"As the world's eighth largest copper mine, the new Kansanshi smelter has very specific requirements for boiler feed, process and drinking water," said Nigel Bester, Project Engineer at Veolia's Engineered Systems & Services division. "The result is a flagship water treatment solution that upgrades river water to match each requirement exactly, with guaranteed availability due to a duty standby design on all process streams."
Veolia will completely manufacture, test and certify the plants at its factory in Sebenza, Gauteng, before they are transported to site. The 40-foot containerised plants are designed to be linked up to one another on site, and will operate as a single plant with multiple output streams to produce a combined 42.5 m3 of treated water per hour.
"The plant has been designed to ensure maximum viability, so we have taken a high-end engineering approach to match each treatment stage's water with the mine's requirements. This means that boiler feed water, for instance, isn't subjected to all the treatment steps necessary for drinking water, which is much more viable than treating all the feed water to high-quality drinking standards regardless of its application," said Bester.
After clarification, iron removal and sand filtration, the drinking water train consists of activated carbon filtration, polishing and ultimately UV disinfection. The boiler feed water will be subjected to the same initial processes, but will be diverted for carbon filtration, double-pass reverse osmosis, passed through a polishing filter and continuous electro deionisation after passing through the initial sand filtration skids. The softened water for use in the smelter's processes will be diverted from the demineralisation stream before the second pass reverse osmosis membranes.
Veolia's position at the upper-end of the containerised plant market secured the contract against international competitors. The company's Engineered Systems & Services division uses only best-of-class componentry, and is highly specialised within the smaller-scale water and wastewater treatment market.
"We have an extensive footprint throughout southern Africa, which means we can service our clients comprehensively. As part of the global Veolia, we further have access to some of the best technologies, which means that, overall, we provide the entire, fully engineered package that provides long-term benefits," said Bester.