MATERIALS HANDLING
TACKLING TAILINGS Erik Vlot details how mines can pump paste tailings sustainably
n the wake of several catastrophic tailing storage facility (TSF) failures, the mining industry is moving away from wet tailings and embracing safer, more sustainable alternatives. Tere is currently around 19 billion m3
I of tailings produced
annually and, with the growing demand for metals and minerals, as well as declining ore grades, this volume will continue to rise. Tailings management has, therefore, become one of the most important challenges facing the industry.
ISSUE OF SUSTAINABILITY Paste tailings allows miners to manage their waste more sustainably, increase their water efficiency and recover value from their waste. Over the past decade, water has become more of an economic and environmental concern for mine operators. Paste tailings reduce a mine’s environmental footprint by utilising considerably less water compared with liquid tailings. For example, at 60% weight solids concentration, paste requires six times less water to pump than tailings with 20% weight solids concentration. Paste tailings can then be used as mine backfill to help ensure the structural stability of the mine; this extends the life of mine (LOM), keeping it profitable for longer so that all the ore can be mined. Sibanye-Stillwater mine in Montana, USA, is a platinum group metals mine. It’s a narrow vein operation and, therefore, it needs to backfill stopes once they’ve been mined. It uses the mill tailings as mine backfill, which are transported by custom-fit Geho pumps from Weir Minerals that pump 275 gallons a minute at 70%
The Sibanye-Stillwater mine A Geho pump in operation
solids, 1,400ft. Tese pumps are critical to their operation from a production standpoint; reliability is paramount because if the operators can’t backfill a stope they have to halt the entire operation. But it’s also important from a sustainability point of view because it’s putting rock back underground where it originally came from, reducing the mine’s environmental footprint.
Te paste that is used as backfill
obviously doesn’t need to be stored on the surface. Despite these obvious advantages, there’s an on-going debate within the industry around whether filtered or paste tailings provide the more sustainable tailings solution. It’s important that miners approach this question holistically, rather than focusing on individual aspects of tailings management. Tere is often a tendency, for instance, to see filtered tailings as the more sustainable
solution because this offers a higher rate of water recovery. However, this comes at the expense of higher fuel and power consumption and, therefore, increases carbon emissions. Filtered tailings, after all, need to be transported to the TSF, spread and compacted. Weir Minerals has taken this into account in the development of the Geho piston diaphragm pump – it has been designed to be the heart of the mine. When compared with other methods of transport, it provides up to a 20% energy saving, which equates to a 20% carbon footprint reduction. It also eliminates noise and dust pollution. Tere is sometimes a perception that PD pumping technology is complex, but when operators see it in action, they understand that the control systems are what makes it so reliable. In recent years the Weir Minerals team has worked hard to improve the pump’s performance, increasing its flow and pressure capacity, while also optimising its reliability and availability.
All tailings management programmes need to be bespoke because no two mines are the same and no two sites are exposed to the same climatic and geological conditions. Weir Minerals works closely with its customers to help them devise the ideal solution based on their specific requirements.
Erik Vlot is with Weir Minerals.
https://info.global.weir/geho
46
www.engineerlive.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
