Techn. Al hydroxide (gibbsite) was lastly calcinated in an electrically heated lab. furnace (capacity 10 kg/h) to a fine powder, wetted with water, nitric acid or aq. NH3, granulated to balls, calcinated at 400-500 degrees C to activated alumina and studied for sp. surface (179-250 M-2/g), porosity (5865,901.), pore size distribution, density (3,0-3,1 g/m(3)), apparent density (1,05-1.27 g/cm(3)) and bending strength (2.44.3 dN/mm). The sp. pore vol. increased while bending strength decreased when the calcination temp. was increased. The highest sp. pore vol. and bending strength were achieved when the powder was wetted with water.