Field flow fractionation is a family of separation techniques applicable to characterize various particulate materials of different nature. In this paper, formation of porous graphite during milling has been investigated by gravitational field flow fractionation. The results from gravitational field flow fractionation were compared to those from Brunauer-Emmett-Teller. The both techniques have shown that particles fracturing and formation of porous graphite was occurred until 50 h milling. Further milling resulted in formation of agglomerated species. There was a good accordance between the results obtained from gravitational field flow fractionation, Brunauer-Emmett-Teller and scanning electron microscopy. Moreover, fractions of porous and non-porous species could be separated by gravitational field flow fractionation technique. Results demonstrated that gravitational field flow fractionation is a simple method with satisfactory results to investigate the evolution of graphite powder during milling process.

Keywords: Gravitational field flow fractionation; Porous graphite; Milling