Fresh water for mining, industry and the community

Built by AREVA Resources Namibia, the Wlotzkasbaken desalination plant is located on the Atlantic coast about 30 kilometers north of Swakopmund. This is the first desalination plant built in Southern Africa.

An effective, energy-efficient process

The reverse osmosis process selected to produce fresh water consists of applying high pressure to seawater, forcing it through a series of semi-permeable membranes. The water molecules pass through, while the salt is held back by the membranes. Beforehand, the water is processed through rotating filters to remove large debris and by ultrafiltration to prevent the development of microorganisms.

This highly energy-efficient process separates the seawater into two streams: pure water and brine. Upon exiting the filtration system, the still highly pressurized brine is recovered to drive a turbine to generate electricity, thereby reducing the plant’s energy bill. The brine is then returned to the ocean by gravity, where it disperses. The reverse osmosis process is highly energy efficient, consuming only 3.5 to 5 kilowatt-hours per cubic meter (kWh/m³). It is used in about 60% of the world’s facilities, making it the most widely used process anywhere. 

Contributing to economic development

The fresh water flows across the desert to the Trekkoppje mine in an aqueduct, also built by AREVA. Three pumping stations will support operation of the 48-kilometer long, 800-mm diameter aqueduct. Once completed, the plant could produce 20 million cubic meters of drinking water per year, with 6 million cubic meters of water distributed locally.

The Wlotzkasbaken plant will thus make an important contribution to adequate water supplies, not just for the mining sector, but for the fishing industry, economic development in general, and domestic consumption.