Abstract: In order to improve the fluidity, sedimentation and strength of the filling slurry for Baixi⁃ angshan iron ore, the micro-fine particle tailings graded cementation filling test was carried out. The results showed that: ① the graded tailings with a yield of 35% and 50% belong to coarse-grained tailings, and can be used for filling slurry preparation directly, among which the graded tailings with a yield of 50% is the best. ② With the increase of the graded yield of tailings, bleeding rate and sedimentation rate showed a downward trend. And it appeared greater impact on the sedimentation rate when the yield is more than 50%, and vice versa is smaller. ③ The graded tailings slurry with a yield of 50% has good fluidity and meets the requirements of self-flowing transportation. ④ The strength of the graded tailings filling body is higher than that of the whole tailings cementation test block, and the highest is reached when the yield is 50%, and the total tailings is the smallest.

Key words: high concentration cementation filling, fine-grained tailing sand, classification with cy? clone, compressive strength, liquidity