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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 392 (1972), S. 69-80 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trennung von Samarium und Europium aus ägyptischem Monazitsand mittels Natriumamalgam. Teil IDie Abtrennung von Sm und Eu von anderen Seltenerden mit Hilfe von Na-Amalgam nach saurem Monazit-Aufschluß gelingt bei pH = 3,5 und Kühlung auf nahe 0°C mit einem Anreicherungsverhältnis Sm: Eu: La = 14:9:1. Zusatz von NaCl vermindert die Verunreinigung des abgetrennten Sm durch La. Die optimale totale Seltenerdkonzentration in der Einsatzlösung liegt bei 35 g/l, gepuffert wird durch ≤ 64 ml Eisessigzusatz/l.Bei alkalisch aufbereiteten Seltenerdlösungen erwies sich eine Natriumamalgam-Dispersion in Dodecylamin als vorteilhaft.
    Notes: Factors affecting the separation of both Sm and Eu from other rare earths, after acid processing of monazite, by sodium amalgam are: Increasing extraction in the order Sm 〉 Eu 〉 La at all pH values, preferably at pH 3.5 with an enrichment ratio of 14:9:1; 0.26% sodium amalgam giving optimal results, preferably on cooling nearer to zero temperature. The pollution by La of separated Sm or Eu could be masked by sodium chloride addition in up to 0.2 N. Buffering by acetate was proved to be indispensable and preferentially in no less than 64 ml glacial acetic acid/l feed. Concerning the total lanthanons concentration, a 35 gm/l feed is recommended. When working on alkali by-produced rare earths liquors, good enhancement in both recoveries and purity was achieved by use of dodecylamine dispersed sodium amalgam.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 347 (1966), S. 205-214 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Es wird eine Methode zur Rückgewinnung von Cer aus Ce(III)-nitrat-Rohlösungen beschrieben, bei der Na—Ce(III)-sulfat ausgefällt, mit 18% wäßriger Natronlauge zersetzt, und nach Trocknen bei 110°C Ceroxidhydrat erhalten wird.Es wurde ferner die Reinigung von Ce-Verbindungen durch Extraktion aus wäßriger Phase und der Einfluß verschiedener Parameter auf den Ce(VI)-Verteilungskoeffizient für Salpetersäure-Tributylphosphat/Kerosin untersucht. Ein Extraktionsverfahren zur Darstellung von spektroskopisch reinem CeO2 wird angegeben.
    Notes: A process is described for the recovery of cerium from crude cerium(III) nitrate solution as sodium cerium sulphate. The double sulphate is then treated with 18% NaOH solution and dried at 110°C to hydrated ceric oxide.The purification of crude cerium by solvent extraction was studied and data are presented on the effect of several variables on the distribution coefficient of Ce(IV) between nitric acid and tributyl phosphate-kerosene. After extraction and scrubbing the cerium compounds obtained were found to be of spectroscopic purity grade.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 371 (1969), S. 106-112 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Es wurde die Extraktion von Thorium aus salpetersaurem wäßrigem Medium durch Tributylphosphat TBP in Abhängigkeit von verschiedenen organischen Verdünnungs-mitteln untersucht. Bei Konzentrationen 〈 150 g ThO2/1 und 5 m HNO3 wurde eine starke Abhängigkeit beobachtet, wobei mit hadelsüblichen Kerosin verdünntes TBP die beste Extraktionswirkung zeigte.
    Notes: Investigations on the extraction of thorium nitrate with TBP diluted with various diluents were made. At lower concentrations of thorium (〈 150g ThO2/1) and lower concentrations of nitric acid (〈 57 - HNO3) in the aqueous solution, extraction depends very much on the nature of diluents used. The greatest extraction ability is shown by TBP diluted with commercial keresene than with toiuene, rising sun kerosene, benzene, n-hexane, xylene, carbon tetrachloride, diethyl ether and di-isopropyl ether. At higher concentrations of thorium (〉 150 gThO2/1) and /or higher nitric acid concentrations (〉10 M-HNO3/1) as well as very low nitric acid concentrations (〈1 M-HNO3/1) differences in the distribution coefficient of thorium decrease and almost disappear. Also, at very low and very high concentrations of TBP the dependence of distribution coefficient of thorium on the nature of the diluents is very small.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 375 (1970), S. 308-314 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Es wird ein Verfahren zur Abtrennung von Uran, Thorium und Cer aus ägyptischem Monazitsand beschrieben, das auf einem Aufschluß mit 50proz. Natronlauge und der Fällung der Metalle als Oxidhydrate beruht.
    Notes: A process is described for the recovery of uranium, thorium and cerium from Egyptian monazite sands. The process consisted of: 1. Treatment of fine ground monazite sands with hot 50% caustic soda solution with a caustic soda to monazite sand ratio of 1:1. 2. Dilution of the reaction slurry with 6 times the weight of the sand with water to dissolve the sodium phosphate formed. 3. Filtration of the reaction slurry to remove the solid hydrous metal oxides from the sodium phosphate and excess sodium hydroxide. 4. Drying of the mixed hyrous oxides at 150°C for 10 hours to oxidise cerium. 5. Dissolution of the trivalent rare earths by addition of dilute nitric acid dropwise to an aqueous suspension of the dried hydrous oxides to pH 1.3.6. Separation of uranium, thorium and cerium by filtration of the dissolved tervalent rare earths from undissolved residue of the mixed hydrous oxides.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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