Abstract: In order to reduce the sulfur content of iron concentrate from 2%~4% to less than 1%，a mine in Anhui carried out relevant experimental research on the basis of ore properties.The results show that it is difficult to reduce the sulfur content of iron concentrate to less than 1% without activation of sulfur minerals by copper-sulfur mixed flotation process. Although the sulfur content of iron concentrate can be re⁃ duced to 0.92% by adding CuSO4 activated sulfur minerals，it also leads to the difficulty of separation of copper and sulfur，which affects the copper separation index.The iron concentrate with sulfur content less than 1% can be obtained by using on-site copper tailings resulfurization scheme and on-site iron concen⁃ trate direct reverse flotation desulfurization scheme.From the aspects of process transformation and mainte⁃ nance cost，it is recommended to adopt the on-site iron concentrate reverse flotation desulfurization scheme.

Key words: copper and iron ore, pyrrhotite, preferential flotation, bulk flotation, desulfurization re? verse flotation