Mechanism of nanostructure bredigite formation by mechanical activation with thermal treatment

This paper reports the successful synthesis of nanostructure bredigite powder by mechanical activation with subsequent annealing. Talc, calcium carbonate, and amorphous silica were used as initial reactants. The initial materials were milled for various times and then annealed in order to obtain single-phase nanostructure bredigite powder. The results showed that during the formation of bredigite powder some intermediate compounds such as wollastonite and larnite were formed. Single-phase nanostructure bredigite powder was synthesized by 10-60 h of mechanical activation with subsequent annealing at 1200 °C for 1 h. The bredigite powder obtained after 60 h milling and subsequent annealing at 1200 °C for 1 h had a mean crystallite size of about 50 nm and mean particle size of about 779 nm.