Abstract: In the process of cement solidification of uranium tailings， uneven mixing often leads to low strength and high radon exhalation rate. In order to improve the properties of the solidified body， some other solidified materials such as granulated blast furnace slag， fly ash and quicklime were added into the solidified body. The saturated water content， mechanical strength and radon exhalation rate of uranium tailings cement solidified body were tested by adjusting the type， dosage and curing age of the admixtures in the solidified body. The experimental results showed that the compressive strength， tensile strength and shear strength of uranium tailings solidified body at 7 d， 14 d and 28 d ages are improved with the separate addition of granulated blast furnace slag， fly ash and quicklime. According to the mechanical properties， it is the best to maintain the solidified body with 25% granulated blast furnace slag at 28 d， with lowest saturated water content； The higher the content of radon， the lower the radon exhalation rate， but the best performance is obtained by the addition of 25% granulated blast furnace slag， followed by 25% fly ash. The research results can provide theoretical reference and decision-making basis for the decommissioning treatment of uranium tailings reservoir in the future.

Key words: Uranium tailings, Cement solidification, Mechanical property, Saturated water content, Radon exhalation rate