scholarly journals Rare Earth Metals Leaching from Coal Ash and Theirs Concentration

2016 ◽  
Vol 5 (1) ◽  
pp. 48-55
Author(s):  
Сеник ◽  
E. Senik ◽  
Виноградов ◽  
M. Vinogradov ◽  
Таранов ◽  
...  
Keyword(s):  
Rare Earth ◽  
Ion Exchange ◽  
Rare Earth Metals ◽  
Experimental Studies ◽  
Cation Exchange Resin ◽  
Acid Leaching ◽  
Coal Ash ◽  
Flow Diagram ◽  
Ion Exchange Resins ◽  
Exchange Resins

Problems related to rare earth metals leaching from coal ash and theirs ion-exchange concentration from sulfuric solutions, in particular the characteristics of scandium, yttrium and lanthanum sorption by different ion exchange resins have been considered in this work. It has been shown that the best way to leach rare earth metals from coal ash is a complex acid and biological treatment of ash waste. Kinetics related to the process of scandium, yttrium and lanthanum acid leaching from ash and slag waste of CHPP in Kumertau has been investigated. Subsequent metal solutions concentration was achieved using ion exchange resins. The results of experimental studies related to the processes of rare-earth metals (in particularly scandium) ion exchange concentration by cation exchange resin in the Naform PC-100 have been presented, as well as the results of experimental studies related to rare earth metals (scandium including) sedimentation process, using special sedimentators. Dependences of rare earth metals (in particular scandium) sedimentation efficiency against pH value have been constructed, and recommendations for pH values, that are optimal for rare earth metals sedimentation, have been given. Based on obtained experimental results it was created and tested an experimental laboratory prototype of plant for rare earth metals (scandium, yttrium and lanthanum including) extraction from located near Moscow brown coal basin’s slag heaps, and from ash dumps of Russian Federation’s energy enterprises. This plant’s process flow diagram as well as its operation description has been presented. The created plant was tested in modes previously fulfilled in laboratory conditions. At the same time, carried out integrated exploration have showed the prospects for implementation of developed technical solutions for processing of ash dumps of Russian Federation’s various energy enterprises.

Removal of Impurities from Saturated Ion-Exchange Resins by Frontal-Gradient Purification in Schemes for Recovery of Nonferrous, Rare, and Rare Earth Metals

2018 ◽  
Vol 52 (5) ◽  
pp. 920-927
Author(s):  
E. I. Gedgagov ◽  
S. V. Zakhar’yan ◽  
O. M. Sinyanskaya ◽  
D. V. Zakhar’yan
Keyword(s):  
Rare Earth ◽  
Ion Exchange ◽  
Rare Earth Metals ◽  
Ion Exchange Resins ◽  
Removal Of Impurities ◽  
Exchange Resins

scholarly journals Treatment of spent ion exchange resins: Comparison between hydrothermal and acid leaching processes

2020 ◽  
Vol 8 (4) ◽  
pp. 103873
Author(s):  
Antoine Leybros ◽  
Jean-Christophe Ruiz ◽  
Thibault D’Halluin ◽  
Egle Ferreri ◽  
Agnès Grandjean
Keyword(s):  
Ion Exchange ◽  
Acid Leaching ◽  
Ion Exchange Resins ◽  
Exchange Resins

scholarly journals Terephthalaldehyde–Phenolic Resins as a Solid-Phase Extraction System for the Recovery of Rare-Earth Elements

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 311
Author(s):  
Ruth Oye Auke ◽  
Guilhem Arrachart ◽  
Romain Tavernier ◽  
Ghislain David ◽  
Stéphane Pellet-Rostaing
Keyword(s):  
Rare Earth ◽  
Ion Exchange ◽  
Solid Phase Extraction ◽  
Rare Earth Elements ◽  
Solid Phase ◽  
Extraction System ◽  
Ion Exchange Resins ◽  
Phase Extraction ◽  
Phenolic Resins ◽  
Exchange Resins

Rare-earth elements (REEs) are involved in most high technology devices and have become critical for many countries. The progress of processes for the extraction and recovery of REEs is therefore essential. Liquid–solid extraction methods are an attractive alternative to the conventional solvent extraction process used for the separation and/or purification of REEs. For this purpose, a solid-phase extraction system was investigated for the extraction and valorization of REEs. Ion-exchange resins were synthesized involving the condensation of terephthalaldehyde with resorcinol under alkaline conditions. The terephthalaldehyde, which is a non-hazardous aromatic dialdehyde, was used as an alternative to formaldehyde that is toxic and traditionally involved to prepare phenolic ion-exchange resins. The resulting formaldehyde-free resole-type phenolic resins were characterized and their ion-exchange capacity was investigated in regard to the extraction of rare-earth elements. We herein present a promising formaldehyde and phenol-free as a potential candidate for solid–liquid extraction REE with a capacity higher than 50 mg/g and the possibility to back-extract the REEs by a striping step using a 2 M HNO3 solution.

scholarly journals Selective Extraction of Rare Earth Elements from Phosphoric Acid by Ion Exchange Resins

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 682 ◽  
Author(s):  
Xavier Hérès ◽  
Vincent Blet ◽  
Patricia Di Natale ◽  
Abla Ouaattou ◽  
Hamid Mazouz ◽  
...  
Keyword(s):  
Rare Earth ◽  
Ion Exchange ◽  
Phosphoric Acid ◽  
Rare Earth Elements ◽  
Moving Boundary ◽  
Cost Effective ◽  
Selective Extraction ◽  
Ion Exchange Resins ◽  
Maximum Sorption Capacity ◽  
Exchange Resins

Rare earth elements (REE) are present at low concentrations (hundreds of ppm) in phosphoric acid solutions produced by the leaching of phosphate ores by sulfuric acid. The strongly acidic and complexing nature of this medium, as well as the presence of metallic impurities (including iron and uranium), require the development of a particularly cost effective process for the selective recovery of REE. Compared to the classical but costly solvent extraction, liquid-solid extraction using commercial chelating ion exchange resins could be an interesting alternative. Among the different resins tested in this paper (Tulsion CH-93, Purolite S940, Amberlite IRC-747, Lewatit TP-260, Lewatit VP OC 1026, Monophos, Diphonix,) the aminophosphonic IRC-747, and aminomethylphosphonic TP-260 are the most promising. Both of them present similar performances in terms of maximum sorption capacity estimated to be 1.8 meq/g dry resin and in adsorption kinetics, which appears to be best explained by a moving boundary model controlled by particle diffusion.

Studies on ion-exchange resins. III. Diffusion of neutral molecules in a sulfonic acid cation-exchange resin

1951 ◽  
Vol 6 (4) ◽  
pp. 304-322 ◽  
Author(s):  
Harry P Gregor ◽  
F.C Collins ◽  
Martin Pope
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Sulfonic Acid ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Ion Exchange Resins ◽  
Acid Cation ◽  
Exchange Resins

Thermochemical Approach on Treating Spent Ion Exchange Resins

2000 ◽  
Vol 663 ◽  
Author(s):  
M.I. Ojovan ◽  
V.l. Klimov ◽  
G.A. Petrov ◽  
S.A. Dmitriev ◽  
A.V. Laurson ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Organic Molecules ◽  
Experimental Studies ◽  
Chemical Species ◽  
Thermochemical Treatment ◽  
Ion Exchange Resins ◽  
Complete Destruction ◽  
Decomposition Of Organic Matter ◽  
Ash Residue ◽  
Exchange Resins

ABSTRACTA thermochemical approach was suggested for treating and conditioning specific streams of radioactive wastes for example spent ion exchange resins (IER), mixed, organic or chlorine-containing radioactive waste (PVC, etc.). Conventional thermal treatment of such waste encounters serious problems concerning complete destruction of organic molecules and possible emissions of radionuclides, heavy metals and chemically hazardous species. The thermochemical treatment uses powdered metal fuels (PMF) that are specifically formulated for the waste composition and react chemically with the waste components. The composition of the PMF is designed in such a way as to minimize the release of hazardous components and radionuclides in the off gas and to confine the contaminants in the ash residue. The thermochemical procedures allow decomposition of organic matter and capturing hazardous radionuclides and chemical species simultaneously. Previous preliminary work demonstrated the feasibility of applying the thermochemical approach to treatment of spent IER using PMF. Herein, the results are presented of theoretical and experimental studies to define the optimal PMF composition as well as the PMF/waste ratio.

scholarly journals Ion-Exchange Resins as Controlled Drug Delivery Carriers

2010 ◽  
Vol 2 (3) ◽  
pp. 597 ◽  
Author(s):  
M. V. Srikanth ◽  
S. A. Sunil ◽  
N. S. Rao ◽  
M. U. Uhumwangho ◽  
K. V. Ramana Murthy
Keyword(s):  
Drug Delivery ◽  
Ion Exchange ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Controlled Drug Delivery ◽  
Ion Exchange Resin ◽  
Ion Exchange Resins ◽  
Exchange Cation ◽  
Therapeutic Applications ◽  
Exchange Resins

Ion exchange resins (IER) are insoluble polymers that contain acidic or basic functional groups and have the ability to exchange counter-ions within aqueous solutions surrounding them. Based on the nature of the exchangeable ion of the resin as a cation or anion, it is classified as cationic or anionic exchange resins, respectively. The efficacy of ion exchange resins mainly depends upon their physical properties such as degree of cross-linking, porosity, acid base strength, stability, purity and particle size. Modified release of drugs from resinate (drug-resin complexes) is another potential application of ion exchange resins.  Due to the versatile utility of ion exchange resins, they are being used for various drug delivery and therapeutic applications. Resins used are polymers that contain appropriately substituted acidic groups, such as carboxylic and sulfonic for cation exchangers; or basic groups, such as quaternary ammonium group for anion exchangers. This review addresses different types of ion exchange resin, their properties, the chemistry; role of IER in controlled drug delivery systems, its therapeutic applications, methods of preparation of IER along with their resonates. Keywords: Anion exchange; Cation exchange; Resin; Controlled release; Resinates; Drug delivery. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i3.4991               J. Sci. Res. 2 (3), 599-613 (2010) 

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