Editing Rare-earth element (section)

===Recycling and reusing REEs===
{{Further|Circular economy|Renewable energy#Conservation areas, recycling and rare-earth elements}}

REEs are amongst the most critical elements to modern technologies and society. Despite this, typically only around 1% of REEs are recycled from end-products.<ref>{{Cite journal |last1=Jowitt |first1=Simon M. |last2=Werner |first2=Timothy T. |last3=Weng |first3=Zhehan |last4=Mudd |first4=Gavin M. |date=2018-10-01 |title=Recycling of the rare earth elements |url=https://www.sciencedirect.com/science/article/pii/S2452223617301256 |journal=Current Opinion in Green and Sustainable Chemistry |series=Reuse and Recycling / UN SGDs: How can Sustainable Chemistry Contribute? / Green Chemistry in Education |language=en |volume=13 |pages=1–7 |doi=10.1016/j.cogsc.2018.02.008 |bibcode=2018COGSC..13....1J |s2cid=135249554 |issn=2452-2236}}</ref> Recycling and reusing REEs is not easy: these elements are mostly present in tiny amounts in small electronic parts and they are difficult to separate chemically.<ref name="Balaram2019">{{Cite journal |last=Balaram |first=V. |date=2019-07-01 |title=Rare earth elements: A review of applications, occurrence, exploration, analysis, recycling, and environmental impact |journal=Geoscience Frontiers |language=en |volume=10 |issue=4 |pages=1285–1303 |doi=10.1016/j.gsf.2018.12.005 |bibcode=2019GeoFr..10.1285B |issn=1674-9871|doi-access=free }}</ref> For example, recovery of  neodymium requires manual disassembly of hard disk drives because shredding the drives only recovers 10% of the REE.<ref>{{Cite journal |last1=Sprecher |first1=Benjamin |last2=Xiao |first2=Yanping |last3=Walton |first3=Allan |last4=Speight |first4=John |last5=Harris |first5=Rex |last6=Kleijn |first6=Rene |last7=Visser |first7=Geert |last8=Kramer |first8=Gert Jan |date=2014-04-01 |title=Life Cycle Inventory of the Production of Rare Earths and the Subsequent Production of NdFeB Rare Earth Permanent Magnets |url=https://pubs.acs.org/doi/10.1021/es404596q |journal=Environmental Science & Technology |language=en |volume=48 |issue=7 |pages=3951–3958 |doi=10.1021/es404596q |pmid=24576005 |bibcode=2014EnST...48.3951S |issn=0013-936X}}</ref>

REE recycling and reuse have been increasingly focused on in recent years. The main concerns include environmental pollution during REE recycling and increasing recycling efficiency. Literature published in 2004 suggests that, along with previously established pollution mitigation, a more circular supply chain would help mitigate some of the pollution at the extraction point. This means recycling and reusing REEs that are already in use or reaching the end of their life cycle.<ref name="Ali 123–134">{{cite journal |last=Ali |first=Saleem H. |date=2014-02-13 |title=Social and Environmental Impact of the Rare Earth Industries |journal=Resources |language=en |volume=3 |issue=1 |pages=123–134 |doi=10.3390/resources3010123 |doi-access=free|bibcode=2014Resou...3..123A }}</ref> A study published in 2014 suggests a method to recycle REEs from waste [[nickel-metal hydride batteries]], demonstrating a recovery rate of 95.16%.<ref>{{cite journal |last1=Yang |first1=Xiuli |last2=Zhang |first2=Junwei |last3=Fang |first3=Xihui |date=2014-08-30 |title=Rare earth element recycling from waste nickel-metal hydride batteries |journal=Journal of Hazardous Materials |language=en |volume=279 |pages=384–388 |doi=10.1016/j.jhazmat.2014.07.027 |issn=0304-3894 |pmid=25089667|bibcode=2014JHzM..279..384Y }}</ref> 

Rare-earth elements could also be recovered from industrial wastes with practical potential to reduce environmental and health impacts from mining, waste generation, and imports if known and experimental processes are scaled up.<ref>{{cite news |title=Rare earth elements for smartphones can be extracted from coal waste |work=New Scientist |url=https://www.newscientist.com/article/2307608-rare-earth-elements-for-smartphones-can-be-extracted-from-coal-waste/}}</ref><ref>{{cite journal |last1=Deng |first1=Bing |last2=Wang |first2=Xin |last3=Luong |first3=Duy Xuan |last4=Carter |first4=Robert A. |last5=Wang |first5=Zhe |last6=Tomson |first6=Mason B. |last7=Tour |first7=James M. |year=2022 |title=Rare earth elements from waste |journal=Science Advances |volume=8 |issue=6 |pages=eabm3132 |bibcode=2022SciA....8M3132D |doi=10.1126/sciadv.abm3132 |pmc=8827657 |pmid=35138886}}</ref> A 2019 study suggests that "fulfillment of the circular economy approach could reduce up to 200 times the impact [[Climate change mitigation|in the climate change category]] and up to 70 times the cost due to the REE mining."<ref>{{cite journal |last1=Amato |first1=A. |last2=Becci |first2=A. |last3=Birloaga |first3=I. |last4=De Michelis |first4=I. |last5=Ferella |first5=F. |last6=Innocenzi |first6=V. |last7=Ippolito |first7=N. M. |last8=Pillar Jimenez Gomez |first8=C. |last9=Vegliò |first9=F. |last10=Beolchini |first10=F. |date=1 May 2019 |title=Sustainability analysis of innovative technologies for the rare earth elements recovery |journal=Renewable and Sustainable Energy Reviews |language=en |volume=106 |pages=41–53 |doi=10.1016/j.rser.2019.02.029 |bibcode=2019RSERv.106...41A |issn=1364-0321 |s2cid=115810707 |hdl-access=free |hdl=11566/264482}}</ref> In 2020, in most of the reported studies reviewed by a [[scientific review]], "secondary waste is subjected to chemical and or bioleaching followed by solvent extraction processes for clean separation of REEs."<ref>{{cite journal |last1=Jyothi |first1=Rajesh Kumar |last2=Thenepalli |first2=Thriveni |last3=Ahn |first3=Ji Whan |last4=Parhi |first4=Pankaj Kumar |last5=Chung |first5=Kyeong Woo |last6=Lee |first6=Jin-Young |date=10 September 2020 |title=Review of rare earth elements recovery from secondary resources for clean energy technologies: Grand opportunities to create wealth from waste |journal=Journal of Cleaner Production |language=en |volume=267 |page=122048 |doi=10.1016/j.jclepro.2020.122048 |bibcode=2020JCPro.26722048J |issn=0959-6526 |s2cid=219469381}}</ref>

Currently, people take two essential resources into consideration for the secure supply of REEs: one is to extract REEs from primary resources like mines harboring REE-bearing ores, regolith-hosted clay deposits,<ref>{{Cite journal |last1=Borst |first1=Anouk M. |last2=Smith |first2=Martin P. |last3=Finch |first3=Adrian A. |last4=Estrade |first4=Guillaume |last5=Villanova-de-Benavent |first5=Cristina |last6=Nason |first6=Peter |last7=Marquis |first7=Eva |last8=Horsburgh |first8=Nicola J. |last9=Goodenough |first9=Kathryn M. |last10=Xu |first10=Cheng |last11=Kynický |first11=Jindřich |last12=Geraki |first12=Kalotina |date=2020-09-01 |title=Adsorption of rare earth elements in regolith-hosted clay deposits |journal=Nature Communications |language=en |volume=11 |issue=1 |page=4386 |doi=10.1038/s41467-020-17801-5 |issn=2041-1723 |pmc=7463018 |pmid=32873784|bibcode=2020NatCo..11.4386B }}</ref> ocean bed sediments, coal fly ash,<ref>{{Cite journal |last1=Liu |first1=Pan |last2=Huang |first2=Rixiang |last3=Tang |first3=Yuanzhi |date=2019-05-07 |title=Comprehensive Understandings of Rare Earth Element (REE) Speciation in Coal Fly Ashes and Implication for REE Extractability |url=https://pubs.acs.org/doi/10.1021/acs.est.9b00005 |journal=Environmental Science & Technology |language=en |volume=53 |issue=9 |pages=5369–5377 |doi=10.1021/acs.est.9b00005 |pmid=30912650 |bibcode=2019EnST...53.5369L |s2cid=85517653 |issn=0013-936X}}</ref> etc. A work developed a green system for recovery of REEs from coal fly ash by using citrate and oxalate who are strong organic ligand and capable of complexing or precipItating with REE.<ref>{{Cite journal |last1=Liu |first1=Pan |last2=Zhao |first2=Simin |last3=Xie |first3=Nan |last4=Yang |first4=Lufeng |last5=Wang |first5=Qian |last6=Wen |first6=Yinghao |last7=Chen |first7=Hailong |last8=Tang |first8=Yuanzhi |date=2023-04-04 |title=Green Approach for Rare Earth Element (REE) Recovery from Coal Fly Ash |journal=Environmental Science & Technology |language=en |volume=57 |issue=13 |pages=5414–5423 |doi=10.1021/acs.est.2c09273 |issn=0013-936X |pmc=10077585 |pmid=36942728|bibcode=2023EnST...57.5414L }}</ref> The other one is from secondary resources such as electronic, industrial waste and municipal waste. E-waste contains a significant concentration of REEs, and thus is the primary option for REE recycling now{{when|date=July 2023}}. According to a 2019 study, approximately 50 million metric tons of electronic waste are dumped in landfills worldwide each year. Despite the fact that e-waste contains a significant amount of rare-earth elements (REE), only 12.5% of e-waste is currently being recycled for all metals.<ref name="Balaram2019"/>