PROCEDURES FOR THE MANUFACTURE OF METALLOXIC POULTRY (zirconium, HAFNIUM, TITAN) WITH CERTAIN SPECIFIC SURFACE AND SURFACE DISTRIBUTION.

摘要

Method for the direct production of a fine powder comprised of crystallites which are little or not agglomerated, of metal oxides such as zirconia, hafnium and/or titanium oxide, having a specific surface or a grain size selected and controlled according to the particular utilization, said grain size having a mean diameter smaller than 0.2 $g(m)m, comprising the treatment by hydrolysis of the corresponding metal tetrachloride by means of water vapor by operating at a partial pressure of tetrachloride, set at a predetermined value function of the specific surface or the grain size searched for, comprised between 3 and 30 % of the total pressure of the mixture of all gas components, while maintaining a molar ratio water/metal tetrachloride comprised between 2 and 10.