Salt, the common name for the compound of sodium (Na+) and chloride (Cl-), is the first substance after water that has attracted humans\' attention in their evolution from wilderness to civilization.
Salt along with water, cereals (bread) and meat of domestic animals, constituted the main commodities of human society in its infancy [Baas-Becking 1931]. Originally, salt was used to supplement the human nutritional needs. However, when its significant food preserving property was discovered, salt became one of the most important commodities for centuries, comparable to the importance of oil in our times.
Humans must have initially found salt, where it can be still found, that is in coastal rock concavities or lagoons, where seawater gets trapped and deposits salt by solar evaporation. It can be reasonably deduced that, after a long period of observation and knowledge building, humans eventually copied nature and began producing salt, in quantities that met the growing social needs.
Production of salt from seawater involves the selective recovery of pure NaCl, free of other soluble or non-soluble salts and other substances. To this end, condensation of seawater by solar evaporation results in the fractional crystallization of all contained salts; a process based on their varying solubility in seawater.
Producing salt in single basins (ponds) such as coastal rock concavities or lagoons, by solar evaporation of seawater, constitutes the first method ever used by man to produce solar sea salt. We define this method as the first step of the Solar Sea Salt production process evolution. The optimization of this process in terms of quantity and quality of the produced salt, eventually led to the creation of an integrated coastal saline ecosystem! The current Solar Saltworks!
Current Solar Saltworks are multi pond (lake) systems that produce salt (NaCl) from seawater by solar evaporation. They are constructed in areas with clayey soils and consist of a number of shallow ponds, connected mainly in series. The first pond is continuously fed with seawater, pumped by the nearby sea and in turn feeds the next pond. In that way, as the seawater flows through the pond system (from one pond to the next), its concentration gradually increases by solar evaporation. Once the brine concentration reaches the saturation value with respect to NaCl, salt crystals begin to form at the pond bottom.
Thus, the pond system of Solar Saltworks consists of two main groups. The Evaporation Ponds, where the seawater is concentrated up to the saturation value with respect to NaCl and the Crystallizers where salt is produced.
The annual capacity of Solar Saltworks varies from some hundred to some million tones of salt, depending on the area used and the prevailing microclimate in the region. In seasonal Solar Saltworks the produced salt is harvested once every year and it is stored in open outdoor piles.