二连盆地乔尔古铀矿区铀赋存状态及铀矿石工艺矿物学研究

STUDY ON URANIUM OCCURRENCE STATE AND URANIUM ORE PROCESS MINERALOGY IN QIAOERGU URANIUM DEPOSIT OF ERLIAN BASIN

可地浸砂岩型铀矿床中铀赋存状态及铀矿物空间嵌布特征会影响地浸时浸出工艺的选择及溶浸液的优化,研究矿石中铀赋存状态及铀矿物工艺参数对于提高矿床的铀浸出效率具有重要意义。本研究采集了二连盆地乔尔古铀矿区矿石样品,通过扫描电镜、电子探针及综合矿物分析仪(TIMA)等方法,分析铀赋存状态及铀矿物粒度、解离度、连生矿物等工艺矿物学参数。结果表明:(1)乔尔古铀矿区矿石中铀的存在形式主要为铀矿物、含铀矿物和吸附态铀。铀矿物主要为沥青铀矿和少量的铀石。(2)铀矿物粒度较小且变化范围较大,铀石粒径最大可达30~35μm,沥青铀矿粒径最大可达60~65μm;多数铀矿物的粒径小于20μm,其中铀矿物粒径在5~10μm的数量是占比最多(铀石和沥青铀矿分别占总颗粒数量的37.88%和27.78%)。(3)铀矿物解离度较低,解离度小于10%的铀石和沥青铀矿的占比分别为99.72%和91.84%。铀的赋存状态表明乔尔古铀矿区适宜地浸,但实际浸出时铀浸出率可能会受到铀矿物粒度及解离度特征的严重制约,使得经济效益受到较大影响。本研究有效查明了乔尔古铀矿区铀赋存状态以及铀矿物工艺参数,有助于研究制定适合该矿区的地浸采铀方式及浸出剂的选择,对推动乔尔古铀矿区以及二连盆地其他铀矿床地浸开采技术的完善与创新具有重要的理论和现实意义。

The occurrence state of uranium and the spatial distribution characteristics of uranium minerals in in-situ leachable sandstone-type uranium deposits play apivotal role in determining the appropriate leaching process and optimizing leaching solutions.Therefore,studying the occurrence state of uranium in raw ore and the process parameters of uranium minerals is essential for enhancing uranium leaching efficiency.In this study,samples from the Qiaoergu uranium mining area in the Erlian Basin underwent analysis using scanning electron microscopy(SEM),electron probe microanalysis(EPMA),and TESCAN integrated mineralogy analyzer(TIMA).The goal was to determine the occurrence state of uranium and process mineralogical parameters such as uranium mineral particle size,dissociation degree,and associated minerals.Results indicate that the primary forms of uranium in the Qiaoergu uranium deposit are independent uranium minerals,uranium-containing minerals,and adsorbed uranium.The predominant uranium minerals identified are pitchblende and a small amount of coffinite.Uranium mineral particle size generally exhibits a small size with considerable variation.Coffinite can reach a maximum particle size of 30-35μm,while pitchblende can reach up to 60-65μm.Most uranium minerals have a particle size less than 20microns,with the highest proportion(37.88%and 27.78%of the total number of particles)falling within the 5-10μm range.Quartz,potassium feldspar,and pyrite are closely associated with uranium minerals.The dissociation degree of uranium minerals is low,with coffinite and pitchblende having a dissociation degree less than 10%(99.72%and 91.84%,respectively).While the occurrence state of uranium suggests the suitability of the Qiaoergu uranium mining area for in-situ leaching,the actual leaching rate is significantly constrained by uranium mineral particle size and dissociation degree characteristics,thereby influencing economic benefits.Understanding the occurrence state of uranium and process parameters in the Qiaoergu uranium mining area offers valuable insights for studying and formulating the selection of in-situ leaching methods and leaching agents suitable for this specific mine area.This research holds both theoretical and practical significance in advancing the improvement and innovation of in-situ leaching mining technology in the Qiaoergu uranium mining area and other uranium deposits in the Erlian Basin.