Abstract: The present invention relates generally to a process for flotation of sulphide minerals where a flotation pulp is separated into a coarse stream and a fine stream, preferably containing particles coarser than about 30 micron and particles finer than about 30 micron, respectively. Typically, alkali and depressant are added to the coarse flotation stream only and acid and activator are added to the fine flotation stream only. During flotation of the fine stream, acid and/or activator may be added at the conditioning, cleaning, re-cleaning, cleaner-scavenging or third cleaning stage. During flotation of the coarse stream, alkali and/or depressant may be added at the conditioning or cleaning stage.

Abstract: The present invention relates generally to a process for flotation of sulphide minerals where a flotation pulp is separated into a coarse stream and a fine stream, preferably containing particles coarser than about 30 micron and particles finer than about 30 micron, respectively. Typically, alkali and depressant are added to the coarse flotation stream only and acid and activator are added to the fine flotation stream only. During flotation of the fine stream, acid and/or activator may be added at the conditioning, cleaning, re-cleaning, cleaner-scavenging or third cleaning stage. During flotation of the coarse stream, alkali and/or depressant may be added at the conditioning or cleaning stage.

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.