新疆512矿床砂岩型铀矿孔隙特征及渗流模拟  

Pore characteristics and seepage simulation of sandstone-type uranium ore in the 512 deposit,Xinjiang

作　　者：刘亚玲 黎广荣[1,2] 周义朋[1] 孙占学[1] 赵凯 刘金辉[1] 徐玲玲[1] LIU Yaling;LI Guangrong;ZHOU Yipeng;SUN Zhanxue;ZHAO Kai;LIU Jinhui;XULingling(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;School of Earth Sciences,East China University of Technology,Nanchang 330013,China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,南昌330013 [2]东华理工大学地球科学学院,南昌330013

出　　处：《地质科技通报》2024年第4期205-218,共14页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(42072285,41772266);中央引导地方科技发展专项(2018ZDB40001)。

摘　　要：地浸采铀工艺是溶浸液在含矿含水层中与铀矿物发生反应,铀元素随溶浸液迁移至地表的一种提铀工艺,精确了解矿区岩石内部结构及金属矿物的分布,对地浸工艺应用具有重要的指导意义。为了解512矿床岩石内部结构及渗流路径,选取该矿床代表性围岩和矿石岩心进行CT扫描,经过图像降噪滤波、图像分割提取孔隙、构建孔隙网络模型等处理与分析,获得各孔喉参数;通过Avizo软件模拟得到绝对渗透率、迂曲率和渗流速度变化。结果表明:围岩和矿石的孔隙度相近,分别为15.42%,15.18%;连通孔隙度分别是9.61%,13.82%。围岩中高密度物质为一些金属矿物,体积分数约为0.54%,矿石中高密度矿物多为次生铀矿物,体积分数为1.06%,其在浸出过程中可与溶浸液充分接触。孔隙内部具有强烈的非均质性,导致流速在流动路径中逐渐降低。围岩和矿石连通的大孔数量多于小孔,指示大孔是决定孔隙发育程度的主要因素。根据速度流线推断围岩和矿石中虽然存在堵塞区,但流通区域占主导地位。[Objective]In situ leaching is a uranium extraction process in which a solution reacts with uraniumbearing minerals in a saturated aquifer and then uranium in the flowing solution is extracted through exchange.To understand the internal structure and seepage path of the 512 deposits,[Methods]representative wallrock and ore cores of the deposit were selected for CT scanning,and the pore throat parameters were obtained via image noise reduction filtering,image segmentation to extract pores,and the construction of pore network models.The changes in the absolute permeability,tortuosity and seepage velocity are simulated with Avizo software.[Results]The results showed that the porosity of the wallrock was 15.42%,the connected porosity was 9.61%,the ore porosity was 15.18%,the connected porosity was 13.82%,and the water permeability was better than that of the wallrock.The high-density materials in the wallrock are metal minerals,accounting for approximately 0.54%,and most of the high-density minerals in the ore are secondary uranium minerals,accounting for 1.06%.It can be fully in contact with the solution during the leaching process.[Conclusion]There is strong heterogeneity inside the pores,which causes the flow rate to gradually decrease in the flow path.The number of large pores connecting the wallrock and ore is greater than that of small pores,indicating that large pores are the main factors determining the degree of pore development.According to the velocity streamlines,although there is a blockage area in the wallrock and ore,the circulation area is dominant.

关 键 词：砂岩型铀矿 地浸采铀 CT扫描 孔隙特征 渗流模拟 新疆512矿床 

分 类 号：P619.14[天文地球—矿床学]