Crystallization and Characterization of Orthorhombic β-MgSO4 · 7H2O

In solution, the growth rate and the crystal habit are influenced by a number of factors such as supersaturation, temperature, pH of the solution, cooling rate, agitation, viscosity, initial state of the seed crystal and the presence of impurities. The crystallization of orthorhombic β-MgSO 4 .7H 2 O, from low temperature aqueous solution by slow cooling process was studied. The metastable zone width, the induction periods (T) for different supersaturations and the effect of pH on the growth rate of the crystals were investigated. The increase of pH yielded bigger crystals. The structural, optical, thermal and mechanical properties of β-MgSO 4 .7H 2 O have been studied using FT-IR, X-ray diffraction, TGA-DTG and micro hardness analyses.