HOW A SALT WORKS WORKS AND ITS IMPACT ON THE ENVIRONMENT - ENVIRONMENT - 2025

The proper functioning of a salt works is essential to make this rock or chemical compound suitable for human consumption. Surely you know what salt is and that its chemical formula is NaCl (sodium chloride).

You will also notice the difference it makes in the flavor of the dishes when it is used for cooking or you will know its indispensable use in many industrial processes, such as food preservation.

Salinera

However, there are few who know that it is the only edible rock for humans or the process that must be carried out to extract it and that it reaches our table. Below, you can see the process that must be carried out to clean it and how it becomes edible.

The process is relatively simple, since we have a huge natural source of salt covering more than ¾ parts of the planet, the oceans, lakes and salty lagoons.

The water of the seas is salty, so approximately 11% of its content is composed of this precious mineral. This means that availability is not an obstacle to obtaining it. Neither is the procedure used to obtain it, make it edible, and package it.

Salineras, as the places where salt is obtained, collected and processed are called, can be near lakes and salty lagoons.

The most common are those located on the coasts, since their proximity to the sea reduces the costs of collection and processing, as well as the time necessary to complete the procedure. In turn, the amount collected increases over a period of time.

How does a salt works work?

There are two main phases in the production of salt by the salt mines: the collection of salt and the refining of the salt.

- Harvest

1- Use of high tides

Shore with accumulation of salt.

Most of the process for obtaining salt is natural, so much of the journey to obtain it is linked to environmental events, one of them, if not the most important, is high tide.

As the sea level rises, the level of the fields of the salt mines located on the coast falls below this and by gravity the water can be guided by simply opening a pair of strategically placed gates.

Taking advantage of this natural phenomenon reduces the effort, expense and production time, which also reduces the cost in the market, despite its high demand.

2- Driving

The salty water from the sea is conducted through the gates and through channels in the ground. These can be made of earth or other materials such as wood and rarely cement and concrete.

These are directed towards huge plots that have ridges and other shallow depressions, and are protected from possible rains by small roofs that divert precipitation into secondary furrows that prevent the water level from rising where the salt water accumulated.

3- Evaporation

Water evaporating in salinera.

Once the plots are full the water is allowed to stagnate. As the sun's heat evaporates the sea liquid contained in the plots, the salt, by not evaporating, remains in greater concentration in the water, this state is known as brine.

As the water level in the brine decreases, the salt remains as coarse grit on the edges of the furrows, where after a while it accumulates in large quantities.

4- Accumulation

Flower of salt. Christian Mertes (Mudd1 12:26, ​​18 April 2007 (UTC)) / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/)

It is the process by which, after evaporation, the salt accumulates in the furrows. This accumulation or crystallization process can be slow, depending on environmental factors, such as ambient temperature, humidity, amount of sunlight, etc.

As the temperature increases and the water level decreases, the upper layers of the brine fill with crystals of salt, which are known as flowers of salt and are highly valued in the market.

Salt flowers form while the deep layers remain less crystallized due to little evaporation due to cooling.

To speed up the crystallization process, once the salt flowers have been removed, some salt mines have workers who, manually and with special equipment, go over the surfaces of the brines.

These carry the already crystallized salt to the edges of the furrows, where the movement helps to accumulate the crystals, leaving the brine in the center and without interference so that the sunlight evaporates more quickly the next layer of salt.

In addition, the previous step allows more salt flowers to form on the surface, making it more economically productive and speeding up crystallization.

5- Desiccation

Salt collection.

After evaporation, the salt is collected and placed in dry places where the remaining moisture is removed.

The salt obtained is known as coarse or grained salt, which is little used in culinary processes and is used in large quantities at an industrial level, since many of the crystals obtained range in diameters of around 0.5 to 1 millimeter, so its use is not common.

Obtaining salt is only half the journey that this seasoning takes to reach your hands, because being a natural process, in reality there are many contaminants and factors that do not make it consumable for humans immediately after its collection.

Below you will find the process by which salt is treated for safe and daily consumption in the common presentations that can be found in supermarkets.

- How is salt refined?

1- Washing

To start the refining process, the salt is poured into containers where it is pressure washed to remove impurities and other contaminants that may be found in the soil where it was collected or contributed by the fauna that inhabits the place.

In addition to the above, the water used in this step is poured in jets under pressure, so that the larger grains are fractionated or disintegrated.

2- Drying

The salt passes into another container, where a fan provides very hot air (around 100 ° C at several kilometers per hour).

In this way, using the evaporation process again, the excess water that remained after washing the salt is eliminated and, in addition, the high speed air and the increase in temperature further disintegrate the salt grains that continued to have a size considerable after pressure washing.

3- Cooling

After the previous step, the salt remains dry but at very high temperatures, so, to facilitate its handling, it is necessary to cool it. For this purpose, a fan that blows air at room temperature is used for a few hours.

The salt remains in the cooling container until it reaches the ambient temperature of the production line, only then is it ready to continue its journey.

4- Grinding and sifting

Once at room temperature, the salt is impact ground to break up and disintegrate the larger crystals, and then it is sweep ground to even out the size of the remaining grains.

Once it has completed the necessary grinding time, it is sifted through mesh with holes that allow the passage of the grains according to the necessary standards for packaging the required presentation of salt.

As can be seen, salt is a condiment of world consumption that has a relatively simple harvesting process and that even occurs naturally.

Most of the salt mines in the world are located in areas where the accumulation of salt on the coast was already happening long before a processing plant took advantage of this phenomenon.

Therefore, despite the worldwide demand for salt, because it is part of daily processes, it requires a large production, its price remains low. This is because its obtaining does not generate too many expenses and it is a very abundant natural resource, considered a renewable product and with very little possibility of being depleted.

Environmental impact of the salt mines

These are the main environmental consequences of the salt mines:

-Chemicals that pollute the ozone layer are used.

-Invasion of species habitat.

-Contamination and change of properties of cultivation soils.

-Loss and reduction of the permeability of soils and drainage areas.

-Alteration of the dynamics of coastal ecosystems and change the salinity levels of waters and soils.

-Destruction of ecosystems such as mangroves and other coastal marine wetlands.

-Erosion of the soil.

-Modification of the coastal zone.

References

1. Carl Walrond, 'Salt - Salt making at Lake Grassmere', Te Ara - the Encyclopedia of New Zealand, Retrieved from TeAra.govt.nz.
2. The Seas Will Save Us: How an Army of Ocean Farmers Is Starting an Economic Revolution April 5, 2016 Recovered from inkct.com.
3. In Wellfleet, a process worth its (sea) saltBy Ann Trieger Kurland GLOBE CORRESPONDENT JULY 30, 2013 Retrieved from bostonglobe.com.
4. Dead Sea Salt Vs. Epsom Salt, by LAURICE MARUEK Recovered from livestrong.com.
5. Copeland BJ. Environmental characteristics of hypersaline lagoons. Publications of the Institute for Marine Science (University of Texas) 1967. pp. 207–218.