Michálek, B, Rapantova, N, Grmela, A & Hájek, A 2008, 'Quasi-Stagnant Mine Waters of Flooded Uranium Deposits as a Utilizable Uranium Source', in AB Fourie, M Tibbett, I Weiersbye & P Dye (eds), Mine Closure 2008: Proceedings of the Third International Seminar on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 587-598, https://doi.org/10.36487/ACG_repo/852_54
(https://papers.acg.uwa.edu.au/p/852_54_Michalek/)
Abstract: As spontaneous flooding of a decommissioned underground mine progresses, the concentrations of 
substances dissolved in mine waters increase. Once the hydrological regime has been stabilized, a distinct 
vertical stratification of mine waters develops, i.e. one that is especially governed by the minimization of 
mine water flow after the cessation of the hydraulic gradient induced earlier by actively draining the mine. 
These principles are evident in practically all ore and also coal mines (Rapantová and Grmela, 2004, 
Michálek et al., 2005). In the case of uranium mines, an increase in the concentration of uranium and other 
elements occurs in mine waters in deeper horizons of the former mine. In so-called quasi-stagnant waters, 
uranium concentrations are also markedly higher than in the upper part of the aquifer. Mine waters 
accumulated in deeper parts of former uranium mines thus represent, with regard to their considerable 
volumes and high concentrations of dissolved uranium, a significant secondary source of this raw material. 
Potential utilization of these mine waters as a secondary uranium source is, to a certain extent, analogous to 
the in situ leaching method of mining. Nevertheless, the process of transferring uranium into solution is not 
intensified by introducing acids into the rock environment, but instead the natural processes of dissolving 
uranium minerals in mine waters after their preceding oxidation in the stage of deposit exploitation are used.