Salt, a natural crystalline mineral derived from Rock Salt or Halite. Salt is mostly made up of sodium chloride, the chemical formula NaCI. But other than sprinkling it on your chips – what do you know about it?
As we spend most days talking about salt, selling salt (yes, we are salt sellers!) and explaining its use in the water softening process, we thought we would dig a bit deeper to truly understand what this common substance is really all about.
Most obviously salt is found in sea water – with the UK coastline being approximately 2.5% salinity. But, this isn’t the only source of salt. Deep underground, in areas across the globe, there are seams of salt – created from prehistoric sea beds which evaporated to leave behind rock sock deposits in vast quantities. In some cases, these turn into natural brine streams as rainwater filters through the earth to dissolve the rock salt.
In the UK, the underground rock salt originated over 250 million years ago, when the UK was closer to the equator and the climate much hotter. The salt crystals combined with sand and marl which blew across the dried sea beds from surrounding land. This is the source of the pink colour of rock salt from Cheshire, one of our main sources.
Rubbing Salt in the wounds
Some of the earliest evidence of salt processing dates back to around 6,000 BC. It became a very important substance for many reasons, including – seasoning and preserving food, cleansing and helping wounds to heal. Then tanning leather, defrosting snow and ice, fertiliser and now more modern applications like water softening, and chemical production e.g. chlorine and soda ash.
There are other uses that include pottery glazing and it’s addition to other chemicals to produce plastics. It can be used to stablise the hole when drilling through sand of gravel – salt is added to the drilling fluid to stop the wall of the hole collapsing.
It is also used in some traditional religious and cultural ceremonies. There are many references to salt across different religions, myths, legends and superstitions. From casting spilt salt over your shoulder, people turning into Pillars of salt, to surrounding your home with salt to protect it from bad energy. Salt features heavily across stories and myths through centuries – not surprising given its value to the human race. Such value that during the middle ages in Africa it was traded with the same value as Gold.
Medically, salt water helps clean and promote healing by osmosis. The sodium chloride solution draws liquid from the body cells when it comes in contact with them. If bacteria are present in this liquid it’s drawn out too, effectively it helps cleanse the wound and surrounding skin.
So, you can see salt was, and still is, a precious commodity. It has been transported by boat across the Mediterranean Sea, moved along routes known as salt roads, and across the Sahara by camel caravans. The universal need for salt, and occasional lack of it has led nations to declare war and impose taxation on its production, export or sale.
Salt of the Earth
The process to extract salt from brine – whether this is by age old methods utilising solar evaporation of sea water and natural brine streams, mining or by twentieth century approaches like vacuum evaporation, still take time, effort and investment.
Salt is produced worldwide, in 2018, approximately 300 million tonnes was created. The top six country producers were China (68 million), the United States of America (42 million), India (29 million), Germany (13 million), Canada (13 million) and Australia (12 million).
Worldwide salt production has grown considerable in the last 45 years, back in 1975 it stood at 162 tonnes, so that’s around a 181% increase compared to 2019 which reported 293 tonnes worldwide.
The UK hovers around the middle of the world producer table of 27 countries, creating around 6 tonnes, a mere 2% of the worlds use.
About 6% of the salt manufactured across the world is used in food. 12% is used in water conditioning processes, 8% for de-icing transport infrastructure and another 6% is used in agriculture. The rest (68%) is used for manufacturing and other industrial processes.
Throughout history the availability of salt has been fundamental in the forming of civilizations and communities. In England, the suffix “wich” in a place name means it was once a source of salt, as in Sandwich and Norwich.
Salt also played its role in the growth, power and location of some the world’s greatest cities. Liverpool for example, was just a small English port but became the major exporting port for salt extracted from the Cheshire salt mines and so became the trading post for much of the world’s salt through the 19th century.
“Let there be work, bread, water and salt for all” – Nelson Mandela
While travelling across the globe you may have seen Salinas, as pictured below. Warmer countries can take advantage of the sun to evaporate the seawater creating white salt, by solar evaporation.
White salt is the result of evaporation until pure crystals of sodium chloride form. As crystals form, they are removed from the brine solution, and left to dry in containers or mounds.
There are other, traditional methods to create salt, methods used by our ancestors like sleeching (also known regionally as muldefang) or pot processes where brine is heated over fire. Most of these processes are now only used in historical re-enactment demonstrations.
Crystal size depends upon the extraction method used. The quicker the evaporation the finer the crystal. A brine solution is topped up as crystals form and they are drawn off to prevent bitter salts sticking to the sodium chloride.
Without the sun’s power, the UK processors relied on artificial heat to hasten evaporation. In the past it took half a ton of coal to make one ton of salt in a large open pan. As fuel costs increased the vacuum evaporation method was more widely adopted.
Vacuum evaporation started at the beginning of the 20th Century. Steam is injected into sealed chambers with reduced atmospheric pressure to heat the brine. The process is more energy and resource efficient and cost effective.
Vacuum evaporation salt results in cubic or spherical crystal, produced from purified brine.
Natural brine streams can be up to eight times stronger than sea water (rock salt dissolves until the solution can take no more – a saturated solution). The stronger the salt solution the less heat is required to evaporate it. Salt from unrefined brine in open pans can be spiky and clustered together.
However, in Essex, the Maldon Crystal Salt Company still continue with the open pan evaporation method which produces larger, flaked crystals which are hollow and pyramidal in shape.
Modern salt manufacturers stress the purity and cheapness of their product, where traditional sea salt producers empathise the natural mineral content and the special nature of the crystal form.
Business is the salt of life
Historically, with smaller producers dotted around the UK’s coast and more moving inland as methods evolved and technology progressed, the market reached a point where regulation and price control were sought.
In 1759, the British East India Company came into possession of land near Calcutta where there were salt works. This opportunity to make money couldn’t go unmissed. The land rent was doubled and transit charges were imposed on the salt. These were the first rules which were to become the Salt Tax.
SInce then, and at different points in time, the British East India Company in the first instance – followed by the British Government in 1857, adjusted the amount of salt tax levied, to suit their own strategic objectives.
In China salt taxes go way back – as far as 300BC. At one time salt taxes made up over one-half of China’s revenue and raised funds that contributed to the building of the Great Wall of China.
Here, there are historical references to there being salt taxes noted in the Domesday Book. It seems though, that these were cancelled before patents were given in Tudor times.
But, it seems Government tried to reinstate taxes in 1641 in the Commonwealth period. This led to huge protests and they were withdrawn upon restoration of the monarchy in 1660. William III did however, reintroduce salt taxes in 1693 with duty set at two shillings a bushel on foreign salt, one shilling on native salt with exemption for fishery salt. In 1696 the tax was doubled, and it stayed this way until it abolished in 1825.
It’s noted that there were around 600 full-time officials employed to collect taxes at this time.
Ten years on, in 1835, the Government appointed a salt commission to review the existing salt tax. The recommendation was that Indian salt should be taxed to enable the sale of imported English salt.
Ever since the introduction of the first salt taxes by the British East India Company, the laws were subjected to heavy criticism. The Chamber of Commerce in Bristol was one of the first to submit a petition opposing the salt tax.
With the English salt trade in turmoil (due to large producers fulfilling contracts 50% below cost price and small producer competition increase) the Salt Union was established on 5th July 1888.
The Union, consisting of 64 firms, monopolised the English salt trade for many years – controlling prices and raising them often. The Salt Union bought out some salt works and closed down other smaller operations to centralise production and supply. It wasn’t an easy time and financially there were problems. In 1936 the Salt Union was absorbed into Imperial Chemical Industries (ICI).
Salt Rocks the Empire
Meanwhile, in India, one of the world’s largest salt producing countries, on the 12th March 1930, Mahatma Gandhi embarked on a satyagraha (passive political resistance) with 79 followers. This took the form of a 240-mile march from Sabarmati Ashram to Dandi on the Arabian Sea coast.
This march, known as the Dandi March or Salt March, was well publicised with film clips and images of Mahatma Gandhi distributed across the world. Gandhi reached Dandi on 6th April 1930.
After his morning devotions, he waded to the sea shore picking up a handful of salt, with it he proclaimed the end of the British Empire. The police arrived, and he was arrested along with thousands of national leaders.
The salt tax in India remained in force until March 1947, when it was abolished by the Interim Government of India.
The route from Sabarmati Ashram to Dandi has been christened as the Dandi Path and declared a historical heritage route. The National Salt Satyagraha Memorial, and memorial museum, was opened in Dandi on 30th January 2019.
The monument is a 40-metre high steel frame, symbolising two hands. At the apex (held in the hands) there is a 2.5-tonne glass cube which represents a salt crystal.
So, as you can see, salt is a very emotive product and topic. And as a family business, dedicated to the water softener industry for over 50 years, we can safely say we have seen some changes.
We’ve had salt shortages, price changes and more recently technology advancement to see water softener machines evolve from the use of granular, to tablets and to blocks. Each iteration making it simpler for the customer to maintain their flow of softened water in their properties.
Softened water is therapeutic for your life – from reducing the time spent cleaning away limescale and soap scum, for the environment as you use less detergent and cleaning products, to your hair and skin. So, maybe this section should be titled Softened Water Therapy, as the salt is used to remove the minerals that make water hard. But we are talking about salt, so for now the title stays – even though salt doesn’t stay in your softened water!
We will continue to sell salt for all water softener makes and models at competitive prices for collection from our showroom or delivered to your door within our operational region.
Call us for more information.
The Salt Industry by Andrew and Annelise Fielding – A Shire Book
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