Abstract: The gold content in slime after washing, classification and concentration at the crushing stage in a Shandong gold processing plant is equivalent to that in raw ores. But its extremely fine crushing made the flotation performance worse in flotation system. Therefore, the flotation tests were carried out by adopting the flotation machine and the cyclonic-static micro-bubble flotation column separately. The results showed that with the flotation machine, qualified concentrate with average gold grade of 90.73 g/t and average gold recovery of 77.91% was obtained from the slime by the process of one-roughing, one-cleaning and two-scavenging; With the cyclonic-static micro-bubble flotation column, qualified concentrate with average gold grade of 98.43 g/t and average gold recovery of 87.93% was achieved by the process of one-roughing and one-cleaning. The cyclonic-static micro-bubble flotation column can not only realize a better separation index, but reduce two-scavenging works than the flotation machine.

Key words: Gold ore, Slime flotation, Cyclonic-static micro-bubble flotation column, Flotation machine