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.
Mankind evolved from the sea and we have a saline “sea” within us as do all fish, reptiles, amphibians, birds, and mammals. Environmental author Rachel Carson is best known for her book on birds, but she also wrote The Sea Around Us offering this insight: "When the animals went ashore to take up life on land, they carried part of the sea in their bodies, a heritage which they passed on to their children and which even today links each land animal with its origins in the ancient sea." Our blood has the same chemical balance of sodium, potassium and calcium found in the oceans.
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.
Tight ionic bonding unites the elements sodium and chloride to make the chemical compound sodium chloride. Man has discovered a vast variety of ways to harness the chemical properties of salt to improve our lives. Chemically, there are many “salts;” the resulting compound created by reacting an acid and a base; positively charged metal atoms (the sodium ion in the case of common salt) replacing the negatively charged hydrogen atoms of an acid, leaving the chloride ion.
Sodium chloride crystals are cubic in form and salt crystals are commonly used to exemplify crystalline structure and many science students are familiar with the process of growing salt crystals. Its color varies from colorless, when pure, to white, gray or brownish when in the solid, halite, form. Salt dissolves readily in water. Salt crystals can be grown in various sizes and salt companies prepare particles in a wide variety of sizes to meet customer needs.
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.
Will we run out of salt?
Never. Salt is the most common and readily available nonmetallic mineral in the world; it is so abundant, accurate estimates of salt reserves are unavailable. In the United States there are an estimated 55 trillion metric tons. Since the world uses 240 million tons of salt a year, U.S. reserves alone could sustain our needs for 100,000 years. And some of that usage is naturally recycled after use. The enormity of the Earth’s underground salt deposits, combined with the saline vastness of the Earth’s oceans makes the supply of salt inexhaustible.
Unlike other strategic minerals, salt is widely available and produced in countless production units spread around the globe. The rapid industrialization of East Asia and South Asia have propelled increases in world salt production with China just easing past the United States as the world’s largest salt producing country.