Selectivity of Co and Ni by K-depleted micas
Cho, Yunchul (University of California at Davis. Peter A. Rock Thermochemistry Laboratory and NEAT ORU)
Komarneni, Sridhar (The Pennsylvania State University. Department of Crop and Soil Science and Materials Research Institute.)
Choi, Sang-Il (Kwangwoon University. Department of Environmental Engineering)

Date:	2009
Abstract:	Contamination of the environment with heavy metals, including cationic radionuclides, is a serious problem which has yet to be fully overcome. A class of potentially effective cation exchangers for sequestering heavy metals which has received little attention is K-depleted mica. The purpose of this study was to investigate the heavy-metal cation exchange properties of K-depleted phlogopite and biotite, which were prepared from a natural phlogopite and biotite, respectively, using sodium tetraphenylborate (NaTPB). The X-ray diffraction (XRD) patterns showed that interlayer K ions were completely replaced with exchangeable Na ions, resulting in the expansion of the d spacing of both K-depleted phlogopite and K-depleted biotite. In order to investigate the cation exchange selectivity of K-depleted phlogopite and biotite for Co and Ni, cation exchange isotherms and Kielland plots were constructed. The isotherms and Kielland plots indicated that both K-depleted phlogopite and biotite are highly selective for Co as well as Ni. The XRD patterns after both 2Na → Co and Ni exchange reactions suggest that double sheets of interlayer water are present in the interlayer. These K-depleted micas are potential cation exchange materials for removal of some heavy metals such as Ni and radioactive species such as Co from solution.
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Heavy-metal Cation ; Ion Exchange ; K-depleted Biotite ; K-depleted Phlogopite
Published in:	Clays and Clay Minerals, Vol. 57, Núm. 3 (2009) , p. 279-289, ISSN 1552-8367

DOI: 10.1346/CCMN.2009.0570301

11 p, 412.8 KB  UAB restricted access

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