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Register to receive updates. Visit the source of this article and learn more! Exploring Our Ocean Join this course for free! Before You Go! In solution mining , wells are erected over salt beds or domes deposits of salt forced up out of the earth by tectonic pressure and water is injected to dissolve the salt. Then the salt solution, or brine, is pumped out and taken to a plant for evaporation.
At the plant, the brine is treated to remove minerals and pumped into vacuum pans , sealed containers in which the brine is boiled and then evaporated until the salt is left behind.
Then it is dried and refined. Depending on the type of salt it will be, iodine and an anti-clumping agent are added to the salt. Most table salt is produced this way. When solution mines are located near chemical plants, they are called brine wells, and the salt is used for chemical production.
After the salt is removed from a salt mine, the empty room often stores other substances, like natural gas or industrial wastes.
Salt is harvested through solar evaporation from seawater or salt lakes. It has been used since salt crystals were first noticed in trapped pools of sea water. Its use is practical only in warm climates where the evaporation rate exceeds the precipitation rate, either annually or for extended periods, and ideally, where there are steady prevailing winds.
Solar salt production is, typically, the capturing of salt water in shallow ponds where the sun evaporates most of the water. The concentrated brine precipitates the salt which is then gathered by mechanical harvesting machines.
Any impurities that may be present in the brine are drained off and discarded prior to harvesting. Usually two types of ponds are used. First is the concentrating pond, where the salty water from the ocean or salt lake is concentrated. The second is called the crystallizing pond, where the salt is actually produced. Crystallizing ponds range from to 40 to acres with a foot-thick floor of salt resulting from years of depositions.
During the salt-making season of four to five months, brine flows continuously through these ponds. This is a saturated brine solution, containing as much salt as it can hold, so pure salt crystallizes out of the solution as the water evaporates. Natural chemical impurities are returned to the salt water source. Morton also uses the second oldest method of producing salt — underground mining. This is probably the most dramatic method of gathering salt.
Large machines travel through vast cave-like passageways performing various operations. Salt mines are among the safest of mines. It used to be very expensive, now it's really cheap, and most of it is used for industrial purposes. It's in the foods we eat, in the planetary oceans, and in us February 1, Reading Time: 3 mins read.
Ponds near Maras, Peru, fed from a mineral spring and used for salt production since the time of the Incas. Image via Wiki Commons. Get more science news like this
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