GB611906A - Improvements in or relating to separation of iron ores - Google Patents

Abstract

In a pretreatment method for concentrating iron ores the pulp of a size suitable for froth flotation is subjected to two conditioning operations, the first with an anionic promoter of the fatty acid type, and the second with a sufficient amount of an alkaline earth metal oxide to convert the anionic reagent to an insoluble soap and produce an alkaline pH, the conditioned pulp being then subjected to a froth flotation process. The ore is ground if necessary, and conditioned with an anionic promoter, e.g., a fatty acid, and then with the oxide of an alkaline earth metal, preferably in its hydrated form, e.g. lime which also has a depressant effect on the iron. The pulp is then subjected to froth flotation, a frother may be added, and the silica floated off. The iron concentrate is then cleaned and deslimed and treated by a further separation process which may comprise a further anionic conditioning and flotation or a gravity concentration. A final iron concentrate suitable for blast furnace feed is obtained. Specification 612,107 is referred to. The Specification as open to inspection under Sect. 91 shows the flow sheet as including a final cationic flotation. This subject-matter does not appear in the Specification as accepted.