JSC “Institute “GINTsVETMET”, Moscow, Russia:

E. I. Gedgagov, Head of Laboratory of Metallurgy and Dressing, e-mail: egedgagov@gmail.com
A. V. Tarasov, Deputy R&D Director
V. G. Giganov, Head of Laboratory of Hydrometallurgical and Sorption-Extraction
M. A. Lunkova, Researcher

A research was made on conditions for obtaining of light-group REM compounds by using new industrial resins and extraction agents. This was the first usage of a frontal method of separation, performed directly in the phase of a saturated sulphocationite Lewatit MonoPlus SP112 with a macroporous structure, through processing of a thick layer of saturated resin with a quadrivalent solution of cerium and a subsequent extraction cleaning of an acid eluate from impurities with high separation coefficients in order to obtain any possible cerium (IV) compounds of the required purity. The used extraction agent was a reagent from a class of quaternary ammoniums. It was also shown that the usage of a strong-basic anionite with a porous structure, instead of the extraction agent Aliquat 336, lowers the cleaning indicators, which is due to regenerative features of hydrocarbon matrix of the anionite. With respect to deep cleaning of a lanthanum solution and other rare-earth metals (REM) from a cerium (IV) micro-impurity, it was the first time that a strongly thickening high-basic anionite (a high level of divinylbenzene) with a porous structure was researched and proposed. A fast method for separation of light-group REM, including a selective sorption of lanthanum from a mixed REM-solution with application of a complexing agent for bonding of REM parts to anionic compounds and a complexing sorbent, which makes it possible to remove lanthanum in a form of any high-pure compound; conditions were developed for regeneration of a complexing agent by returning it to a technological cycle and “soft” regimes of lanthanum sorption, which increases the lifetime of single load of the recommended sorbent in a multi-cycle process. The complexing agent used was an ethylenediaminetetraacetate acid based reagent. Regimes of extraction separation of praseodymium and neodiumium with obtainment of re-extracts, containing their individual compounds, were proposed. A process for fine cleaning of acid (рН < 1) eluates or re-extracts from impurities of non rare-earth metals by application of a new class of chelating and impregnated resins was researched. It was determined that the usage of these ionites in recommended scopes and according to each of the extracted metals-impurities, allows us to propose the most rational method for obtaining high-pure REM compounds. In particular, with respect to fine cleaning of re-extractors of cerium (IV), praseodymium, neodymium and eluate, an impregnated sorbent Lewatit TP272 was researched and is recommended for industrial use.

1. Gedgagov E. I., Myshkovskiy A. M., Ospanov N. A., Zakharyan S. V. Development of sorption processes for extraction, purification and separation of non-ferrous, rare and rare-earth metals. Materials of the first All-Russian scientificpractical conference “Prospects of extraction, production and application of REM”. Moscow, September 26–27, 2011. Moscow, 2011. pp. 57–59.
2. Gedgagov E. I., Zakharyan S. V., Khayrullin I. I., Shilov S. L. Investigation of new sorbents of LANXESS (Germany) for extraction and deep purification of non-ferrous and rare metals and usage prospects for separation of rare-earth elements. New approaches in chemical technology of mineral raw materials. Usage of extraction and sorption : materials of the second Russian conference with international participation. Saint Petersburg, June 3–6, 2013. Apatity : Izdatelstvo KNTs RAN, 2013. Part 2. pp. 25–27.
3. Gedgagov E. I., Tarasov A. V., Giganov V. G., Lunkova M. A. Prospects of use of sorption processes in the technology of obtaining of high-pure rare-earth metals with ultimate concentrates processing. Anniversary XXV International scientific symposium “Miner's week-2017”. Moscow, January 23–27, 2017.
4. Aymbetova I. O., Ustimov A. M., Bakhov Zh. K., Seysenbaev F. E., Tulekbaeva F. K. How to extract rare-earth metals from anthropogenic solutions of uranium industry. Redkie zemli. 2014. No. 3. pp. 126–131.
5. Pashkov L. I., Saykova S. V., Kuzmina V. I., Panteleeva M. V., Kokorina A. N., Linok E. V. Natural Coal Ash – Unconventional Source of Rare Elements. Zhurnal Sibirskogo federalnogo universiteta. Seriya: Tekhnika i tekhnologii. 2012. No. 5. pp. 520–530.
6. Ksenofontov B. S., Kozodaev A. S., Taranov R. A., Vinogradov M. S., Butorova I. A., Senik E. V., Voropaeva A. A. Rare-earth metal leaching from furnace dusts of thermal power stations. Inzhenernyy vestnik. 2014. No. 11. p. 7.
7. Gortsunova K. R., Rychkov V. N., Smirnov A. L., Skripchenko S. Yu., Golovko V. V., Solovev A. A., Dementev A. A. Kinetics and dynamics of sorbtion processes on the example of Khiagda uranium deposit industrial solutions. Sorbtsionnye i khromatograficheskie protsessy. 2014. Vol. 14, No. 5. pp. 847–855.
8. Zakutevskiy O. I., Psareva T. S., Strelko V. V., Zhuravlev I. Z., Khan V. E. Sorbents for Accumulation and Uptake of Radionuclides and Uranium from Aqueous Solutions. Khіmіya, fіzika ta tekhnologіya poverkhnі. 2012. Vol. 3, No. 2. pp. 199–204.
9. Unuabonah E. I., Olu-Owolabi B. I., Omolehin E. B., Adebowale K. O. SARK: A Novel Composite Resin for Water Treatment with Very High Zn²⁺, Cd²⁺, and Pb²⁺ Adsorption Capasity. Industrial & Engineering Chemistry Research. 2013. Vol. 52, No. 2. pp. 578–585.
10. Taraba B., Vesela P. Sorption of Lead (II) Ions on Natural Coals and Activated Carbon: Mechanistic, Kinetic, and Thermodynamic Aspects. Energy Fuels. 2016. Vol. 30, No. 7. pp. 5846–5853.
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12. Kamio E., Matsumoto M., Kondo K. Extraction mechanism of rare metals with microcapsules containing organophosphorus compounds. Journal of Chemical Engineering of Japan. 2002. Vol. 35, No. 2. pp. 178–185.
13. Xie F., Zhang T. A., Dreisinger D., Doyle F. A critical review on solvent extraction of rare earths from aqueous solutions. Minerals Engineering. 2014. Vol. 56. pp. 10–28.
14. Cuiping Wang, Jingting Liu, Zhiyuan Zhang, Bao Lin Wang, Hongwen Sun. Adsorption of Cd (II), Ni (II), and Zn (II) by Tourmaline at Acidic Conditions: Kinetics, Thermodynamics, and Mechanisms. Industrial & Engineering Chemistry Research. 2012. Vol. 51, No. 11. pp. 4397–4406.