Walvis Bay Saltworks
Walvis Bay Salt Holdings (Pty) Ltd, through its various subsidiaries, is the largest producer of solar evaporated sea salt in sub-Saharan Africa and a well-respected player in the Namibian mining and manufacturing sectors.
The company producers over 1,000 000 tonnes of sea salt, on an area of 6000ha, and exports various grades of Salt to various countries like Nigeria, Cameroon, Europe, East Africa and South Africa.
In addition to producing Salt for the chemical industry and other general-purpose industries, it also produces triple refined Table Salt for southern African countries.
The Walvis Bay Salt Refiners site is located in the Kuiseb river delta at the southern end of the Walvis Bay lagoon. We visit the Ramsar Convention proclaimed wetlands and Saltworks on our half-day, full-day, and combo tours.
The capacity of the pans in 1976 was about 370 000 tons per annum and was increased to about 450 000 tons in 1988. In 2014 the pan capacity was about 750 000 tons with a wash and drying capacity of about 800 000 tons p.a. The Plant ran at a very high-efficiency rate, 365 days a year 24 hours a day to produce these figures, and subsequent investments had to be made if they wanted to increase production output.
In November 2019, a new N$93.6 million wash plant and centrifuge drying plant was completed, with the ability to wash op to 220 tons of salt an hour and a capacity of 1,200 000 tons per annum. In January 2020, the first load of 50 000 tons of salt left for the east coast of America and future markets in Europe and South America are being investigated.
The salt field operation in Walvisbay comprises two companies, Salt and Chemicals (PTY) Ltd, who produce the raw salt, and Walvisbay Salt Refiners who process and market the Salt; both owned subsidiaries of Walvisbay Salt Holding (PTY) Ltd who hold the mining license.
Seawater, which is the only raw material used, is pumped at a rate of 240m3 per minute, from the natural Lagoon into a new manmade lagoon within the old existing Walvis bay lagoon and salt pan. A dam wall was built from the existing Lagoon all the way to the other side of the Pelican Point Peninsula and a further 3 dams along the existing salt pan were flooded, comprising a total area of almost 2000ha.
These 4 pre-evaporation ponds are used to increase the salt content from 2.9% to 3.5%. As the Lagoon is a Ramsar appointed wetland and the most important for Namibia, the dams had to comply strictly with the International Ramsar Wetland protection policy. Islands for roosting and sleeping had to be made and enough food must be generated to sustain the rich birdlife. At 3.5 % salinity, all plankton, algae, and small animal life continue.
From here the water is pumped into concentration ponds where the brine salt salinity increases to 25% at which point it is pumped into square crystallization ponds each with a surface area of 20ha. The salt then crystalizes to form a layer of salt crystals.
To enhance production more modern technology was applied with the main aim of increasing evaporation. The quicker the ponds evaporate, by wind and sun, the sooner one can harvest. Once the salt crystals have grown to the required depth, of between 10-15cm, the salt is harvested by mechanical harvesters. Salt is dropped into a huge bin and by conveyor belt taken to the wash plant. The salt undergoes a process of washing, using fresh seawater mixed with gypsum as a washing medium. Impurities like Calcium Sulphate, Magnesium, and Potassium ion concentration, that are not suitable for chemical-grade salt, stick to the gypsum brine solution and is called Bitters,due to its bitter taste, and pumped back into the ocean. The two black pipes can be seen along the road to Paaltjies, pumping fresh water into the fresh seawater pond and the other pipe the Bitters back to the ocean. The salt is washed and dried at a rate of 220tons per hour, and then by conveyor belt stockpiled outside for further draining and drying.
The salt is transported by truck at a rate of 3000 tons a day through Walvisbay to its own bulk storage site in the Walvisbay Harbour. To avoid contamination the salt is transported by a conveyor belt and spout trimmed into the ships hold in the Walvisbay Dockside. Loading can take place 24hours a day 7 days a week as and when the ships are available.