It is well known that South Africa is a water-scarce country, but weather variability due to climate change is now another complicating factor to consider when engineering solutions to mines’ water demands.
Mines are traditionally considered as fairly water-intensive operations, especially because most processing plants require large volumes of water for effective mineral extraction. Ever more stringent environmental standards and regulations ensure that mines control the quality of their discharged water and design their systems so that clean water and dirty water are kept separate, as per the requirements of the National Water Act (36 of 1998), with specific reference to Government Notice 704. It should also be remembered that many of the country's mining regions are located in provinces where annual rainfall is relatively low.
Recycling and Re-use
In the local mining sector, there is already considerable progress in applying water treatment techniques to allow water to be re-used in plant processes. In the coal mining region of Mpumalanga, for example, mines have even collaborated to improve water quality to a potable standard where it can be sold back to a municipality for community use. Where mines are close to the coastline, desalination of seawater is a growing option.
While there are various water treatment technologies available, they all of course come at a cost. As the country's population grows along with industries including mining there is likely to be increased acceptance that procuring water of the appropriate standard will require more investment. One of the main reasons for this is that mines are increasingly attentive to their relationships with communities their social licence to operate and they recognise the need to balance their own demands with those of the towns and settlements around them.
Sound water stewardship involves taking into consideration the broader catchment around a mine, which includes engaging with stakeholders like communities and other industries. Given the water shortages faced by many municipalities around South Africa, the focus for mines is to draw as little water as possible from the traditional municipal sources and for mines to work towards self-sufficiency.
