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    <journal-meta>
      <journal-id journal-id-type="issn">2411-3336</journal-id>
      <journal-id journal-id-type="eissn">2541-9404</journal-id>
      <journal-title-group>
        <journal-title xml:lang="ru">Записки Горного института</journal-title>
        <journal-title xml:lang="en">Journal of Mining Institute</journal-title>
      </journal-title-group>
      <publisher>
        <publisher-name xml:lang="ru">Санкт-Петербургский горный университет императрицы Екатерины ΙΙ</publisher-name>
        <publisher-name xml:lang="en">Empress Catherine II Saint Petersburg Mining University</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.31897/pmi.2020.4.10</article-id>
      <article-id custom-type="pmi" pub-id-type="custom">pmi-13441</article-id>
      <article-id pub-id-type="uri">https://pmi.spmi.ru/pmi/article/view/13441</article-id>
      <article-categories>
        <subj-group subj-group-type="section-heading" xml:lang="ru">
          <subject>Металлургия и обогащение</subject>
        </subj-group>
        <subj-group subj-group-type="section-heading" xml:lang="en">
          <subject>Metallurgy and concentration</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title xml:lang="en">Sorption of rare earth coordination compounds</article-title>
        <trans-title-group xml:lang="ru">
          <trans-title>Сорбция координационных соединений редкоземельных элементов</trans-title>
        </trans-title-group>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name name-style="eastern">
            <surname>Cheremisina</surname>
            <given-names>Olga V.</given-names>
          </name>
          <name-alternatives>
            <name name-style="eastern" xml:lang="ru">
              <surname>Черемисина</surname>
              <given-names>О. В.</given-names>
            </name>
            <name name-style="western" xml:lang="en">
              <surname>Cheremisina</surname>
              <given-names>Olga V.</given-names>
            </name>
          </name-alternatives>
          <email>cheremisina_ov@pers.spmi.ru</email>
          <contrib-id contrib-id-type="orcid">0000-0002-3045-3313</contrib-id>
          <xref ref-type="aff" rid="aff1"/>
        </contrib>
        <aff-alternatives id="aff1">
          <aff>
            <institution xml:lang="ru">Санкт-Петербургский горный университет (Санкт-Петербург, Россия)</institution>
          </aff>
          <aff>
            <institution xml:lang="en">Saint Petersburg Mining University (Saint Petersburg, Russia)</institution>
          </aff>
        </aff-alternatives>
        <contrib contrib-type="author">
          <name name-style="eastern">
            <surname>Cheremisina</surname>
            <given-names>Elizaveta A.</given-names>
          </name>
          <name-alternatives>
            <name name-style="eastern" xml:lang="ru">
              <surname>Черемисина</surname>
              <given-names>Е. А.</given-names>
            </name>
            <name name-style="western" xml:lang="en">
              <surname>Cheremisina</surname>
              <given-names>Elizaveta A.</given-names>
            </name>
          </name-alternatives>
          <email>elizaveta.cheremisina@k1-met.com</email>
          <xref ref-type="aff" rid="aff2"/>
        </contrib>
        <aff-alternatives id="aff2">
          <aff>
            <institution xml:lang="ru">K1-Met GmbH (Линц, Австрия)</institution>
          </aff>
          <aff>
            <institution xml:lang="en">K1-Met GmbH (Linz, Austria)</institution>
          </aff>
        </aff-alternatives>
        <contrib contrib-type="author" corresp="yes">
          <name name-style="eastern">
            <surname>Ponomareva</surname>
            <given-names>Maria A.</given-names>
          </name>
          <name-alternatives>
            <name name-style="eastern" xml:lang="ru">
              <surname>Пономарева</surname>
              <given-names>М. А.</given-names>
            </name>
            <name name-style="western" xml:lang="en">
              <surname>Ponomareva</surname>
              <given-names>Maria A.</given-names>
            </name>
          </name-alternatives>
          <email>ponomareva_ma@spmi.pers.ru</email>
          <contrib-id contrib-id-type="orcid">0000-0002-7790-8178</contrib-id>
          <xref ref-type="aff" rid="aff3"/>
        </contrib>
        <aff-alternatives id="aff3">
          <aff>
            <institution xml:lang="ru">Санкт-Петербургский горный университет (Санкт-Петербург, Россия)</institution>
          </aff>
          <aff>
            <institution xml:lang="en">Saint Petersburg Mining University (Saint Petersburg, Russia)</institution>
          </aff>
        </aff-alternatives>
        <contrib contrib-type="author">
          <name name-style="eastern">
            <surname>Fedorov</surname>
            <given-names>Аleksander Т.</given-names>
          </name>
          <name-alternatives>
            <name name-style="eastern" xml:lang="ru">
              <surname>Федоров</surname>
              <given-names>А. Т.</given-names>
            </name>
            <name name-style="western" xml:lang="en">
              <surname>Fedorov</surname>
              <given-names>Аleksander Т.</given-names>
            </name>
          </name-alternatives>
          <email>bers10@bk.ru</email>
          <xref ref-type="aff" rid="aff4"/>
        </contrib>
        <aff-alternatives id="aff4">
          <aff>
            <institution xml:lang="ru">Санкт-Петербургский горный университет (Санкт-Петербург, Россия)</institution>
          </aff>
          <aff>
            <institution xml:lang="en">Saint Petersburg Mining University (Saint Petersburg, Russia)</institution>
          </aff>
        </aff-alternatives>
      </contrib-group>
      <pub-date pub-type="epub" iso-8601-date="2020-10-08">
        <day>08</day>
        <month>10</month>
        <year>2020</year>
      </pub-date>
      <pub-date date-type="collection">
        <year>2020</year>
      </pub-date>
      <volume>244</volume>
      <fpage>474</fpage>
      <lpage>481</lpage>
      <history>
        <date date-type="received" iso-8601-date="2020-01-27">
          <day>27</day>
          <month>01</month>
          <year>2020</year>
        </date>
        <date date-type="accepted" iso-8601-date="2020-05-22">
          <day>22</day>
          <month>05</month>
          <year>2020</year>
        </date>
        <date date-type="rev-recd" iso-8601-date="2020-10-08">
          <day>08</day>
          <month>10</month>
          <year>2020</year>
        </date>
      </history>
      <permissions>
        <copyright-statement xml:lang="ru">© 2020 О. В. Черемисина, Е. А. Черемисина, М. А. Пономарева, А. Т. Федоров</copyright-statement>
        <copyright-statement xml:lang="en">© 2020 Olga V. Cheremisina, Elizaveta A. Cheremisina, Maria A. Ponomareva, Аleksander Т. Fedorov</copyright-statement>
        <copyright-year>2020</copyright-year>
        <copyright-holder xml:lang="ru">О. В. Черемисина, Е. А. Черемисина, М. А. Пономарева, А. Т. Федоров</copyright-holder>
        <copyright-holder xml:lang="en">Olga V. Cheremisina, Elizaveta A. Cheremisina, Maria A. Ponomareva, Аleksander Т. Fedorov</copyright-holder>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by/4.0" xml:lang="ru">
          <license-p>Эта статья доступна по лицензии Creative Commons Attribution 4.0 International (CC BY 4.0)</license-p>
        </license>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by/4.0" xml:lang="en">
          <license-p>This article is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0)</license-p>
        </license>
      </permissions>
      <self-uri xlink:type="simple" xlink:href="https://pmi.spmi.ru/pmi/article/view/13441">https://pmi.spmi.ru/pmi/article/view/13441</self-uri>
      <abstract xml:lang="ru">
        <p>Редкоземельные элементы (РЗЭ) являются ценными и стратегически важными для многих технологических областей, таких как лазерная техника, медицина и металлургия. Основными методами выделения РЗЭ являются осаждение, экстракция и сорбция, в частности ионный обмен с использованием различных сорбентов, которые позволяют проводить селективное извлечение и отделение элементов от сопутствующих компонентов, а также проводить разделение близких по своим химическим свойствам редкоземельных металлов. В работе изучен процесс извлечения иттербия в виде координационных соединений с трилоном Б на слабоосновном анионите D-403 из нитратных растворов. Для определения термодинамических параметров сорбции анионных комплексов иттербия ионообменный процесс проводили из модельных растворов при постоянной ионной силе за счет введения NaNO3, оптимальном соотношении масс твердой и жидкой фаз, уровне рН, температурах 298 и 343 К методом переменных концентраций. Описание термодинамического равновесия проводилось с использованием закона действующих масс, записанного для уравнения ионного обмена и математически преобразованного в линейную форму. Рассчитаны значения констант ионообменного равновесия, энергии Гиббса, энтальпии и энтропии сорбционного процесса. На основании рассчитанных значений энергии Гиббса получен сорбционный ряд комплексных ионов РЗЭ с трилоном Б на анионите D-403 из нитратных растворов при температуре 298 К. Получены сорбционные характеристики анионита: полная емкость, предельная сорбция комплексного иона, полная динамическая емкость и динамическая емкость до проскока.</p>
      </abstract>
      <abstract xml:lang="en">
        <p>Rare earth elements (REEs) are valuable and strategically important in many high-technology areas, such as laser technology, pharmacy and metallurgy. The main methods of REE recovery are precipitation, extraction and sorption, in particular ion exchange using various sorbents, which allow to perform selective recovery and removal of associated components, as well as to separate rare earth metals with similar chemical properties. The paper examines recovery of ytterbium in the form of coordination compounds with Trilon B on weakly basic anion exchange resin D-403 from nitrate solutions. In order to estimate thermodynamic sorption parameters of ytterbium anionic complexes, ion exchange process was carried out from model solutions under constant ionic strength specified by NaNO3, optimal liquid to solid ratio, pH level, temperatures 298 and 343 K by variable concentrations method. Description of thermodynamic equilibrium was made using mass action law formulated for ion exchange equation and mathematically converted to linear form. Values of equilibrium constants, Gibbs free energy, enthalpy and entropy of the sorption process have been calculated. Basing on calculated values of Gibbs energy, a sorption series of complex REE ions with Trilon B was obtained over anion exchange resin D-403 from nitrate solutions at temperature 298 K. Sorption characteristics of anion exchange resin have been estimated: total capacity, limiting sorption of complex ions, total dynamic capacity and breakthrough dynamic capacity.</p>
      </abstract>
      <kwd-group xml:lang="ru">
        <title>Ключевые слова</title>
        <kwd>термодинамика сорбции и ионного обмена</kwd>
        <kwd>константа и энергия Гиббса ионообменного равновесия</kwd>
        <kwd>иттербий</kwd>
        <kwd>редкоземельные металлы</kwd>
      </kwd-group>
      <kwd-group xml:lang="en">
        <title>Keywords</title>
        <kwd>thermodynamics of sorption and ion exchange</kwd>
        <kwd>equilibrium constant</kwd>
        <kwd>Gibbs free energy of ion exchange equilibrium</kwd>
        <kwd>ytterbium</kwd>
        <kwd>rare earth metals</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body/>
  <back>
    <ref-list>
      <ref id="ref1">
        <label>1</label>
        <mixed-citation xml:lang="ru">Васильев В.П. Термодинамические свойства растворов электролитов. М.: Высшая школа, 1982. 320 с.</mixed-citation>
        <mixed-citation xml:lang="en">Vasilev V.P. Thermodynamic Properties of Electrolyte Solutions. Мoscow: Vysshaya shkola, 1982, p. 320 (in Russian).</mixed-citation>
      </ref>
      <ref id="ref2">
        <label>2</label>
        <mixed-citation xml:lang="ru">Мартыненко Л.И. Особенности комплексообразования редкоземельных элементов (III) // Успехи химии. 1991. Т. 60. Вып. 9. С. 1969-1998.</mixed-citation>
        <mixed-citation xml:lang="en">Martynenko L.I. Specifics of Rare Earth Elements (III) Complex Formation. Uspekhi khimii. 1991. Vol. 60. Iss. 9. p. 1969-1998 (in Russian).</mixed-citation>
      </ref>
      <ref id="ref3">
        <label>3</label>
        <mixed-citation xml:lang="ru">Мировой рынок редкоземельных металлов и соединений 2019-2025 (9 издание): Аналитическое исследование; Группа аналитиков по изучению рынков сырья, металлов и продукций из них. International Metallurgical Research Group. 2019. 104 с. URL: https://docplayer.ru/134894766-Mirovoy-rynok-redkozemelnyh-metallov-i-soedineniy-9-izdanie.html (дата обращения 27.01.2020).</mixed-citation>
        <mixed-citation xml:lang="en">Global Market of Rare Earth Metals and Compounds 2019-2025 (9th edition): Analytical Study; Research Group Specializing on the Markets of Raw Materials, Metals and Associated Products. International Metallurgical Research Group. 2019, p. 104. URL: https://docplayer.ru/134894766-Mirovoy-rynok-redkozemelnyh-metallov-i-soedineniy-9-izdanie.html (date of access 27.01.2020) (in Russian).</mixed-citation>
      </ref>
      <ref id="ref4">
        <label>4</label>
        <mixed-citation xml:lang="ru">Миронов И.В. Влияние среды и комплексообразование в растворах электролитов. Новосибирск: ИНХ СО РАН, 2003. 240 с.</mixed-citation>
        <mixed-citation xml:lang="en">Mironov I.V. Environmental Effect and Complex Formation in Electrolyte Solutions. Novosibirsk: INKh SO RAN, 2003, p. 240 (in Russian). </mixed-citation>
      </ref>
      <ref id="ref5">
        <label>5</label>
        <mixed-citation xml:lang="ru">Иванки С.А. Флотационное выделение элементарной серы из золотосодержащих кеков / С.А.Иванки, Д.А.Илюхин // Записки Горного института. 2020. Т. 242. С. 202-208. DOI: 10.31897/PMI.2020.2.202</mixed-citation>
        <mixed-citation xml:lang="en">Ivanik S.A., Ilyukhin D.A. Flotation extraction of elemental sulfur from gold-bearing cakes. Journal of Mining Institute. 2020. Vol. 242, p. 202-208. DOI: 10.31897/PMI.2020.2.202</mixed-citation>
      </ref>
      <ref id="ref6">
        <label>6</label>
        <mixed-citation xml:lang="ru">Современное физико-химическое описание равновесений в системе Na₂O-Al₂O₃-H₂O и ее аналогах / В.М.Сизяков, Т.Е.Литвинова, В.Н.Бричкин, А.Т.Федоров // Записки Горного института. 2019. Т. 237. С. 298-306. DOI: 10.31897/PMI.2019.3.298</mixed-citation>
        <mixed-citation xml:lang="en">Sizyakov V.M., Litvinova T.E., Brichkin V.N., Fedorov A.T. Modern physicochemical equilibrium description in Na2O–Al2O3–H2O system and its analogues. Journal of Mining Institute. 2019. Vol. 237, p. 298-306. DOI: 10.31897/PMI.2019.3.298</mixed-citation>
      </ref>
      <ref id="ref7">
        <label>7</label>
        <mixed-citation xml:lang="ru">Adsorption kinetics, thermodynamics, and isotherm studies for functionalized lanthanide-chelating resins / J.C.Callura, K.M.Perkins, J.P.Baltrus, N.R.Washburn, D.A.Dzombak, A.K.Karamalidis // Journal of Colloid and Interface Science. 2019. Vol. 557. P. 465-477. DOI: 10.1016/j.jcis.2019.08.097</mixed-citation>
        <mixed-citation xml:lang="en">Callura J.C., Perkins K.M., Baltrus J.P., Washburn N.R., Dzombak D.A., Karamalidis A.K. Adsorption kinetics, thermodynamics, and isotherm studies for functionalized lanthanide-chelating resins. Journal of Colloid and Interface Science. 2019. Vol. 557, p. 465-477. DOI: 10.1016/j.jcis.2019.08.097</mixed-citation>
      </ref>
      <ref id="ref8">
        <label>8</label>
        <mixed-citation xml:lang="ru">A facile process for enhanced rare earth elements separation from dilute solutions using N, N-di(2-ethylhexyl)-diglycolamide grafted polymer resin / H.Cui, X.Feng, J.Sh, W.Liu, N.Yan, G.Rao, W.Wang // Separation and Purification Technology. 2020. Vol. 234. 116096. DOI: 10.1016/j.seppur.2019.116096</mixed-citation>
        <mixed-citation xml:lang="en">Cui H., Feng X., Sh J., Liu W., Yan N., Rao G., Wang W. A facile process for enhanced rare earth elements separation from dilute solutions using N, N-di(2-ethylhexyl)-diglycolamide grafted polymer resin. Separation and Purification Technology. 2020. Vol. 234. 116096. DOI: 10.1016/j.seppur.2019.116096</mixed-citation>
      </ref>
      <ref id="ref9">
        <label>9</label>
        <mixed-citation xml:lang="ru">Cheremisina O.V. Thermodynamic Characteristics of Sorption Extraction and Chromatographic Separation of Anionic Complexes of Erbium and Cerium with Trilon B on Weakly Basic Anionite / O.V.Cheremisina, M.A.Ponomareva, V.N.Sagdiev // Russian Journal of Physical Chemistry A. 2016. Vol. 90 (3). P. 664-670. DOI: 10.1134/S0036024416030079</mixed-citation>
        <mixed-citation xml:lang="en">Cheremisina O.V., Ponomareva M.A., Sagdiev V.N. Thermodynamic Characteristics of Sorption Extraction and Chromatographic Separation of Anionic Complexes of Erbium and Cerium with Trilon B on Weakly Basic Anionite. Russian Journal of Physical Chemistry A. 2016. Vol. 90 (3), p. 664-670. DOI: 10.1134/S0036024416030079</mixed-citation>
      </ref>
      <ref id="ref10">
        <label>10</label>
        <mixed-citation xml:lang="ru">Determination of rare earth elements by inductively coupled plasma-mass spectrometry after dispersive solid phase extraction with novel oxidized graphene oxide and optimization with response surface methodology and central composite design / N.Manousi, B.Gomez-Gomez, Y.Madrid, E.A.Deliyanni, G.A.Zachariadis // Microchemical Journal. 2020. Vol. 152. 104428. DOI: 10.1016/j.micro.2019.104428</mixed-citation>
        <mixed-citation xml:lang="en">Manousi N., Gomez-Gomez B., Madrid Y., Deliyanni E.A., Zachariadis G.A. Determination of rare earth elements by inductively coupled plasma-mass spectrometry after dispersive solid phase extraction with novel oxidized graphene oxide and optimization with response surface methodology and central composite design. Microchemical Journal. 2020. Vol. 152. 104428. DOI: 10.1016/j.microc.2019.104428</mixed-citation>
      </ref>
      <ref id="ref11">
        <label>11</label>
        <mixed-citation xml:lang="ru">Development of a solvometallurgical process for the separation of yttrium and europium by Cyanex 923 from ethylene glycol solutions / N.K.Batchu, B.Dewulf, S.Riaño, K.Binnemans // Separation and Purification Technology. 2020. Vol. 235. 116193. DOI: 10.1016/j.seppur.2019.116193</mixed-citation>
        <mixed-citation xml:lang="en">Batchu N.K., Dewulf B., Riaño S., Binnemans K. Development of a solvometallurgical process for the separation of yttrium and europium by Cyanex 923 from ethylene glycol solutions. Separation and Purification Technology. 2020. Vol. 235. 116193. DOI: 10.1016/j.seppur.2019.116193</mixed-citation>
      </ref>
      <ref id="ref12">
        <label>12</label>
        <mixed-citation xml:lang="ru">Extraction of Rare-Earth Elements (III) from Nitric Acid Solutions with Diethyl 2-[(Diphenylphosphoryl)methoxy]-5-ethylphenylphosphonate / A.N.Turanov, V.K.Karandashev, V.E.Baulin, D.V.Baulin, V.A.Khvostikov // Russian Journal of Inorganic Chemistry. 2019. Vol. 64(10). P. 1297-1303. DOI: 10.1134/S0036023619100164</mixed-citation>
        <mixed-citation xml:lang="en">Turanov A.N., Karandashev V.K., Baulin V.E., Baulin D.V., Khvostikov V.A. Extraction of Rare-Earth Elements (III) from Nitric Acid Solutions with Diethyl 2-[(Diphenylphosphoryl)methoxy]-5-ethylphenylphosphonate. Russian Journal of Inorganic Chemistry. 2019. Vol. 64(10), p. 1297-1303. DOI: 10.1134/S0036023619100164</mixed-citation>
      </ref>
      <ref id="ref13">
        <label>13</label>
        <mixed-citation xml:lang="ru">Improving the selective extraction of lanthanides by using functionalised ionic liquid / L.Maria, A.Cruz, J.M.Carretas, B.Monteiro, C.Galinha, S.S.Gomes, M.F.Araújo, I.Paiva, J.Marçalo, J.P.Leal // Separation and Purification Technology. 2020. Vol. 237. 116354. DOI: 10.1016/j.seppur.2019.116354</mixed-citation>
        <mixed-citation xml:lang="en">Maria L., Cruz A., Carretas J.M., Monteiro B., Galinha C., Gomes S.S., Araújo M.F., Paiva I., Marçalo J., Leal J.P. Improving the selective extraction of lanthanides by using functionalised ionic liquid. Separation and Purification Technology. 2020. Vol. 237. 116354. DOI: 10.1016/j.seppur.2019.116354</mixed-citation>
      </ref>
      <ref id="ref14">
        <label>14</label>
        <mixed-citation xml:lang="ru">Removal of Impurities from Saturated Ion-Exchange Resins by Frontal-Gradient Purification in Schemes for Recovery of Nonferrous, Rare, and Rare Earth Metals / E.I.Gedgagov, S.V.Zakharvan, O.M.Sinyanskaya, D.V.Zakharvan // Theoretical Foundations of Chemical Engineering. 2018. Vol. 52 (5). P. 920-927. DOI: 10.1134/S0040579518050111</mixed-citation>
        <mixed-citation xml:lang="en">Gedgagov E.I., Zakharyan S.V., Sinyanskaya O.M., Zakharyan D.V. Removal of Impurities from Saturated Ion-Exchange Resins by Frontal-Gradient Purification in Schemes for Recovery of Nonferrous, Rare, and Rare Earth Metals. Theoretical Foundations of Chemical Engineering. 2018. Vol. 52 (5), p. 920-927. DOI: 10.1134/S0040579518050111</mixed-citation>
      </ref>
      <ref id="ref15">
        <label>15</label>
        <mixed-citation xml:lang="ru">Kiskov V.B. Research of physical and mechanical properties of briquettes, concentrated from loose high-grade iron ores / V.B.Kuskov, Y.V.Kuskova // 17th International Multidisciplinary Scientific GeoConference SGEM 2017, 29 June – 5 July 2017. Vol. 17. Iss. 11. P. 1011-1016. DOI: 10.5593/sgem2017/11/S04.129</mixed-citation>
        <mixed-citation xml:lang="en">Kuskov V.B., Kuskova Y.V. Research of physical and mechanical properties of briquettes, concentrated from loose high-grade iron ores. 17th International Multidisciplinary Scientific GeoConference SGEM 2017, 29 June – 5 July 2017. Vol. 17. Iss. 11, p. 1011-1016. DOI: 10.5593/sgem2017/11/S04.129</mixed-citation>
      </ref>
      <ref id="ref16">
        <label>16</label>
        <mixed-citation xml:lang="ru">Review and new life cycle assessment for rare earth production from bastnäsite, ion adsorption clays and lateritic monazite / G.Bailey, P.J.Joyce, D.Schrijvers, R.Schulze, A.M.Sylvestre, B.Sprecher, E.Vahidi, D.Wedulf, K.Van Acker // Resources, Conservation and Recycling. 2020. Vol. 155. 104675. DOI: 10.1016/j.resconre.2019.104675</mixed-citation>
        <mixed-citation xml:lang="en">Bailey G., Joyce P.J., Schrijvers D., Schulze R., Sylvestre A.M., Sprecher B., Vahidi E., Dewulf W., Van Acker K. Review and new life cycle assessment for rare earth production from bastnäsite, ion adsorption clays and lateritic monazite. Resources, Conservation and Recycling. 2020. Vol. 155. 104675. DOI: 10.1016/j.resconrec.2019.104675</mixed-citation>
      </ref>
      <ref id="ref17">
        <label>17</label>
        <mixed-citation xml:lang="ru">Selective extraction of thorium from uranium and rare earth elements using sulfonated covalent organic framework and its membrane derivate / X.H.Xiong, Y.Tao, Z.W.Yu, L.X.Yan, L.J.Sun, Y.L.Fan, F.Luo // Chemical Engineering Journal. 2020. Vol. 384. 123240. DOI: 10.1016/j.cej.2019.123240</mixed-citation>
        <mixed-citation xml:lang="en">Xiong X.H., Tao Y., Yu Z.W., Yan L.X., Sun L.J., Fan Y.L., Luo F. Selective extraction of thorium from uranium and rare earth elements using sulfonated covalent organic framework and its membrane derivate. Chemical Engineering Journal. 2020. Vol. 384. 123240. DOI: 10.1016/j.cej.2019.123240</mixed-citation>
      </ref>
      <ref id="ref18">
        <label>18</label>
        <mixed-citation xml:lang="ru">Swain N. Hydrometallurgical route for recovery and separation of samarium (III) and cobalt (II) from simulated waste solution using tri-n-octyl phosphine oxide – A novel pathway for synthesis of samarium and cobalt oxides nanoparticles / N.Swain, S.Mishra, M.R.Acharya // Journal of Alloys and Compounds. 2020. Vol. 815. 152423. DOI: 10.1016/j.jallcom.2019.152423</mixed-citation>
        <mixed-citation xml:lang="en">Swain N., Mishra S., Acharya M.R. Hydrometallurgical route for recovery and separation of samarium (III) and cobalt (II) from simulated waste solution using tri-n-octyl phosphine oxide – A novel pathway for synthesis of samarium and cobalt oxides nanoparticles. Journal of Alloys and Compounds. 2020. Vol. 815. 152423. DOI: 10.1016/j.jallcom.2019.152423</mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>
