Abstract: Based on the recent years' flotation practice of AnSteel Qidashan Iron Mine, the causes for the fluctuation of flotation indexes due to the high return amount of the primary scavenging concentrate are analyzed by investigating the site flotation system capacity or flotation throughput, flotation time, return amount of the primary scavenging concentrate, and product size composition.

Key words: Reverse flotation, Flotation size, Primary scavenging concentrate