scholarly journals Leaching and Recovery of Rare-Earth Elements from Neodymium Magnet Waste Using Organic Acids

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 721 ◽  
Author(s):  
Marino Gergoric ◽  
Christophe Ravaux ◽  
Britt-Marie Steenari ◽  
Fredrik Espegren ◽  
Teodora Retegan
Keyword(s):  
Acetic Acid ◽  
Rare Earth ◽  
Citric Acid ◽  
Solvent Extraction ◽  
Rare Earth Elements ◽  
Organic Acids ◽  
End Of Life ◽  
Partial Solution ◽  
The European Union ◽  
Ndfeb Magnets

Over the last decade, rare-earth elements (REEs) have become critical in the European Union (EU) in terms of supply risk, and they remain critical to this day. End-of-life electronic scrap (e-scrap) recycling can provide a partial solution to the supply of REEs in the EU. One such product is end-of-life neodymium (NdFeB) magnets, which can be a feasible source of Nd, Dy, and Pr. REEs are normally leached out of NdFeB magnet waste using strong mineral acids, which can have an adverse impact on the environment in case of accidental release. Organic acids can be a solution to this problem due to easier handling, degradability, and less poisonous gas evolution during leaching. However, the literature on leaching NdFeB magnets waste with organic acids is very scarce and poorly investigated. This paper investigates the recovery of Nd, Pr, and Dy from NdFeB magnets waste powder using leaching and solvent extraction. The goal was to determine potential selectivity between the recovery of REEs and other impurities in the material. Citric acid and acetic acid were used as leaching agents, while di-(2-ethylhexyl) phosphoric acid (D2EHPA) was used for preliminary solvent extraction tests. The highest leaching efficiencies were achieved with 1 mol/L citric acid (where almost 100% of the REEs were leached after 24 h) and 1 mol/L acetic acid (where >95% of the REEs were leached). Fe and Co—two major impurities—were co-leached into the solution, and no leaching selectivity was achieved between the impurities and the REEs. The solvent extraction experiments with D2EHPA in Solvent 70 on 1 mol/L leachates of both acetic acid and citric acid showed much higher affinity for Nd than Fe, with better extraction properties observed in acetic acid leachate. The results showed that acetic acid and citric acid are feasible for the recovery of REEs out of NdFeB waste under certain conditions.

Solvent extraction study of rare earth elements from chloride medium by mixtures of sec-nonylphenoxy acetic acid with Cyanex301 or Cyanex302

2009 ◽  
Vol 100 (1-2) ◽  
pp. 15-19 ◽  
Author(s):  
Shanshan Tong ◽  
Xiaowei Zhao ◽  
Naizhong Song ◽  
Qiong Jia ◽  
Weihong Zhou ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Rare Earth ◽  
Solvent Extraction ◽  
Rare Earth Elements ◽  
Chloride Medium ◽  
Extraction Study

scholarly journals Study on the Effect and Mechanism of Impurity Aluminum on the Solvent Extraction of Rare Earth Elements (Nd, Pr, La) by P204-P350 in Chloride Solution

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 61
Author(s):  
Wenjie Zhang ◽  
Xian Xie ◽  
Xiong Tong ◽  
Yunpeng Du ◽  
Qiang Song ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solvent Extraction ◽  
Rare Earth Elements ◽  
Organic Phase ◽  
Extraction Process ◽  
Industrial Applications ◽  
Separation And Purification ◽  
Aluminum Ion ◽  
Hydrochloric Acid Medium ◽  
Impurity Ion

Solvent extraction is the most widely used method for separation and purification of rare earth elements, and organic extractants such as di(2-ethylhexyl) phosphoric acid (P204) and di(1-methyl-heptyl) methyl phosphonate (P350) are most commonly used for industrial applications. However, the presence of impurity ions in the feed liquid during extraction can easily emulsify the extractant and affect the quality of rare earth products. Aluminum ion is the most common impurity ion in the feed liquid, and it is an important cause of emulsification of the extractant. In this study, the influence of aluminum ion was investigated on the extraction of light rare earth elements by the P204-P350 system in hydrochloric acid medium. The results show that Al3+ competes with light rare earths in the extraction process, reducing the overall extraction rate. In addition, the Al3+ stripping rate is low and there is continuous accumulation of Al3+ in the organic phase during the stripping process, affecting the extraction efficiency and even causing emulsification. The slope method and infrared detection were utilized to explore the formation of an extraction compound of Al3+ and the extractant P204-P350 that entered the organic phase as AlCl[(HA)2]2P350(o).

scholarly journals Two-Step Solvent Extraction of Radioactive Elements and Rare Earths from Estonian Phosphorite Ore Using Nitrated Aliquat 336 and Bis(2-ethylhexyl) Phosphate

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 388
Author(s):  
Silvester Jürjo ◽  
Liis Siinor ◽  
Carolin Siimenson ◽  
Päärn Paiste ◽  
Enn Lust
Keyword(s):  
Rare Earth ◽  
Solvent Extraction ◽  
Rare Earth Elements ◽  
Toxic Elements ◽  
Downstream Processing ◽  
Liquid Extraction ◽  
Aliquat 336 ◽  
Radioactive Elements ◽  
Improved Method ◽  
Ph Values

Estonian phosphorite ore contains trace amounts of rare earth elements (REEs), many other d-metals, and some radioactive elements. Rare earth elements, Mo, V, etc. might be economically exploitable, while some radioactive and toxic elements should be removed before any other downstream processing for environmental and nutritional safety reasons. All untreated hazardous elements remain in landfilled waste in much higher concentration than they occur naturally. To resolve this problem U, Th, and Tl were removed from phosphorite ore at first using liquid extraction. In the next step, REE were isolated from raffinate. Nitrated Aliquat 336 (A336[NO3]) and Bis(2-ethylhexyl) Phosphate (D2EHPA) were used in liquid extraction for comparison. An improved method for exclusive separation of radioactive elements and REEs from phosphorite ore in 2-steps has been developed, exploiting liquid extraction at different pH values.

scholarly journals Effect of organic acids fed through drinking water on carcass and internal organs of broiler chickens

2021 ◽  
Vol 41 (1) ◽  
pp. 60-67
Author(s):  
E. K. Ndelekwute ◽  
H. O. Uzegbu ◽  
K. U. Amaefule ◽  
C. O. Okereke ◽  
B. I. Umoh
Keyword(s):  
Drinking Water ◽  
Acetic Acid ◽  
Citric Acid ◽  
Gall Bladder ◽  
Organic Acids ◽  
Formic Acid ◽  
Butyric Acid ◽  
Broiler Chickens ◽  
Internal Organs ◽  
Carcass Yield

A Six week study was carried out to investigate effect of different organic acids (OAs) fed through drinking water on carcass yield and internal organs weight of broiler chickens. The OAs were acetic acid (AA) butyric acid (BA), citric acid (CA) and formic acid (FA). One hundred and fifty (150) day old AborAcre-plus chicks were used. There were five treatments. Treatment 1 which served as control (CON) consumed water with no organic acid, while treatments 2,3, 4 and5 respectively were offered drinking water treated with 0.25% acetic acid (AA), butyric acid (BA), citric acid (CA) and formic acid (FA). Each treatment was replicated three times each having 10 birds arranged in completely randomized design (CRD). Feed and water were offered ad libitum. Results showed that dressed carcass weight and breast weight were improved by all the organic acids. While only AA positively influenced the thigh weight, all the OAs drinking water fed resulted to smaller drumstick compared to the CON. Feeding of AA, BA and FA through drinking water increased (PSO.05) deposition of abdominal fat. Weight of pancreas, small intestine, caecum and large intestine was significantly (P<0.05) higher in CON. The gall bladder was significantly (P<0.05) bigger in all the OA groups. Conclusively, OAs could be fed through the drinking water for improved percentage carcass yield, breast meat and larger gall bladder and invariably bile volume

Recycling and substitution of light rare earth elements, cerium, lanthanum, neodymium, and praseodymium from end-of-life applications - A review

2019 ◽  
Vol 236 ◽  
pp. 117573 ◽  
Author(s):  
Linda Omodara ◽  
Satu Pitkäaho ◽  
Esa-Matti Turpeinen ◽  
Paula Saavalainen ◽  
Kati Oravisjärvi ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
End Of Life ◽  
Light Rare Earth ◽  
Light Rare Earth Elements
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