METHOD OF PREPARING ALPHA-ALUMINUM POWDER AND ALPHA-ALUMINUM POWDER Russian patent published in 1999 - IPC

FIELD: inorganic syntheses. SUBSTANCE: alpha-aluminum powder is prepared by calcining at least one initial material selected from group including aluminum oxide modifications other than alpha-aluminum oxide and other aluminum compounds. Calcination is carried out in halogen-containing atmosphere including gaseous hydrogen halide, gaseous halogen or mixture of gaseous halogen with water steam. Calcined material is then freed from halogen. Alpha-aluminum powder thus prepared contains particles having close-packed lattice and polyhedron forms with at least 8 faces, D/H ratio 0.5 to 3,0, wherein D and H are maximum particle dimensions in direction, respectively, parallel and perpendicular to hexagonal lattice, D₉₀/D₁₀ ratio is equal to 10 or less, wherein D₉₀ and D₁₀ are particle dimensions respectively at 90 and 10% accumulation going from minimum particle size. Purity of product is at least 99.9%. EFFECT: improved product quality. 17 cl, 5 dwg, 2 tbl, 30 ex