Utilizing numerical analysis of unsaturated seepage to design tailings management strategy

Considerable amounts of data on the unsaturated flow parameters of uranium tailings have been published. These and other published data were used in numerical analyses to simulate drainage and evaporation of water from a layer of deposited tailings. The program UNSAT2 was used in the analyses. The effect of evaporation on a 3 m initally saturated profile with a static water table at the base was investigated. This paper presents a summary of the results obtained for coarse and fine tailings. One of the important questions in the design of a tailings management strategy is how long to wait between deposition cycles to obtain the maximum dewatering benefit from evaporation and drainage. This and other management considerations are described in the paper and it is discussed on the basis of the results obtained, how an unsaturated analysis can be used to design a management strategy for a specific set of material and climatic conditions