Salt has been in use since ancient times. It was used to preserve Egyptian mummies, and sprinkled onto the stage in old Japanese theatres to ward off evil spirits.
Salt is essential for human life. A well-known food ingredient, salt is also critical for many industries. The majority of the salt Rio Tinto produces is used by the chemical industry, where it helps make materials like glass, paper, plastics, textiles and even soaps and detergents. Some of our salt is also used to process foods and de-ice roads.
Salt at Rio Tinto
Our Dampier Salt operations in Western Australia are the world’s largest exporter of seaborne salt – meaning salt that is produced from evaporating seawater, as opposed to being mined as a solid mineral. We export more than 5 million tonnes of salt every year, with most of it going to customers in Asia and the Middle East.
Dampier Salt is one of our oldest businesses and uses a unique and sustainable production process that relies almost entirely on the power of the sun and wind.
The shallow evaporation flats at Dampier have the potential to produce salt almost infinitely. The operation relies on natural processes of evaporation over an area equivalent to 27,900 soccer fields (19,500 hectares) to transform seawater into salt, predominantly used for industrial purposes. The million tonnes of seawater pumped over these shallow flats every day has created an important habitat that supports a variety of wading birds, including over 1% of the world populations of the red-capped plover and red-necked stint. Similarly, the Oriental plover and sharp-tailed sandpiper are occasionally spotted here. The site is designated a Key Biodiversity Area by BirdLife Australia.
As the sun and wind evaporate the water over months of exposure, we are left with a salty crust when salt crystals begin to form. Once dry, a specialised harvester collects the salt and transfers it to 320 tonne trucks for transfer to the washing plant. Here the salt is cleaned of impurities and stockpiled based on end-use specifications. From these stockpiles it is loaded onto ships at our on-site dock and transported to customers around the world.