Construction World September 2018

ENVIRONMENT & SUSTAINABILITY

Finding ECONOMICAL USES for coal ash Mountains of ash from our coal burning power stations can be avoided if new uses can be found to convert it from waste product to a valuable commodity.

tallest building, the Burj Khalifa, as well as improving concrete used to construct the Katse Dam, South Africa’s highest, deepest and one of the largest water storage dams, as well as the architecturally superb Maputo Bridge in Mozambique. This proves its worth and shows that with a bit of willpower and innovation, South Africa’s powerful business and technical sectors have the ability to solve the growing ash dilemma while at the same time using the free resource to over- come some of the biggest challenges of the current generation. SACAA has recently joined forces with the large surface mining industry association, Aspasa, to improve its reach to a similar and broader cross-section of industries.  of its members and the benefit of the South African economy in compliance with the environmental legislation. SACAA is associated to most of the world Ash Associations and have had representation at World Ash Conferences including the presenting of papers, train- ing courses and poster stands. About SACAA SACAA is the umbrella association for the ‘ASH’ producers, marketers, users, universities, research organisations and individuals playing an active role in the promotion of responsible ash utilisation. Its purpose is for growth and develop- ment of the industry for the development

A lready some of the ash is making its way into the country’s cement products to lend strength and aid curing of concrete, as well as having applications in agriculture, ground stabilisation and other uses. But the combined offtake of these is below 7% of the ash produced and needs to be boosted considerably higher to 18% if environmental goals are to be met. For some time now, the South African Coal Ash Association (SACAA), has been working with Government, environmental agencies and business to develop solutions to growing ash dumps. Simultaneously, the aim is to alleviated other social or economic issues affecting the population which, if successful, can have positive and far-reach- ing benefits. Take the challenge At a recent fact-finding tour of the Matimba and new Medupi power station, SACAA general manager, Mark Hunter, revealed that research is underway to determine the viability of treating the scourge of acid mine drainage throughout the gold mining areas known as the Reef with suitable coal ash. Certain building products made with ash are

also being tested and reviewed for suitability to alleviate housing shortages. “However, these are not new ideas and we believe that a myriad of other uses exists for this waste product. There are certainly more uses in civil engineering for roads, concrete structures etc, as well as uses in manufacturing, chemical industries, landscaping and other uses. All one must do is look at the amazing composition and structure of different types of ash produced in each power station, from fine and poten- tially valuable fly-ash, to course bottom ash and everything in between. “We simply need to challenge our tech- nical brains-trust to look for applications in their fields of work or study and to find ways of overcoming challenges to integrate ash into their supply chains. And, for those who think that it is an impossible challenge, it is worth noting that certain countries in devel- oped economies are using as much as 80% of their ash produced,” Mark says. Valuable elsewhere It is worth noting that South African fly ash and ash products were used to enhance concrete used to build the world’s then

SACAA general manager, Mark Hunter with Aspasa director, Nico Pienaar. SACAA has joined forces with Aspasa to better regulate and communicate the use of coal ash products in the economy.

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CONSTRUCTION WORLD SEPTEMBER 2018