Development of Hydrometallurgical Process for Recovery of Rare Earth Metals (Nd, Pr, and Dy) from Nd-Fe-B Magnets

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1987
Author(s):  
Pankaj Kumar Choubey ◽  
Nityanand Singh ◽  
Rekha Panda ◽  
Rajesh Kumar Jyothi ◽  
Kyoungkeun Yoo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Mixing Time ◽  
Rare Earth Metals ◽  
Selective Extraction ◽  
Salt Leaching ◽  
Hydrometallurgical Processing ◽  
Extraction Separation ◽  
Pre Treatment ◽  
Two Stages ◽  
Solvent Extraction Technique

Non-availability of rich primary resources of rare earth metals (REMs) and the generation of huge amounts of discarded magnets containing REMs, compelled the researchers to explore the possibilities for the recovery of REMs from discarded magnets. Therefore, the present paper reports the recovery of REMs (Nd, Pr, and Dy) from discarded Nd-Fe-B magnets. The process consists of demagnetization, pre-treatment, and hydrometallurgical processing to recover REMs as salt. Leaching studies indicate that 95.5% Nd, 99.9% Pr, and 99.9% Dy were found to be dissolved at the optimized experimental condition i.e., acid concentration 2 M H2SO4, temperature 75 °C, pulp density 100 g/L, and mixing time 60 min. Solvent extraction technique was tried for the selective extraction/separation of REMs and Fe. The result indicates that 99.1% (24.42 g/L) of Nd along with 90% (1.08 g/L) of Pr and total Fe were co-extracted using 35% Cyanex 272 at organic to aqueous (O/A) ratio 1/1, eq. pH 3.5 in 10 min of mixing time. It requires multistage separation and therefore, not feasible in view of economics. Thus, direct precipitation of REMs salt and iron oxide as pigment was studied using two stages of precipitation at different pH. The obtained precipitate of REMs and Fe hydroxides were dried separately to remove the moisture and further treated at elevated temperature to get pure REMs oxide and red oxide.

Selective Extraction and Recovery of Rare Earth Metals (REMs) from NdFeB Magnet Grinding Sludge

2018 ◽  
pp. 2399-2407 ◽  
Author(s):  
Waraporn Piyawit ◽  
Pisit Sawananusorn ◽  
Loeslakkhana Srikhang ◽  
Panya Buahombura ◽  
Narong Akkarapattanagoon ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Selective Extraction ◽  
Ndfeb Magnet

Selective extraction and recovery of rare earth metals from waste fluorescent powder using alkaline roasting-leaching process

2017 ◽  
Vol 35 (10) ◽  
pp. 1008-1013 ◽  
Author(s):  
Chunfa LIAO ◽  
Zhenyuan LI ◽  
Yanliang ZENG ◽  
Jingyuan CHEN ◽  
Liqin ZHONG ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Selective Extraction ◽  
Leaching Process ◽  
Fluorescent Powder

scholarly journals Application of Ionic Liquids to Extraction Separation of Rare Earth Metals with an Effective Diglycol Amic Acid Extractant

2011 ◽  
Vol 44 (5) ◽  
pp. 307-312 ◽  
Author(s):  
Fukiko Kubota ◽  
Yousuke Shimobori ◽  
Yuzo Baba ◽  
Yusuke Koyanagi ◽  
Kojiro Shimojo ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Rare Earth ◽  
Rare Earth Metals ◽  
Amic Acid ◽  
Extraction Separation ◽  
Acid Extractant

scholarly journals Rare-earth metal ore processing technologies when developing new deposits

2020 ◽  
pp. 47-53
Author(s):  
T. I. Yushina ◽  
◽  
I. M. Petrov ◽  
S. A. Cherny ◽  
A. I. Petrova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Raw Materials ◽  
Rare Earth Metals ◽  
Earth Metal ◽  
Dense Medium ◽  
Clear Trend ◽  
Processing Technologies ◽  
Hydrometallurgical Processing ◽  
Mass Fractions ◽  
Materials Used

The article provides a brief overview of processing technologies for rare-earth raw materials used under greenfield development projects in different countries of the world (Africa, Greenland, Australia, Canada). The projects feature deposits with different mineral compositions, mass fractions of rare-earth metals (REM) in ores of 0.2 to 15 %, and the presence of niobium, zirconium, tantalum, phosphorus, uranium, and thorium. The resulting production facilities will extract 180 kt to 7.2 Mt rare-earth ore annually to generate 1.5 to 20 kt oxides of heavy and light groups of rare-earth metals along with the rare metals. The analysis of technologies for the projects considered demonstrates that magnetic and radiometric separation, dense-medium concentration and flotation with hydrometallurgical processing in the form of leaching with sulfuric or hydrochloric acid, followed by extraction of the target products, will be used for the processing of rare-earth raw materials. A characteristic feature of a number of projects is, first of all, the direct hydrometallurgical processing of the feed. The concentration technologies for ores containing rare-earth metals also indicate a clear trend towards a more active use of high-intensity magnetic separation. The main products to be obtained with these technologies will include composite concentrates of oxides or carbonates of rare-earth metals. At the same time, the commissioning dates for the projects are being repeatedly postponed; the implementation of many projects remains uncertain, which is largely due to the stagnant dynamics of global prices for rare-earth metals.

scholarly journals BEHAVIOR OF RARE-EARTH METALS IN HYDROMETALLURGICAL PROCESSING OF PYROCHLOR-MONAZITE-GOETHITE ORES

2018 ◽  
Vol 13 (3) ◽  
pp. 64-71
Author(s):  
N. A. Permyakova ◽  
E. I. Lysakova ◽  
S. I. Anufrieva ◽  
E. G. Likhnikevich
Keyword(s):  
Rare Earth ◽  
Nitric Acid ◽  
Acid Solution ◽  
Nitric Acid Solution ◽  
Elevated Temperatures ◽  
Rare Earth Metals ◽  
Acid Leaching ◽  
Earth Metal ◽  
Hydrometallurgical Processing ◽  
Nitric Acid Leaching

The article is dedicated to finding out the specific features of the behavior of rare-earth metals in hydrometallurgical processing of pyrochlore-monazite-goetite ores of the Chuktukonsky ore field is shown in the work. Chuktukonsky ore field is a potential source of rare earth metals. The mentioned ores are practically unenforceable. Hydrometallurgical methods for their complex processing were suggested. Agitational and autoclave nitric acid leaching depending on such technological parameters as temperature, HNO3 concentration, process duration, S:L ratio and the use of H2O2 were studied. The possibility of transferring manganese (that is present in a significant amount in the ore) into a nitric acid solution by hydrogen peroxide was considered. Based on the results of the conducted studies, the distribution of REM in the products of the hydrometallurgical conversion of pyrochlore-monazitegoetite ore was estimated. It was found out that incomplete opening of the ore material was observed during agitational leaching: average REM recovery into the solution is 60%. The study made it possible to solve the problem of purifying nitric acid solutions from phosphorus that hinders the subsequent extraction and separation of rare earth metal ions forming strong complexes with rare earths. Removal of phosphorus from the solution was achieved by conducting the process under pressure at elevated temperatures (200-230 0C). It was found that the optimal decomposition conditions ensuring the transfer of almost 99% of the REM into the nitric acid solution are: 25% solution of HNO3, ore size - 0.071 mm; 5% by volume H2O2; t(160 0С) = 1 h; t(230 0С) = 1 h, gradual temperature increase from 160 to 230 0С; S:L = 1:8. Autoclave nitric-acid leaching allows selecting rare earth metals from the main part of iron, phosphorus and niobium.

scholarly journals Selectivity of extraction of rare earth metals from sulfuric acid media by neocarboxylic acid hydrazides

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 185-187
Author(s):  
V. A. Nikitina ◽  
◽  
A V. Radushev ◽  
L. G. Chekanova ◽  
◽  
...  
Keyword(s):  
Rare Earth ◽  
Sulfuric Acid ◽  
Rare Earth Metals ◽  
Selective Extraction ◽  
Acid Solutions ◽  
Acid Media ◽  
Sulfuric Acid Solutions

The effect of Fe3+, Al3+, and PO43- ions on the efficiency of extraction of REM ions from sulfuric acid solutions was studied. The effectiveness of the HD1519 reagent for the concentration and selective extraction of REM ions is shown.

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