Improving the efficiency of oxide copper–cobalt ores flotation by combination of sulphidisers

Sulphidising flotation of oxide copper–cobalt ores with sodium hydrosulphide used as sulphidising agent is common practice in Katanga, Democratic Republic of Congo. aboratory investigations, sodium hydrosulphide proved to enhance flotation selectivity of copper and cobalt towards the gangue minerals, while ammonium sulphide emerged as a strong non-selective sulphidiser. Best results were recorded with a synergistic combination of sulphidisers; a 1/1 mixture of sodium hydrosulphide and ammonium sulphide.