GB872865A - Improvements relating to chlorination processes - Google Patents

Abstract

In the chlorination of a ferro titaniferous material in a static or fluidized bed by passing chlorine upwardly into a hot bed containing the material and a reducing agent, the hot reaction products are quenched by the injection of a vaporisable or gaseous coolant into the hot reaction products, in an amount such that the reaction product gas temperature is reduced from between 900 and 1000 to below 700 DEG C. and preferably from 300 to 400 DEG C. Chlorides of impurities such as zirconium, aluminium, magnesium, manganese, nobium and silicon and in particular ferrous chloride condense to the solid phase and are carried out in suspension with the gaseous reaction products. Chilling is preferably effected by spraying the gases with a liquid coolant such <PICT:0872865/III/1> as titanium silicon, or tin tetrachloride or other liquid halides which may contain a sublimable solid, such as ferric chloride, in suspension. Alternatively or additionally cool gases such as carbon dioxide and carbon monoxide, which may be recycled from a later stage in the process, may be employed as coolant. As shown in the Figure, a shaft furnace contains a bed of titaniferous ore and carbon maintained at 800-1000 DEG C. Temperature control in the bed may be effected by withdrawing a portion of the bed cooling and recycling, cooling by the injection of an inert gas or a vaporizable liquid, or heating by the injection of an oxygen-containing gas which burns part of the carbon content of the bed. Chlorine is injected through a pipe 4 and distributed by block 3 and the hot gaseous reaction products are exposed to liquid sprays 11, preferably of titanium tetrachloride which vaporize before they reach the walls 12 or the top of the fluidized bed. Reaction products containing contaminant chlorides in finely divided solid form leave through line 13 at 300-400 DEG C. and are subjected to conventional cooling and collecting operations. Specifications 724,193, 762,583, 792,151, 794,666 and 813,489 are referred to.