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Effect of trace metals on reactive crystallization of gypsum
Author(s) -
Sayan Perviz,
TitizSargut Sibel,
Avcı Burcu
Publication year - 2007
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.200710939
Subject(s) - gypsum , citric acid , crystallization , chemistry , sulfate , particle size , filtration (mathematics) , inorganic chemistry , ion , calcium hydroxide , morphology (biology) , calcium , hydroxide , nuclear chemistry , mineralogy , materials science , metallurgy , geology , organic chemistry , paleontology , statistics , mathematics
The effect of Fe 2+ , Fe 3+ , and Cr 3+ ions on crystallization of calcium sulfate dihydrate (gypsum) produced by the reaction between calcium hydroxide suspension and sulphuric acid solution was investigated at 3.5 pH and 65°C in the absence and presence of 2500 ppm citric acid concentration. Crystal size distributions, filtration rates, and morphology of gypsum were determined and discussed as a function of ion concentration. Average particle size of gypsum was not affected significantly by the presence of Fe 2+ , Fe 3+ , and Cr 3+ ions individually. Variation of gypsum morphology depending on ion concentration affected the filtration characteristics. The presence of Fe 3+ or Cr 3+ ions besides 2500 ppm citric acid influenced both average particle size and filtration characteristics. The effect of citric acid on gypsum morphology was suppressed at high Fe 3+ and Cr 3+ ion concentrations. The change of morphology is related to the complex formation between Fe 3+ or Cr 3+ ions and citric acid at high ion concentrations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)