Experimental Research on Permeability and Effective Radon Reduction of Chemical Solidification of Uranium Tailings

Abstract

To be able to study the permeability coefficient and radon reduction effect of three materials before and after the solidification of uranium tailings. Firstly, uranium tailings, blast furnace slag, lime, fly ash and cement were selected as raw materials for the experiment. Three solidified materials were mixed with 7.5%, 10% and 12.5% of equal proportions of cement. The curing samples of nine kinds of solidified bodies were prepared after curing. Subsequently, the permeability coefficient was determined through the utilization of X-ray diffraction (XRD) and scanning electron microscopy (SEM). And cumulative radon concentrations in uranium tailings and samples were measured by RAD7. Thus, the radon exhalation rate of the original sample and the sample were determined. The experimental results show that the permeability coefficient of nine samples decreased with the quadratic function with the increase in the amount of curing agent. Microscopic scanning results show that there is a positive correlation among the radon exhalation rate, permeability coefficient and cementation degree. The best material for solidifying uranium tailings and radon insulation was blast furnace slag, followed by fly ash.