Anglo American’s Thermal Coal business continues to produce innovative technology in mine water treatment through mobile desalination plants
Anglo American’s Thermal Coal business continues to lead the way in mine water treatment through the installation of two of the largest mobile water treatment plants in the country at its New Vaal operationin the Free State.
The entire volume of treated water is being taken up by Eskom’s nearby Lethabo Power Station for use in the generation of electricity, replacing the water the power station previously extracted from the Vaal River for use in its processes.
The need to install the mobile water treatment plants at New Vaal was prompted by extreme rainfall in 2009 and 2010, which saw the Vaal River rise three metres, while the operation’s water storage facility rose by five metres.
This increase became not only a threat to the health and safety of employees through the possible flooding of pits, but an environmental risk in the event of an uncontrolled discharge into the river.
Previously, the mine had effectively and reliably managed to contain surplus water by reducing, minimising, reusing and separating clean and dirty water streams to reduce its operational footprint.
The implementation of these plants is consistent with the significant investment Thermal Coal has made into the research anddevelopment of water treatment technologies over the past decade, culminating in its ground-breaking eMalahleni Water Reclamation Plant which desalinates water to potable quality from three of its Mpumalanga-based mines.
New Vaal hasformed a steering committee with representatives from its operations and Eskom, and will soon begin implementation of a freeze crystallisation facility that will treat brine formed as a by-product of the desalination process, thereby removing 40 tonnes of salt from the system on a daily basis. The brine treatment plant will be designed, implemented and operated by a well-established player in the water treatment industry.The entire project will run over a period of three years.
The programme’s next stage involves investigating the possibility of using the salt that will be produced as a marketable product in the fertilizer and industrial explosives industries.
Desalination involves processes to remove a requiredamount of salt and other minerals from saline water. This is achieved through a process called reverse osmosis, whereby water is passed through membranes that allow the clean water through but retain the dissolved salts.
New VaalGeneral manager, Johan van Schalkwyk, concludes that the company is committed to effecting sustainable progress in the treatment of mine water.
“Anglo American aims to mine in an environmentally responsible manner, and we have clearly stated our commitment to efficient water management.As such, we are proud of the achievements of New Vaal in implementing a lasting solution to its excess water challenges.
“Moving forward, our company will remain a recognised leader in investigating treatment technologies, developing infrastrucutre and parntering with our water stakeholders.”
During the last quarter of 2010, NuWater started working with Anglo American Thermal Coal to deliver a completely ‘Modular & Mobile’ mine drainage wastewater reclamation plant. The plant is capable of treating and desalinating up to 20 million litres per day (MLD) of wastewater pumped from the mine pits, and then used as high-quality cooling water at the Eskom’ s Lethabo power station in the Vaal Region.
NuWater designs, builds, owns and operates specialist water treatment and wastewater reclamation plants based on its patented large-diameter Reverse Osmosis (RO) technology and other leading technologies. The company provides large-capacity, highly compact, modular and rapidly deployable plants specifically to the mining, and Oil and gas industries both in South Africa and internationally.
The development believed to be the largest capacity plant of its type in the world, has demonstrated that modular, rapidly deployable, and if necessary re-deployable, plants can meet the demanding performance and treatment capacity requirements of the mine over time. The plant addresses the bulk of the water treatment and desalination requirement for the mine.
In order to offer extended services to the mining sector, NuWater is currently working on a project to further treat the RO brine/ or waste stream so as to fully remove salts from the reject water. The trialing of NuWater’s brine treatment technology as an add-on to its existing plant is currently underway.