Salt, also known as sodium chloride and used in the preparation of innumerable food items, has a large and constant demand worldwide. In America alone, an average person consumes as much as 4,600 mg of sodium every day. This is equivalent to almost two teaspoons of salt every twenty-four hours. The salt industry in the United States of America is a billion dollar industry, second only to the Chinese salt industry. In fact, it was one of the earliest mineral industries on the earth, involving either the physical extraction of salt from the sea or earth, or chemical production of the mineral by various methods. Salt has a myriad of uses, from food preservation to removal of snow from roadways to "water softening".
The worldwide production of salt is more than 200 million tons. As per the available statistics, the salt industry is dominated by five nations. These are China, the US, India, Canada and Germany. The salt industry located in Germany, Australia, Mexico, Chile, Brazil and the United Kingdom also produces a massive amount of salt annually. The top salt exporters are the Netherlands, Canada and Germany while the top salt importers are the United States, China and Japan.
In the case of salt production from rock salt, undercutting, drilling and blasting are used to extract large chunks of rock salt from the mining area. These chunks are then crushed repeatedly to reduce the size, and meanwhile foreign particles are removed using sieves and filters. These small salt particles are then passed through graded screens for sorting by size, and then packed for use. Salt production from briny water, however, is often carried out by using solar power and evaporation, leaving only crude salt behind. Here, after allowing the impurities present in the brines to deposit in shallow ponds, the salt is scooped. It is then thoroughly washed with saltwater as well as freshwater. In some places, vacuum evaporators are also used instead of the sun for salt production from brine. To produce table salt, iodine and other chemicals are added in small quantities before shipping. Iodized salt is the main source of this important mineral in most individuals' diets, and helps prevent thyroid disorders and other serious abnormalities.
Salt was a commodity of high value in prehistoric times, and as such was taxed by ancient rulers. There were specific trade routes for salt, and it enjoyed being placed into a great significance in many ancient civilizations, including those of the Greeks, Egyptians, and Chinese. Salt is also used in many religious rituals across the world. In the US, the early settlers made salt by boiling down "brines' (i.e. water with high salt concentration) sourced from salt springs. Its commercial production domestically in the US, however, did not really get underway until a large-scale operation was started in Michigan in 1838. This drastically reduced the salt imports from England over the next 50 years, putting America on the path to becoming one of the world's leaders in salt production.
The salt industry is currently experiencing a great controversy due to conflict in the outcomes of some research study findings. Some claim that high salt intake can be harmful to health, as it triggers increases in blood pressure while, according to other studies, there is little need to worry about salt consumption in those without already present risk factors for high blood pressure. Nonetheless, the UK, Finland, and South Africa are some of the nations which have addressed this issue head-on, by reducing salt intake successfully through national initiatives. Meanwhile, many other nations have chosen not to make any dietary recommendations specific to salt intake for their own citizens.