China
Africa
Explore chapters and articles related to this topic
Lanthanides
Published in Alina Kabata-Pendias, Barbara Szteke, Trace Elements in Abiotic and Biotic Environments, 2015
Alina Kabata-Pendias, Barbara Szteke
LAs are constituents of several minerals, such as monazite [(La,Ce,Th)PO4], bastnasite [(Ce,F)CO3], and cheralite [(Ce,La,Y,Th)PO4]. Lanthanum is also associated with xenotime (YPO4). All these minerals are likely to be concentrated in phosphorites, which resulted in elevated amounts of some LAs in P fertilizers. In addition, some calcite rocks may contain higher amounts of LAs.
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).
Late Paleoproterozoic deposition and Mesoproterozoic metamorphism of detrital material in the southernmost Baltic Sea region (Gdańsk IG1 borehole): monazite versus zircon and chemical versus isotopic age record
Published in GFF, 2023
Dominik Gurba, Anna Grabarczyk-Gurba, Ewa Krzemińska
REE-phosphate is represented by monazite only (cheralite end-member up to 8.1%, with 0.51–2.06 wt% CaO and 1.53–8.21 wt% ThO2; huttonite end-member up to 7.3% with 0.14–0.99 wt% SiO2; Appendix 1G and 1H). Concentrations of La2O3, Ce2O3 and Nd2O3 are 10.86–16.59 wt%, 24.30–29.82, and 9.83–12.38 wt%, respectively, which results in the classification of monazite as monazite-(Ce). The Y2O3 content is variable (1.15–5.41 wt%) but it is not correlated with specific age domains in monazite grain. Monazite has significant U content of 0.12–1.45 wt% UO2.
Contrasting coronas: microscale fluid variation deduced from monazite breakdown products in altered metavolcanic rocks associated with the Grängesberg apatite-iron oxide ore, Bergslagen, Sweden
Published in GFF, 2022
Jarosław Majka, Adam Włodek, Erik Jonsson, Karin Högdahl
The sample contains abundant, chemically homogenous monazite (up to 200 µm in diameter; Fig. 2), which is Ce dominant, with low ThO2 content, not exceeding 0.36 wt% (Table 1). The yttrium content is moderate, ranging from 0.45 to 1.13 wt% Y2O3 (Table 1). The contents of SiO2 and CaO reach 0.65 and 0.89 wt%, respectively. These limited enrichments in Si and Ca thus indicate only minor roles of the huttonite and cheralite-type substitutions.