b-axis disordered kaolinite.