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 ,
172:1190-1197 .
QUARRY SA | MAY 2017 _ 27