GB457605A - A process for the separation of iron from iron-containing substances - Google Patents

Abstract

In a process for the separation of iron from bauxite, the bauxite mixed with solid fuel is subjected in a rotary tubular furnace at 900--1400 DEG C. to a reducing process such that only the iron is reduced, the sponge iron so produced being converted into lumps by the admission of oxidizing gases, the alumina remaining in the slag. Alkalies or sulphiding agents such as soda or gypsum may be added during the process, the final slag then being lixiviated to enable the alumina to be separated and the slag associated with the iron lumps being also similarly treated to obtain the alumina contained therein. Specification 402,743, [Group II], is referred to.ALSO:In a process for the separation of iron from ores containing, in addition to iron, metals which are more difficult to reduce than the iron, the ores, mixed with solid fuels, are subjected in a rotary tubular furnace at 900-1400 DEG C. to a reducing process such that only the iron is reduced, the sponge iron so produced being converted into lumps, the other metals remaining in the slag, by the admission of oxidizing gases. The process may be applied to the treatment of bauxite to produce pure alumina. The oxide of the metals present other than iron, such as manganese chromium, tungsten and vanadium may be decomposed simultaneously with the iron by the addition of alkalies or sulphiding agents such as soda or gypsum. When these substances are added during the treatment of bauxite the final slag may be lixiviated to enable the alumina to be separated and the iron lumps and slag containing alumina may be similarly treated to obtain the alumina contained in the slag. Specification 402,743 is referred to.