Mining Mirror March 2019 | Page 36

Mining in focus Mining: reducing water usage – more than just an aspiration Water management is emerging as the pre-eminent sustainability issue within the global energy and mining resource industries, and mining companies are under increasing pressure to balance costs, increase productivity, and reduce water usage, writes Tarren Bolton. T he mining sector remains a key economic contributor to the South African economy and is one of the toughest industrialised working environments. Driven by a constant need to maximise on yield for profitability, the sector faces several challenges, and often simultaneously. Not least of all is the constant need of having to balance costs versus return-on-investment (ROI) in the wake of fluxes in the global economy that directly impact investment, cash flows and planning, and trade or export potential of mineral resources. Added to this, water management is emerging as the pre-eminent sustainability issue within the global energy and mining resource industries. Darryl Macdougall, managing director of Verder Pumps South Africa, says that water has always been a fundamentally important resource across all mining and quarrying developments and operations. However, as water scarcity becomes a reality, mining companies are faced with numerous civil and environmental pressures and need to proactively review the impact that their upstream and downstream operations are having on the availability and quality of this non-renewable resource. This includes having a deeper understanding of where the mine gets its water from, how it disposes of or recycles it, what the water is being used for, potential losses or gains, and the related risks and opportunities — from both a corporate and an individual operation site level — and start to implement innovative solutions that will reduce the mine’s reliance on and usage of water. Adopting peristaltic pump technology is a solution that will improve the dewatering of the product and subsequently water conservation, and in the process contribute to higher production capacity and a reduction in maintenance and operating costs. Bottom line, peristaltic pumps use less water. Hose pumps can circulate slurry specific gravities (SGs) of 1.6 to 1.8 or up to 80% solid content, whereas the traditional centrifugal pump loses efficiency when the slurry SG reaches 1.3 or 30% solids. Given this limitation, slurry pumps have significant process water demands: for example, on a plant processing 75 tonnes of ore per hour, and at 65% solids, every time a peristaltic hose replaces a process slurry pump, it could save up to 1 100 million litres of water annually when compared with the traditional slurry pump. The hose pump requires less than 25% of the process water of a slurry pump. Adopting peristaltic pump technology Adopting peristaltic pump technology is a solution that will improve the dewatering of the product and subsequently, water conservation. [36] MINING MIRROR MARCH 2019 Local mining companies are undoubtedly under increasing pressure to balance costs, increase productivity, and reduce water usage. However, navigating the technical www.miningmirror.co.za