BENEFICIATION
Limiting the amount of material in landfills is a priority, not only because of legislative requirements, but also because of land availability.
you’ ve got a better quality product, as well as a more consistent product.” However, he points to inconsistency, which comes from the contaminants that are part of the crushed material, as being the biggest problem with C & D waste.“ You’ ve got everything from concrete to original stone and insulation, not to mention your organics, in the mix, which can result in fluctuating quality. Putting it through a wash plant gives you a consistent final product, which is what the industry wants,” he says.
Pienaar stresses the necessity of implementing quality control procedures if recycled material is to become accepted as a viable product:“ We need to establish that the recycled material can be used in exactly the same way as a non-waste, that it can be stored and used with no worse environmental effects versus the material it is intended to replace, and that it conforms to the same specifications as aggregate products.”
Despite the purported benefits of wet processing, Govender says that there is not yet a single comprehensive wet processing C & D plant anywhere in South Africa— or in Africa. However, he believes that this will not be the case for much longer.“ Two years ago, when we developed our 2020 Vision, I forecast that 2018 would be the year that C & D waste recycling would start to take off, and now it looks like that might not be far off. We are in talks with quite a few companies locally to get our first plant into this sector.”
“ The problem is that people’ s pockets are tight right now. In a market like this, companies look at the capital investment required for this kind of project,” Govender continues.“ It doesn’ t matter how attractive the return on investment is, that initial outlay of R10-million or R15-million is all they see. But when you weigh that against the other costs associated with C & D waste, such as dumping costs, together with the fact that there is a limited amount of dumping space available, then this becomes a much more attractive option to dumping.”
However, he firmly believes that the C & D waste recycling sector will continue to grow in the future,“ If you see the scale at which C & D recycling happens in Europe, it’ s only a matter of time before it catches on more here in South Africa. Whether it takes five, 10 or 20 years, it will come; it has to, if only because we are going to run out of land for landfill sites. Unfortunately, we are not making more land— we are using it. And given the growth of Africa’ s infrastructure market and the expansion of urban areas, we are going to need to optimise land use.”
While the advantages of recycling C & D waste are numerous – land conservation, landfill life extension, cost-effectiveness, decreased environmental impact, lowered resource consumption and job creation – economic incentives are needed to promote the recycling and use of secondary materials within the industry.
“ Globally the trend is towards recycling to make better use of our available resources. Despite South Africa’ s abundant mineral wealth, it is foreseeable that aggregates may become more difficult to obtain and therefore will need to be shipped from further afield. Recycled aggregates will play an important role in offsetting the rising price of virgin aggregates because of transport and handling costs. As a result, companies and municipalities should think twice about relegating all building waste to landfill sites,” says Pienaar. n
References
1. Barnes, K. 2016. Builders’ rubble: opportunities in processing and application. Industry brief. GreenCape. 2. Ulubeyli, S, Kazaz, A & Arslan, V. 2017. Construction and demolition waste recycling plants revisited: Management issues. Procedia Engineering,
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QUARRY SA | MAY 2017 _ 27