Key process mineralogy parameters for rare earth fluorcarbonate-bearing carbonatite deposits: The example of Songwe Hill, Malawi
Key process mineralogy parameters for rare earth fluorcarbonate-bearing carbonatite deposits: The example of Songwe Hill, Malawi
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DOI：
10.1016/j.mineng.2020.106617
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发表时间：
2020-09
影响因子：
4.8
通讯作者：
S. Al-Ali;F. Wall;R. Fitzpatrick;S. Broom-Fendley;G. Rollinson;A. Brady;J. Pickles;Adam Williams-Ada
中科院分区：
文献类型：
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作者：
S. Al-Ali;F. Wall;R. Fitzpatrick;S. Broom-Fendley;G. Rollinson;A. Brady;J. Pickles;Adam Williams-Ada
含稀土元素碳酸盐岩矿床通常含有各种不同的稀土和稀土矿物与各种脉石基质。为了选择最适合这些矿床的矿物加工技术，必须查明和量化有关矿物，包括其游离、共生和粒度分布，沿着整个岩石的组成。这些数据对于选矿流程设计期间和之后的矿石进料优化和冶金故障排除也至关重要。本文以Songwe Hill碳酸盐存款矿床为例，总结了进行冶金提纯试验前所需的关键矿物学参数。该稀土矿存款由弱释放的正长岩-（Ce）和良好释放的磷灰石组成，正长岩-（Ce）承载轻稀土元素，包括Nd和一些重稀土元素，磷灰石承载存款中50%的Gd、63%的Dy和71%的Y（重稀土元素）。对于所有比Gd重的稀土元素，磷灰石是最重要的稀土元素宿主，然而，对于两种稀土元素，其中数据可在正长岩-（Ce）和磷灰石（Dy和Y）中获得，正长岩-（Ce）仍然容纳全岩HREE含量的25%以上。这两种矿石矿物都与铁白云石、方解石有关，并在较小程度上与氧化铁/碳酸盐、钾长石、菱锶矿和重晶石有关。根据定量的矿物学数据，讨论了重选、磁选、泡沫浮选和浸出工艺处理松威山碳酸盐矿石的可能性，提出了可行的选矿流程。
Rare earth element (REE)-bearing carbonatite deposits commonly contain a wide range of different REE- and REE-bearing minerals associated with various gangue matrices. In order to select the most-suitable mineral processing technique for these deposits, it is essential to identify and quantify the minerals of interest, including their liberation, associations and grain size distribution, along with whole rock compositions. These data are also vital for ore feed optimisation and metallurgical troubleshooting during and after designing a mineral processing flowsheet. This paper summarises the key mineralogical parameters needed before conducting metallurgical beneficiation tests, using the Songwe Hill carbonatite deposit as an example. This REE ore deposit consists of poorly-liberated synchysite-(Ce), which hosts the light rare earth elements including Nd plus some heavy rare earths and well-liberated apatite, which hosts 50% of Gd, 63% of Dy and 71% of Y (heavy rare earth elements) in the deposit. For all REE heavier than Gd, apatite is the most important REE host, however, for the two REE where data are available in both synchysite-(Ce) and apatite (Dy and Y), synchysite-(Ce) still accommodates >25% of the whole-rock HREE content. Both of these ore minerals are associated with ankerite, calcite, and to a lesser extent with iron oxides/carbonates, K-feldspar, strontianite and baryte. According to the quantitative mineralogical data, the possibility of using gravity separation, magnetic separation, froth flotation and leaching to process Songwe Hill carbonatite ore is discussed and a potential beneficiation flowsheet is presented.