Abstract
Uranium tailings are generated as solid and liquid wastes in uranium mining/milling operations. Since most of the uranium deposits in the world have low grades, millions of tonnes of such wastes are produced annually. Often, the uranium tailings are locally disposed of, using sites with suitable conditions to construct tailings basins. The main concern during the operation of a disposal site is the presence of radium in the liquid phase which overflows from dewatered tailings. This barium is precipitated by adding proper chemical reagent. The potential environmental hazards of uranium tailings arise when the disposal site is abandoned after the decommissioning of the uranium mill. Huge amounts of solid waste as small particles of depleted ore remain in place. Top soils are usually for soil stabilization and for controlling radon emissions. Hence water infiltration through uranium tailings presents a potential hazard to underground aquifers. Water plays a dual role by triggering a sequence of reactions and by carrying contaminants away from the wastes sites. The situation is more serious in a country like Canada, where the precipitation rate is higher than the evaporation rate and the water table is about one metre beneath the ground surface. For permanent disposal of uranium tailings, either the hazardous constituents of these wastes have to be isolated from the percolating water, or the subsoils must have acceptable sealing and sorptive characteristics. The first approach is effected by blending proper solidifying reagents with the tailings in order to totally block them from the leaching effects of aggressive pore water. Solid waste treatment may prove costly in additive usage and the blending operation. The leaching of toxic constituents, however, becomes effective so long as the tailings are in a loose form. This is because of the acid-generating properties of the pyrite, a substantial constituent (up to 8% wt) of the tailings. Two types of contaminants tend to leave the solid and migrate to the pore water. These are the heavy metals and the radioactive elements, both of which are hazardous for their toxicity and persistence. The sorptive and neutralizing capacities of the underlying soils have to be carefully examined and measures have to be taken to stop the progression of acidic interstitial water. This paper focuses on three aspects of crucial importance to the permanent disposal of uranium tailings. These are: leaching in uranium tailings, sorption on natural geological barriers, and radium immobilization.
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Al-Hashimi, A., Evans, G. J. and Cox, B.: 1994a, Contaminant Mobility in Acid-Generating Wastes/Subsoil Systems, Environmental Science and Health, Part A — Environmental Science and Engineering, A29 (4), pp. 713–728.
Al-Hashimi, A., Evans, G. J. and Cox, B.: 1994b, Intern. J. Environmental Studies, 46, 59–68.
Al-Hashimi, A., Evans, G. J. and Cox, B.: 1993, ‘Evaluation of Geochemical Barriers for Confinement of Hazardous Wastes’, Research Report, University of Toronto, Department of Chemical Engineering and Applied Chemistry.
Al-Hashimi, A., Evans, G. J. and Cox, B.: 1993b, ‘Sealing and Retentive Characteristics of Ottawa Clay’, Research Report, University of Toronto, Department of Chemical Engineering and Applied Chemistry.
Al-Hashimi, A.: 1992, Uranium Tailings Disposal: Review of Current Technology, Intern. J. Environmental Studies, 42, 53–62.
Al-Hashimi, A.: 1989, ‘Raffinate Treatment for a Pilot Uranium Mill’, in Chalkley, M. E. et al. (eds.), Tailings and Effluent Management (Vol. 14), Proceedings of International Symposium Sponsored by The Metallurgical Society of the Canadian Institute of Mining and Metallurgy, Nova Scotia, Halifax, Canada, 20–24 August 1989, Pergamon Press, pp. 305–311.
Alter, I., Flora, E., Hadare, Z., Peri, G. and Trocher, J. (1958), ‘Selective Leaching of Uranium from Phosphate Rock by Dilute Mineral Acids, Proceedings of the Second International Conference on the Peaceful Uses of Atomic Energy’, Vol. 3, Geneva, 1–13 September 1958.
Auck, Y. T. and Wads Worth, M. E.: 1973, ‘Physical and Chemical Factors in Copper Dump Leaching’, Proceedings of International Symposium on Hydrometallurgy.
Bourg, A. C. M.: 1988, ‘Metals in Aquatic and Terrestrial Systems: Sorption, Speciation, and Mobilization’, in Salomons, W. and U. Forstner (eds.), Chemistry and Biology of Solid Waste, Springer-VerlagBerlin Heidelberg, pp. 1–32.
Bruhl, H. et al, ‘Influence of Micro Environments and Microorganisms on the Transport Properties of Redox-Sensitive Elements’, in Abrajano, T, Jr. and L. H. Johnson (eds.), Scientific Basis for Nuclear Waste Management XIV, Vol. 212, Materials Research Society, Pittsburgh, Pennsylvania, pp. 593–599.
Civin, V. and Prochozka, J. 1966, ‘Processing Uranium Bearing Materials Containing Coal and Loam’, Proceedings of a Panel on Processing of Low Grade Uranium Ores, IAEA, Vienna, 27 June–1 July 1966.
Constable, T W. and Snodgrass, W. J.: 1987, ‘Leachability of Radioactive Constituents from Uranium Tailings’, Report ESP 3/MM/2, Environment Canada.
Environment Canada: 1987, ‘Conservation & Protection’, Proceedings of Acid Mine Drainage Seminar/Workshop, Environment Canada, 23–26 March 1987.
Erickson, K. L.: 1979, ‘Radionuclide Sorption Studies of Abyssal Red Clays’, in Dried, S. (ed.), Radioactive Waste in Geologic Storage, Symposium Sponsored by the Division of Nuclear Chemistry and Technology at the 176th Meeting of the American Chemical Society, Miami Beach, Florida, 11–13 September 1978, American Chemical Society, Washington, D. C. 267–290.
Fried, S. (ed.): 1979, Radioactive Waste in Geologic Storage, Symposium Sponsored by the Division of Nuclear Chemistry and Technology at the 176th Meeting of the American Chemical Society, Miami Beach, Florida, 11–13 September 1978, American Chemical Society, Washington, D.C.
Hamel, P. and Howieson, J.: 1982, ‘A Summary of the Canadian Uranium Mill Tailings Situation’, in Management of Wastes from Uranium Mining and Milling, Proceedings of Symposium Jointly Organized by IAEA and NEA (OECD), 10–14 May 1982, IAEA, Vienna, pp. 21–39.
Jayaram, K. M. V., Dwivedy, K. K., Deshpande A. S. and Ramachar, T, M.: 1975, Studies on the Recovery of Uranium from Low Grade Ores in India, Proceedings of an Advisory Group Meeting on Uranium Ore Processing, IAEA, Washington D.C., 24:26 November 1975.
Kalin, M. and van Everdingen, R. O.: 1989, ‘Ecological Engeneering Measures Developed for Acid Generating Waste-The Close-out of a Decant Pond’, in Chalkley, M. E. et al. (eds.), Tailings and Effluent Management (Vol. 14), Proceedings of International Symposium Sponsored by The Metallurgical Society of the Canadian Institute of Mining and Metallurgy, Nova Scotia, Halifax, Canada, 20–24 August 1989, Pergamon Press, pp. 195–204.
Kelly, B. C. and Tuovinen, O. H.: 1988, ‘Microbiological Oxidation of Minerals in Mine Tailings’, in Salomons, W. and U. Forstner (eds.), Chemistry and Biology of Solid Waste, Springer-Verlag Berlin Heidelberg.
Kharbanda, J. L., Panicker, P. K. and Balu, K.: 1982, ‘A Study on the Development of a Process for Treating Uranium Mill Effluents’, in Proceedings of a Symposium on Management of Wastes from Uranium Mining and Milling, IAEA-SM-269/49, Vienna, pp. 325–337.
Longmire, P. A. et al.: 1991, ‘Application of Sphagnum Peat, Calcium Carbonate, and Hydrated Lime for Immobilizing Uranium Tailings’, in Abrajano, T, Jr. and L. H. Johnson (eds.), Scientific Basis for Nuclear Waste Management XIV Vol. 212, Materials Research Society, Pittsburgh, Pennsylvania, pp. 623–631.
Merritt, R. C.: 1971, The Extractive Metallurgy of Uranium, Colorado School of Mines Research.
Matthess, G. et al.: 1979, Tritium Tracing in Hydrogeological Studies Using Model Lysimeters, Isotope Hydrology, Proceedings of a Symposium, Neuherberg, 19–23 June 1978, IAEA, Vienna, pp. 769–785.
Ohnuki, T.: 1991, ‘Characteristic of Migration of 137Sr and 137Cs in Alkaline Solution Through Sandy Soil’, in Abrajano, T., Jr. and L. H. Johnson (eds.), Scientific Basis for Nuclear Waste Management XIV, Vol. 212, Materials Research Society, Pittsburgh, Pennsylvania, pp. 609–616.
Peterson, A.: 1966, Status Report from Sweden, Proceedings of a Panel on Processing of Low Grade Uranium Ores, Vienna, 27 June–1 July 1966.
Stewart, J. R.: 1966, Uranium Research in Australia, ibid.
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Al-Hashimi, A., Evans, G.J. & Cox, B. Aspects of the permanent storage of uranium tailings. Water Air Soil Pollut 88, 83–92 (1996). https://doi.org/10.1007/BF00157414
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DOI: https://doi.org/10.1007/BF00157414