Abstract: In order to make th backfill body meet the required strength to ensure safe mining，ground supporting and environmental conservation，the cemented powder was used to replace the traditional Portland cement，which is known for poor strength at early age and high costs in backfill process.A series of mixing proportion experiments were conducted with full tailings from an iron mine in Jilin.The two types of binder，the cemented powder and the ordinary Portland cement，were used respectively with different dosages to test the 28 d uniaxial compressive strength (UCS) of their backfill samples.The results showed that the 28 d UCSs of the samples made from the cemented powder were observed to be 3~5 times of that of samples made from ordinary Portland cement.With each growth of 3% in binder dosage，the 28 d UCSs of the samples made from the cemented powder，which is proportional to the binder dosage and mass concentration，had an increase of 4~9 MPa.Therefore，a better mechanical property can be gained by slightly decreasing binder dosage and increasing slurry concentration，which consequently will contribute to lower producing costs and improving the economic benefits.

Key words: Cemented powder, Uniaxial compressive strength, Cemented backfill body, Economic benefit