Three methods of improving zinc concentrate grade in the flotation of two m
assive sulphide ores were investigated. These methods involve the use of ox
ygen gas conditioning, copper specific collectors or selective polymeric de
pressants. The results obtained demonstrated that all three methods provide
high zinc concentrate grades through depression of iron sulphide minerals.
It was also found that by combining two methods, reagent consumption could
be decreased without decreasing overall performance. (C) 2001 Elsevier Sci
ence Ltd. All rights reserved.