What is rock salt - origin and extraction methods. Interesting ways to use salt

The formula of which is NaCl, is a food product. In inorganic chemistry, this substance is called sodium chloride. In the crushed version, table salt, the formula of which is given above, is a white crystal. Insignificant gray shades may appear in the presence of other mineral salts as impurities.

It is produced in various forms: crude and peeled, small and large, iodized.

biological significance

Salt crystal, which has an ionic chemical bond, is necessary for the full life and activity of a person, other living organisms. Sodium chloride is involved in the regulation and maintenance of water-salt balance, alkaline metabolism. Biological mechanisms control the constancy of the concentration of sodium chloride in various fluids, such as blood.

The difference in NaCl concentrations inside the cell and outside is the main mechanism for the entry of nutrients into the cell, as well as the removal of waste products. A similar process is used in the generation and transmission of impulses by neurons. Also, the chlorine anion in this compound is the main material for the formation of hydrochloric acid, the most important component of gastric juice.

The daily requirement for this substance is from 1.5 to 4 grams, and for a hot climate, the dose of sodium chloride increases several times.

The body does not need the compound itself, but the Na+ cation and the Cl- anion. With an insufficient amount of these ions, the destruction of muscle and bone tissue occurs. There are depressions, mental and nervous diseases, disturbances in the activity of the cardiovascular system and digestive processes, muscle spasms, anorexia, osteoporosis.

Chronic lack of Na+ and Cl- ions leads to death. Biochemist Zhores Medvedev noted that in the absence of salt in the body, one can last no more than 11 days.

Tribes of pastoralists and hunters in ancient times, to meet the body's need for salt, used raw meat products. The agricultural tribes consumed vegetable food, in which there was a small amount of sodium chloride. As signs signaling a lack of salt, weakness and headache, nausea, dizziness are distinguished.

Production features

In the distant past, salt was extracted by burning certain plants in fires. The resulting ash was used as a condiment.

Purification of table salt obtained by evaporating sea water was not carried out, the resulting substance was immediately eaten. This technology originated in countries with a hot and dry climate, where a similar process took place without human intervention, and then, when it was adopted by other countries, sea water began to be heated artificially.

Salt works were built on the shores of the White Sea, in which concentrated brine and fresh water were obtained by evaporation and freezing.

natural deposits

Among the places characterized by large reserves of table salt, we highlight:

• Artemovskoye field, located in the Donetsk region. Salt is mined here by the mine method;
• Lake Baskunchak, transportation is carried out on a specially built railway;
• potassium salts were found in large quantities in the Verkhnekamskoye deposit, where this mineral is mined by the mine method;
• in the Odessa estuaries, mining was carried out until 1931, at present the deposit is not used on an industrial scale;
• in the Seregovskoye deposit, brine is being evaporated.

salt mine

The biological properties of table salt have made it an important economic object. In 2006, about 4.5 million tons of this mineral were used on the Russian market, with 0.56 million tons going to food expenses, and the remaining 4 million tons going to the needs of the chemical industry.

physical characteristics

Consider some of the properties of table salt. This substance is quite soluble in water, and the process is influenced by several factors:

• temperature;
• the presence of impurities.

Salt crystal contains impurities in the form of calcium and magnesium cations. That is why sodium chloride absorbs water (it becomes damp in the air). If such ions are not part of table salt, this property is absent.

The melting point of table salt is 800.8 °C, which indicates a strong crystalline structure of this compound. By mixing fine sodium chloride powder with crushed ice, a high quality coolant is obtained.

For example, 100 g of ice and 30 g of common salt can bring the temperature down to -20 °C. The reason for this phenomenon is that the salt solution freezes at temperatures below 0 ° C. Ice, for which this value is the melting point, melts in such a solution, absorbing the heat of the environment.

The high melting point of table salt explains its thermodynamic characteristics, as well as its high dielectric constant - 6.3.

Receipt

Considering how important the biological and chemical properties of salt are, its significant natural reserves, there is no need to develop an option for the industrial production of this substance. Let us dwell on the laboratory options for obtaining sodium chloride:

1. This compound can be obtained as a product by reacting copper (2) sulfate with barium chloride. After removing the precipitate, which is barium sulfate, evaporating the filtrate, you can get salt crystals.
2. In the exothermic combination of sodium with gaseous chlorine, sodium chloride is also formed, and the process is accompanied by the release of a significant amount of heat (exothermic form).

Interactions

What are the chemical properties of table salt? This compound is formed by a strong base and a strong acid, so hydrolysis in an aqueous solution does not occur. The neutrality of the environment explains the use of table salt in the food industry.

During the electrolysis of an aqueous solution of this compound, gaseous hydrogen is released at the cathode, and chlorine is formed at the anode. Sodium hydroxide accumulates in the interelectrode space.

Given that the resulting alkali is a substance in demand in various production processes, this also explains the use of table salt on an industrial scale in chemical production.

The density of common salt is 2.17 g/cm 3 . The cubic face-centered crystal lattice is characteristic of many minerals. Inside it is dominated by ionic chemical bonds formed due to the action of forces of electrostatic attraction and repulsion.

Halite

Since the density of table salt in this compound is quite high (2.1–2.2 g/cm³), halite is a solid mineral. The percentage of sodium cation in it is 39.34%, chlorine anion - 60.66%. In addition to these ions, in the composition of halite there are ions of bromine, copper, silver, calcium, oxygen, lead, potassium, manganese, nitrogen, hydrogen in the form of impurities. This transparent, colorless mineral with a glassy luster is formed in closed water bodies. Halite is a product of runoff on volcanic craters.

Rock salt

It is a sedimentary rock from the evaporite group, which consists of more than 90 percent halite. For rock salt, a snow-white color is more characteristic, only in exceptional cases the presence of clay gives the mineral a gray tint, and the presence of iron oxides gives the compound a yellow, orange color. Rock salt contains not only sodium chloride, but also many other chemical compounds of magnesium, calcium, potassium:

• iodides;
• borates;
• bromides;
• sulfates.

Depending on the conditions of formation, the main deposits of rock salt are divided into several types:

• underground salt water;
• brines of modern basins;
• deposits of mineral salts;
• fossil deposits.

Sea salt

It is a mixture of sulfates, carbonates, potassium and sodium chlorides. In the process of its evaporation in the temperature range from +20 to +35 °C, the less soluble salts initially crystallize: magnesium and calcium carbonates, as well as calcium sulfate. Further, soluble chlorides, as well as magnesium and sodium sulfates, precipitate. The sequence of crystallization of these inorganic salts may vary depending on the temperature index, the rate of the evaporation process, and other conditions.

In commercial quantities, sea salt is obtained from the water of the seas by evaporation. It differs significantly in microbiological and chemical parameters from rock salt, has a large percentage of iodine, magnesium, potassium, manganese. Due to the different chemical composition, there are differences in organoleptic indicators. Sea salt is used in medicine as a remedy for the treatment of skin diseases, such as psoriasis. Among the common products offered in the pharmacy chain, we highlight the salt of the Dead Sea. Also, purified sea salt is also offered in the food industry as iodized.

Regular table salt has weak antiseptic properties. With a percentage of this substance in the range of 10-15 percent, the appearance of putrefactive bacteria can be prevented. It is for these purposes that sodium chloride is added as a preservative to food, as well as other organic masses: wood, glue, leather.

salt abuse

According to the World Health Organization, excessive consumption of sodium chloride leads to a significant increase in blood pressure, resulting in kidney and heart diseases, stomach diseases, and osteoporosis.

Together with other sodium salts, sodium chloride is the cause of eye diseases. Table salt retains fluid inside the body, which leads to an increase in intraocular pressure, the formation of cataracts.

Instead of a conclusion

Sodium chloride, commonly referred to as common salt, is an inorganic mineral that is widely distributed in nature. This fact greatly simplifies its use in the food and chemical industries. There is no need to spend time and energy resources for the industrial production of this substance, which affects its cost. In order to prevent an overabundance of this compound in the body, it is necessary to control the daily intake of salty foods.

Salt was once worth its weight in gold, but in this century it has suddenly acquired the status of a white poison. There is some rational grain in this, because even the most useful substance, if used in excessive amounts, becomes harmful to health, and, on the contrary, consumption within reasonable limits provides undoubted benefits to the body. This fully applies to salt.

Salt tradition

Old traditions say that one who starts his meal with salt and ends with salt can protect himself from seventy-two diseases, including madness and leprosy. Dear guests were always greeted with bread and salt. Salted mushrooms, cucumbers, herring to this day are the decoration of the festive table. Our ancestors knew a lot about healthy and tasty food.

What is salt

Salt is represented by two elements Na and Cl. But, if you look more closely at the elemental composition of table salt in one hundred grams of the product, it turns out that it contains a complex set of trace elements necessary for the human body.

The daily norm of salt intake per day for an adult is considered to be a dose of no more than a teaspoon, on average from three to six grams, taking into account the salt contained in other foods eaten.

Salt is considered extremely useful for melancholic people. They are shown short-term hot baths with sea or ordinary food salt before going to bed, at the rate of one teaspoon per liter of water. It is useful for phlegmatic people to rub salt while visiting the sauna. Salt promotes the digestion of food, can eliminate heaviness in the stomach, and has the ability to open blockages in the spleen and liver.

To whom salt is contraindicated

Salt is considered harmful in case of excessive consumption for weakened people with a thin body, sanguine people, choleric people. Salt is not good for the bladder, kidneys and in case of hypertension. Excessive salt consumption reduces the amount of semen and sometimes causes eye diseases, skin disorders, and impaired vision.

Salt is included in some eczema medications. Salt can help:

• with all types of mucous tumors;
• with gout;
• with the appearance of itching;
• with deprivation.

Mix its salt with vinegar, olive oil, honey, and you can use this remedy for all kinds of sore throats. Salt with honey can help in case of stings of bumblebees, bees, wasps. When tumors appear, salt is mixed with dry mint, raisins, vinegar and applied to the so-called wind tumors. In case of mushroom poisoning, folk healers suggest drinking vinegaromed. To prepare a healing potion, take two teaspoons of honey and two teaspoons of apple cider vinegar to a glass of boiled water, add salt. The solution should be pleasant, sweet and sour.

How to cure scabs and bad teeth

Salt with vinegar is used in the form of lotions when scabs appear on the head, lichen. In combination with aloe, salt is useful in catarrhs ​​(taken orally). Gargling with vinegar and salt will help with gum disease and loose teeth. Rinse your mouth with a salt solution in water, this is useful for strengthening the gums, for healing the holes that form during the removal of teeth.

When periodontal disease appears, it is useful to rub salt, which is dissolved in honey, into the gums (add five to ten grams of table salt to twenty grams of honey and mix thoroughly until dissolved).

Everyone has probably heard the expression: “bread is the head of everything, but without salt you can’t go anywhere.” Indeed, table salt is used not only in the kitchen for cooking, but has a wide range of uses. Do you know where to use salt? I want to talk about the unconventional use of salt. I hope this information is useful to you.

Using salt in the kitchen but not for cooking

Salt is an excellent cleaning agent. It is indispensable if you need:

Clean a frying pan or pan that is burnt on the stove (just pour salt on the bottom in a thick layer, fill it with water, let it stand overnight, then boil it and the burnt food will be easily cleaned off);

Refresh kitchen sponges for dishes (soak them briefly in salt water);

Remove mold (with a paste of lemon juice and salt, wipe the places where mold accumulates);

Clean silverware (soak silver for several hours in saline solution (1 teaspoon per glass of water), then boil for 10-15 minutes, wash and wipe);

Cleans darkened crystal vases, glasses, jugs (wipe them with a mixture of coarse salt and vinegar, then rinse);

Clean porcelain cups or coffee pot from plaque (wipe them with dry salt);

Remove bad smell from the pipes under the sink (spill the pipes with hot concentrated salt solution);

Eliminate the unpleasant smell in the refrigerator (wipe it with a damp cloth soaked in a solution of salt and soda);

Get rid of unpleasant smells in the oven or microwave (wash them with salt mixed with cinnamon);

Use of salt in washing and drying clothes

Terry bathrobes and towels will be soft and fluffy if you hold them in salt water, then rinse, dry and do not iron;

Colored fabrics do not shed if they are washed in cold water with the addition of salt;

To refresh the color of black fabrics, you need to add a pinch of salt to the water during the last rinse;

Things embroidered with colored threads should be soaked in salt water (two teaspoons of salt per liter of water), then washed in salted water at room temperature. Then dry well and iron the product from the inside out;

Chocolate stains are easy to remove with heavily salted water;

A solution of table salt (one tablespoon per glass of water) can remove fresh traces of sweat from clothes (clothes should be soaked in this solution for half an hour);

If you want to keep your laundry from freezing when drying in cold winters, be sure to rinse it in salt water;

Wooden clothespins will last longer if boiled in salt water;

Salt will help clean the surface of the iron (you just need to run a heated iron over a sheet of paper several times, on which a thin layer of fine salt is poured);

Salt will help whiten a bathtub by rubbing it with a powder consisting of equal parts salt and baking soda, or a mixture of turpentine and salt in equal parts.

The use of salt in the house and in the country

The salt will help freshen the air in the room.

An accelerated version is possible (cut the orange into two parts and sprinkle salt on them) and long-playing (put orange peel 6-12 mm thick and salt 6 mm in layers in a glass jar and put it in the room, if desired, orange peel can be replaced with rose or lavender petals) .

Salt will help to quickly melt the stove or fireplace in the house.

To do this, it is enough to throw a pinch of salt on raw firewood, then they will flare up faster and will burn longer.

Salt will clean the chimney of soot.

It is enough to regularly throw two tablespoons of salt into the fire of a fireplace or stove.

Salt will help clear frozen windows.

It is necessary to wipe the windows with saline solution (2 tablespoons of salt per glass of water). The same solution will also help clean the windshield of the car if it is covered with ice.

Just add a pinch of salt to the water.

Salt will help remove fresh white spots from hot on a wooden table.

It is necessary to make a pasty mixture of one teaspoon of salt and a little vegetable oil and gently rub it into the stain, leave for 20 minutes, then remove the residue with a dry cloth.

Salt will restore the original appearance of burnt-out wicker furniture.

It is enough to wipe it with a stiff brush dipped in warm salt water and let it dry, preferably in the sun.

Salt will help seal nail holes in the wall.

You need to prepare a paste (for 5 teaspoons of water you need to take two teaspoons of salt and food starch) and apply it to the holes in the wall and let it dry for 3 hours.

Sick plants should be sprayed with a strong solution of table salt (100 grams per liter of water). As a result, the leaves will turn yellow and fall off, the plant will stop growing and all the power will be spent on the ripening of the tomato. In addition, the salt film will protect the fruit from further infection.

The salt will protect the onion from the onion fly.

At the first yellowing of the onion, you need to sprinkle the bed with coarse table salt (about a kilogram of salt per 10 square meters) and spill it well with water, the salt should dissolve.

Salt will help get rid of burdock.

It is necessary to cut them at ground level and sprinkle with salt.

• Salt will protect strawberries from garden ants.

If an anthill appears on your strawberries, then pour it with a solution of table salt.

• Salt will stop the growth of horseradish or unnecessary bushes

Dig up unnecessary bushes, sprinkle salt on the remaining roots.

The use of salt for cosmetic purposes

regular baths with sea salt and iodine will help (100 grams of salt and 2 drops of iodine per liter of water).

Soap-salt (3 tablespoons of salt and ¼ grated soap per 8 liters of water) will make your heels tender and soft.

Salt cream (¼ cup table salt, ¼ cup Epsom salts, ¼ cup vegetable oil) will soften and smooth rough skin on elbows, knees and soles.

If you want to have, then try doing hand peeling using fine table salt and olive oil. Rub this mixture into the skin of the hands with a cotton swab for only 2 minutes, and then rinse with warm water.

Fine salt acts like a scrub on the skin, removing dead cells. Sprinkle salt on a sponge and wipe dampened skin.

The use of salt in folk medicine

If your throat starts to hurt, make a saline solution (half a teaspoon of salt in a glass of warm water, you can add the same amount of baking soda and a few drops of iodine) and gargle.

If a runny nose begins, then heat the salt in a pan, put it in a cloth bag and warm the maxillary sinuses, or make a circular salt bandage through the forehead and back of the head at night.

• Salt will help with bruises.

Bruises will heal faster if they are covered with a bandage of salt and vinegar.

• Salt will relieve the sting of a wasp or bee.

Apply a wet pinch of salt to the bite site, the pain will subside, the swelling will subside.

For toothache, rinse your mouth with salt water after every meal and before going to bed.

Every day for a week, salt ground on a coffee grinder massages the gum area and rubs the surface of the teeth, which leads to the removal of tartar and teeth whitening. The course can be repeated no earlier than in a month.

• Salt will relieve fatigue from the legs if, after a hard day, put your feet in warm water with table salt.

Today you learned where to use salt. However, there are a lot of ways to use salt, I hope that you will tell us about your ways of using it.

For many millennia, table salt was used almost exclusively for food, to protect food from spoilage, to pickle vegetables.

Small quantities were used to make hides. To obtain rawhide, loosened skins are treated with a mixture of alum and table salt; salt enhances the tanning effect of alum and dehydrates the leather fibers, thereby preventing them from sticking together when dried. Since ancient times, dyers have used table salt to make pickles, and soap makers to salt out soap.

This continued almost until the end of the 18th century, until the development of weaving and spinning, the production of cheap fabrics from cotton, required soda and chlorine. Salt turned out to be the most suitable raw material for obtaining these products. In addition, as scientists have established, it could be used in the preparation of Glauber's salt and hydrochloric acid, alkalis, paints and many hundreds of other chemical products. For example, the preservation of leather is also not complete without the use of table salt: the washed skins are dipped in a concentrated salt solution to prevent decay.

As with table salt, people got acquainted with soda in ancient times. Egyptian craftsmen widely used soda for making glass and degreasing wool, and used it in medicine.

Until the beginning of the XIX century. soda was extracted from the soda lakes of Egypt and some other countries, as well as from the ashes of plants containing sodium salts in their tissues. In the Middle Ages and later, the Spanish soda "barilla" was famous, which was extracted from a specially bred salsola plant. In France, the source of vegetable soda was the selicor plant, in Scotland it was extracted from the ashes of algae. In the 40s of the XVIII century. French chemist Duhamel de Monceau made an important discovery: he proved that table salt and soda have the same base - sodium. At that time, sodium had not yet been obtained in a free form, and scientists thought that soda was not a chemical compound, but an element, like sulfur or phosphorus.

Duhamel's discovery prompted scientists to use table salt to produce soda. After all, if nature transforms the salt contained in the soil into the soda of soda plants, then why can't a person carry out such a metamorphosis in the laboratory?

In 1775, the French Academy of Sciences announced a prize of 12,000 francs for the best way to obtain artificial soda. Many methods have been proposed for producing soda, but they were all expensive and unprofitable, and chemists continued to look for new ways to produce artificial soda.

In 1789, under the blows of the victorious revolution in France, the absolutist monarchy collapsed. From the first days of the birth of the new system, the French people had to defend the gains of the revolution with weapons in their hands. Surrounded by a ring of hostile states, the young republic was in dire need of ammunition. The basis of black powder, which was then used, was saltpeter; potash was needed to produce it.

In 1794, a government report appeared in the Parisian newspapers: “The Republic needs potash for the manufacture of saltpeter, and soda could in many cases replace potash; nature gives us table salt in immeasurable quantities, from which soda can be extracted. Many well-known French chemists responded to this call - more than 30 proposals were received. Leblanc's method was unanimously recognized as the best.

A mixture of Glauber's salt, limestone (or chalk) and coal is heated in large brick kilns. The mass melts with thorough stirring with iron pokers or scrapers. Blue lights appear on the surface of the molten mass, and when they disappear, the alloy is removed from the furnace.

So as a result of the reaction between the constituent parts of the mixture, soda was born. Glauber's salt was obtained by decomposing table salt with sulfuric acid.

Leblanc's invention freed France from foreign dependence, but the fate of the scientist himself was very tragic: in 1806, being in deep poverty, he committed suicide. The talented inventor and scientist could not overcome the heartlessness and greed of capitalist society.

Only some time after the death of Leblanc, the production of sulfur according to his method began to develop rapidly. Soda plants appeared in many European countries, producing hundreds of thousands of tons of soda and other chemical products. However, there were many shortcomings in Leblanc's method. The most significant of these is the abundance of waste products in the form of hydrogen chloride and calcium sulfide.

In the 30s of the last century, a new, simpler and more profitable way of obtaining soda from table salt was found, but almost 60 years passed before it became widespread. The method is as follows. A concentrated solution of table salt is saturated with ammonia, and then carbon dioxide, a product of burning limestone in kilns, is passed through the brine under pressure. Ammonia reacts with carbon dioxide and water to form ammonium bicarbonate. The latter enters into an exchange decomposition reaction with sodium chloride and the resulting bicarbonate of soda precipitates, which is filtered off and calcined. The result is soda ash, carbon dioxide and water. The gas is again used to saturate the brine. From a solution containing ammonium chloride, ammonia is isolated by heating the solution with lime obtained by burning limestone. Ammonia is also returned to the production cycle.

Thus, with the ammonia method of soda production, the amount of waste is much less than with the Leblanc method. Waste is only calcium chloride, which finds some industrial use: calcium chloride solutions are watered on roads to destroy dust, it is introduced into the composition of cooling mixtures, it is used for drying gases, dehydrating ether and other organic liquids, it is used in medicine.

In Russia, the scale of soda production began to expand only from the 80s of the last century, although small soda plants appeared already in the 60s. In 1864 M.P. Prang built a soda plant in Barnaul; at the plant, according to the Leblanc method, soda was obtained from natural Glauber's salt. The latter was mined from the Marmyshan lakes, located in the Kulunda steppe, 200 km from Barnaul.

The problem of obtaining soda by artificial means was of interest to Russian scientists as early as the 18th century. Academician Kirill Laxman in 1764, 11 years earlier than Malherbe and 27 years earlier than Leblanc, received soda from natural Glauber's salt. He was the first to propose replacing soda and potash with this salt in glass production.

At the same time, Russian scientists studied the possibility of industrial use of table salt. Many of them - Kireevsky, Krupsky, Mendeleev and others - ardently advocated the creation of a domestic production of soda. Moreover, even then the production of many important chemical products was associated with it: sulfuric and hydrochloric acids, sodium sulfate, berthollet salt, chlorine. Mendeleev wrote that "it is now impossible to imagine the development of industry without the consumption of soda." The appearance on the market of domestic soda, in his opinion, would also render a service to agriculture. The replacement of potash with soda in many industries would contribute to the conservation of forests.

However, the successful development of soda production in Russia was hampered by a high excise tax on table salt. Despite the persistent demands of scientists and industrialists, the tsarist government for a long time did not want to remove the excise tax on salt. It was not until 1881 that the fetters that fettered the emergence of large-scale soda production were broken, and the results were not long in coming. Two years later, the first large soda plant in the Northern Urals was launched in Berezniki, built by the merchant Lyubimov together with the Belgian firm Solvay. For 35 years from the date of foundation of this plant until the Great October Revolution, 878 thousand g of soda ash was produced at the Bereznikovsky plant.

During the years of Soviet power, the Bereznikovsky plant was reconstructed and expanded, the production of soda increased several times compared to pre-revolutionary. More recently, at the plant, soda, as in tsarist times, was obtained from natural salt brine pumped out of the bowels of the earth. Now it is produced from artificial brine obtained by dissolving potash production waste. This significantly reduced the cost of soda.

In our time, a number of large soda plants operate in the Soviet Union.

The use of soda in the national economy has expanded enormously. Soda is no longer needed only by soap makers, glass makers and textile workers, but also by metallurgists (separation and purification of non-ferrous metals, removal of sulfur from cast iron), dyers, furriers and food workers (production of confectionery and mineral waters, clarification of vegetable oils). A lot of soda is used to soften water used in factories and plants, in steam boilers of locomotives and power plants. Soda serves as a raw material for the production of many chemical products (magnesia, sodium sulfate, sodium fluoride, etc.).

If all the table salt that is processed all over the world for soda per year is loaded into freight cars, then the train would stretch from Moscow to Vladivostok.

Most of the salt consumed by the chemical industry goes to the production of soda, caustic soda (caustic soda) and chlorine. Back in 1883, Russian scientists Lidov and Tikhomirov developed an industrial method for obtaining caustic soda from table salt by electrolysis of its aqueous solutions. In this case, along with caustic soda, chlorine is also obtained. Both of these products are very necessary for many branches of the national economy.

In recent years, salt has not only become a source of chemicals, medicines, fertilizers, explosives, but also acquired some new "professions". It is successfully used to extinguish burning soot, to harden steel products. It is used to accelerate the melting of ice, for the preparation of cooling mixtures used in refrigerators. Salt is needed for clarification of turpentine and rosin, in the production of the highest grades of glove husky. In the tobacco industry, some varieties of tobacco are treated with salt to improve its quality.

During the construction of artificial reservoirs, the walls and bottom of reservoirs are usually protected with clay, lined with concrete or asphalt. However, clay does not completely hold water, and concrete and asphalt are too expensive. It was necessary to find some cheap and at the same time sufficiently waterproof material. Academician A. N. Sokolovsky became interested in this problem several years ago. Studying the properties of soils, he noticed that the soil impregnated with salt does not allow water to pass through. Salt fills the pores of the soil, making it waterproof. Such soils are called salt marshes, often their surface is covered with a thin snow-white coating of salt.

In the steppes of Kazakhstan and the Crimea, in the Caspian Sea and the Dnieper region, small lakes form on salt marshes in early spring, which sometimes do not dry out until the end of summer. Such an artificial "lake" was made in Sokolovsky's laboratory. Soil was poured onto a thin sieve inserted into the funnel and washed with a solution of common salt; an artificial salt marsh was formed. But after all, in natural conditions, the salt marsh is watered by rains, melted spring waters are washed. Therefore, fresh water was poured through the funnel. At first, it leaked quite quickly - about 30-50 drops per minute, but gradually the drops fell less and less, and finally they were gone. Water does not seep through a thin layer of earth - only 3-4 mm, which has turned into a salt lick.

Therefore, if you cover the walls and bottom of any reservoir with a thin layer of earth soaked in salt, there will be no leakage. The experiments conducted by Sokolovsky on salinization of irrigation canals in some collective farms of the Volga region turned out to be successful - the leakage of water completely stopped.

Salinization of water bodies is beginning to be widely used in Ukraine, in the Lower Volga region, and Uzbekistan. Salt successfully replaces asphalt and concrete. In addition, soil treatment with a salt solution is much cheaper than covering with asphalt or concrete. Indeed, for solonetzation, you can take dirty, non-edible salt, waste from some chemical plants.

Salt provides invaluable services to builders. For example, in winter, during the construction of the Bratsk hydroelectric power station, clay soil froze and turned into hard stone. Even excavators and bulldozers could not cope with the frozen ground. The Leningrad Civil Engineering Institute has developed a way to protect clay soil from freezing. Plots of land on which it is necessary to dig ditches or pits in winter are thickly sprinkled with table salt in autumn, and then even in the most severe frosts the earth remains soft.

Salt is a substance of inexhaustible possibilities. Already now there are more than a thousand different ways to use it. And how many of them, and how many unexpected ones, will appear in our atomic age!..

How can salt be used?

2. For cosmetic purposes

Fine salt is used in many scrubs that are easy to make at home. The naturalness of this component and its natural texture provide a good result and no harm to the skin. However, it is important to remember that for people with too sensitive skin, it is also better to refrain from such methods or try them very carefully, salt causes irritation and redness.

If a piece of plaster has fallen off or a small hole needs to be repaired (for example, from a nail), then a mixture of water, salt and starch can be used. Cheap, easy to do yourself, and you don't have to take extra steps to fix it.

Of course, such a solution may not withstand the load, this must be taken into account. But it is quite possible to return the former attractiveness to the interior and hide minor flaws.

Here the functionality of salt is very extensive. For example, figures can be made from salted bread. Salt can create an interesting texture for some paints. In the end, craftsmen simply lay out paintings from salt, sometimes achieving amazing detail and elegance. Of course, such a work is very easy to spoil with one careless movement, but being captured in the picture, it can always please the author.