High-temperature thermo-structural behaviour of mechanically deformed talc

A commercial talc was treated by planetary ball milling in controlled thermodynamic conditions to evaluate the thermo-modification of the main physical and technological properties as a result of the induced progressive mechanical stress. Mechanical grinding produces a progressive reduction of the particles size and the increase of the specific surface leading to both an enhanced absorption and cation exchange capacity of talc in the initial and intermediate stage of grinding, whereas the re-aggregation of the particles produces apparent larger particles that restores the starting characteristics. The mechanical treatment performed in our experimental conditions does not induce talc amorphization thus preserving the main properties of talc even after prolonged grinding. The knowledge of the main changes of properties in relation to different stages of deformation can be exploited in various industrial applications of talc.