Combustion of titanium tetrachloride with oxygen

Claim 1

A PROCESS FOR REDUCING THE TENDENCY OF TITANIUM DIOXIDE PIGMENT PARTICLES TO "PLATE" IN THE MANUFACTURE OF TITANIUM DIOXIDE BY REACTION OF TITANIUM TETRACHLORIDE WITH OXYGEN IN A COMBUSTION CHAMBER, WHICH CONSISTS IN CONTINUOUSLY REACTING TITANIUM TETRACHLORIDE WITH OXYGEN AT ABOUT 900* C. TO 1600* C. TO FORM TITANIUM DIOXIDE AND CHLORINE IN A COMBUSTION CHAMBER HAVING A REACTION ZONE AND A COOLING ZONE, AT LEAST ONE OF SAID ZONES BEING DEFINED BY A POROUS REFRACTORY MATERIAL, AND COMTINUOUSLY PASSING A GAS CONSISTING ONLY OF CARBON MONOXIDE TRANSVERSELY THROUGH SAID POROUS REFRACTORY MATERIAL INTO THE ZONE DEFINED BY SAID MATERIAL WHILE THE TEMPERATURE OF THE TITANIUM DIOXIDE THEREIN IS IN EXCESS OF ABOUT 600* C., THE AMOUNT OF SAID OXYGEN ADMITTED WITH SAID TITANIUM TETRACHLORIDE BEING SLIGHTLY IN EXCESS OF THAT REQUIRED FOR COMPLETE COMBUSTION OF SAID TITANIUM TETRACHLORIDE AND SAID CARBON MONOXIDE AND ANY OTHER METAL CHLORIDES; WHEREBY ANY FREE OXYGEN ADJACENT TO THE INNER SURFACE OF SAID POROUS REFRACTORY MATERIAL IS REDUCED TO CARBON DIOXIDE WITH WHICH TITANIUM TETRACHLORIDE CAN NOT COMBINE AND THEREBY THE SURFACE OF SAID REFRACTORY IS MAINTAINED SUBSTANTIALLY FREE FROM TITANIUM DIOXIDE INCRUSTATIONS.