The Walvis Bay salt production site covers approximately 12,350 acres. (Photo credit: RM Nunes/Getty Images)
Walvis Bay is a port city on the Atlantic coast of Namibia, home to a large sea salt factory. The factory has been in operation for over 60 years, thanks to the area's dry climate and coastal winds, which are ideal for evaporating the salt-laden seawater.
The salt works are about 5 miles (8 kilometers) southwest of central Walvis Bay. The operation covers 12,350 acres (5,000 hectares), according to Walvis Bay Salt Holdings, or about half the size of Disney World in Florida.
According to tour operator Desert, Dunes and Dust Tours, salt production at Walvis Bay relies on Atlantic seawater, which is pumped into man-made ponds at a rate of 8,500 cubic feet (240 cubic meters) per minute. The plant gets its supply from the Benguela Current, a cold ocean current that flows north and forms the eastern portion of the South Atlantic Subtropical Gyre.
The evaporation process, powered by solar heat and wind, increases the salt concentration in the ponds from about 2.9% to 3.5%, which still allows plankton, algae and small sea creatures to exist. These organisms and microorganisms make the ponds so colorful that from above they look like a mosaic of tiles.
Pumps move the brine produced by this initial evaporation stage to concentration ponds, where the salt concentration reaches 25%. Another set of pumps then moves this liquid to crystallization ponds, each of which covers an area of about 50 acres (20 hectares), the equivalent of about 38 football fields.
At the end of the crystallization stage, each pond has a crust of salt 4 to 6 inches (10 to 15 centimeters) thick, which is removed by mechanical harvesters and loaded into large bins. A conveyor belt then transports these bins to a plant where the salt crystals are washed with a mixture of seawater and gypsum, which dissolves impurities such as magnesium and potassium while keeping the salt intact.
After washing, the salt is dried in large piles outside. Walvis Bay washes and dries about 240 tons (220 metric tons) of salt every hour, totaling more than 1.1 million tons (1 million metric tons) of salt per year, according to Walvis Bay Salt Holdings.
The company exports chemical salt used in industries such as animal feed, water treatment and pharmaceuticals to Nigeria, Cameroon, South Africa and Europe. It also exports table salt for human consumption to a number of African countries, including South Africa, Angola and the Democratic Republic of Congo.
The Walvis Bay salt works also provide habitat for shrimp and larval fish, which attracts birds. Together with the nearby Walvis Bay Lagoon and Bird Sanctuary, the salt works create a coastal wetland habitat for birds such as flamingos and pelicans, according to Birdingplaces.
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