Environmental effects on sulphuric acid in situ uranium leaching in the permafrost zone

An in situ leaching mid-test program is being carried out at the Khiaga deposit in Vitim Region, Russian Federation. the deposit is of a basal-channel sandstone-type containing 15000 t u with an ore grade of 0.05% U on average. Uranium mineralization occurs in the Late Tertiary unconsolidated fluvial sediments. Beneath a frozen zone of about 100 m thick, the permeability of the ore-bearing horizons are from 0.1 m/d to 20 m/d (2-3 m/d on average). As shown by the modern theory and the experimental investigation, the host rocks are resistant to effect of chemical reactions and appears a tendency of self-rehabilitation of the environment after the in situ leaching mining operation. (author)