Thermal decomposition of talc: A review

Abstract

A literature review is presented concerning the application of thermoanalytical methods, such as differential thermal analysis (DTA), thermogravimetry (TG) and derivative TG (DTG) as well as isothermal measurements for the examination of the thermal decomposition of talc. The crystal structure of this mineral is characterized and relations between the talc structure and its physico-chemical properties and thermal stability are given. The usefulness of isothermal and dynamic thermal methods in studies of the mechanism of talc decomposition to cristobalite and magnesium metasilicate, as well as in talc dehydration kinetics is emphasized. Moreover, attention is paid to the interpretation of the shape of endothermic DTA peaks due to dehydroxylation of the mineral, as well as to the possibilities of detection, identification and quantitative determination of the mineral contaminations frequently encountered in talc, such as carbonates, quartz and chrysotile. In a separate chapter, questions connected with the utilization of thermoanalytical curves for the identification of talc, and its distinction from minerals belonging to other groups than the silicate and aluminosilicate classes are discussed. © 1984.