Liquid assets

Research is showing many alternative uses for mine water

Liquid assets

Nelson Mandela Bay’s recent brush with Day Zero had me thinking about Cape Town’s drought disaster in 2018. I recall, with no fondness at all, how I would take splash-and-dash showers and pray for rain … while the guy across the road used municipal water to hose down his driveway and poured soapy buckets from washing his car down the drain.

My neighbour wasn’t the biggest water user on our block, but he soon became known as the worst.

Miners have a similar reputation. The mining sector isn’t the largest consumer of water in SA, not even close. Research by the CSIR found that mining consumes just 5% (at most) of SA’s available H2O. Agriculture drinks a massive 61%. Yet what farmers will tell you (and what my neighbour didn’t understand) is that it’s okay to use water but inexcusable to waste it, and unforgivable to contaminate it. Acid mine drainage continues to be a problem in SA; and water-related mining disasters such as those seen recently in Jagersfontein and Welkom only deepen the divide between the mining and agricultural camps.

It’s hugely encouraging, then, to hear about the good work some mining industry players are doing to improve their water efficiencies – and to support their neighbouring farmers.

A year ago, a group of stakeholders, among them mining major Glencore, concluded a pilot programme at the Wonderfontein colliery near Belfast in rural Mpumalanga. They investigated whether remediated mining sites and mine water could be used to grow and irrigate crops.

The first pilot experimented with a variety of winter wheat, which cereal company Kellogg’s had said could be used in the manufacture of its popular cereals.

The results were very promising. ‘The pilot confirmed that winter wheat can be grown in Mpumalanga successfully, and that rehabilitated mine land and mine water can be used to grow and irrigate this important crop,’ according to Glencore. More than that, the first crop proved to be compliant with WHO and SA food-safety standards; and the crops using mine-impacted water were shown to offer higher yields than those planted on virgin soil.

Then, in October 2022, Orion Minerals announced that it had started a series of field trials for the treatment of mine water at its copper/zinc mine in Prieska, using ‘a proprietary electrolytic technology to produce saleable products’. Those include hydrogen, iron hydroxide, magnesium and calcium – all useful in the agricultural space, and all extracted from contaminated mine water.

Prieska is located in the big red nowhere of the Northern Cape. Orion’s media statement describes it as ‘a region where renewable energy is abundant’ and where ‘irrigation agriculture is a core industry’.

That suggests the potential for economic development opportunities in the community – and that’s where this turns into a story that’s bigger than mining, bigger than water, and bigger than a handful of farms in remote areas. It becomes a story about climate change. Droughts will come – and in an age of extreme weather events, they will come harder and more frequently than ever. Farmers will find themselves under increasing pressure to provide food, despite environmental threats to their crop yields.

The innovative projects in Wonderfontein and Prieska show that the mining sector has the capacity to use less water in better ways; and – from the perspective of nearby farmers – that mines are well placed to turn from polluters to providers. If only everybody were such a good neighbour.

By Mark van Dijk