The recovery of copper from reverberatory furnace slag utilizing flotation has been studied. The effective factors such as particle size, pH, the amount and type of collector and additives, and flotation time were examined. The effect of cooling rate on flotation behavior of the slag was also studied. For an air-cooled slag at optimized conditions, 72% of copper was recovered in one stage flotation and a 12.6%, copper concentrate was achieved. The best recovery efficiency was obtained when 30 g/t R407 was used as collector. It was found that recovery was also affected by the cooling rate of molten slag, and increased up to 84% when the slag was cooled slowly. (C) 2003 Elsevier Ltd. All rights reserved.