Life said that the salt, refers to the seawater, salt ponds, salt wells and salt mines by the processing of the extraction of salt, which is the main ingredient is sodium chloride (
NaCl
), known as sea salt, pool salt, well salt and rock salt. Humans have relied on these types of salt for our essential inorganic salt intake in the past and in the future.
With the development of the chemical industry and chemical science, the meaning of the word "salt" has been greatly expanded. Secondary school chemistry textbooks, "salt" refers to the "metal ions" (including ammonium ions) and acid ions composed of compounds. They come in many varieties, with different properties, different appearances, and very different uses.
Because of the importance and high profitability of salt, successive governments have adopted a monopoly policy for salt, so there is a difference between "government salt" and "private salt". In recent years, due to the requirements of nutritional hygiene, a small amount of potassium iodide (
KI
) and other nutrients have been added to the process of processing raw salt into refined salt, which has led to the difference between "qualified" and "unqualified" salt. The difference between "qualified" and "unqualified" salt is thus made. The reference to these types of salt is a difference in policy and management, and there is no substantive difference in the composition of the "salt". Private salt" and "substandard salt" without added potassium iodide, although illegal, will not harm lives, and there is no difference between "real salt" and "fake salt". There is no difference between "real salt" and "fake salt", their main ingredient is sodium chloride.
The chemical industry uses a lot of raw salt and processed salt as raw materials to produce chemical products such as chlorine, bleaching powder, caustic soda and soda ash, which are the main components of salt chlorine and sodium. The "salt" used for food and the "salt" used in industry are both of the same chemical composition, but only for different purposes. Because the original salt is a product of nature, refined salt is also a simple processing of the original salt, in addition to the main ingredient sodium chloride, but also contains a variety of impurities, so it can not be called sodium chloride, and the convention is to use only one word "salt", specifically referred to as sodium chloride as the main ingredient, such as salt, sea salt, well salt, rock salt, iodized salt, non-iodized salt, refined salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt, salt. Iodized salt, non-iodized salt, refined salt, large salt, crushed salt, washed salt, and so on. If it is other chemical composition of the salts, be sure to say its specific trade name or chemical name, such as soda ash, baking soda, alum, ammonium sulfate, potassium nitrate, potassium chloride, diammonium phosphate, etc., can never be generalized to call "industrial salt".