| abstract |
Pyrogenically producing Nb oxide involves vapourising anhydrous Nb chloride, leading it together with an inert gas into the mixing chamber of a burner, there mixing it with H2 and dry air and/or O2 and burning the mixt. in the combustion chamber, subsequently sepg. the Nb2O5 from the gaseous reaction prods. and opt. freeing it of entrained HCl by heating in moist air. USE/ADVANTAGE - The prod. is easier to produce in pure anhydrous form than when using the known wet processes. The pyrogenic Nb2O5 has typical properties of BET surface = 20-120 m2/g, chloride content (after deacidification) less than 1 wt.%, powder density 80-200 g/l, prim. particle size 20-100 nm and ignition loss (2 h at 1000 deg. C) 0.5-5 wt.%. The prod. is useful in the prodn. of catalysts, ceramic materials and glasses |