Abstract: In order to better utilize tailings to fill underground mined-out area, with the tailing of Nanjing Lead-zinc-silver Mine as material, the influence of tailing concentration on the initial fluidity and strength of solidified tailing was studied.The results show that the initial fluidity of solidified tailing decreases with the increase of tailing concentration in quadratic parabola relationship, and the strength increases linearly with the increase of tailing concentration.Under the prerequisite of satisfying the pumping capacity of tailing, the possible highest tailing concentration can effectively reduce the cement consumption so as to decrease the solidifying cost.

Key words: Tailing, Solidification, Concentration, Fluidity, Strength