冻土带酸法地浸采铀的环境影响

ENVIRONMENTAL EFFECTS ON SULPHURIC ACID IN SITU URANIUM LEACHING IN THE PERMAFROST ZONE

俄罗斯联邦维季姆地区的希阿格达矿床目前正在进行地浸的中试。该矿床为底部河道砂岩型，它包含15000tU，矿石品位平均为0．05％U。矿化出现在位于约100m厚的冻土带之下的可渗透未固结的新第三纪河流沉积物中，基底岩石为古生代花岗岩。新第三纪—第四纪玄武岩覆盖着赋矿的沉积物。含矿层的渗透率为0．1—20m／d(平均为2—3m／d)。最新的理论和实验研究表明，主岩能抵抗化学作用的影响，同时还显示出在地浸之后有一种使环境自动复原的趋势。

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 15 000 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.