The process mineralogy of leaching sandstone-hosted uranium-vanadium ores
The process mineralogy of leaching sandstone-hosted uranium-vanadium ores
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DOI：
10.1016/j.mineng.2022.107811
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发表时间：
2022-09
影响因子：
4.8
通讯作者：
Molly R. Radwany;Isabel F. Barton
中科院分区：
文献类型：
--
作者：
Molly R. Radwany;Isabel F. Barton
在美国，Paradox盆地(科罗拉多高原)的砂岩矿床是铀和钒的主要资源，这两种金属对绿色能源和其他应用非常重要。尽管历史和当前的采矿兴趣，以及它们作为关键元素的主要国内资源的重要性，这些矿床的几何几何几乎没有得到研究。本文介绍了铀钒矿石的几何矿物学和工艺矿物学，并确定了酸浸最佳回收的主要障碍。大多数金属以沥青铀矿(混合氧化铀-硅酸盐)、V-氢氧化物、含V的层状硅酸盐以及各种铀、铅、铜和其他金属的钒酸盐的形式存在。工业浸出采用两段加热槽--H_2SO_4和NaClO_3浸出，铀含量高，钒回收率低(工业生产中为70-75%)。实验室浸出实验结合头部和残渣矿物学对比表明，未回收的铀由包裹在石英中的微米级沥青铀矿颗粒和其他不溶矿物组成。V回收率不佳的主要原因是V-层状硅酸盐，它们在室温下表现出可变的但通常较差的溶解度。一个辅助原因是自生石英和V型层状硅酸盐对少量细粒V-氢氧化物和沥青铀矿的锁定。与全球其他钒资源的比较表明，钒-层状硅酸盐矿石矿物的不同溶解度也可能会降低更常见的矿床类型的回收率，例如赋存于黑色页岩或石煤中的钒，特别是在粗粒低品位矿石的堆浸中。
In the United States, sandstone-hosted ore deposits of the Paradox Basin (Colorado Plateau) are major resources of uranium and vanadium, two metals important to green energy among other applications. Despite historic and current mining interest, and their significance as major domestic resources of critical elements, the geometallurgy of these deposits has received little study. This article documents the geometallurgy and process mineralogy of the U-V ores and identifies the principal barriers to optimal recovery by acid leaching.Most of the metals occur as pitchblende (mixed uranium oxide-silicate), V-hydroxides, V-bearing phyllosilicates, and diverse vanadates of U, Pb, Cu, and other metals. Commercial extraction is by two-stage heated tank leaching with H2SO4and NaClO3, yielding high U but lower V recovery (70–75% in the industrial operation). Laboratory leaching experiments coupled with comparisons of head and residue mineralogy indicate that the unrecovered U consists of micron-scale pitchblende grains locked within quartz and other insoluble minerals. The principal cause of suboptimal V recovery is the V-phyllosilicates, which show variable but generally poor solubility at room temperatures. An ancillary cause is locking of a small amount of fine-grained V-hydroxide and pitchblende by authigenic quartz and V-phyllosilicates. Comparison with other global V resources suggests that variable solubility of V-phyllosilicate ore minerals may also diminish recovery from more common ore deposit types, such as V hosted in black shales or stone coal, particularly in heap leaching of low-grade ores at coarse grain sizes.