Extraction of samarium as a chloride or oxychloride from a Sm2O3-CeO2 mixture

M. R. ESQUIVEL; A. E. BOHÉ; D. M. PASQUEVICH

Madrid

Simposio; GLOBAL SYMPOSIUM ON RECYCLING, WASTE TREATMENT AND CLEAN TECHNOLOGY; 2004

TMS

Samarium is one of the most difficult metals to be obtained. Its extraction from lanthanide oxide mixtures is frequently hindered because of the chemical similarities and both high thermodynamic and thermal stabilities of these compounds. Chlorination using Cl2(g) or Cl2(g) + C(s) offers the possibility of separate Sm as SmCl3 or SmOCl as products. The separation process is enhanced if operation parameters such as temperature and carbon content are optimized. A Sm2O3 (50wt%)-CeO2 (50wt%) mixture was chlorinated with Cl2(g) and Cl2(g) + C(s) at temperatures between 400 and 950ºC by thermogravimetry and the results were compared to those obtained from previous studies of the individual CeO2-Cl2, CeO2-C-Cl2, Sm2O3-Cl2 and Sm2O3-Cl2-C systems. Reactants and products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). An optimum of the separation process involving the carbochlorination is obtained at 700ºC and for carbon contents higher than 10 %wt in the CeO2(45 wt%s)-Sm2O3(45 wt%)-C(10 wt%) mixture where Sm is separated as SmCl3 from the Sm2O3–CeO2 mixture.2(g) or Cl2(g) + C(s) offers the possibility of separate Sm as SmCl3 or SmOCl as products. The separation process is enhanced if operation parameters such as temperature and carbon content are optimized. A Sm2O3 (50wt%)-CeO2 (50wt%) mixture was chlorinated with Cl2(g) and Cl2(g) + C(s) at temperatures between 400 and 950ºC by thermogravimetry and the results were compared to those obtained from previous studies of the individual CeO2-Cl2, CeO2-C-Cl2, Sm2O3-Cl2 and Sm2O3-Cl2-C systems. Reactants and products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). An optimum of the separation process involving the carbochlorination is obtained at 700ºC and for carbon contents higher than 10 %wt in the CeO2(45 wt%s)-Sm2O3(45 wt%)-C(10 wt%) mixture where Sm is separated as SmCl3 from the Sm2O3–CeO2 mixture.2O3 (50wt%)-CeO2 (50wt%) mixture was chlorinated with Cl2(g) and Cl2(g) + C(s) at temperatures between 400 and 950ºC by thermogravimetry and the results were compared to those obtained from previous studies of the individual CeO2-Cl2, CeO2-C-Cl2, Sm2O3-Cl2 and Sm2O3-Cl2-C systems. Reactants and products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). An optimum of the separation process involving the carbochlorination is obtained at 700ºC and for carbon contents higher than 10 %wt in the CeO2(45 wt%s)-Sm2O3(45 wt%)-C(10 wt%) mixture where Sm is separated as SmCl3 from the Sm2O3–CeO2 mixture.2-Cl2, CeO2-C-Cl2, Sm2O3-Cl2 and Sm2O3-Cl2-C systems. Reactants and products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). An optimum of the separation process involving the carbochlorination is obtained at 700ºC and for carbon contents higher than 10 %wt in the CeO2(45 wt%s)-Sm2O3(45 wt%)-C(10 wt%) mixture where Sm is separated as SmCl3 from the Sm2O3–CeO2 mixture.2O3-Cl2-C systems. Reactants and products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). An optimum of the separation process involving the carbochlorination is obtained at 700ºC and for carbon contents higher than 10 %wt in the CeO2(45 wt%s)-Sm2O3(45 wt%)-C(10 wt%) mixture where Sm is separated as SmCl3 from the Sm2O3–CeO2 mixture.2(45 wt%s)-Sm2O3(45 wt%)-C(10 wt%) mixture where Sm is separated as SmCl3 from the Sm2O3–CeO2 mixture.3 from the Sm2O3–CeO2 mixture.