{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,8]],"date-time":"2026-11-08T12:08:49Z","timestamp":1794139729756,"version":"4.8.0"},"reference-count":49,"publisher":"American Chemical Society (ACS)","issue":"34","license":[{"start":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T00:00:00Z","timestamp":1787097600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002322","name":"Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior","doi-asserted-by":"publisher","award":["NA"],"award-info":[{"award-number":["NA"]}],"id":[{"id":"10.13039\/501100002322","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico","doi-asserted-by":"publisher","award":["305096\/2023-0"],"award-info":[{"award-number":["305096\/2023-0"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico","doi-asserted-by":"publisher","award":["402208\/2024-2"],"award-info":[{"award-number":["402208\/2024-2"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004586","name":"Funda??o Carlos Chagas Filho de Amparo ? i Pesquisa do Estado do Rio de Janeiro","doi-asserted-by":"publisher","award":["E-26\/203.832\/2025"],"award-info":[{"award-number":["E-26\/203.832\/2025"]}],"id":[{"id":"10.13039\/501100004586","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004809","name":"Financiadora de Estudos e Projetos","doi-asserted-by":"publisher","award":["0951\/24"],"award-info":[{"award-number":["0951\/24"]}],"id":[{"id":"10.13039\/501100004809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004901","name":"Funda??o de Amparo ? i Pesquisa do Estado de Minas Gerais","doi-asserted-by":"publisher","award":["RED-00102-16"],"award-info":[{"award-number":["RED-00102-16"]}],"id":[{"id":"10.13039\/501100004901","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>The separation of zirconium and hafnium remains a major challenge in hydrometallurgical processing due to their similar chemical behavior and strong tendency toward hydrolysis and complexation in acidic media. In this work, a combined experimental and density functional theory (DFT) investigation was performed to elucidate the mechanism of Hf(IV)\/Zr(IV) extraction by di(2-ethylhexyl) phosphoric acid (D2EHPA) in sulfuric acid solutions. DFT calculations indicate that both metals preferentially adopt 8-fold coordination in aqueous solution and undergo favorable first-stage hydrolysis even under strongly acidic conditions. Sulfate coordination was found to be highly exergonic, with bidentate sulfate complexes slightly more stable than monodentate species. Thermodynamic analysis demonstrates that extraction pathways involving concomitant sulfate transfer and proton exchange are significantly more favorable than purely hydroxide-based mechanisms, supporting the formation of neutral sulfate-containing metal\u2013phosphonate complexes in the organic phase. The calculations further indicate a small energetic preference for Hf(IV) extraction relative to Zr(IV), consistent with the experimentally observed selectivity of D2EHPA in sulfuric media. Solvent extraction experiments were carried out using sulfate liquors produced directly from zircon concentrate supplied by Indu\u0301strias Nucleares do Brasil, reproducing realistic industrial conditions. Aging of the feed solution promoted increased Zr extraction and pronounced sulfate coextraction, indicating substantial changes in aqueous speciation over time. Addition of iodide reduced sulfur coextraction while maintaining relatively high metal extraction efficiencies, suggesting modification of the aqueous coordination environment. The combined theoretical and experimental results demonstrate that Hf\/Zr separation in sulfate media is governed by tightly coupled hydrolysis, sulfate coordination, and proton-transfer equilibria, highlighting the critical role of sulfate-containing species in controlling extraction efficiency and selectivity under industrially relevant conditions. From a process-design perspective, the results suggest that tailored extractants capable of modulating the aqueous hydrolysis of Zr(IV) and Hf(IV), while preserving efficient coordination in the organic phase, may provide an effective strategy for enhancing extraction selectivity and developing more sustainable Hf\/Zr separation processes.<\/jats:p>","DOI":"10.1021\/acsomega.6c06044","type":"journal-article","created":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T15:01:21Z","timestamp":1787151681000},"page":"51721-51730","source":"Crossref","is-referenced-by-count":2,"title":["Mechanistic Insights into Hf(IV)\/Zr(IV) Extraction\nby D2EHPA in Sulfate Media: A DFT Study Supported by Experiments with\nIndustrial Sulfate Liquors"],"prefix":"10.1021","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6807-4116","authenticated-orcid":true,"given":"Pedro Augusto de Andrade","family":"Novaes","sequence":"first","affiliation":[{"name":"Universidade Federal de Minas Gerais \u2212 UFMG , , , ,","place":["Belo Horizonte, MG, Brazil, 31270-901"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raquel Maia","family":"Mingote","sequence":"additional","affiliation":[{"name":"Centro de Desenvolvimento da Tecnologia Nuclear \u2212 CDTN , , ,","place":["Belo Horizonte, MG, Brazil, 31270-901"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlos Antonio","family":"Morais","sequence":"additional","affiliation":[{"name":"Centro de Desenvolvimento da Tecnologia Nuclear \u2212 CDTN , , ,","place":["Belo Horizonte, MG, Brazil, 31270-901"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexandre Carvalho","family":"Bertoli","sequence":"additional","affiliation":[{"name":"Universidade Federal do Rio de Janeiro \u2212 UFRJ , , , ,","place":["Rio de Janeiro, RJ, Brazil, 21941-901"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8164-4454","authenticated-orcid":true,"given":"He\u0301lio Anderson","family":"Duarte","sequence":"additional","affiliation":[{"name":"Universidade Federal de Minas Gerais \u2212 UFMG , , , ,","place":["Belo Horizonte, MG, Brazil, 31270-901"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,8,19]]},"reference":[{"key":"2026090307175122900_cit1","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.jiec.2016.06.004","article-title":"A Review on the Aqueous Chemistry of Zr(IV) and Hf(IV)\nand Their Separation by Solvent Extraction","volume":"39","author":"Wang","year":"2016","journal-title":"Journal of Industrial and Engineering Chemistry"},{"issue":"2","key":"2026090307175122900_cit2","doi-asserted-by":"publisher","first-page":"1471","DOI":"10.1007\/s42461-026-01491-6","article-title":"A Comprehensive\nReview of Hydrometallurgical Methods for the Extraction and Separation\nof Zirconium and Hafnium","volume":"43","author":"de Oliveira Rodrigues","year":"2026","journal-title":"Min. Metall. Explor."},{"issue":"6","key":"2026090307175122900_cit3","doi-asserted-by":"publisher","first-page":"2816","DOI":"10.1021\/jacs.1c13338","article-title":"Oxo-Cluster-Based Zr\/Hf IV Separation: Shedding Light\non a 70-Year-Old Process","volume":"144","author":"Sommers","year":"2022","journal-title":"J. Am. Chem. Soc."},{"key":"2026090307175122900_cit4","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1016\/j.jnucmat.2015.07.010","article-title":"Production\nof Nuclear Grade Zirconium: A Review","volume":"466","author":"Xu","year":"2015","journal-title":"J. Nucl.\nMater."},{"key":"2026090307175122900_cit5","doi-asserted-by":"publisher","first-page":"105600","DOI":"10.1016\/j.hydromet.2021.105600","article-title":"Separation\nof Hafnium from Zirconium in HNO3 Solution by Solvent Extraction with\nCyanex572","volume":"202","author":"He","year":"2021","journal-title":"Hydrometallurgy"},{"issue":"2\u20134","key":"2026090307175122900_cit6","doi-asserted-by":"publisher","first-page":"115","DOI":"10.1016\/j.hydromet.2007.10.002","article-title":"Determination\nof Optimum Process Conditions for the Extraction and Separation of\nZirconium and Hafnium by Solvent Extraction","volume":"90","author":"Taghizadeh","year":"2008","journal-title":"Hydrometallurgy"},{"key":"2026090307175122900_cit7","doi-asserted-by":"publisher","first-page":"84","DOI":"10.1016\/j.hydromet.2014.12.005","article-title":"Separation\nof Hf(IV)-Zr(IV) in H2SO4\nSolutions Using Solvent Extraction with D2EHPA or Cyanex 272 at Different\nReagent and Metal Ion Concentrations","volume":"152","author":"Lee","year":"2015","journal-title":"Hydrometallurgy"},{"issue":"5","key":"2026090307175122900_cit8","doi-asserted-by":"publisher","first-page":"759","DOI":"10.1080\/01496395.2015.1119841","article-title":"Solvent Extraction\nReaction of Hafnium(IV) from Strong\nSulfuric Acid Solutions with D2EHPA and PC 88A","volume":"51","author":"Wang","year":"2016","journal-title":"Sep. Sci. Technol."},{"issue":"4","key":"2026090307175122900_cit9","doi-asserted-by":"publisher","first-page":"205","DOI":"10.1016\/0020-708X(81)90050-8","article-title":"Sequential\nSeparation of Hafnium,\nZirconium and Niobium from Sulphuric Acid Medium Using Di(2-Ethylhexyl)\nPhosphoric Acid as an Extractant","volume":"32","author":"Das","year":"1981","journal-title":"International\nJournal of Applied Radiation and Isotopes"},{"issue":"12","key":"2026090307175122900_cit10","doi-asserted-by":"publisher","first-page":"1175","DOI":"10.1002\/ejic.202001140","article-title":"Unveiling\nthe Zirconium and Hafnium Speciation in Fluoride-Nitric Acid Solutions\nby Paper Spray Ionization Mass Spectrometry Combined with DFT Calculations","volume":"2021","author":"Bertoli","year":"2021","journal-title":"Eur. J. Inorg. Chem."},{"key":"2026090307175122900_cit11","doi-asserted-by":"publisher","first-page":"465894","DOI":"10.1016\/j.chroma.2025.465894","article-title":"Adsorption\nand Separation of Zirconium and Hafnium from Sulfate Media by a Conveniently\nSynthesized (2,4,4-Trimethylpentyl)(2-Methylpropyl)Phosphinic Acid\nFunctionalized Merrifield Resin: A Combined Study of Experiments and\nDFT Calculations","volume":"1749","author":"Wang","year":"2025","journal-title":"J. Chromatogr. A"},{"issue":"1","key":"2026090307175122900_cit12","doi-asserted-by":"publisher","first-page":"333","DOI":"10.1007\/s10967-019-06585-8","article-title":"Preferential\nExtraction of Hafnium over Zirconium with D2EHPA through Selective\nComplexation of Organic Acids","volume":"321","author":"Zhao","year":"2019","journal-title":"J. Radioanal.\nNucl. Chem."},{"key":"2026090307175122900_cit13","doi-asserted-by":"publisher","first-page":"12","DOI":"10.1016\/j.hydromet.2015.11.013","article-title":"Development of a Separation Process\nfor the Selective\nExtraction of Hafnium(IV) over Zirconium(IV) from Sulfuric Acid Solutions\nby Using D2EHPA","volume":"160","author":"Wang","year":"2016","journal-title":"Hydrometallurgy"},{"issue":"2","key":"2026090307175122900_cit14","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1007\/s41365-019-0548-8","article-title":"Separation\nof Hafnium from Zirconium in Hydrochloric Acid Solution with Di(2-Ethylhexyl)Phosphoric\nAcid by Solvent Extraction","volume":"30","author":"Yang","year":"2019","journal-title":"Nuclear Science\nand Techniques"},{"issue":"6","key":"2026090307175122900_cit15","doi-asserted-by":"publisher","first-page":"119771","DOI":"10.1016\/j.jece.2025.119771","article-title":"Advances in Zirconium\/Hafnium\nSeparation Leveraging Solution Chemistry: Mechanisms and Applications","volume":"13","author":"Dong","year":"2025","journal-title":"J. Environ. Chem. Eng."},{"key":"2026090307175122900_cit16","first-page":"154313","article-title":"Limitac\u0327o\u0303es\nDa Separac\u0327a\u0303o Hf\/Zr a Partir de Licor Sulfu\u0301rico\nObtido Por Processamento Qui\u0301mico Do Zirca\u0303o","volume-title":"Anais do XXIX Encontro Nacional de Tratamento de Mine\u0301rios\ne Metalurgia Extrativa","author":"Mingote","year":"2022"},{"issue":"18","key":"2026090307175122900_cit17","doi-asserted-by":"publisher","first-page":"3865","DOI":"10.1103\/PhysRevLett.77.3865","article-title":"Generalized\nGradient Approximation\nMade Simple","volume":"77","author":"Perdew","year":"1996","journal-title":"Phys. Rev. Lett."},{"issue":"13","key":"2026090307175122900_cit18","doi-asserted-by":"publisher","first-page":"6158","DOI":"10.1063\/1.478522","article-title":"Toward Reliable Density Functional Methods without\nAdjustable Parameters: The PBE0Model","volume":"110","author":"Adamo","year":"1999","journal-title":"J. Chem.\nPhys."},{"issue":"32","key":"2026090307175122900_cit19","doi-asserted-by":"publisher","first-page":"9955","DOI":"10.1002\/chem.201200497","article-title":"Supramolecular\nBinding Thermodynamics by Dispersion-Corrected Density Functional\nTheory","volume":"18","author":"Grimme","year":"2012","journal-title":"Chem.\u2500Eur. J."},{"issue":"18","key":"2026090307175122900_cit20","doi-asserted-by":"publisher","first-page":"3297","DOI":"10.1039\/b508541a","article-title":"Balanced Basis Sets\nof Split Valence, Triple Zeta Valence\nand Quadruple Zeta Valence Quality for H to Rn: Design and Assessment\nof Accuracy","volume":"7","author":"Weigend","year":"2005","journal-title":"Phys. Chem. Chem. Phys."},{"issue":"13","key":"2026090307175122900_cit21","doi-asserted-by":"publisher","DOI":"10.1063\/1.3484283","article-title":"Property-Optimized\nGaussian Basis Sets for Molecular Response Calculations","volume":"133","author":"Rappoport","year":"2010","journal-title":"J. Chem. Phys."},{"issue":"22","key":"2026090307175122900_cit22","doi-asserted-by":"publisher","DOI":"10.1063\/5.0004608","article-title":"The\nORCA Quantum\nChemistry Program Package","volume":"152","author":"Neese","year":"2020","journal-title":"J. Chem. Phys."},{"issue":"5","key":"2026090307175122900_cit23","doi-asserted-by":"publisher","DOI":"10.1002\/wcms.1606","article-title":"Software Update:\nThe ORCA Program System\u2500Version 5.0","volume":"12","author":"Neese","year":"2022","journal-title":"WIREs Computational Molecular Science"},{"issue":"18","key":"2026090307175122900_cit24","doi-asserted-by":"publisher","first-page":"6378","DOI":"10.1021\/jp810292n","article-title":"Universal Solvation Model Based on\nSolute Electron Density and on a Continuum Model of the Solvent Defined\nby the Bulk Dielectric Constant and Atomic Surface Tensions","volume":"113","author":"Marenich","year":"2009","journal-title":"J. Phys. Chem. B"},{"key":"2026090307175122900_cit25","doi-asserted-by":"publisher","first-page":"137455","DOI":"10.1016\/j.seppur.2026.137455","article-title":"Mechanism\nInsight into the Separation of Zirconium and Hafnium by Dibenzoylmethane:\nCrystal Structures, Spectroscopy, and Theoretical Calculations","volume":"394","author":"Qi","year":"2026","journal-title":"Sep. Purif. Technol."},{"issue":"51","key":"2026090307175122900_cit26","doi-asserted-by":"publisher","first-page":"11534","DOI":"10.1021\/jp012536s","article-title":"Absolute Hydration Free Energy of the Proton from First-Principles\nElectronic Structure Calculations","volume":"105","author":"Zhan","year":"2001","journal-title":"J. Phys.\nChem. A"},{"issue":"3","key":"2026090307175122900_cit27","doi-asserted-by":"publisher","first-page":"535","DOI":"10.1590\/S0100-40422006000300023","article-title":"Modelos Conti\u0301nuos Do Solvente: Fundamentos","volume":"29","author":"Pliego","year":"2006","journal-title":"Quim. Nova"},{"issue":"9","key":"2026090307175122900_cit28","doi-asserted-by":"publisher","first-page":"1622","DOI":"10.1039\/b109595a","article-title":"Gibbs Energy\nof Solvation of Organic\nIons in Aqueous and Dimethyl Sulfoxide Solutions","volume":"4","author":"Pliego","year":"2002","journal-title":"Phys. Chem. Chem. Phys."},{"key":"2026090307175122900_cit29","doi-asserted-by":"publisher","DOI":"10.1007\/s00894-024-06213-7","article-title":"Insights Intro Rare Earth Element\nSpeciation: Unraveling Sulfate\nand Hydrolysis Complexes Through DFT Calculations","volume":"30","author":"Bertoli","journal-title":"J. Mol. Model."},{"issue":"12","key":"2026090307175122900_cit30","doi-asserted-by":"publisher","first-page":"6321","DOI":"10.1021\/ic500938k","article-title":"Changing Hafnium\nSpeciation in Aqueous Sulfate Solutions: A High-Energy X-Ray Scattering\nStudy","volume":"53","author":"Kalaji","year":"2014","journal-title":"Inorg. Chem."},{"issue":"6","key":"2026090307175122900_cit31","doi-asserted-by":"publisher","first-page":"1083","DOI":"10.1134\/S0022476614060110","article-title":"New Structure Types\nof Polymeric Chain Anions in the Crystal Structures of Complex Zirconium\nFluorides","volume":"55","author":"Davidovich","year":"2014","journal-title":"Journal of Structural Chemistry"},{"issue":"8","key":"2026090307175122900_cit32","doi-asserted-by":"publisher","first-page":"735","DOI":"10.1080\/18811248.2008.9711474","article-title":"Hydrolysis Constant\nand Coordination Geometry of Zirconium(IV)","volume":"45","author":"SASAKI","year":"2008","journal-title":"J. Nucl. Sci. Technol."},{"issue":"14","key":"2026090307175122900_cit33","doi-asserted-by":"publisher","first-page":"2142","DOI":"10.1039\/B402804J","article-title":"Structure\nof the Hydrated, Hydrolysed\nand Solvated Zirconium(iv) and Hafnium(iv) Ions in Water and Aprotic\nOxygen Donor Solvents. A Crystallographic, EXAFS Spectroscopic and\nLarge Angle X-Ray Scattering Study","author":"Hagfeldt","year":"2004","journal-title":"Dalton Trans."},{"issue":"6","key":"2026090307175122900_cit34","doi-asserted-by":"publisher","first-page":"965","DOI":"10.1016\/0022-1902(64)80259-1","article-title":"Stability of Some\nInorganic and Organic Complex Compounds of Zirconium and Hafnium","volume":"26","author":"Ryabchikov","year":"1964","journal-title":"Journal of Inorganic and Nuclear Chemistry"},{"issue":"11","key":"2026090307175122900_cit35","doi-asserted-by":"publisher","first-page":"655","DOI":"10.1070\/RC1962v031n11ABEH001326","article-title":"THE CHEMISTRY\nOF AQUEOUS SOLUTIONS OF ZIRCONIUM SALTS\n(DOES THE ZIRCONYL ION EXIST?)","volume":"31","author":"Solovkin","year":"1962","journal-title":"Russ. Chem.\nRev."},{"issue":"11","key":"2026090307175122900_cit36","doi-asserted-by":"publisher","first-page":"1765","DOI":"10.1002\/(SICI)1099-0682(199811)1998:11&lt;1765::AID-EJIC1765&gt;3.0.CO;2-%23","article-title":"Thermodynamic\nStability of Zirconium(IV) Complexes with Hydroxy Ions","volume":"1998","author":"Veyland","year":"1998","journal-title":"Eur. J. Inorg. Chem."},{"issue":"9","key":"2026090307175122900_cit37","doi-asserted-by":"publisher","first-page":"3182","DOI":"10.1021\/ja01177a070","article-title":"The Aqueous Chemistry\nof Zirconium","volume":"71","author":"Connick","year":"1949","journal-title":"J. Am. Chem. Soc."},{"issue":"3","key":"2026090307175122900_cit38","doi-asserted-by":"publisher","first-page":"1171","DOI":"10.1021\/ja01147a087","article-title":"The Hydrolysis and Polymerization of Zirconium in Perchloric\nAcid Solution 1","volume":"73","author":"Connick","year":"1951","journal-title":"J. Am. Chem. Soc."},{"issue":"2","key":"2026090307175122900_cit39","doi-asserted-by":"publisher","first-page":"173","DOI":"10.1016\/0020-1650(76)80194-8","article-title":"Identification of the Zirconium Sulfate Species in\nHighly Acidic Aqueous Solutions by Raman Spectroscopy","volume":"12","author":"Baglin","year":"1976","journal-title":"Inorganic and Nuclear Chemistry Letters"},{"issue":"6\u20137","key":"2026090307175122900_cit40","doi-asserted-by":"publisher","first-page":"229","DOI":"10.1016\/0020-1650(78)80066-X","article-title":"A Lasar Raman Study\nof the Coordination Chemistry of\nZr(IV) and Hf(IV) in Highly Acidic Sulfate and Lactate Media","volume":"14","author":"Baglin","year":"1978","journal-title":"Inorganic and Nuclear Chemistry Letters"},{"issue":"4","key":"2026090307175122900_cit41","doi-asserted-by":"publisher","first-page":"93","DOI":"10.3390\/separations11040093","article-title":"The Extraction\nMechanism of Zirconium and Hafnium in the MIBK-HSCN System","volume":"11","author":"Xiong","year":"2024","journal-title":"Separations"},{"issue":"25","key":"2026090307175122900_cit42","doi-asserted-by":"publisher","first-page":"4240","DOI":"10.1021\/ic00272a020","article-title":"Crystal Structure\nof a Complex Basic\nZirconium Sulfate","volume":"26","author":"Squattrito","year":"1987","journal-title":"Inorg. Chem."},{"issue":"9","key":"2026090307175122900_cit43","doi-asserted-by":"publisher","first-page":"3500","DOI":"10.1021\/la0116286","article-title":"Particle Growth Kinetics in Zirconium Sulfate Aqueous\nSolutions Followed by Dynamic Light Scattering and Analytical Ultracentrifugation:\nImplications for Thin Film Deposition","volume":"18","author":"Co\u0308lfen","year":"2002","journal-title":"Langmuir"},{"issue":"11","key":"2026090307175122900_cit44","doi-asserted-by":"publisher","first-page":"1712","DOI":"10.1002\/jctb.4249","article-title":"Selective\nExtraction of Hf(IV) over\nZr(IV) from Aqueous H 2 SO 4 Solutions by Solvent\nExtraction with Acidic Organophosphorous Based Extractants","volume":"89","author":"Banda","year":"2014","journal-title":"J. Chem. Technol. Biotechnol."},{"key":"2026090307175122900_cit45","doi-asserted-by":"publisher","first-page":"77","DOI":"10.1016\/j.hydromet.2013.09.006","article-title":"The Influence of the Treatment of\nZr(IV) and Hf(IV) Sulfate Solution on the Ion-Exchange Purifying of\nZirconium from Hafnium on Diphonix\u00ae Resin","volume":"140","author":"Jako\u0301bik-Kolon","year":"2013","journal-title":"Hydrometallurgy"},{"issue":"20","key":"2026090307175122900_cit46","doi-asserted-by":"publisher","first-page":"15456","DOI":"10.1021\/acs.inorgchem.1c02078","article-title":"Aqueous Stability of Zirconium Clusters,\nIncluding the Zr(IV) Hexanuclear Hydrolysis Complex [Zr 6 O 4 (OH) 4 (H 2 O) 24] 12+, from Density Functional Theory","volume":"60","author":"Stern","year":"2021","journal-title":"Inorg. Chem."},{"issue":"5","key":"2026090307175122900_cit47","doi-asserted-by":"publisher","first-page":"468","DOI":"10.3390\/met15050468","article-title":"Selective\nExtraction of Zirconium from Sulfuric Acid\nSolutions at High Concentration with Trioctylamine (TOA)","volume":"15","author":"Tian","year":"2025","journal-title":"Metals (Basel)."},{"key":"2026090307175122900_cit48","unstructured":"Lee, H. Y.; Cho, B. W.; Lee, J. K.\n          Separation\nMethod of Zirconium and Hafnium with Acidic Extractants. US8557202\nB1, October 15, 2013."},{"key":"2026090307175122900_cit49","doi-asserted-by":"publisher","first-page":"451","DOI":"10.1007\/978-3-319-48765-6_53","article-title":"Separation of Zirconium and Hafnium: A Review","volume-title":"Energy Materials 2014","author":"Xu","year":"2014"}],"container-title":["ACS Omega"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acsomega.6c06044","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/11\/34\/51721\/66879025\/acsomega.6c06044.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/11\/34\/51721\/66879025\/acsomega.6c06044.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T11:18:01Z","timestamp":1788434281000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/acsodf\/article\/11\/34\/51721\/5276659\/Mechanistic-Insights-into-Hf-IV-Zr-IV-Extraction"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,19]]},"references-count":49,"journal-issue":{"issue":"34","published-online":{"date-parts":[[2026,8,19]]},"published-print":{"date-parts":[[2026,9,1]]}},"URL":"https:\/\/doi.org\/10.1021\/acsomega.6c06044","relation":{},"ISSN":["2470-1343"],"issn-type":[{"value":"2470-1343","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,19]]}}}