稀土礦物

稀土礦物(英語:Rare earth mineral)是指主要成分包含一種或是多種稀土元素礦物。稀土礦物通常發現於性至過鹼性火成岩組合中、與鹼性岩漿伴生的偉晶岩中,或是存在/伴生於碳酸鹽深成岩中。[1]具有鈣鈦礦結構的礦物是稀土元素鹼性錯合物的常見宿主。[2]來自地幔的碳酸鹽熔體也是稀土的載體。[3]與鹼性岩漿作用相關的熱液礦床含有多種稀土礦物。[1]

稀土礦物 (以一枚直徑19毫米1美分硬幣來與礦石做對比)
位於中國包頭白雲鄂博礦區假色衛星相片,2006年

而稀土元素是一組共17種,銀白色、質軟、具有光澤,但彼此性質相似難以區別的金屬元素[4][5] 雖然名為稀土元素,但實際上這些元素在地殼中的數量相對豐富,其中豐度最高的是地殼中排名第25常見的元素(參見地殼元素豐富度列表),佔68百萬分率,含量超過。然而,由於稀土元素的地球化學特性,它們在地殼中分佈通常十分分散,而罕有富集到高濃度的稀土礦物存在,因此世界上少有具開採價值的礦場,故得「稀土」之名。[6]

中國的儲藏量佔全世界的36.7%,[7]但中國的產量曾佔全世界的95%以上,[8]在2017年佔全世界的81%。到2021年中國的產量佔全世界的60.63%,而同年美國的產量排名第2,佔比為15.52%。[9]

中國的白雲鄂博礦區是世界已知最大的稀土礦物蘊藏區。[10]在2005年,這個礦區的稀土元素產量曾高達全世界的45%。[11][12][13]

常見稀土礦物

以下所列的是比較常見的熱液稀土礦物,以及經常含有顯著稀土元素替代物的礦物:[14]

開採作業對環境的可能影響

在自然環境中的稀土元素濃度非常低。蘊藏這類資源的礦山通常位於環境和社會標準非常低的國家,因為礦山的開發,而導致有侵犯人權、森林砍伐的事情,並且污染到當地的土地和水源。[15][16]

在採礦和工業生產場所附近,稀土元素的濃度會上升到正常背景水準的許多倍。稀土元素一旦進入環境,就會滲入土壤中,然後它們的遷移取決於多種因素,例如侵蝕作用、風化作用、pH值、降水和地下水等。如同金屬一樣,它們可根據土壤條件形成,無論是移動,或是被吸附到土壤顆粒中。根據它們的生物利用度,稀土元素可被植物吸收,然後被人類和牲畜攝入。對於稀土元素的開採,使用( 肥料添加劑)和磷肥的生產,都會導致稀土元素污染 。[17]此外,在萃取稀土元素的過程中會用到強酸,而這些酸會滲入環境,並通過水體而導致水生環境酸化。

對於稀土元素的開採、提煉和回收,如果管理不當,會對環境造成嚴重後果。稀土元素尾礦中的釷和鈾因有低放射性,而存有潛在危害,[18]這些物質如果處理不當,會對環境造成廣泛的傷害。

參見

參考文獻

  • Jones, Adrian P., Francis Wall and C. Terry Williams, eds. (1996) Rare Earth Minerals: Chemistry, Origin and Ore Deposits, The Mineralogy Society Series #7, 372 pp. ISBN 978-0-412-61030-1
  1. ^ 1.0 1.1 Dostal, Jaroslav. Rare Metal Deposits Associated with Alkaline/Peralkaline Igneous Rocks. ResearchGate. April 2016. doi:10.5382/Rev.18.02. 
  2. ^ Campbell, Linda S; Henderson, Paul. Rare Earth Chemistry of Perovskite Group Minerals from the Gardiner Complex, East Greenland. Mineralogical Magazine. April 1997, 61 (405): 1970212. doi:10.1180/minmag.1997.061.405.04. 
  3. ^ Yaxley, Gregory M.; Sujoy Ghosh, Sujoy. Deep Carbon. 6 - CO2-Rich Melts in Earth: Cambridge University Press. : 129 - 162 [2022-06-20]. (原始內容存檔於2022-06-27). They are also of particular economic importance as hosts or sources of many critical metals, including the rare earth elements (REEs) Nb, Ta, P, and others. 
  4. ^ Professor of Chemistry at University College London, Andrea Sella, YouTube上的Andrea Sella: "Insight: Rare-earth metals", Interview on TRT World / Oct 2016, minutes 4:40 - ff.
  5. ^ T Gray. Lanthanum and Cerium. The Elements. Black Dog & Leventhal. 2007: 118–122. 
  6. ^ Haxel G.; Hedrick J.; Orris J. Rare Earth Elements—Critical Resources for High Technology (PDF). Edited by Peter H. Stauffer and James W. Hendley II; Graphic design by Gordon B. Haxel, Sara Boore, and Susan Mayfield. United States Geological Survey. 2002 [2012-03-13]. USGS Fact Sheet: 087‐02. (原始內容 (PDF)存檔於2010-12-14). However, in contrast to ordinary base and precious metals, REE have very little tendency to become concentrated in exploitable ore deposits. Consequently, most of the world's supply of REE comes from only a handful of sources. 
  7. ^ Suzanne Goldenberg. Rare earth metals mine is key to US control over hi-tech future: Approval secured to restart operations, which could be crucial in challenging China's stranglehold on the market. The Guardian (London). 26 December 2010 [2022-06-20]. (原始內容存檔於2022-06-14). 
  8. ^ Tse, Pui-Kwan. USGS Report Series 2011–1042: China's Rare-Earth Industry. pubs.usgs.gov. [2018-04-04]. (原始內容存檔於2022-01-20). 
  9. ^ Distribution of rare earths production worldwide as of 2021, by country. statista. 2022-03-04 [2022-06-12]. (原始內容存檔於2022-06-08). 
  10. ^ Rare Earths: The Hidden Cost to Their Magic" (Part 2), Distillations Podcast and transcript, Episode 242. Science History Institute. June 25, 2019 [2019-08-28]. (原始內容存檔於2019-08-03). 
  11. ^ Lawrence J. Drewa, Meng Qingrunb and Sun Weijun. The Bayan Obo iron-rare-earth-niobium deposits, Inner Mongolia, China. Lithos. 1990, 26 (1–2): 43–65. doi:10.1016/0024-4937(90)90040-8. 
  12. ^ Xue-Ming Yang, Michael J. Le Bas. Chemical compositions of carbonate minerals from Bayan Obo, Inner Mongolia, China: implications for petrogenesis. Lithos. 2004, 72 (1–2): 97–116. doi:10.1016/j.lithos.2003.09.002. 
  13. ^ Chengyu Wu. Bayan Obo Controversy: Carbonatites versus Iron Oxide-Cu-Au-(REE-U). Resource Geology. 2007, 58 (4): 348–354. doi:10.1111/j.1751-3928.2008.00069.x. (原始內容存檔於2012-12-17). 
  14. ^ Rare element substitution a tricky proposition. CHEMISTRYWORLD. 2014-01-06 [2022-01-07]. (原始內容存檔於2022-03-23). 
  15. ^ Rizk, Shirley. What colour is the cloud?. European Investment Bank. 2019-06-21 [2020-09-17]. (原始內容存檔於2021-04-14) (英語). 
  16. ^ Standaert, Michael. China Wrestles with the Toxic Aftermath of Rare Earth Mining. Yale Environment 360. Yale School of the Environment. 2019-07-02 [2021-06-16]. (原始內容存檔於2022-07-09). 
  17. ^ Volokh, A. A.; Gorbunov, A. V.; Gundorina, S. F.; Revich, B. A.; Frontasyeva, M. V.; Chen Sen Pal. Phosphorus fertilizer production as a source of rare-earth elements pollution of the environment. Science of the Total Environment. 1990-06-01, 95: 141–148. Bibcode:1990ScTEn..95..141V. ISSN 0048-9697. PMID 2169646. doi:10.1016/0048-9697(90)90059-4 (英語). 
  18. ^ Bourzac, Katherine. "Can the US Rare-Earth Industry Rebound?"頁面存檔備份,存於互聯網檔案館Technology Review. 2010-10-29.

外部連結

外部媒體連結
音訊
  "Rare Earths: The Hidden Cost to Their Magic", Distillations Podcast and transcript, Episode 242, June 25, 2019, Science History Institute
影片
  「10 ways rare earth elements make life better」, animation, Science History Institute
  Rare Earth Elements: The Intersection of Science and Society, presentation and discussion led by Ira Flatow, Science History Institute, 2019-9-24