rock salt


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.

rock salt:

see sodium chloridesodium chloride,
NaCl, common salt. Properties

Sodium chloride is readily soluble in water and insoluble or only slightly soluble in most other liquids. It forms small, transparent, colorless to white cubic crystals.
..... Click the link for more information.
.

Rock Salt

 

halite, table salt. (1) The mineral halite, or, in terms of chemical composition, sodium chloride, NaCl (39.34 percent Na and 60.66 percent CI). Rock salt crystallizes in a cubic system. In nature it is ordinarily encountered in granular crystalline aggregates of varying size. In pure form it is colorless and semitransparent, but more often it is found with admixtures of clay, organic matter, and iron oxide, which tint the halite gray, brown, red, or pink. The hardness on the mineralogical scale is 2; the density is 2.173 kg per cu m. Rock salt is easily soluble in water. There is significant absorption of heat when it is dissolved. Halite that is dissolved or melted (at 772°C) is characterized by high electrical conductivity. It possesses antiseptic properties, protecting saturated organic tissues against putrefactive decomposition.

(2) A sedimentary rock composed almost exclusively or predominantly of halite (in pure varieties, 99 percent or more). The impurity, when present, is usually clay or, less often, fine sandy material, which is either finely dispersed through the rock or in the form of intercalations, seams, or galls. In the clay intercalations or along the periphery of the halite grains (occasionally inside) there are carbonates, anhydrite, authigenic quartz, clay minerals, and, less often, potassium minerals.

A considerable amount of the sodium chloride found in nature has been dissolved in the water of the seas and oceans. Most rock salt, like other salts that have been dissolved in water, was formed through exogenic processes in the basins of arid zones with a negative water balance. Rock salt is produced in small quantities through volcanic activity, in solonchaks, and as a weathering product of chlorine-containing minerals. Rock salt occurs in sedimentary rock in the form of thick seams that extend for dozens of sq km. It also forms cores of domelike structures (salt-dome tectonics) and intercalations, galls, pockets, and impregnations. Mineral deposits of rock salt are encountered in deposits of almost all geological periods. The greatest quantity of salt-bearing rock is concentrated in deposits of the Lower Cambrian, the Middle and Upper Devonian, the Permian, and the Myocene.

Recent salt deposits (native salt; Lakes Baskunchak and El’-ton), associated with Permian salt stocks, are of great industrial interest in the USSR. The largest deposits are located in the Byelorussian SSR (Starobin and Davydovka), the Ukrainian SSR (Solotvin, Romny, Slaviansk and Artemovsk), the Urals (Solikamsk and Shumkovo), the Caspian depression and the adjacent Bashkir and Orenburg-Aktiubinsk salt basins, and Middle Asia. Abroad, rock salt is found in Poland, the German Democratic Republic, the Federal Republic of Germany, Switzerland, Italy, Great Britain, the United States, Canada, and India.

Rock salt deposits are worked by the underground method (with the chamber system) and by leaching. The rock salt, which is pumped out of the deposits through pipes as brine, is evaporated in special vacuum devices (vacuum salt). A considerable amount of the salt (native salt) in the USSR is also obtained by evaporation from salt lakes and salt springs. Rock salt is widely used in the national economy. Purified, it is a very important food product and preservative; it is also used in refrigeration. The chemical industry uses rock salt to produce compounds of sodium or chlorine (ammonium chloride, soda ash, gaseous chlorine, hydrochloric acid, ammonium hydroxide, calcium chloride). Rock salt is used in the aniline dye, paint and varnish, wood chemical, nitrogen, textile, pharmaceutical, metallurgical, leather, petroleum, and plastics industries. Large semi-transparent crystals of rock salt are used in optical instruments.

REFERENCES

Ivanov, A. A., and Iu. F. Levitskii. Geologiia galogennykh otlozhenii (formatsii) SSSR. Moscow, 1960.
Valiashko, M. G. Geokhimicheskie zakonomernosti formirovaniia mestorozhdenii kaliinykh solei. Moscow, 1962.
Ivanov, A. A., and M. L. Voronova. Galogennye formatsii. Moscow, 1972.

A. B. PAVLOVSKII

rock salt

[′räk ‚sȯlt]
(mineralogy)
References in periodicals archive ?
There are around 25-30 rock salt processing units in the tehsil that are categorised as SMEs.
Understand that the purpose of rock salt isn't to melt snow and ice--it's supposed to be applied before a snow event so it's easier to remove accumulation," Ashkin clarifies.
The dog brought to me this week had not eaten rock salt, but had walked through a patch of rock salt that had been spread over an icy pavement.
The good news is that if rock salt is needed to de-ice driving and walking surfaces, ATAK is ready with adequate supplies of rock salt available for delivery or pick-up.
Labovites said Worcester can easily spend more than $500,000 (and use 10,000 to 15,000 tons) on rock salt for an average winter.
The cold winter of 2013-2014 and its many subzero days have seen supplies of rock salt dwindle as demand rises to record levels.
This has resulted in the huge amount of rock salt which was shipped into Dandy's packaging plant at the start of the summer, already having been packed up and shipped out.
The B corporate credit rating on American Rock Salt combines its "vulnerable" business risk profile and its "aggressive" financial risk profile, based on its limited diversity, seasonal demand and narrow financial flexibility, the agency said.
But we benefited in one way because we bought rock salt and sold it easily so we made good money on that because we bought at the right price.
Coun Harvard estimated rock salt was used at a similar rate throughout last week as sub-zero temperatures prevented any thaw.
An indication of the amount of the stuff being mined can be seen for the figures in 1850 which revealed that in that year 525,000 tons of white salt and 86,238 tons of rock salt were transported along the Weaver navigation.
It was only months ago we were told of mountains of rock salt and how these knights of the road were ready and able to keep our highways on the move.