Salt is Salty. Remember when when history records the struggle of Mahatma Gandhi in gaining independence for India, one of it has thing to do with salt.
There is much to learn about salt. Salt, sodium chloride, touches our lives more than any other chemical compound. The chemical properties and physical properties of sodium chloride are a treasure to mankind. Salt or salt-derived products are ubiquitous in our material world and the very cells of our bodies swim in a saline solution. We take for granted the salt crystals that make our foods safe and palatable and we give thanks for salt’s lifesaving properties when applied to slick winter roads. Most are unaware of the 14,000 known uses for salt, how it’s produced and our success in ensuring the environmental compatibility as it provides the foundation for the quality of our lives. Our blood has the same chemical balance of sodium, potassium and calcium found in the oceans.
Chloride and sodium ions, the two major components of salt, are needed by all known living creatures in small quantities. Salt is involved in regulating the water content (fluid balance) of the body. However, too much salt increases the risk of health problems, including high blood pressure. Therefore health authorities have recommended limitations of dietary sodium
Salt occurs naturally all over the world as the mineral halite, as well as in seawater and salt lakes. Some salt is one the surface, the dried-up residue of ancient seas like the famed Bonneville Salt Flats in Utah. Surface salt depositions and man-made saltworks can be seen from space. In ocean coastal areas, saltwater can "intrude" on underground freshwater supplies, complicating the lives of those who provide our drinking water supplies. Scientists have also found salt in meteors and on Mars where its presence signals the possibility of extra-terrestrial life.
There is enough salt in the oceans of the world that we could use salt to sculpt a full-scale topographic map of Europe – five times over. Oceans contain an average of 2.7% salt, by weight (total solids in seawater average 3.5% and 77% of that is salt). In addition, evaporation of ancient oceans has left vast deposits of solid (rock) salt over huge areas of the world. These deposits can be in the form of bedded sedimentary layers or deep salt domes.
Salt producers use three basic technologies to create salt for its myriad uses. Now-buried dried-up oceans of geologic ages past have left many areas, under both land and sea, with concentrated salt sedimentary layers which can exceed fifty feet in thickness. Two technologies exploit these underground deposits: conventional shaft mining where miners go underground to remove solid rock salt and solution mining where water is pumped underground dissolving the solid salt and then pumping out the salty brine which is de-watered to crystallize the salt. The third method extracts salt from oceans and saline lakes, growing salt crystals much as a farmer grows crops of vegetables or grain. Respectively, the products of these technologies are known as rock salt, evaporated salt (or vacuum pan salt) and solar (or sea) salt.
Among the three technologies, most producers around the world are engaged in solar salt production, the least expensive technology available, when favored by a dry and windy climate. But vast quantities of rock salt are extracted in large commercial mines and chemical companies utilize an enormous amount of salt in the form of brine that never is crystallized into dry salt.
