process for the purification of højdisperse oxides, oxidblandinger or blandingsoxider.

摘要

PICT:1003957/C1/1 A process for removing halogens and/or halogen hydride from highly dispersed oxides, oxide mixtures or mixed oxides of Si, Al, Ti and/or Zr, which have been obtained by vapour-phase hydrolysis or oxidation of halides of these elements, and if desired, in the presence of an inert gas, at elevated temperatures, comprises introducing the said oxides, oxide mixtures or mixed oxides into a chamber in parallel with a stream of steam, which may be diluted with an inert gas, so as to form a turbulent suspension of oxides in the steam, which suspension is heated at 450-1000 DEG C., and removing the treated oxides and the resultant gases containing impurities from the end of the treatment chamber opposite to the end at which they were introduced. As shown, the process may be carried out in an apparatus comprising furnace 1, having electrical heating rods 6 arranged within. Air is passed through heater 9, together with water from pipe 10, and the hot air-stream mixture entrains oxides from vessels 12 prior to entry into furnace. The furnace may be equipped with an additional gas-heating device 7. The treated oxides and waste gases are discharged via outlets 3 and 4 respectively.