Геохімія техногенезу (Dec 2021)

MOBILITY OF URANIUM AND SATELLITE ELEMENTS IN URANUS ORBIT ALBITITES

  • Yu. Fomin,
  • Yu. Demikhov,
  • V. Verkhovtsev,
  • N. Borisova

DOI
https://doi.org/10.15407/geotech2021.33.042
Journal volume & issue
Vol. 5, no. 33
pp. 42 – 49

Abstract

Read online

The work considers the mobility series, the features of the hydrogenous mobilization of uranium and elements-satellites of the material complexes of the mineral-forming systems in the weathering crust of uranium-ore albitites of the Ukrainian Shield. Chemical elements that are companions of uranium can enter both concentrating minerals and ordinary rock-forming minerals containing these elements. The first include native metals – gold, bismuth, lead; sulfides: Cu, Zn, Pb, Ni, Co; monazite, zircon. Examples of the second group of the minerals are feldspars with rubidium, strontium, lead; egirin, ribecite, sphen with vanadium. Samples of rocks to calculate the average content of chemical elements and their mobility were formed taking into account the composition of the rocks and the degree of weathering. Titanium, the least mobile element, was used as a conditionally stable element, for which, in fact, all calculations were performed. Approbation of the method at all levels, including the root base, disintegration zone, hydromica-kaolin and kaolin weathering crust, soil layer (B- and A-horizons) and scattering fluxes, showed quite satisfactory results. Wastes from the industrial development of uranium deposits of albite formation, that are (and will be) stored, being essentially a crushed mineral concentrate enriched in uranium and heavy metals, which in conditions of hypergenic processes conducive to oxidation and decomposition, undoubtedly pose a potential threat of environmental pollution . A significant part of uranium and related elements in all blocks of rocks that are subject to operational excavation can be classified as “mobile”, ie has a fairly high migration capacity. This form can be a source of contamination of groundwater and surface water, and soils. Calculations show that uranium in all areas of the weathering crust behaves as a mobile element, prone to scattering. The share of uranium removed from different zones is 25-42% (0.11-0.19 g/t), which in absolute terms is the maximum in the kaolin zone. The main role in the migration of radionuclides is played by water erosion under the influence of precipitation. Therefore, to reduce hydrogen pollution, it is necessary to provide underlayment of dumps with clay and carbonate rocks. To limit the impact of wind erosion, it is necessary to fill the dumps with a layer of inert soil.

Keywords