砂岩型铀矿碱性地浸过程孔隙结构演化特征  

Evolution Characteristics of Pore Structure During Alkaline In⁃Situ Leaching of Sandstone Type Uranium Deposit

作　　者：杨鑫 张通 杜志明[4] 唐明 李燕芳 毛钧林 王鸣超 YANG Xin;ZHANG Tong;DU Zhiming;TANG Ming;LI Yanfang;MAO Junlin;WANG Mingchao(School of Mining Engineering,Anhui University of Science and Technology,Huainan 232000,Anhui,China;Institute of Energy,Hefei Comprehensive National Science Center(Anhui Energy Laboratory),Hefei 230031,Anhui,China;School of Safety Science and Engineering,Anhui University of Science and Technology,Huainan 232000,Anhui,China;Beijing Research Institute of Chemical Engineering Metallurgy,Beijing 101149,China)

机构地区：[1]安徽理工大学矿业工程学院,安徽淮南232000 [2]合肥综合性国家科学中心能源研究院(安徽省能源实验室),安徽合肥230031 [3]安徽理工大学安全科学与工程学院,安徽淮南232000 [4]核工业北京化工冶金研究院,北京101149

出　　处：《矿冶工程》2023年第2期21-25,共5页Mining and Metallurgical Engineering

基　　金：合肥综合性国家科学中心能源研究院重大培育项目(21KZS216);国家自然科学基金(51904011);安徽省高校协同创新项目(GXXT⁃2021⁃019)。

摘　　要：采用NaHCO_(3)+H_(2)O_(2)碱性溶浸液对铀矿柱状岩芯进行了柱浸实验,利用电镜扫描图像分析了砂岩型铀矿表面特征和孔隙分布状况,以核磁共振T2谱定量表征碱性地浸过程中含铀砂岩微观孔隙结构变化。结果表明,溶浸液化学溶蚀作用下岩芯内部基质首先形成连通型孔隙,大、小孔间孔喉增加;反应生成的Al(OH)_(3)矿物胶体和CaCO_(3)集中沉淀堆积于小孔和微裂隙中,减小了溶浸液与基质有效接触反应面积,降低了铀矿浸出效率;97~158 h为溶蚀优势期,该阶段化学溶蚀量远大于沉淀堆积量,形成大量连通型孔隙,使铀矿物与溶浸液进一步反应溶解,铀矿采收率达到峰值。A core of uranium deposit was taken in an experiment of column leaching with alkaline solution(NaHCO_(3)+H_(2)O_(2)),and then the surface characteristics and pore distribution of sandstone⁃type uranium deposit were analyzed by using scanning electron microscope images.The variation in the microscopic pore structure of uranium⁃bearing sandstone in alkaline in situ leaching process was characterized by using T2 spectrum of nuclear magnetic resonance(NMR).The results show that the matrix in the core firstly becomes connected pores due to chemical dissolution of leaching solution,resulting in more pore throats among large and small pores.The Al(OH)_(3) mineral colloid and CaCO_(3) generated by the reaction are deposited intensively in the pores and microcracks,which reduces the effective reaction area between leaching solution and matrix,thus reducing the uranium leaching efficiency.During the period of 97-158 h,dissolution is predominant,leading to the amount of chemical dissolution much higher than the amount of precipitation and accumulation,thus forming a large number of connected pores.Further reaction and dissolution of uranium minerals in the leaching solution can increase the recovery of uranium mineral to the peak.

关 键 词：砂岩型铀矿 碱性地浸 孔隙结构 核磁共振 铀 柱浸 

分 类 号：P631[天文地球—地质矿产勘探]