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Coal wastewater reclamation plant a ‘model’ for others

World Coal,


Anglo American’s Emalahleni water-reclamation plant, 120 km east of Johannesburg, South Africa, should be seen as “a model” for how coal mines deal with waste water, according to Marius Keet, acting head of the Department of Water Affairs in the Guateng region.

According to Keet, the Emalahleni plant is “a very good example of how [water-reclamation] should be done.”

The US$ 130 million Emalahleni plant takes wastewater from coal mines operated by Anglo American and turns it into treated water than people can drink. Water from the plant provides as much as 12% of the municipal drinking supply in Witbank.

The plant processes 30 million litres/day of water and, via reverse-osmosis, recovers 99.5% of mine wastewater, which will increase to 100% after an expansion project is completed this year. This recovery rate is excellent, according to Thubendran Naidu, hydrology manager at the Emalahleni plant, who said that seawater desalination plants, by comparison, “have recovery rates of 60 – 70%.”

According to Anthony Turton, a University of the Free State in South Africa professor and trustee at the Water Stewardship Council, Anglo American “was brave to try a technology that wasn’t tried before.”

BHP Billiton and Glencore Xstrata are set to replicate Anglo’s treatment works. Cleaning mine wastewater to a higher quality allows the companies to continue producing coal, keep their water licenses and reduce the acidity that corrodes equipment.

Graham Sim, global mining industry director for GE Power and Water, explained that public pressure is often a significant driver that makes companies look to develop and improve wastewater treatment plants for coal mining operations: People are concerned about how water is used and disposed of, so demand that companies manage and recycle water, as well as report their efforts.”

Glencore is currently constructing a water-treatment plant in the Middleburg coal mining area east of Emalahleni. The plant will be commissioned later this year with a capacity of 20 million litres/day of water. BHP Billiton is set to invest in the Middleburg water plant.

The taste test: not for whisky

According to Turton, water from the reclamation plant is “tasteless. What gives taste to the water is the minerals in it. This is purified of its minerals so I wouldn’t put it in my whisky. But once it’s blended into the drinking water supply, it’s not noticeable.” 

Written by Sam Dodson

Read the article online at: https://www.worldcoal.com/mining/07052014/emalahleni_treatment_plant_praised_807/


 

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