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AbstractAbstract
[en] Extraction of zirconium, especially at high concentration (0.1M), by dodecane diluted DEHPA (HA) from hydrochloric or nitric aqueous phases of 0.1 to 10 M acidity was studied. The composition, structure and polymerisation of the complexes extracted were determined by chemical analysis, viscosimetry, infrared spectrometry and light scattering. A Zr(OH)2A2.2HNO3, type structure is proposed for these complexes instead of the generally accepted form: Zr(OH)2(NO3)2.2HA. Similarly in hydrochloric solution: Zr(OH)2A2.2HCl. Polymerisation in the organic phase results from the juxtaposition of two factors; firstly zirconium saturation (formation of bridges by DEHPA between zirconium atoms) and secondly the nature the equeous phase. In slightly acid hydrochloric solution (pH = 1.3) the aqueous plymers of zirconium are extracted in the organic phase as polynuclear complexes; in nitric solution no polynuclear complexes are observed but the nitric acid molecules extracted set up hydrogen bonds which explain the increased viscosity and gelification of the organic phases
[fr]
L'extraction du zirconium, notamment a concentration, elevee (0,1M), par le DEHPA (HA) dilue dans le dodecane, a partir de phases aqueuses chlorhydriques ou nitriques d'acidite 0.1 a 10M, a ete etudiee. On a determine par analyse chimique, viscosimetrie, spectrometrie infra-rouge et diffusion de la lumiere, la composition, la structure et la polymerisation des complexes extraits. On propose pour ces complexes une structure du type: Zr(OH)2A2.2HNO3, au lieu de la forme generalement admise: Zr(OH)2(NO3)2.2HA. De meme en milieu chlorhydrique: Zr(OH)2A2.2HCl. La polymerisation en phase organique est le resultat de la juxtaposition de deux facteurs: le premier est la saturation en zirconium (formation de ponts par le DEHPA entre atomes de zirconium); le second est lie a la nature de la phase aqueuse. En milieu chlorhydrique peu acide (pH = 1,3) les polymeres aqueux de zirconium sont extraits en phase organique sous forme de complexes polynucleaires; en milieu nitrique on n'observe pas de complexes polynucleaires, mais les molecules d'acide nitrique extraites etablissent des liaisons hydrogenes, qui expliquent l'augmentation de viscosite et la gelification des phases organiquesOriginal Title
Contribution a l'etude des mecanismes physico-chimiques de l'extraction des cations metalliques par les acides alkylphosphoriques. Extraction du zirconium (IV) par l'acide di-2-ethylhexyl phosphorique (DEHPA)
Primary Subject
Source
Feb 1979; 179 p; These (D. es S.).
Record Type
Report
Literature Type
Thesis/Dissertation; Numerical Data
Report Number
Country of publication
CHLORINE COMPOUNDS, COMPLEXES, DATA, DATA FORMS, ELEMENTS, ESTERS, HALOGEN COMPOUNDS, HYDROGEN COMPOUNDS, INFORMATION, INORGANIC ACIDS, METALS, NITROGEN COMPOUNDS, NUMERICAL DATA, ORGANIC COMPOUNDS, ORGANIC PHOSPHORUS COMPOUNDS, OXYGEN COMPOUNDS, PHOSPHORIC ACID ESTERS, SEPARATION PROCESSES, TRANSITION ELEMENTS
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