Salt manufacture : At one time almost all the salt used in commerce was produced from the evaporation of seawater and sea salt still is a staple commodity in many maritime countries, especially where the climate is dry and the summer is long. Commercial salt manufactured from rock salt, as well as from seawater and other natural and artificial brine. pumping water into underground salt beds is one of the ways to acquire underground artificial water. A considerable amount of brine directly use in industrial countries.
first of all There are two main sources of salt. there are three types of salt extraction: solar evaporation, rock salt mining and solution mining. So Each one involves specific technology and manufacturers select the most appropriate technique depending upon the particular topographic and socioeconomic conditions in their area of operation.
Manufacture from rock salt
Also the beds of rock salt are mined or quarried by the usual excavation methods, depending on the depths and thicknesses of the deposits and on local conditions. sometimes the mined rock salt dissolved and the salt manufactured by treatment of the brine, as described below. The methods affords opportunities for purification of the salt:
- first crushed of salt mined in large lumps
- then more finely ground and screened by size into various grades
- salt bulk-loaded into trucks, hoppers, or barges or loaded into bags for further handling
Manufacture from seawater and brine:
only a certain quantity of salt will dissolve in water at any given temperature.
Evaporation is the reverse of this process. Thus, the different salts in seawater will precipitate at different times, forming layers on the bottom of the evaporating pond. For seawater and many brine, the order of deposition is a:
- calcium carbonate
- calcium sulfate
- sodium chloride
- magnesium sulfate
- potassium magnesium chloride
- magnesium chloride
