Abstract:The selection of cemented paste backfill(CPB) materials and the study on strength characteristics are helpful to solve the problems of mining safety, environmental damage and backfilling cost. In order to reuse the solid waste residue in smelting and cement it with tailings and apply it to backfill mine goafs, tin smelting slag-total tailings were selected as the CPB material, and the characteristics of different tin smelting slag content, mass concentration, cement-to-tailings ratio, and unconfined compressive strength(UCS) of CPB specimens under different curing periods were studied by indoor experiment, stepwise regression analysis and two-factor interaction analysis. The experimental results show that the other conditions are fixed, and the UCS of the CPB increases with the increase of curing ageperiods. Under the conditions of mass concentration and cement-to-tailings ratio, the UCS of the CPB decreased with the increase of tin smelting slag content. During the 28d curing period, the UCS of cement-to-tailings ratio 1:4 with a mass concentration 78% was 7.04MPa, which is 25.9% lower than that of smelting slag without tin smelting slag of 9.5MPa. Low cement-to-tailings ratio, low mass concentration, and the addition of the same amount of tin smelting slag have little effect on the UCS of the fCPB. Through stepwise regression analysis, the UCS regression equation of the CPB and the ranking of factors affecting the UCS of CPB were obtained. The interaction between the smelting slag content and the cement-to-tailings ratio has a significant effect on the strength of the CPB.