AngloAmerican, one of the world's largest mining firms, is using its industrial waste in South Africa to build homes for the local workforce. The company’s water purifying operations (which reclaim water contaminated during its coal mining activities) produce gypsum as a by-product. As reported by Ayesha Durgahee and George Webster for CNN, AngloAmerican is mixing the gypsum with cement to make ‘low cement’ bricks for housing in the city of eMalahleni.
According to Peter Gunther, AngloAmerican’s head of sustainable development, two hundred tons of gypsum are removed from the water every day, which is more than enough for the eight tons required per house. Gunther claims the new bricks have a lower environmental impact than traditional bricks since the bonding strength of gypsum requires less cement in the mixture. He estimates that the low-cement bricks save three tonnes (three metric tons; 3000 kilograms) of carbon dioxide for every home built.
The company’s sustainable initiative reflects some awareness of its ecological karma:
Global carbon emissions from coal are second only to oil, according to the UN Environment Program, while other environmental factors such as air-pollution from coal dust and damage caused by mining also remain a serious problem.
Gunther acknowledges these issues, but says that coexistence between energy sources is necessary "for as long as the world is so much set up around running on coal.
"While we're still using it, the question is: What can we do to make it cleaner and even more useful? I think our approach goes some way to achieving that goal."
The company has built 62 homes with the bricks and 400 homes are scheduled for next year. AngloAmerican’s goal is to build homes for its entire local labor force.