Patent ID: 6872402
Filing Date: 2005-03-29
Classification: A01N,A61K,A61L,A61Q,B01J,C01B,C01P,C08K,Y10S

Abstract:
1. A process for the preparation of pyrogenic silica doped with silver or silver oxide, comprising: vaporizing silicon tetrachloride; mixing vaporized silicon tetrachloride with hydrogen and air; preparing an aerosol using as a starting material a salt solution containing salts or salt mixtures of silver or silver metal in dissolved or suspended form or mixtures thereof, the aerosol being produced by atomization by means of a two-component nozzle; mixing the aerosol homogeneously with a gas mixture used for flame oxidation or flame hydrolysis and the vaporized silicon tetrachloride with hydrogen and air; feeding the mixture of the aerosol and gas and the vaporized silicon tetrachloride with hydrogen and air into a flame used for preparation of pyrogenic oxides by flame oxidation or flame hydrolysis; reacting the mixture of aerosol and gas and the vaporized silicon tetrachloride with hydrogen and air in the flame; and separating pyrogenic silica doped with silver or silver oxide from a resulting gas stream.