Patent ID: 7753212

Claim:
A continuous flotation process for iron-containing sulphides in ores and concentrates of ores includes the following steps: (a) adjusting the pH of an aqueous pulp of the ores or concentrates of the ores to be in the range of 6.5-8.5; (b) adding a reducing agent to modify an iron hydroxide film on the surface of iron-containing sulphides in the ores or ore concentrates to enable adsorption of a collector onto iron-containing sulphides; (c) adding the collector to the pulp prior to, during, or after adding the reducing agent in step (b); (d) aerating the pulp to increase the pulp potential to a level sufficient to allow collector adsorption onto the iron-containing sulphides; (e) bubbling gas through the pulp and thereby subjecting the aqueous pulp to froth flotation to produce a froth containing said sulphide containing minerals; and (f) adding a complexant to the pulp prior to or during step (b) to minimize iron hydroxide reforming a film on the iron-containing sulphides.