Abstract: In order to compare the difference between flocculation settlement filling and natural settlement filling of a fine copper tailings，the industrial practice of natural settlement filling and flocculation settlement filling was carried out based on the experiments of natural settlement and flocculation settlement. The results showed that in the natural settlement，the sedimentation rate decreases and the bottom flow concentration increases with the increase of slurry concentration，and the maximum bottom flow concentration reached 68%. The flocculant could significantly improve the settlement velocity of whole tailings. When the concentration of tailings slurry was 20%，adding 20 g/t PAM could increase the settlement velocity of whole tailings by 4.66 times，the bottom flow concentration decreased by six percentage points. With the increase of feeding concentration，the sedimentation velocity decreases and the bottom flow concentration increases，and the bottom flow concentration reaches about 55%. The effective core extraction rate，integrity and available samples of the natural settlement backfill were not as good as those of the flocculated settlement backfill，and the strength of effective samples of the backfill by the two processes all meet the strength requirements of the backfill.

Key words: whole tailings, natural sedimentation, flocculation settlement, sedimentation rate, strength of backfill