Laboratory Scale Study for the Control Crystallization of Sodium Chloride Pyramid Crystals(fleur de sel),Prepared by Solar Salt

摘要

In this study,an accelerated method to crystallize well-formed pyramidal crystals of salt is achieved.The square pyramidal crystals of salt,Fleur de Sel salt are known for their unique crystal structure and used in specialty gourmet foods.The natural crystallization conditions include hot summer days on the surface of ponds containing concentrated sea water.The current study has established a controlled production of pyramidal crystals as an alternate to natural crystallization which is only possible in summer weathers. A saturated solution of salt(brine)is prepared by dissolving sea salt in water.This brine is evaporated in an open crystallizer by gentle evaporation with heating from bottom of the crystallizer.Temperature plays an important role in formation of pyramidal crystals.It was noted that a meta-stable condition in brine for the nucleation and crystal growth is achieved between 55 to 65 °C temperature range.Brine purification was also applied for removal of sulphate and subsequent crystallization of uninterrupted pyramidal shaped crystals.The study,when applied,not only yields the well defined shape of pyramidal crystals but also produces a high purity form of salt crystals in comparison with naturally crystallized Fleur de Sel.