Geochemistry of Rare Earth Elements, Applications and Environmental Challenges: Intrusive Mass of Songun Copper Mine as a Case Study, Varzaqan, North-West of Iran

Rare Earth Elements (REEs) include a wide range of technological applications due to their unique catalytic, magnetic, and optical properties. The environmental pollution of REEs has increased significantly as a result of their widespread use. Gadolinite, xenotime, samarskite, euxenite, fergusonite, itrotantalite, itrotungstite, and itrialite are minerals that mainly contain yttrium and HREEs. Bastnasite, monazite, allanite, luparite, ansilite, parasite, lanthanite, schwinite, cerite, stylolite, britolite, fluosite, and cerianite are minerals that mainly contain LREE. However, commercial mines around the world mainly extract bastnasite, monazite, and xenotime. This research aims to evaluate the concentration of rare earth elements in the Songun copper mine and their economic and environmental potential. For this purpose, microscopic studies and chemical analyses were performed on the collected samples. Apatite, zircon, carbonate minerals, clay minerals, rutile, sphene, sericite, sausorite, opaque minerals, epidote, limonite, and mullite are among the minerals that have the potential to host rare earth elements in the intrusive mass of Songun copper mine. The average amount of cerium (79 ppm), europium (1.41 ppm), lanthanum (38 ppm), neodymium (29 ppm), and praseodymium (8.47 ppm) in the intrusive mass rocks of Songun copper mine have increased compared to the average amount of crustal rocks. Also, the average amount of dysprosium (2.05 ppm), erbium (1.01 ppm), gadolinium (3.28 ppm), scandium (5.7 ppm), samarium (3.87 ppm), terbium (0.4 ppm), yttrium (7.3 ppm), and ytterbium (0.6 ppm) have decreased compared to Clark's value. REEs include the following important groups based on the cluster analysis diagram: yttrium, ytterbium, erbium, scandium, and terbium; gadolinium, samarium, and dysprosium; neodymium and praseodymium; cerium and lanthanum.