In a first for South Africa, state-owned power utility Eskom is incorporating recycled coal ash into a road it’s building at the Kusile Power Station in the Mpumalanga province, saying this will help it use less cement.
The company says the new heavy-duty access road, which stretches 759 metres across two sections, is designed to support the daily passage of up to 1,600 trucks — each weighing around 34 tonnes — during the construction of a new coal conveyor belt.
Eskom is using 2,904 tonnes of legacy coal ash per kilometre of road, which will meaningfully reduce its cement requirements and therefore carbon emissions. The ash is chemically transformed into geopolymer concrete for road building — an application that the cash-strapped utility says could open up new revenue streams. Coal ash can also be used to make bricks, it says.
Eskom produces around 34 million tonnes of coal ash annually, of which only 7% to 10% is beneficiated. The rest is stored in ash disposal facilities and is classified as Type 3 hazardous waste, meaning the utility incurs significant environmental and financial liabilities.
Putting it to better use reduces ash volumes in dumps, thereby reducing environmental impacts and costs and minimising fugitive dust. Eskom also earns carbon credits by doing so, it says.
Tags: Coal ash
