The salt
Salt is called table salt. It mainly consists of sodium chloride (chemical formula NaCl) and is a basic component of the human diet. With it, we salt food and prepare spreads.
Salt is very widespread in nature. It is found dissolved in sea water and in the water of some lakes. It is also found in a solid state inside the earth, such as e.g. in Poland, Austria, Germany etc (mineral salt or halite). The sea contains salt at a rate of 2.7 – 3.8%. In regions, where the climate is warm, this percentage increases while it decreases in seas, where many rivers flow. Salt is a necessary component of every living organism and plays an important role in biological phenomena.
Composition and Properties
Table salt is 97% to 99% sodium chloride (chemical formula NaCl). Commercially, salt is sold with impurities, mainly potassium iodide (KI) (also essential in the diet), so it has a slightly bitter taste and is quite hygroscopic. It also contains anti-caking agents, usually sodium aluminum silicate (E554).
Pure salt is a solid, crystalline body with a specific gravity of 2.165. It melts at 801° C and boils at 1413° C. It dissolves in cold and hot water. When its crystals are heated, a characteristic crackling noise is heard. This is due to the water held by the crystals, which evaporates when heated. Because it absorbs water from the atmosphere it is characterized as hygroscopic. When 100% pure, salt has a salty taste and does not retain moisture (it is not hygroscopic).
Salt has the property of preventing the growth of microorganisms, which is why it is used to preserve food. The salt that comes from the sea is considered more beneficial than the mineral and is used in the daily human diet. It is necessary to take a small amount of it daily with food. There are, of course, cases where it is completely prohibited, such as in kidney diseases and in cases of hypertension. When it is in the body it facilitates digestion, opens the appetite, contributes to the secretion of gastric juices, prevents fermentation in the stomach and intestines, prevents constipation and helps the metabolism of foods containing proteins. It is also beneficial in certain pathological conditions, because it prevents hemoptysis, acts as a laxative, etc. Salt helps to increase the number of red blood cells and helps them absorb oxygen more easily. Thus, the blood acquires a brighter color.
Its abuse in the diet can cause diseases. From excessive use it is possible for a person to get an ulcer, indigestion or damage his kidneys. For all of this, care is required in determining the daily required amount. This amount varies depending on the body, age and general diet.
Extraction
Usually the extracted salt contains foreign substances, such as clay, magnesium and calcium salts, etc. Only the mineral, obtained by mining, can be used immediately, without further processing. The “impure” mineral salt is received in solution. Various chemical substances are added to this solution, with which many foreign impurities react and precipitate in the form of sediments, which are removed by filtration. Fractional crystallization follows. The sea salt, after receiving it from the salt pans, is cleaned with salt solutions and then with alkaline solutions. Thus, it gets rid of foreign substances. It is then dried, powdered and sold on the market as table salt.
Cleaning
Salt is called table salt. It mainly consists of sodium chloride (chemical formula NaCl) and is a basic component of the human diet. With it, we salt food and prepare spreads.
Salt is very widespread in nature. It is found dissolved in sea water and in the water of some lakes. It is also found in a solid state inside the earth, such as e.g. in Poland, Austria, Germany etc (mineral salt or halite). The sea contains salt at a rate of 2.7 – 3.8%. In regions, where the climate is warm, this percentage increases while it decreases in seas, where many rivers flow. Salt is a necessary component of every living organism and plays an important role in biological phenomena.
Applications
Salt is essential in the daily human diet. When added to foods, it opens the appetite and makes them delicious. Also, it is a means to preserve food. That is, various products, such as fish, meat, are pickled with salt to keep them in good condition for a long time. This work is called degreasing and the products degreased. These products are thus protected from rotting. Of course, with defatting, they lose a part of their nutritional value, because some of the vitamins they contain are destroyed and become indigestible. Today, fattening tends to be abandoned, because there are newer forms of food preservation (canning, refrigeration, etc.).
Salt in food is stimulating and tonic. In veterinary medicine, it is used as a laxative, in a dose of a few grams. In larger doses it has fatal effects. Man normally consumes about 5-6 kg of salt per year. In medicine, a 0.9% salt solution is used as normal saline, because this solution has the same osmotic pressure as blood plasma. In agriculture it is used to improve crops, but when found in more than normal amounts, it makes the soil dry and barren. In industry it has many applications: It is used for the preparation of sodium carbonate, sodium metal, sodium caustic, chlorine, hydrogen chloride, hydrogen, hypochlorite salts, sodium sulfate, etc. It is also used in the preparation of cooling mixtures and for the glazing of various ceramic items. In soap making, to make soap, table salt is added to its solution and thus it separates more easily.
Folklore – Expressions
Salt occupies an important place in peoples’ lives, habits, religion and traditions. According to the ancient Greeks, it symbolizes friendship and solidarity. With this they sealed their agreements. They also used it in their sacrifices and offerings to the gods. Thus, they had the habit of spreading salt on fields dedicated to their gods. Salt is mentioned in many Greek proverbs: “salt and bank do not transgress” “together we ate bread and salt” = we were closely connected, “don’t throw salt on a stranger’s food” = don’t meddle in foreign affairs, “I made him the salt” = slaughter etc.
Also, the Mosaic Law considers salt as a symbol and as a necessary element of the offering to God. In the New Testament it is mentioned: “you are the salt of the earth”. And other peoples, such as the Assyrians, the Persians, used salt in their religious ceremonies.
To this day, several precautions regarding salt have been maintained. E.g. the villagers do not lend salt, because they believe that they “eat the living”. They also avoid spilling salt from the salt shaker. In Germany the discovery of a salt spring is considered a blessing.