ROCK SALT
Salt, which is used in a wide sense in the chemical industry, is expressed with the symbol "NaCl". The salt crystallized in the cubic system consists of "Na" and "Cl" ions. In its pure form, it consists of approximately 40% sodium and 60% chlorine. The hardness of the salt, which has plastic properties under high pressure, is 2-2.5 and its specific gravity varies between 2.1-2.55 g/cm. Its melting point is 800 °C and its boiling point is 1412 °C. Generally colorless, as produced, its color can be grey, yellow, red or even blue and green. Salt resources that have economic value are divided into solid and liquid. Salt is found in liquid form in the seas, lakes, salt water springs and salt water wells, and in solid form it is in the form of rock salt.
SEA SALTS
Seas, which are endless and inexhaustible sources of salt, constitute the largest salt reserves of our world. The degree of salinity in the seas varies depending on whether they receive fresh water or not, their geographical situation and climatic conditions.
ROCK SALTS
Salt obtained in solid form from more or less deep underground is defined as rock salt. Rock salt deposits were formed by the drying of seas or closed inland basins as a result of evaporation in geological periods. There are rock salt deposits formed in this way in many parts of our country in different periods. Unlike sea salts, rock salts vary greatly in terms of the proportions of foreign substances in their composition. In particular, purity rates may be different for each mine, and various samples taken from the same mine may vary greatly. Foreign substances and clay in rock salt give the salt different colors. Rock salt, which is usually gray, almost black clay color, is rarely found in white or transparent white. In our country, rock salt mines are generally gray in color, and some of them are close to black.
WELDING SALTS
Apart from rock salts, there are also streams, wells, springs and lakes on land whose water contains more or less salt. In general, their source is rock salt. As underground water flows pass through a layer of rock salt, they melt some of the salt and take it to the surface in the form of wells and streams. The NaCl content of these waters is more or less in proportion to the duration and intensity of contact of fresh water with the salt layer.
LAKE SALTS
While some of the salt lakes may be the remains of ancient inland seas, some may be formed by salt water collected in large depressions, passing through the rock salts in the surrounding areas and collecting in these pits. Salt water lakes, salt water springs and wells can be found in almost every country. Salt Lake in our country is one of the most important salt lakes. The salt taken from these lakes is almost pure.
Raw salt production in Turkey is done using 4 different natural resources. These;
Salt production from sea water
Salt production from lake water
Salt production by rock (underground mining) method
Salt production from spring (ground) water
The production method of sea and lake salt is natural evaporation under the influence of wind and sunlight. Rock Salt production system is the chamber-heel method. Spring salt is obtained by increasing the bome degree of water in salt water springs in evaporation and crystallization pools.
Sea, Lake, Spring Salt Production
In our country, salt production from sea water is carried out in İzmir / Çamaltı and Balıkesir / Ayvalık Saltworks. Production; It is supplied by Solar Evaporation method depending on climatic conditions. The process of flooding the evaporation pools from the sea begins in March. These waters, which are at 2-2.5 or 4.5-5 bomes depending on the season, are evaporated in the pools under the influence of the sun and brought to 6 bomes. These waters are sent to the next pools called cold water reserve. The water coming to the cold water reserve pools is kept between 6-9 bomes in these pools. During waiting, foreign substances such as CaCO3 and Fe2O3 precipitate to the bottom. Then, these waters are sent to the reserve water pools one by one. It is waited until it reaches 9-13 bomes, 13-17 bomes and 17-20 bomes in each one, respectively. CaSO4 precipitates in these pools, and these waters, whose density increases up to 20 bomes, are sent to hot water pools and kept there until they reach 25 bomes. Hot water pools are the main solution source of crystallization pools. By repeating this process until the end of production, approximately 18-20 cm thick salt can be obtained.
Rock Salt Production
Salt is produced by closed mining method in five rock salt pans in our country. The production method is chamber heel, and the technology used is very old. The size of the rooms and heels was left at 10x10 and 8x8 m for work safety and economical recovery of the ore. The height is 6 meters. Since there is enough production in our Lake Salt Pans to meet the demand, it is not currently considered to make capacity-increasing investments in our mining Salt Pans, which are more costly to operate. More than 95% of the rock salt produced is used in the chemical industry and 3% is used as table salt. rock salt