摘要
随着稀土离子不断地浸出,矿体渗透性也在不断发生变化,研究浸矿过程中不同深度矿土的孔隙结构演化规律对赣南离子型稀土环保高效开采有较大意义。通过离子型稀土柱浸对比试验,利用核磁共振技术,从孔隙度、孔隙半径、T2谱、反演图像4个方面,分析比较MgSO_(4)溶液与去离子水柱浸不同深度的各组重塑试样孔隙结构演化规律。研究结果表明,在浸矿初期,无论哪种浸矿液,孔隙结构的改变主要受渗流作用的控制,孔隙度均急剧增大;达到饱和状态后,不同浸矿液的作用开始显现,随着时间的推移,去离子水组的孔径分布几乎不发生改变,镁盐组的孔隙结构处于动态变化。用2%MgSO_(4)溶液浸出时,反演成像出现明显黑带随着浸矿向下迁移,即离子交换反应是一个从上向下迁移的过程;从力场和化学反应场阐释了镁盐浸矿过程孔隙结构改变的机制。
As the permeability of ore body is changing with the continuous leaching of rare earth ions,it is of great signifi⁃cance to study the evolution law of pore structure of mine soil at different depths in the process of leaching for the environmen⁃tal protection and efficient mining of ionic type rare earth deposits in southern Jiangxi.Through the comparison test of ionic rare earth ore column leaching,the evolution law of pore structure of remolded samples at different depths of magnesium sulfate so⁃lution and deionized water column leaching was analyzed and compared from porosity,pore radius,T2 spectrum and inversion image by using NMR technology.Results show that in the initial stage of ore leaching,the variation of pore structure is prima⁃rily controlled by seepage and the porosity increases sharply in any leaching solution.After reaching the saturation state,the effect of different leaching solutions begins to appear.With the passage of time,the pore size distribution of deionized water group almost does not change,and the pore structure of magnesium salt group changes dynamically.When sample leached with 2%magnesium sulfate solution,the inversion image shows that the black zone moves down with the leaching ore,that is,ion exchange reaction is a process of downward migration.The mechanism of pore structure change during the process of magnesi⁃um salt leaching is explained from the perspective of force field and chemical reaction.
作者
王丹
饶运章
刘戈
石亮
张美道
WANG Dan;RAO Yun-zhang;LIU Ge;SHI Liang;ZHANG Mei-dao(School of Resources and Environment Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China)
出处
《稀土》
CAS
CSCD
北大核心
2023年第5期92-102,共11页
Chinese Rare Earths
基金
国家自然科学基金项目(51964014)。
关键词
离子型稀土
柱浸试验
核磁共振
孔隙分布
演化机制
ionic type rare earth
column leaching test
NMR
pore distribution
evolutionary mechanism
