Patent ID: 6852306
Filing Date: 2005-02-08
Classification: B82Y,C01G,C01P,C09C

Abstract:
1. A method to determine a point of introduction of silicon tetrachioride into a plug flow reactor for the oxidation of a mixture of titanium tetrachloride and aluminum trichloride in a gas containing at least a stoichiometric amount of oxygen to produce titanium dioxide rutile particle having a thin, uniform and complete layer of surface oxides comprising a mixture of amorphous aluminum oxide and silicon dioxide, the steps of the method comprising; (a) reacting titanium tetrachloride vapor and aluminum chloride and at least a stoichiometric amount of oxygen in a plug flow reactor to form a product stream containing titanium dioxide particles; (b) determining the temperature in the reactor where not more than 3% of the titanium tetrachloride remains unreacted using U TiCl4 =unreacted TiCl4(%) β=O2(%) in excess of the stiochiometric amount φ=feed Cl2 mole ratio (mol/mol TiCl4), and T=temperature (C); and c) introducing the silicon tetrachioride into the reactor where the temperature is equal to or less than the temperature determined in step (b).