Brine

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Brine is water saturated or nearly saturated with salt (NaCl). It is used (now less popular than historically) to preserve vegetables, fish, and meat. Brine is also commonly used to age Feta cheese. Although brine is used in preservation much like sugar or vinegar, it can be used to great effect in transportation. Brine is a common fluid used in the transport of heat from place to place. It is used because the addition of salt to water lowers the freezing temperature of the solution and the heat transport efficiency can be greatly enhanced for the comparatively low cost of the material. At a concentration of 23.3%, the freezing point of the solution is lowered to -21°C (-6°F). This is called the eutectic point.

At 60 °F (15.5 °C) saturated brine is 26.4% salt by weight (100 degree SAL). At 0 °C (32 °F) brine can only hold 23.3% salt.

Uses

Road treatment

Brine is also used to pre-treat roads for winter storms. The solution is poured onto the roadways along with actual salt pellets to create a safer roadway when winter weather is in the forecast.

Heat exchange

Brine is also used in removing heat from ice surfaces such as hockey or figure skating rinks. The brine is cycled through the refrigeration plant and returned under the slab of ice at a colder temperature. Brine is used in cruise vessels' cooling systems.

Medicinal purposes

In Europe, brine baths are sometimes used medicinally for curing a variety of ailments from skin conditions to bladder trouble.

Oil extraction

Brines are also used in the offshore oil and gas industry where a pipeline, prior to commissioning, is flooded with a meg/brine mix to prevent the formation of hydrates on production start-up. This is dependent on the well properties. It is useful for refrigeration and heating.

Mining industry

Brine can be used for underground mining in the Arctic where the ground is permanently frozen (permafrost) in order to use water-fed drills without having them freeze.

Synthetic Chemistry

Brine is commonly used to dry organic solvents after an aqueous wash. The brine wash is intended to remove the majority of the water from the organic solvent and the remainder is removed by chemical methods (typically anhydrous magnesium sulfate).

Chemical industry

Brine is electrolyzed in the chloralkali process to make sodium hydroxide, chlorine and hydrogen, as well as the hypochlorite and chlorate salts on an industrial scale. In this case, the chloride ions are oxidized to chlorine, while water is reduced to hydrogen gas and hydroxide anions, which, together with the sodium ions already present, give sodium hydroxide on evaporation.

By adjusting the conditions, the chlorine gas produced also reacts with the hydroxide anions to give hypochlorite and chlorate anions as well.

It is also used in the Solvay process to produce sodium carbonate, and in the solution mining of salt from underground deposits. Brines are also used in the pharmaceutical industry.

See also

• Brining
• Sea salt
• Salt pan
• Sea water
• Salinity
• Brine lakes
• Brine pools