Mg(OH)2 was pptd. from aq. soln. of Mg(NO(3))(2) with NaOH at 20-80 degrees C, sepd. by filtration, dried at 105 degrees C and calcinated to MgO at 450 degrees C for 1.5 h. The product was studied for structure, grain size distribution, sp. surface, wettability and sedimentation profiles and showed low grain polydispersity 0.240 and high sp. surface 81 m(2)/g.