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Influence of Trivalent Metal Ions on the Metastable Zone Width of Ammonium Sulfate
Author(s) -
Buchfink R.,
Ulrich J.
Publication year - 2011
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201000422
Subject(s) - impurity , metal ions in aqueous solution , inorganic chemistry , ammonium sulfate , metal , chemistry , aqueous solution , crystallization , ion , sulfate , metastability , hydrolysis , ammonium , qualitative inorganic analysis , chromatography , organic chemistry
The metastable zone width (MZW) is a vital parameter for the design of industrial crystallization processes of inorganic salts and could be affected by the addition of impurities. Here, the effect of the trivalent ions Fe 3+ , Cr 3+ , and Al 3+ on the MZW of ammonium sulfate was observed. All the experiments were performed with the help of ultrasonic speed measurements. Impurity concentrations up to 100 ppm at a solution pH of 4 increase the MZW depending on the metal ion. The pH value also showed a major influence on the effect of trivalent metal impurities. The results were compared to the distribution of metal‐aquo‐complexes existing in aqueous solutions contaminated by trivalent metal ions. The distribution was determined by using the computer‐based simulation software Hyss. The first hydrolysis product was identified to be active in widening the MZW.