Oxidised zinc ores are traditionally floated with fatty amines as collector. The effectiveness of this reagent requires a pre-sulphidisation stage with sodium sulphide in conjunction with soda ash. Especially in the case of calamine ores, a dispersing agent becomes necessary. The collector must be emulsified with a fuel oil and the frother. This flotation system is characterised by the use of very large amounts of reagents. The proportion of each reagent in the reagents system must be carefully optimised. (C) 2004 Elsevier Ltd. All rights reserved.