Abstract: Based on the present situation of the application of finegrained tailings,combined with the big hidden danger of dam construction and storage of fine-grained tailings and the long-term goal of the 14th Five-year Plan,the comprehensive utilization of ultra-fine metal tailings and its problems and countermeasures in the application of backfill materials are discussed.In view of the low utilization rate of fine tailings in building materials,this paper expounds the methods of applying tailings to ecological cementitious materials,cementbased materials and concrete admixtures.In view of the problems of low thickening concentration of the fine-grained tailings,poor workability and mechanical of backfilling materials,the dense synergist,anti-bleeding material and crystal nuclear material are put forward,and the improvement effect of water reducing agent and microbeads on transport performance was studied.Meanwhile,their action mechanism is expounded.The deficiency in the research of metal tailings and the countermeasures of comprehensive utilization in the future are discussed.It provides technical and theoretical support for comprehensive utilization of fine-grained metal tailings and solving the problems existing in mine backfilling.

Key words: ultra-fine tailing, building materials, backfill materials, workability, mechanical properties