Kara-Bogaz-Gol and the mirabilite

The giant natural laboratory in which crystallization of the solution is Kara-Bogaz-Gol, the Caspian Sea bay, separated from the sea by a narrow oblique. Kara-Bogaz-Gol is shallow, its waters evaporate strongly under the sun. Therefore, the salt content here is 15-20 times greater than in the Caspian Sea itself. About 200 grams of salts containing bromine, potassium, sodium and magnesium are dissolved in each liter of the Gulf of Kara-Bogaz-Gol. The main one is mirabilite, or Glauber's salt.

Kara-Bogaz-Gol is shallow, its waters evaporate strongly under the sun

Mirabilite (sulphate soda) is a valuable raw material for glass production, for the production of caustic soda, sulphurous soda, sulfuric acid and many other substances needed in the industry. In winter, when the temperature drops, the solubility of the mirabilite decreases. If before the solution was saturated, now it becomes supersaturated, and crystals begin to form in it, which float on the water surface, grow, settle on the bottom and on the shore of the bay. At a brine temperature of +5,50 C, a solid, crystalline precipitate of pure mirabilite precipitates, while all other salts remain in the dissolved state, because they have a different solubility. In winter, from November to March, the water of Kara-Bogaz-Gol becomes saturated with respect to the mirabilite, while remaining unsaturated in relation to other salts. Over the winter, from the waters of Kara-Bogaz-Gol, a grand amount (up to 6 million tons) of crystals of pure mirabilite stands out. In the same winter months, the strongest storms prevail in the Kara-Bogaz-Golsky Bay. They throw the crystallized mirabilite ashore. Around the bay grow white hills of crystals of the mirabilite. The most valuable chemical raw materials in millions of tons can be collected directly from the ground.

But here comes the spring, the temperature rises, and with it the solubility of the mirabilite grows! Now the solution is becoming undersaturated and grown up in the winter crystals for the summer again dissolve. What happens to those heaps of crystals that are thrown ashore? The hot sun of the desert dries them, the wind blows into powder. All the air near Kara-Bogaz-Gol is saturated with the smallest mirabilite dust. Getting into the waters of the bay, the salt dust dissolves again. By the autumn the cold starts, and the solubility of the Kara-Bogaz-Gol mirabilite again decreases. Everything starts from the beginning. While the work of this "big boiler, where the Caspian water boils," people did not interfere, its products were annually destroyed by the activities of the sun, wind and water. Mountains of unused mirabilite grew on the deserted shores of Kara-Bogaz-Gol. And at the same time in many countries of the world there were factories for the production of artificial mirabilite, because without this raw material it is impossible to develop the chemical industry. Scientific expeditions found out that in addition to valuable salts dissolved in the waters of Kara-Bogaz-Gol, there are coal deposits near its shores, oil, barite, sulfur, limestone, phosphorite. The Mirabilite is now mined directly from the bottom of the bay by machines - sowsers and excavators. In addition, the water of Kara-Bogaz-Gol is pumped into specially dug on the shore basins: there it evaporates, secreting the crystals of pure mirabilite.

Kara-Bogaz-Gol is practically inexhaustible by mirabilite. In this world's largest natural "crystal factory" there are reserves of several tens of billion tons of mirabilite and other salts. The waters of the Caspian Sea bring more and more salt reserves to Kara-Bogaz-Gol. Prospects for using the wealth of Kara-Bogaz-Gol are grandiose. Kara-Bogaz is now a powerful base of the large chemistry.