Metal Ions Extraction from Solid Matrix in Supercritical Carbon Dioxide with DMBP as Chelating Ligand

Authors

  • Jia Tian,

    1. Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, Key Laboratory of Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan, P. R. China
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  • Hai-Jian Yang,

    Corresponding author
    1. Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, Key Laboratory of Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan, P. R. China
    • Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, Key Laboratory of Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, P. R. China.
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  • Wei Wang,

    1. Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, Key Laboratory of Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan, P. R. China
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  • Hakwon Kim

    Corresponding author
    1. Department of Applied Chemistry, Industrial Liaison Research Institute, College of Applied Science, Kyung Hee University, Gyeonggi, Republic of Korea
    • Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, Key Laboratory of Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, P. R. China.
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Abstract

The effects of pressure, temperature, time, and ligand to metal ratio (50:1–200:1) on the extraction efficiency of metal ions with 4,4′-dimethyl-2,2′-bipyridyl (DMBP) as a chelating ligand were systematically investigated in supercritical carbon dioxide (sc-CO2). Eight metal ions (Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+) were tested, respectively, to be extracted from solid matrix into sc-CO2. The best extraction efficiency for Co2+ (83.68%) was obtained in the optimized condition (DMBP and perfluoro-1-octanesulfonic acid tetraethylammonium salt as a co-ligand used, 25 MPa, 323 K, 20 min, ligand to metal ratio of 200). Extraction from mixed metal ions with DMBP was also achieved and the results showed that selectivity for Co2+ ion was notable (98.17%) in the above-mentioned conditions. Finally, the detailed calculation results exhibited that the extraction constants (Kex) of the metal ions increased with the increase of the extraction efficiency in the same extraction system.

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