Table salt is an inorganic compound that consists of sodium and chloride ions. In crushed form, it is white crystals of various sizes. In most cases, it has impurities that can change the color of the salt from light brown to gray.

Types of table salt

According to the genesis and method of obtaining table salt is divided into:

  • Stone;
  • evaporation;
  • Ozernaya;
  • Basin.

Rock salt, or halite, is a mineral that consists of cubic crystals. It is the main source of table salt, as well as a raw material for the production of chlorine, sodium hydroxide and hydrochloric acid. It is located in sedimentary rocks, the thickness of halite deposits reaches 350 meters. It differs from other types of salt in a relatively small amount of impurities.

Evaporated salt is obtained in the process of evaporating natural brines, which are mined from the bowels of the earth, or artificial brines, which are made by dissolving halite in water that is injected into wells. After purification of the brines, they are evaporated in vacuum apparatuses.

Lake salt, or self-planting salt, is mined from the bottom of lakes. It is called sedimentary because it precipitates due to an excess of salt in the water. This type of table salt is distinguished by high hygroscopicity and humidity.

Basin, or garden salt, is obtained from ocean or sea water, which is transferred to artificial, large in area, pools in the southern regions. The water evaporates and the salt precipitates.

According to the type of processing, table salt is divided into: fine-crystalline, ground, unground and iodized; quality: extra, premium, first and second grade.

Deposits and production

The natural reserves of table salt on Earth are almost inexhaustible.

The main types of common salt deposits are rock salt deposits, ocean, sea and lake waters, brines and ground waters, salt marshes. The largest Russian and Ukrainian deposits are Verkhnekamskoye, Seryogovskoye, Astrakhanskoye and Artemovskoye.

In our time, table salt is mined by the mine method (the most common), crystallization, freezing, and evaporation.

The use of table salt

Salt is of primary importance in the food industry in the form of seasoning. In its pure form, it is used in metallurgy for the roasting of ores and the purification of metals. It is used even in transport - sprinkling the bottom of wagons to protect coke or manganese ore during transportation. Also, table salt is used to treat leather products in order to prevent their decay.

SALT sodium chloride NaCl. It is moderately soluble in water, the solubility depends little on temperature: the solubility coefficient of NaCl (in g per 100 g of water) is 35.9 at 20 ° C and 38.1 at 80 ° C. The solubility of sodium chloride is significantly reduced in the presence of hydrogen chloride, sodium hydroxide , salts metal chlorides. It dissolves in liquid ammonia, enters into exchange reactions. Density of NaCl 2.165 g/cm3, melting point 800.8°C, boiling point 1465°C.
They used to say: “Salt is the head of everything, without salt and zhito grass”; “One eye on the police (where is the bread), the other on the salt cellar (salt cellar)”, and more: “Without bread it’s not satisfying, without salt it’s not sweet” ... Buryat folk wisdom says: “When you are going to drink tea, put a pinch in it salt; food is digested faster from it, stomach diseases will disappear.
It is unlikely that we will know when our distant ancestors tasted salt for the first time: we are separated from them by ten to fifteen thousand years. At that time there were no dishes for cooking, people soaked all vegetable products in water and baked them on smoldering coals, and meat, planted on sticks, was fried in a fire flame. The “table salt” of primitive people was probably ash, which inevitably fell into food during its preparation. The ash contains potash potassium carbonate K2CO3, which in places remote from the seas and salt lakes has long served as a food seasoning.
Perhaps one day, for lack of fresh water, meat or roots and leaves of plants were soaked in salty sea or lake water, and the food turned out to be tastier than usual. Perhaps, in order to protect it from birds of prey and insects, people hid the meat they got for the future in sea water, and then found that it acquired a pleasant taste. Observant hunters of primitive tribes could notice that animals like to lick salt licks white crystals of rock salt, protruding in some places from the ground, and tried to add salt to food. There could be other cases of the first acquaintance of people with this amazing substance.
Pure table salt, or sodium chloride NaCl is a colorless, non-hygroscopic (does not absorb moisture from the air) crystalline substance that is soluble in water and melts at 801 ° C. In nature, sodium chloride occurs in the form of the mineral halite rock salt. The word "halite" comes from the Greek "galos", meaning both "salt" and "sea". The bulk of halite is most often found at a depth of 5 km below the earth's surface. However, the pressure of the layer of rocks located above the salt layer turns it into a viscous, plastic mass. "Floating up" in places of low pressure of the covering rocks, the salt layer forms salt "domes" that go out in a number of places.
Natural halite is rarely pure white. More often it is brownish or yellowish due to impurities of iron compounds. There are, but very rarely, blue halite crystals. This means that for a long time they were in the depths of the earth in the neighborhood of rocks containing uranium, and were exposed to radioactive irradiation.
In the laboratory, blue crystals of sodium chloride can also be obtained. This does not require radiation; just in a tightly closed vessel, you need to heat a mixture of table salt NaCl and a small amount of metallic sodium Na. The metal is able to dissolve in salt. When sodium atoms penetrate into a crystal consisting of Na + cations and Cl anions, they “complete” the crystal lattice, occupying suitable places and turning into Na + cations. The released electrons are located in those places of the crystal where the chloride anions Cl? would be supposed to be. Such unusual places inside the crystal, occupied by electrons instead of ions, are called "vacancies".
When the crystal is cooled, some vacancies are combined, and this is the reason for the appearance of a blue color. By the way, when a blue crystal of salt is dissolved in water, a colorless solution is formed, just like from ordinary salt.
The Greek poet Homer (8th century BC), who wrote the Iliad and the Odyssey, called table salt "divine." In those days, it was valued more than gold: after all, as the proverb said, “you can live without gold, but you can’t live without salt.” Because of the deposits of rock salt, military clashes took place, and sometimes the lack of salt caused "salt riots".
On the tables of emperors, kings, kings and shahs there were salt shakers made of gold, and they were in charge of a particularly trusted person - a salt shaker. Warriors were often paid salaries in salt, and officials received salt rations. As a rule, salt springs were the property of rulers and crowned persons. In the Bible there is an expression "drinks salt from the king's palace", meaning a person who receives maintenance from the king.
Salt has long been a symbol of purity and friendship. “You are the salt of the earth,” Christ said to his disciples, referring to their high moral qualities. Salt was used during sacrifices, newborn children of the ancient Jews were sprinkled with salt, and in Catholic churches, when baptized, a crystal of salt was placed in the baby's mouth.
It was in the custom of the Arabs, when approving solemn treaties, to serve a vessel with salt, from which, as a sign of proof and guarantee of permanent friendship, the persons who concluded the agreement “covenant of salt” ate several grains of it. “To eat together a pood of salt” among the Slavs means to get to know each other well and make friends. According to Russian custom, when they bring bread and salt to guests, they wish them good health.
Salt is not only a food product, but has long been a common preservative; it has been used in the processing of leather and fur raw materials. And in technology, it is still the raw material for the production of almost all sodium compounds, including soda.
Table salt was also part of the most ancient medicines, it was attributed to healing properties, a cleansing and disinfecting effect, and it has long been noticed that table salt from different deposits has different biological properties: the most useful in this regard is sea salt. In the Herbal Medicine, published in Russia in the 17th century, it is written: “Two essences of salt, one was dug from the mountain, and the other was found in the sea, and the one from the sea is lutchi, and besides sea salt, that lutchi that is white.”
However, the use of salt must be observed in moderation. It is known that the average European daily absorbs up to 15 g of salt with food, while the average Japanese is about 40 g. It is the Japanese who hold the world championship in the number of patients with hypertension retains more fluid than it needs. Cells swell from its excess, compress blood vessels, so blood pressure rises, from which the heart begins to work with overload. It also becomes difficult for the kidneys, which cleanse the body of excess sodium cations.
No plant can grow on soil covered with salt, salt marshes have always been a symbol of the barren and uninhabited land. When the ruler of the Holy Roman Empire, Frederick I Barbarossa, destroyed Milan in Italy in 1155, he ordered that the ruins of the defeated city be sprinkled with salt as a sign of its complete destruction... For different peoples at all times, scattering salt meant bringing trouble and losing health.
In ancient times, people used several methods for extracting table salt: the natural evaporation of sea water in "salt gardens", where sodium chloride NaCl "sea" salt fell out, the digestion of water from salt lakes to obtain "evaporated" salt, and breaking out "rock" salt in underground mines. All these methods give a salt with impurities of magnesium chloride MgCl2 6 H2O, potassium sulfates K2SO4 and magnesium MgSO4 7H2O and magnesium bromide MgBr2 6H2O, the content of which reaches 8-10%.
In sea water, on average, 1 liter contains up to 30 g of various salts, and table salt accounts for 24 g. The technology for obtaining sodium chloride NaCl from sea and lake water has always been quite primitive.
For example, at the end of the "Bronze Age" three, three and a half thousand years BC the ancient salt pans doused logs with sea water, and then burned them and chose salt from the ashes. Later, salty waters were evaporated on large baking sheets, and animal blood was added to remove impurities, collecting the resulting foam. Around the end of the 16th century salt solutions were purified and concentrated by passing through towers filled with straw and bushes. Evaporation of a salt solution in air was also carried out in a very primitive way, pouring the brine over a wall made of bundles of brushwood and straw.
Salt making, the oldest of the chemical crafts, originated in Rus', apparently at the beginning of the 7th century. Salt mines belonged to the monks, who were favored by the Russian tsars, they were not even taxed on the sold salt. Salt boiling brought huge profits to the monasteries. Pickles were extracted not only from lakes, but also from underground salt springs; boreholes that were built for this, in the 15th century. reached a length of 6070 m. Pipes made of solid wood were lowered into the wells, and brines were evaporated in iron pans on a wood-burning firebox. In 1780, more than a hundred thousand tons of salt were boiled in this way in Russia ...
Currently table salt is mined from deposits of salt lakes and deposits of rock salt halite.
Salt is not only an important food seasoning, but also a chemical raw material: sodium hydroxide, soda, chlorine are obtained from it.
Ludmila Alikberova

Table salt is a crystalline natural sodium chloride containing a small amount of impurities. Table salt not only improves the taste of food, it is of great physiological importance for the human body. It is found in blood, bile and cell fluid. Thanks to table salt, a normal metabolism in various tissues of the body is ensured. With a lack of it, thickening of the blood is observed, spasms of smooth muscles can develop, dysfunction of the nervous system and blood circulation, regulation of water metabolism and acid-base balance are disturbed. Salt chlorine is involved in the formation of hydrochloric acid, which is necessary for the normal digestion of food. To ensure normal physiological functions, a person should receive 10-15 g of salt daily with food. In some diseases (kidney, hypertension, etc.), it is necessary to limit the intake of salt in the body.

Salt is used as a food preservative. Its action is based on the fact that saline solutions increase osmotic pressure. Microorganisms in such an environment are dehydrated and their vital activity stops. In addition, table salt is necessary for almost all industries: for the production of ferrous and precious metals, soap, rubber, paper, glass, fabrics, leather, etc.

The natural reserves of salt on Earth are practically inexhaustible. According to the nature of the deposit and the method of extraction, rock salt, self-planting, cage, boiled salt are distinguished.

Rock salt occurs in the form of large deposits (Artemovskoye, Nakhichevanskoye, Dzhebelovskoye, etc.). It is mined by mine and quarry methods. Rock salt is of high purity (NaCI - 99%), contains few impurities (magnesium and calcium salts).

Self-planting salt is mined in many salt lakes. The most important deposit is Lake Baskunchak with an area of ​​100 km2. Seams of self-planting salt here reach a depth of over 250 and its reserves are so large that they would be enough for one and a half thousand years for the entire population of the world. Salt contains impurities of silt, clay, sand, which give it a yellowish or grayish tint.

Garden salt is obtained by evaporation of sea water or lake brine diverted into shallow, but vast artificial pools. In small quantities, it is mined from the Perekop salt lakes and estuaries of the Black and Azov Seas.

Evaporated salt is extracted from brines formed as a result of natural dissolution of underground rock salt deposits (natural brines) in water or obtained by dissolving such salt in water injected into wells drilled to the salt formation. The brines are evaporated to remove water in special vats or vacuum apparatus (vacuum salt). Its production is carried out in the Perm region, Ukraine, Siberia and other regions of the country.

According to the processing method, salt can be fine-crystalline, ground (various grinding sizes of numbers 0, I, 2, 3), lumpy (lump), grain, crushed, unground and iodized (contains 25 g of potassium iodide per 1 g of salt).

The quality of table salt is evaluated according to GOST 13830-84. Depending on the chemical composition and quality indicators, varieties are distinguished: extra, highest, 1st and 2nd. Extra grade salt contains at least 99.7% sodium chloride and 0.1% moisture. This grade produces only boiled vacuum salt, corresponding in crystal size to grinding No. 0. In other grades of salt, depending on its type, sodium chloride is 96.5-98%, and humidity is 0.28-5%. Salt should be free-flowing, dry to the touch, without lumps, a 5% salt solution should be pure salt, transparent, without foreign tastes and odors, a slight smell of iodine is allowed in iodized. Salt should not have mechanical impurities, with the exception of salt from the Artemovsky and Solotvinsky deposits. The content of impurities of calcium, magnesium, iron oxide, sodium sulfate, sulfate ion is normalized. Salt is packaged in small (up to 1 kg) and large (up to 50 kg) paper packaging (packs, bags, bags).

Store at a temperature not exceeding 20 ° C and relative air humidity not more than 75%. The main defect in the storage of salt is its caking into lumps or into a continuous monolithic mass. Salt caking increases with increasing its moisture content due to its high hygroscopicity. Contribute to hydration and impurities in the form of calcium and magnesium salts.

Table salt is an important food additive, without which it is impossible to cook many dishes. When ground, this product has the appearance of small white crystals. Various impurities in the composition of table salt of natural origin can give it shades of gray.

Salt is chemically composed of 97% sodium chloride. Other names for this product are rock, table or edible salt, sodium chloride. In industrial production, such varieties of salt are obtained as purified or unrefined, fine or coarse grinding, iodized, fluorinated, pure, sea salt.

The admixture of magnesium salts in the composition of table salt gives it a bitter aftertaste, and calcium sulfate - earthy.

Salt has been mined for thousands of years. At first, the method of obtaining it was the evaporation of sea or salt lake water, the burning of some plants. Now on an industrial scale, salt deposits are being developed on the site of the dried up ancient seas, getting it from the mineral halite (rock salt).

In addition to direct use in food, table salt is used as a safe and common preservative for food preservation, as a component in the production of hydrochloric acid, soda. The properties of table salt in the form of its strong solution in water have long been used for leather dressing.

In the body, salt is not formed, so it must necessarily come from the outside, with food. Salt absorption occurs almost entirely in the small intestine. Its excretion from the body is carried out with the help of the kidneys, intestines and sweat glands. Excessive loss of sodium and chloride ions occurs with profuse vomiting, severe diarrhea.

Salt is the body's main source of sodium and chloride ions, which are found in all organs and tissues. These ions play an important role in maintaining water and electrolyte balance, including activating a number of enzymes involved in the regulation of this balance.

Useful properties of table salt also lie in the fact that it is involved in the conduction of nerve impulses and muscle contractions. One-fifth of the total daily salt requirement goes to the production of gastric hydrochloric acid, without which normal digestion is impossible.

With insufficient intake of salt in the human body, blood pressure decreases, heart rate increases, convulsive muscle contractions appear, and weakness.

In medicine, sodium chloride solutions are used to dilute drugs, to replenish fluid deficiency in the body and detoxify. For colds and sinusitis, the nasal cavity and paranasal sinuses are washed with saline. Salt solutions have weak antiseptic properties. With constipation, enemas with a solution of sodium chloride help, which can stimulate the peristalsis of the large intestine.

The daily requirement for sodium chloride is about 11 grams, this amount of salt contains 1 teaspoon of salt. In a hot climate with severe sweating, the daily need for table salt is higher and amounts to 25-30 g. But often the actual amount of salt consumed exceeds this figure by 2-3 times. Salt has almost zero calories.


With the abuse of table salt, arterial hypertension develops, the kidneys and heart work in a stressful mode. With its excess content in the body, water begins to linger, which leads to edema and headaches.

With diseases of the kidneys, liver and cardiovascular system, with rheumatism and obesity, it is recommended to limit salt intake or completely eliminate it.

Salt poisoning

The use of salt in large quantities can not only adversely affect health, but also be the cause of death. It is known that the lethal dose of table salt is 3 g/kg of body weight, these figures were established in experiments on rats. But salt poisoning is more common in pets and birds. The lack of water exacerbates this situation.

When so much salt enters the body, the composition of the blood changes and blood pressure rises sharply. Due to the redistribution of fluid in the body, the work of the nervous system is disrupted, blood cells - red blood cells, as well as cells of vital organs are dehydrated. As a result, the delivery of oxygen to tissues is disrupted, and the body dies.

Video from YouTube on the topic of the article:

STATE (REGIONAL) EDUCATIONAL INSTITUTION

ADDITIONAL EDUCATION FOR CHILDREN

"CHILDREN'S ECOLOGICAL AND BIOLOGICAL CENTER"

Geological association "Amethyst"

Section: Minerals

Abstract on the topic:

"PRODUCTION AND USE

SALT"

Performed: 8th grade student

Protsenko Ekaterina Andreevna

Supervisor: teacher

additional education

Shepelina O. G.

Lipetsk, 2010

Introduction 3

§ 1. General characteristics of table salt 4

§ 2. Methods of extraction and use of salt in the history of the development of different states 8

§ 3. Salt mines of Russia 17

§ 4. The value of table salt for living organisms.

Its economic use 23

Conclusion 27

References 28


Introduction

Among all the salts, the most important is

which we simply call salt.

A.E. Fersman

Table salt, familiar to every person in the modern world, plays a huge role in nature and the life of living organisms. Now none of us in ordinary life pays much attention to her, and it is hard to imagine that in the old days she was worshiped, she was valued like gold, and people went on distant wanderings in search of her. In the work I would like to recall the importance, and sometimes even the need for ordinary table salt.

Goal of the work– review and analyze the extraction and use of table salt.

Tasks:

1. characterize table salt,

2. show the methods of extraction and use of salt in the history of the development of different states,

3. consider the salt mines of Russia,

4. indicate the value and identify areas of human use of salt.

To make our essay more interesting, we will try to provide it with photographs and, for greater clarity, draw up a series of diagrams and maps, which we will also place in the text.

§ 1. General characteristics of table salt

There are only about 100 minerals and varieties on our planet that can be called salts. Table salt is the number 1 salt, both in terms of distribution in nature and for human life. Table or rock salt consists of the mineral halite (NaCl).

The name of the mineral comes from the Greek. "gallos" - sea salt.

Pure halite is transparent and colorless (Fig. 1). Inclusions and impurities can color it red (iron inclusions), gray (gives organic matter) and yellow (sulfur, some iron oxides) tones. Under the influence of radioactive irradiation, halite turns blue. The mineral has a colorless or white streak and a vitreous luster.

It usually occurs in the form of dense, fine-grained Fig.1. Halite (2 cm) on plaster

nisty masses, much less often in the form of cubic crystals.

The mineral halite is very brittle, its hardness is 2 - 2.5. It dissolves easily in water at any temperature. Has high thermal conductivity. A salty taste is a diagnostic sign of halite. In addition, if a solution of silver nitrate is added to an aqueous solution of halite, one can see the formation of a dense precipitate of silver chloride AgCl.

The mineral forms massive accumulations.

Halite is widespread. It occurs in the form of layers or salt domes. Salt layers do not come to the surface due to the high solubility of the mineral, they are opened by wells or mines. Halite is the main salt component of ocean and sea waters, as well as salt lakes and highly mineralized groundwater. It can be found in layers of sedimentary rocks among other minerals - products of water evaporation - in drying estuaries, lakes, seas. The sedimentary layer is up to 350 m thick and extends over vast territories. For example, in America and Canada, underground salt deposits extend from the Appalachian Mountains west of New York through Ontario to the Michigan Basin.

Halite deposits are the main source of table salt, which is used directly for food, is the main component in food preservation, and is used in technology as a raw material for the production of hydrochloric acid and other substances.

Salt deposition requires a hot (for the rapid evaporation of water saturated with salt) and dry (so that precipitation and high air humidity do not prevent crystallization) climate. This is a subtropical climate of deserts and semi-deserts (arid zone).

Halite, or table salt, is formed:

1. in sea bays with poor connections with the sea, in lagoons;

2. in sea coastal sands of low plains (sebkhas). Salt water, falling on the surface of the sand, seeps into it. Over time, pure water evaporates, and the precipitated salt remains in the sand and crystallizes. Repeating from time to time, this process contributes to the accumulation of salt in the sand and the formation of whole salt-bearing layers;

3. in lakes with few inflowing rivers, with rapid evaporation of water, they are also sources of salt accumulation. These are mainly dry (desert) lakes in areas with low rainfall and during the hot season. Soda can also accumulate in such lakes.

It should be noted that the main industrial accumulation is carried out in sea bays and lagoons and, to a lesser extent, in lakes.

Halite crystals, found in some stagnant salt lakes and water bodies not subject to waves and storms, can form funnel-shaped skeletal crystals (dendrites). A funnel is one crystal that has grown from one embryo, which is formed on the very surface of the reservoir and grows only from below and from the sides - where it comes into contact with the nutrient solution. As the crystal grows, it becomes hollow and floats like a boat on the surface of a supersaturated aqueous solution.

Since the solubility of halite is almost independent of temperature, evaporation acts alone: ​​supersaturation is reached in the surface layer of the salt solution, and crystal nuclei appear in it. And since the solution is motionless, the funnel grows into a kind of dendrite.

And here is another example. A. E. Fersman describes his observations in the Karakum Desert. After a heavy night rain, in the morning the clay surfaces of the shores are suddenly covered with a continuous snow cover of salts - they grow in the form of twigs, needles and films, rustle underfoot ... but this continues only until noon, - a hot desert wind rises, and its gusts are dispelled for several hours of salt flowers.

However, the most remarkable stone flowers can be seen in the polar regions. Here, during six cold months, the mineralogist P. L. Dravert observed remarkable formations in the salt brines of Yakutia. In cold salt springs, the temperature of which dropped 25° below zero, large hexagonal crystals of the rare mineral hydrohalite appeared on the walls. By spring, they crumbled into a powder of simple table salt, and by winter they began to grow again.

Rock salt is usually found in the places of ancient dried-up sea basins. As early as 1715, the scientist Halley raised the question of why the sea is salty; he tried to give an answer, rightly striving to find it in the past fate of water. After all, over the long history of its occurrence on the surface of the Earth, the water of the oceans managed to produce a huge chemical work. Many times she made her constant circulation on the surface of the earth, washing out everything that dissolves easily, sorting by specific gravity, accumulating sparingly soluble, stable compounds at the bottom of her pools. The complex life of organisms again extracted some of these compounds without touching others, and thus, during the entire geological past, enormous amounts of various salts accumulated in the mass of surface waters. This process of enrichment with salts continues at the present time, and rivers bring millions of tons of dissolved substances with them every year.

Experts calculated that if the water of all the seas and oceans suddenly evaporated, the salt accumulated in the sediment would be enough to build a wall 1 m thick and 280 m high, which would encircle our planet along the equator.

Huge deposits are not only approximately horizontally occurring layers of various thicknesses. Sometimes salt deposits have a dome shape: their bases rest at a depth of 5 - 8 km, and the peaks rise to the earth's surface, sometimes even protrude from it. Domes are formed in the following way. At high temperature and due to high pressure in the bowels of the Earth, salt becomes plastic. It expands and pushes up. Salt intrudes into the rocks lying above it.

Salt domes occur in weakened areas of the earth's crust, in particular at the intersection of faults. The dome consists of a salt mass (stock) and a subsalt structure formed by rocks raised above it. Large salt domes are known in many parts of the world. For example, in Tajikistan there are some of the highest salt domes, one of which rises to a height of 900 m. It is called Khoja-Mumyn (Salt Mountain) and is located near the city of Kulyab.

Depending on the conditions of occurrence of salt, on its origin, there are several varieties:


Self-planting salt (Fig. 3), which is formed at the bottom of closed water basins in the form of layers in countries with a hot and dry climate.

Rice. 3. Lake Baskunchak is one of the largest deposits of self-planting salt

3. Volcanic salt is sublimations of volcanoes.

4. Efflorescence are films and raids on the surface of the earth in the steppe and desert regions.

According to the method of extraction, salt is also divided into several types:

1. Stone. It is mined by mining, with the help of underground mining.

2. Self-planting salt or lake salt, mined from layers at the bottom of salt lakes

3. Garden salt is obtained by evaporating or freezing estuaries and lakes from the water.

4. Evaporated salt is obtained by evaporation from groundwater or by dissolving rock salt, followed by pumping out the solution, which is then subjected to evaporation.

Other methods of salt production are known, but they are of little use. For example, in Yakutia (Russian Federation) at the Kempendyai deposit, salt from underground sources is precipitated using low temperatures, which no one else in the world does.

According to experts, the cheapest salt is obtained using cage and self-planting technologies, the most expensive - with a vacuum-evaporation method of production.

§ 2. Methods of extraction and use of salt

in the history of the development of different states

When a person first found salt and seasoned his food with it - no one knows. Only one thing is clear: salt began to be mined many millennia before our era, and the salt industry was one of the most ancient. At first, man used natural salt springs and lake brines, then moved on to boiling salt and, finally, to extracting rock salt from the bowels of the earth. After all, salt is absolutely necessary for man, necessary for all animals and plants. The main thing is not its taste, but the role that sodium chloride plays in all living organisms.

The Celts were among the first to obtain salt from brine. In the 1st millennium BC. e. they extracted it from salt springs in many parts of Germany. The Celts poured brine on hot stones, the water evaporated, and the salt remained on the stone in the form of a crust. Later, they began to build brick and tower-like structures with scaffolding of poles and stone slabs, under which a fire was kindled, and brine was poured on these slabs. After a sufficient amount of salt had settled, the scaffolding was dismantled and the salt scraped off. Plates unsuitable for further use were piled up. Now scientists find a large number of such plates in Lorraine, a region of Germany, in the valley of the river Sey. In this swampy area with ancient salt pans, called Sei by the Celts, which means “salt water”, the abandoned remains of broken bricks form whole brick “mountains”, the volume of which reached almost 2 million m 3.

This was a grueling and time-consuming method of extraction, so the Celts tried to find a new way to evaporate the brine in order to obtain salt in large quantities. At the Salt Museum in Bad Nauheim, contemplating the exhibits, today one can only marvel at how they managed to achieve this.

Initially, the brine was settled for some time in specially constructed dams. At the same time, due to the evaporation of water, a more concentrated brine was formed, it evaporated faster, and less firewood was required for this. This process was carried out in a large clay cauldron, under which a fire burned between two rows of bricks. They were installed obliquely and at some distance from each other. In this way, the air flowed evenly from both sides to the fire, the flame was concentrated under the boiler, creating a large heat. It was a simple and rational way to show how excellently the Celts handled fire and water two and a half thousand years ago.

The brine was evaporated until it thickened, then it was poured into small crucibles and heated until its contents crystallized into a dense mass. Finally, the crucible was broken, and the “salt cap” appeared. This form, invented by the Celts and existed almost to our time, was a well-known item of trade.

The ancient Romans mined salt in this way. They collected a saturated saline solution from natural sources and evaporated it over a fire.

The first of the great Roman roads, the Via Salaria ("Salt Road"), was built to transport the products of the salt works throughout the peninsula. The Roman government did not have a monopoly on the sale of salt, but, if necessary, actively intervened in price regulation.

Periodically in Rome, the price of salt dropped - a gift to the plebeians. It was "given" when the government needed popular support. For example, on the eve of the decisive battle with Mark Antony and Cleopatra, Emperor Augustus distributed salt and olive oil for free. And in the end, he won.

To raise money for the Punic Wars (264-146 B.C.), Rome manipulated prices with virtuosity. In the capital, salt remained cheap, but elsewhere the price depended on the distance to the saltworks.

Salt was of exceptional military importance. She needed both soldiers and horses. The special ration of salt that every Roman soldier received was called salarium argentum and became the forerunner of the English word salary (salary). The Latin word sal among the French became solde ("to pay"), and soldier ("soldier") came from it. And our salads (salad - "salty") also came from the Romans, because they always salted vegetables. And even salt was added to wine for preservation (there were no bottle caps then).

On the table of the plebeians, white crystals stood in a simple seashell; at the feast of the patricians - in a skillful silver salt shaker. And since salt symbolized friendly bonds, its absence from the banquet table was interpreted as an unfriendly act.

Powdered salt is also mentioned in Chinese sources dating back to the 7th century BC. BC. Salt production (Figure 4) was politically significant in ancient China, as salt has always been a major source of income. In the 2nd century BC e. Rice. 4. Salt production in China

The Chinese government nationalized salt production.

The most common salt in China was sea salt, accounting for 76% of the total production; salt obtained from deep sea water - 16.5%; salt from salt lakes - 5.4%; mineral salt - 1%; salt obtained as a by-product of gypsum mining - 0.4%.

The salt production process was quite complex and required high skill. The most primitive way to obtain salt was to repeatedly sprinkle sea water on burning firewood, followed by separation of salt from the ashes after they burned out. Salt was also produced by simply evaporating sea water in the sun in a flat dish. With this evaporation, a little salt was thrown into the water, which was necessary for further crystallization. The salt was then collected and purified.

Another method was to boil seaweed that had previously been dried in the sun. If drying salt in the sun was difficult, then sea water was boiled in large tanks. At the same time, millet chaff and soap bean pods were thrown into boiling water. This helped eliminate calcium sulfate impurities. At a low salt concentration in the water, a biological purification method was used, in which “wood splitter worms” (a kind of crustacean) were placed in the water, removing impurities by digesting them.

Salt was collected on the seashore when the tide was receding and the remaining moisture evaporated in the sun. A more complex method was also used. Deep holes were dug and covered with reed mats with a layer of sand placed on them. When the tide came up, the seawater seeped through the sand mats, which acted as a filter. At low tide, sea water was scooped out of the pits with ladles and poured into special dishes left in the sun. After the water evaporated, the salt was collected. The drying was slow, but it came in handy, as time allowed the anaerobic bacteria that are present in the seawater to convert the calcium sulfate into calcium sulfide, which precipitated as a “black slush” that could be easily separated from the pure salt. Since the Chinese do not like wasteful expenses, calcium sulfide has been used medicinally as an emetic and as a remedy for insect bites, ringworm, scabies, etc.

Since the Han Dynasty, deep drilling has been carried out to extract salt from sea water, the deposits of which were in the western parts of China (in Sichuan). This produced natural gas as a by-product, which was used to heat containers of sea water, from which the salt was evaporated.

All the centers of civilization on the American continents arose where there was access to salt. Salt springs were in close proximity to Cuzco. In Colombia, nomadic tribes founded their first permanent settlements near natural salt licks. The highland Chibcha tribe became dominant because its men were the best salt workers. By the way, in this tribe there was an interesting custom: twice a year, in order to honor the gods, they abstained from the use of salt.

The Aztecs did not have their own salt licks and during the years of war hard times they received salt by evaporating it from urine. And the inhabitants of Honduras used the ocean instead of urine. They dipped hot sticks into the waves of the surf and cleaned off the white grains.

Salt-rich countries were proud and proud of this circumstance to this day. A salt-mining area in Bolivia attracts tourists with a hotel made entirely of salt.

On the map of Europe, places rich in salt have retained in their name the echoes of medieval labors for the extraction of a much-needed product. Salt City is the Austrian city of Salzburg. And the city of Tuzla in Bosnia (from the Turkish tuz - salt) reminds not only of the main industry, but also of Turkish rule.

It is safe to say that rock salt was of great importance not only in the economic, but also in the political life of peoples: it served as an object of trade and exchange, a source of replenishment of the treasury. Salt became the cause of bloody wars, popular unrest and riots.

Several thousand years ago in the countries of the East, in China, Japan and India, salt began to be subject to duties and taxes. Later taxes on salt were introduced in almost all countries of Western Europe and in Rus'. In the summer of 1648 a salt riot broke out in Moscow and lasted three days. It served as an impetus for unrest in Solvychegodsk, Ustyug the Great, and Solikamsk. In the XVI century. a real armed uprising broke out in the French port of La Rochelle, through which salt was traded with many overseas states. In the Middle Ages, the uprising of Chinese peasants, outraged by salt extortions, lasted 9 years.

In the 19th century, salt money, bars equivalent to gold, were introduced into circulation in Ethiopia. In China, during the life of M. Polo, there were hallmarked salt coins.

Until recently, salting was the main method of long-term storage of food. This is why the Egyptians used salt to make mummies. Due to the ability of salt to preserve, protect from decay, and prolong life, many symbolic meanings were attributed to it.

The British did without bread, but they brought salt for housewarming for a long time.

Since salt prevents rotting, it also protects against spoilage. In the early Middle Ages, the peasants of Northern Europe learned to save their crops from the poisonous ergot fungus by soaking the grains in saline before sowing.

The Maasai, a tribe of East African nomadic pastoralists, satisfy their need for salt when they bleed cattle and drink it. However, potassium-rich vegetarian diets often lack sodium chloride. And all historical documents, including those relating to North America of the 17th-18th centuries, testify: at various stages of human development, one rule remains unchanged - agricultural tribes extract or buy salt, while hunter tribes do not.

The first attempts at domestication were probably made before the end of the ice age, and even then people knew that animals needed salt. It has been observed that reindeer come to human sites attracted by a source of salt. People realized that if they had salt, deer would come all the time, and maybe they could be tamed. In the end, deer really became a constant source of food for humans, but they never really became domestic [...]

Where people ate mostly grains and vegetables, only supplementing them with the meat of slaughtered domestic animals, salt mining became a vital necessity. And this, of course, gave sodium chloride an enormous economic value. Salt became one of the first objects of international trade, its production - one of the first industries and, as a result, the first state monopoly.

The world's salt resources are practically inexhaustible. Almost every country has either rock salt deposits or salt water evaporation plants. A colossal source of table salt is the World Ocean itself. One liter of ocean water contains about 26-30 grams of salt.

Each region of the world has its own salt reserves, which affect the share of salt production (Figure 5). North America currently produces the most salt, followed by Asia and Europe. Other regions of the world have small shares in salt production.

Rice. 5. Regional structure of salt production in the world (2005), in %

Currently, table salt is mined in more than 100 countries (Fig. 6). Salt is mined in the world in various ways, the main of which include four technologies:

1) obtaining sodium chloride in solutions;

2) evaporation of lake and sea salt in the sun;

3) underground mining of rock salt;

4) the production of boiled salt by the vacuum method, which is a way to obtain the highest quality products.


The main methods of production of table salt in the whole world should be considered its release in the form solutions and method evaporation in the sun: the share of each of them is about 35%, while the share of underground prey rock salt accounts for about 30%. At the same time, it is important to emphasize that the methods for the production of sodium chloride in different countries vary greatly, both in terms of production technologies and in the equipment used.

Looking at the map, we can say that according to our data, the first places in the production of table salt are occupied by the USA and China, followed by Canada, Australia and India. Russia ranks only 14th in terms of salt production in the world.

In Russia, salt is mined at a number of deposits in the Caspian Sea (Lakes Elton and Baskunchak), Cis-Urals, Eastern Siberia, in the central and northwestern regions of the European part, both from rock salt deposits and from salt lakes and salt domes. There are large deposits of rock salt in the Ukraine and Belarus. Large industrial salt reserves are concentrated in the lakes of Kazakhstan and the Kara-Bogaz-Gol Bay in Turkmenistan.

The CIS currently has reserves of various types of salt (Fig. 7). A larger percentage of the reserves falls on rock salt.

The need for human consumption of salt for many millennia posed the most difficult tasks for engineers, forcing them to invent the most bizarre, but at the same time very ingenious machines. Some of the most ambitious public works in history were undertaken to transport salt. Salt making was at the forefront of the development of chemistry and geology. New trade routes were forged, alliances formed, empires strengthened and revolutions raged - all for the sake of a substance that fills the ocean, bubbles in springs, forms a crust on the bottom of lakes and lies abundantly in most geological rocks close enough to the surface.

§ 3. Salt mines of Russia

Salt fishing in Rus', obviously, dates back to the beginning of its use in the diet of our ancestors. Salt was also used for harvesting skins and foodstuffs: vegetables, fish and meat.

Extraction of table salt was carried out in three ways: brittle rock salt; decoction from sea water and groundwater brines. Salt deposits were intensively searched for and developed. The most ancient information about the extraction of rock salt among the Proto-Slavs dates back to the 5th century BC. BC e. Trade with the West through the Carpathians went along the salt route, along which salt was exported to Scythia from the Galich deposit, known to Herodotus. Salt was also mined near the mouth of the Dnieper. Later, at least from the 11th century, salt was obtained by boiling out the water of the Black Sea and Azov estuaries in the south and the White Sea in the north. Such salt was called "moryanka". For several centuries, sea water has been the main source of salt production on the coast of the White Sea.

The method of extracting salt from sea water was suggested to man by nature itself. On gently sloping shores, dunes or sandy spits separate estuaries, which communicate with the sea only during high water levels. In a dry and hot climate, water evaporates rapidly in estuaries, and salt is deposited on their banks and bottom. Observing the process of salt deposition, man learned to arrange auxiliary devices for the extraction of salt where climatic conditions allowed it, for which they built pools that communicated with the sea and with each other.

Initially, salt production was artisanal in nature, later they began to build "salt plants".

In the XII-XIV centuries. there are salt mines on the Kama, in Staraya Russa, Rostov the Great, Torzhok, Chukhloma, Vologda, Kostroma, Vychegda, Salt-Galitskaya, Gorodets on the Volga, Pereslavl-Zalessky, Balakhna, Ustyug, Galich Mersky, Nerekhta, etc. Written and material documents have been preserved about the numerous points of extraction of salty underground water and salt production during this period on the vast territory of the Russian Plain from Pereslavl-Zalessky, Rostov-Yaroslavsky and Balakhna in the south to the Northern Dvina and Pechora in the north, i.e. on the territory of distribution and relatively shallow occurrence of salt-bearing rocks. Many cities of Russia, establishing their coat of arms, displayed on it the method of salt production of their region (Solikamsk, Perm province).

Salt boiling brought huge profits to both the state and monasteries. The Russian tsars favored the monasteries and did not charge them duties for salt.

Over time, large salt mining centers began to appear, and its technology became more complicated. In the 20s. 15th century in the Kama Cis-Urals, the Kallinnikov brothers, immigrants from Novgorod, began the construction of salt factories, which later became the property of the Stroganov merchants. This area became known as Usolye-Kamsky or Solya-Kamskaya (now the city of Solikamsk).

End of the 16th century was marked by the development of Siberia by Russian explorers. Detachments of Cossacks, setting off in search of "unknown" lands, received special instructions to look for places where salt water beats out of the earth and to cut varnitsa in those places, since without salt it was impossible to harvest food and furs. Initially, the explorers developed self-sustaining lakes in Western Siberia, known to local nomadic tribes. Later it turned out that in the Irtysh region, the Kulunda steppe and in other places, not only salt lakes, but also sulfate and soda lakes are common. As the Russians penetrated into Eastern Siberia, salt works were also built there.

At the end of the XVII century. The rock salt of the Iletsk Protection in the Southern Urals (now the city of Sol-Iletsk, Orenburg Region), as well as the Kempendyai salt pans in the Vilyui basin, were already generally known.

Further development of salt mining continues during the reign of Peter I. He "renewed" the inactive old Russian salt pans.

The exploitation of workers in the salt mines was monstrous, it was aggravated by difficult and harmful working conditions, since primitive production did not provide for the removal of combustion products and steam released from heated brines. Such working conditions remained without significant changes until the 19th century. Galician, Vychegda, Pomeranian and other places saltworkers created in the vast expanses of the Russian state, from the Carpathians to the Urals and Siberia, a large-scale production of table salt, which provided not only the internal needs of the country, but also trade with foreign states. Table salt has become one of the main articles of Russian export.

After various events (expansion, closure, transition to coal fuel, etc.), the following salt mines operated under Catherine II: Bakhmutsky, Vychugotsky, Yenisei (since 1768), Irkutsk, Ledensky, Nenoksky, Nikolsky, Permsky, Balakhninsky ( from 1785), Starorussky (since 1771), Seregovsky, Selenginsky, Spassky, Torsky, Totemsky, Unsky, Lutsky, Ust-Kutsky and some others.

On Lake Elton (Kalmyk name Altannor, i.e. Golden Lake), salt mining began in 1747. As a result of an increase in salt production on the lake to millions of pounds per year, the export of salt from the previously developed South Astrakhan lakes fell sharply. Over 134 years of continuous operation on Lake Elton, more than 513 million poods of salt have been mined; the cessation of mining was associated with the construction of a railway to Lake Baskunchak (1855), which from that time until the present day has been the main "salt cellar" of the country.

From the second half of the 18th century, rock salt was mined on Mount Chapchachi (Guryev region). In the Far East in the middle of the XVIII century. The Okhotsk salt plant was founded, where sea water was concentrated by freezing, followed by evaporation of the resulting brines. The plant ceased to exist in 1836, and in the middle of the 19th century, the extraction of salt from sea water was practically stopped everywhere.

Lake Baskunchak is a unique creation of nature, a kind of deepening on top of a huge salt mountain, leaving its base thousands of meters deep into the earth. The breaking of salt on it was carried out with the help of ordinary crowbars and shovels by Kyrgyz workers; camels harnessed to wagons brought salt to the shore. And then on the oxen - to all ends of the empire.

The first boreholes, which were laid in the early 70s. 19th century mining engineer A.D. Kondratiev, allowed to develop deposits of rock salt. The extraction of rock salt began to increase steadily.

By the end of the 19th century, industrial salt mining had become widespread.

The total production of table salt in Russia in 1896 reached 82,188,489 pounds, of which the share of rock salt was 25%, self-planting 48% and evaporation obtained by evaporating natural salt brines - 27%.

In Soviet times, in 1924, a large fishery was established in the Kara-Bogaz-Gol Bay. During the Civil War, salt mining on Lake Baskunchak fell into decay. The revival of the salt industry began in 1919.

In 1926, the first Crimean salt research station was established in our country in Saki. Later, similar stations that studied salt lakes were organized in the Kulunda steppe and the Lower Volga region. In 1930, the Salt Laboratory of the Academy of Sciences of the USSR in Leningrad began its work, which in 1935 was reorganized into the All-Union Research Institute of Halurgy.

A great contribution to the study of the wealth of salt deposits was made by such scientists as N.S. Kurnakov, V.I. Vernadsky, A.E. Fersman, A.P. Vinogradov, K.B. Kim and many others.

At present, the natural resources of salt in Russia are practically inexhaustible. The deposits are represented by deposits of rock salt, modern self-sustaining lakes and underground brines.

The largest salt deposits in Russia are visible in fig. 9. Also in the lower left corner of the map there is a diagram that clearly shows us what share of salt reserves in the CIS is in Russia and other countries.

If we look at the diagram (Fig. 8), which will show us the main companies producing and supplying salt to the Russian market, it turns out that most of all salt in Russia comes from 2 private Russian companies Bassol and Iletsksol.

25% of Russia's salt has to be purchased from abroad.

Rice. 8. Share of manufacturers and suppliers of edible salt

to the Russian market, in %

Rice. 10. Major countries importing salt to the Russian Federation (as of 2006), in %

Rice. 11. Major countries exporting salt to the Russian Federation (2006), in %