The Morphology and Dehydration Mechanism of Heptacrystallohydrates of Transition Metal Sulfates
Thermodynamic parameters and dehydration processes of heptacrystallohydrates of transition metal sulfates, Ni, Co, Fe, grown from aqueous solutions were investigated by optical thermal microscopy, X-ray analysis and differential scanning microcalorimetry. Temperatures and heats of the first stage dehydration and process reversibility conditions were identified; the morphology and the mechanism of widespread topochemical reaction were established. It was shown that dehydration process depends on many physical parameters and proceeds as a nonoriented crystal growth of a new phase accompanied by exudation of crystallization water.