Abstract: A process for floating fine particles containing metal values of an iron-bearing sulphide mineral ore including the steps of conditioning the aqueous pulp of ore at a pH of between about 7 and about 10 with a reducing agent which is preferably oxy-sulphur compound which dissociates to form oxy-sulphur ions having the general formula: SnOyz− where n is greater than 1; y is greater than 2; and z is the valance of the ion. A suitable collector is then added to the conditioned aqueous pulp to further condition the pulp and the pulp potential of the pulp raised to a sufficient level for the collector to adsorb onto the sulphide mineral ore. Gas is then bubbled through the aqueous pulp to subject the pulp to froth flotation. The froth from the flotation process is recovered to produce a concentrate of fine sulphide mineral and other metal values.