The synthesis of hercynite (FeAl2O4) by thermal treatment of mechanochemically activated (Al + Fe3O4) mixtures is studied. The evolution of structure, texture and physicochemical behavior with activation time is analyzed by XRD, DTA and SEM. From activated samples, it is possible to obtain hercynite by dynamic thermal treatment at 1200 degreesC in Ar atmosphere, in conditions significantly easier than those required for non-activated samples, through a reaction path which is not the prevalent one in conventional methods. (C) 2002 Elsevier Science B.V. All rights reserved.