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Investigation of the crystallization of the system KAl(Cr)(SO 4 ) 2 12 H 2 O under various conditions
Author(s) -
Kirkova E.,
Nikolaeva R.
Publication year - 1973
Publication title -
kristall und technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0023-4753
DOI - 10.1002/crat.19730080409
Subject(s) - crystallization , supersaturation , chemistry , ion , adsorption , analytical chemistry (journal) , activation energy , crystallography , thermodynamics , chromatography , physics , organic chemistry
The crystallization of the isomorphous system KAl(Cr)(SO 4 ) 2 · 12 H 2 O under various conditions has been studied. It has been found that the rate of linear crystallization of the face (100) passes through a maximum on the interval of Cr 3+ concentrations 0.02–0.08 g ions/l which is shifted to the right with increasing temperature. Under the same conditions, the equilibrium coefficient of distribution of the microcomponent D has been determined in single crystals. D decreases with the increase of the Cr 3+ concentration and the crystallization temperature. These results can be explained with the formation of complexes of Cr 3+ in the solution which decreases the active concentration of the ion and are selectively adsorbed on the face (100). At the same Cr 3+ concentration (0.058 g ion/l), the temperature dependence of the rate of growth of the face (100), as well as the influence of supersaturation on the rate of growth of the faces (100) and (111), have been studied. The apparent activation energy of crystallization of the face (100) has been determined to be E = 11.2 Kcal. · mol −1 . The data obtained are compared with analogical results for pure KAl(SO 4 ) 2 12 H 2 O.