GB677690A - Improvements in the production of ferric chloride - Google Patents

Abstract

A fluidized bed of a ferric-oxide-containing ore is treated with hydrochloric acid gas to produce ferric chloride at one or more temperatures, the final temperature being high enough to cause the ferric chloride to volatilize and leave the reaction vessel with excess hydrochloric acid gas. Ores which contain hydrated ferric oxide are preferably first heated at 300-500 DEG C to remove combined water; carbonate and magnetite ores should be roasted under <PICT:0677690/III/1> oxidising conditions at 400-800 DEG C. As shown, the ore particles varying in size from 1/10 inch to those just passing a 200 mesh per linear inch sieve pass from hopper 8 to refractory lined mild steel vessel 4 divided into two chambers 6, 7 by an imperforate diaphragm 14-16, 19-20 supporting the ore beds, the fluidized particles passing from bed to bed through pipes 21-24. Hydrochloride acid gas at 1-5 p.s.i.g. is led into the upper chamber through pipe 26 at 100-200 DEG C. Steam, excess acid and a very small quantity of the ferric chloride formed escape through pipe 28. The partially chloridized ore entering chamber 7 is fluidized and fully chloridized by hydrochloric acid gas at 200-700 DEG C. The chloride vapours, excess hydrochloric acid and steam escape through pipe 33, and may be subsequently treated with steam for the production of ferric oxide as disclosed in Specification 677,645. The methods disclosed in that Specification for the treatment and return to the chloridizing chambers of the hydrochloric acid liberated may also be employed. Two to six times the theoretical amount of hydrochloric acid is employed for the chloridization. Air, or small quantities of chlorine may be present in the reacting gases. Specification 677,691 also is referred to.