Crystalization

From the reservoirs the concentrated brine is led into crystallization pans which are rectangular in shape and have flat clay bottoms. These pans are connected by roadways, brine supply channels and storm water protection canals. In the pans, the water will evaporate further, increasing the salt concentration of the brine, until salt crystals start precipitating at the bottom of the pan. This process continues until most of the salt in the solution has crystallized out on the pan floor. The remaining fluid, called “bitterns” or “mother liquor” is drawn off. The draw-off point is carefully selected to take place before impurities, e.g. Magnesium Sulphate, Epson Salt, Sodium Sulphate and Potassium Sulphate, can crystallize out onto the pure salt. As much as 19g salt per liter of seawater is recovered in this manner. The “bitterns” drawn off represents 3% of the original volume, the rest having been evaporated.