Abstract: Aiming at the difficulty in effectively removing strongly magnetic pyrrhotite (accounting for 57.15% of the to tal sulfur) from a high-sulfur magnetic iron concentrate in Inner Mongolia by magnetic and gravity separation methods,which adversely affects the quality of the iron concentrate,this study proposes a direct flotation process for deep desulfurization and synchronous sulfur recovery without further grinding.Based on process mineralogy studies,a closed-circuit flotation flowsheet consisting of one roughing,four cleaning,two scavenging,and middlings recirculation was adopted.Under the feed conditions of 64.82% TFe and 1.30% S,a high-quality iron concentrate with 65.27% TFe,0.16% S,and TFe recovery of 97.85% was ob tained,along with a sulfur concentrate grading 40.44% S with a sulfur recovery of 87.36%.This process achieves deep desul furization of iron concentrate and efficient recovery of sulfur resources without grinding,offering a new technical route for the ef ficient and clean utilization of similar high-sulfur iron concentrates.

Key words: iron concentrate by magnetic separation,pyrrhotite,physical separation,reverse flotation