Abstract: In order to accelerate the settlement of tailings，reduce the residual amount of flocculant in the supernatant and reduce the influence on flotation index，Daye Iron Mine concentrator carried out flocculant selection，stirring tank improvement and concentration equipment modification test. The test results show that after the selection of flocculant and a series of measures to improve，the amount of flocculant added in tailings concentration is reduced from 40 g/t to 15 g/t，and the recovery rate of copper concentrate is restored from 82.54% to 84.35%，which greatly reduces the influence of residual flocculant in return water on flotation index. The economic benefit is remarkable，and it has certain popularization and application value.

Key words: flocculant, dosage, backwater, recovery