Sea salt is obtained from the evaporation of sea water which gets into the salt works through an Archimedes's screw. The flow of the water, managed by the man, is fed into large ponds. Thanks to water displacement (the number of ponds varies according to the width of the salt works) and to natural evaporation due to sun and wind,the water is drawn out and salt concentration rises until water flows into an auxiliary ponds where is saturated.
Now water is ready to be sunk into the salt ponds to deposit the sea salts.
Saturation point is that stage at which, for a chemical process, whichever liquid becomes solid.
Salt reaches that stage at a salinity of 25 degrees Baume, so the constituent salts crystallise in a set order for a chemical process.
The cycle starts in June and lasts until September. If the climate is suitable salt can be harvested after about 50 days since the beginning of the production cycle, for the first time, and after 30 days for the second time.
Saltmen will hand collect the salt using a shovel and a wheelbarrow, and will place the salt on a stockpile to drain.
A levee surrounding the salt works separates it from the sea .The structure of the levee is shown in a topographic map here included.
The salt works in Trapani stretches on the coast from Trapani to Marsala and was built in about 1500. It includes four series of ponds. The first one is called "fridda" or first entering pond. Seawater gets into it through an Archimedes's screw (see pond n. 1 in cartography) here it reaches 1 meter of height and 4 degrees Baume of salinity. The water flows from the first pond (fridda) into the second one, called "vasu coltivu" or evaporation pond (see pond n. 2), through a hand regulated lock. Here it reaches 12 degrees Baume of salinity. Then, also because of difference in level, it flows from here into ponds called "caure" or auxliary ponds (see ponds n. 3). From here it gets into ponds n. 5 through a coil path. Here salinity reaches 25 degrees Baume ,saturation point at which seawater starts precipitating salts.
Saturized water is now led into salt ponds through a channel where the salts start depositing.(see ponds n. 4).
Work in salt works starts in March with the salt ponds being washed to remove insoluble matter like sand and clay heaped up during the winter. It goes on with the introduction of water in the salt works and in the pipe coil to make sea water concentrate.
Salt is harvested about two times a year from June to September. Every 45 days the salt ponds are dried up and salt is placed on a stockpile in the ponds, then with shovels and wheelborrows it is put in the "arioni".
Therfore the only elements which take part in the process are seawater, with the trace elements you then find in the salt, sun and wind which allow natural evaporation and consequently salt concentration.
We will send you some chemical analysis showing all our salt mineral components