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Mining Methods Vary Widely
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Karlheinz Spitz, John Trudinger
The rare earth metal thorium is an alternative to uranium as fuel for nuclear reactors. The most common ore of thorium, the phosphate mineral monazite, which contains up to 12% of thorium oxide, also contains other economically extractable rare earth metals such as cerium, lanthanum, and neodymium, together with yttrium and iridium. Another rare earth phosphate mineral – xenotime – is a source of heavy rare earth elements such as dysprosium (Dy).
Review on the environment friendly leaching of rare earth elements from the secondary resources using organic acids
Published in Geosystem Engineering, 2022
Riya Banerjee, Saswati Chakladar, Ashok Mohanty, Sanchita Chakravarty, Shyamal Kumar Chattopadhyay, M.K. Jha
The most commonly mined minerals for REEs are monazite, bastnaesite and xenotime, (Clark & Henderson, 1984; Jordens et al., 2013). The largest deposits of bastnaesite in the world are found in China and the United States. Monazite deposits are widespread, found primarily in Brazil, South Africa, China, India, Australia, Malaysia, Sri Lanka, Thailand and the United States. Xenotime, which is iso-structural with zircon, is found in Norway, Sweden, Brazil and North Carolina. Apatite, eudialyte, cheralite, loparite, phosphorites, secondary monazite and spent uranium solutions comprise the remaining resources. Another interesting occurrence of REEs is in the form of ion-adsorbed deposits, which are abundant in southern China. It is typically formed as a result of weathering which leads to adsorption of REEs onto the surfaces of clay minerals such as kaolin, feldspar and mica (Chi & Tian, 2008; Liu et al., 2018).
A critical review of bioleaching of rare earth elements: The mechanisms and effect of process parameters
Published in Critical Reviews in Environmental Science and Technology, 2021
Payam Rasoulnia, Robert Barthen, Aino-Maija Lakaniemi
Bastnesite is the most abundant primary source of REEs (Wang et al., 2017). It is a fluorocarbonate mineral containing approximately 60–70 wt% rare earth oxides (REO), including 33 wt% La with considerable amounts of Ce, Nd, Pr, Sm, and Gd (Perämäki, 2014; Sinha, Abhilash, Meshram, & Pandey, 2016; Wang et al., 2017). Monazite is a phosphate mineral present in acidic igneous rocks and vein deposits containing mainly LREEs including 10–40 wt% La, 20–30 wt% Ce along with remarkable amounts of Sm, Pr, and Nd, but deposits often contain also 4–12 wt% Th and variable quantities of U (Kumari et al., 2015; Sinha et al., 2016). Typically, bastnesite contains more La and less Nd, HREEs, and Th (0.2–0.3 wt%) in comparison to monazite (Perämäki, 2014; Sinha et al., 2016; Wang et al., 2017). Xenotime is an yttrium phosphate that contains approximately 67 wt% REO and significant amounts of HREEs, which increases its importance as a primary REE resource as HREEs are less available in comparison to LREEs (Perämäki, 2014). Apatite, utilized in phosphoric acid production, contains typically only 0.1–1 wt% REO, but its widespread occurrence makes it an important REE resource (Ogata et al., 2016). Loparite, is an oxide mineral that is no longer widely used for REE extraction, because of its high content of radioactive thorium (Massari & Ruberti, 2013).
Studies on Liquid-Liquid Extraction of Yttrium and Separation from Other Rare Earth Elements Using Bifunctional Ionic Liquids
Published in Mineral Processing and Extractive Metallurgy Review, 2019
Niharbala Devi, Lala Behari Sukla
The rare earth elements consist of 17 elements of which 15 are lanthanides and the other two are scandium and yttrium. Based on their electronic configuration, they are classified as light group rare earth elements (LREE) and heavy group rare earth elements (HREE). These elements are now highly in demand for advanced technologies due to their unique chemical and physical properties. Yttrium, which is one of the heavy group rare earth elements, has enormous applications in many high-tech industries such as wind turbines, fluorescent lamps, cathode ray tubes, hybrid cars, disk drives, electronic components for missile and others. The main source of yttrium is xenotime, but it also occurs in other rare earth minerals, monazite and bastnasite. Recent review on yttrium from primary and secondary sources (Valentina et al. 2014) focused on the removal of yttrium from generic wastes, contaminant solutions and electronic wastes through hydrometallurgical process which consists of three steps, i.e. leaching, solvent extraction and electro-winning. Solvent extraction is a simple and vital technique used for metal recovery since long back. Literature review revealed that extraction and separation of yttrium from other rare earth elements using different types of classical extractants were studied by many researchers. Recently, the use of green solvents like ionic liquids has gained special attention in solvent extraction technique, where they were used to extract different metal ions. All these surveys are presented in Table 1.