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Studies on the Kinetics of Exchange on Silica Gel
Author(s) -
Zaki M. R.,
AbdElMoneim I.
Publication year - 1969
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.19693650514
Subject(s) - silanol , uranyl , hydrochloric acid , kinetics , diffusion , chemistry , colloidal silica , porosity , ion exchange , silica gel , particle (ecology) , uranium , inorganic chemistry , colloid , ion , chemical engineering , materials science , catalysis , chromatography , organic chemistry , thermodynamics , metallurgy , coating , physics , oceanography , quantum mechanics , engineering , geology
The kinetics of uptake of uranium(VI) ion were studied on three silica samples. The exchange reactions were found to obey the simple unimolecular reversible equation. The rate of exchange, in case of colloidal silica, was governed by both film and particle diffusion mechanisms. Uranyl ions were taken up on the preheated silica samples by a fast uptake process followed by a slow one. The rate of the former process was mainly chemically controlled, while that of the latter one was governed by chemical reaction as well as by particle diffusion. Soaking of a preheated silica sample in hot dilute hydrochloric acid solution was found to increase its silanol group content and its porosity.