PURPOSE: To efficiently remove a harmful gas stuck to a solid particle by intro ducing the solid granular particle powder containing the harmful component gas into a solid-gas contact vessel, allowing to contact countercurrently with an inert gas stream to release the harmful component gas and next, introducing into a stirring fluidized bed to remove the residual harmful component gas.
CONSTITUTION: At the time of producing a titanium dioxide pigment by the gas phase oxidation reaction of titanium tetrachloride, a reaction gas A is separated into the solid particle and a by-product gas B in a solid-gas separation device 1. The solid-gas contact vessel 2 is connected to the bottom of the separation device 1 and chlorine gas is roughly replaced by allowing the solid particle containing a chlorine gas component to contact countercurrently with the inert gas flow. And in the case that the oxidation reaction is executed by a high pressure system, the reaction system is isolated by a pressure reducing vessel and is exhausted up to the atmospheric pressure. After that, the solid particle is fluidized with a fluidizing gas D in the stirring fluidized bed to reduce the concn. of chlorine gas. After that, the solid particle powder is supplied to a pressure roll type compactor 11 and is taken out as an intermediate product.
ISHIMARU MASAO
WATANABE MASAHIRO
