Maximising recovery of construction and demolition materials
30 July 2015
Generally defined as waste from residential, civil and commercial construction and demolition activities, the largest components of C&D waste are concrete, bricks, asphalt, soil, timber and ferrous metals (National Waste Report 2010).
Whilst many of these materials are readily recyclable, recovery rates across jurisdictions in Australia vary significantly - from 15 to 80 percent.
Why the variation in recovery rates?
Recycling performance is generally attributed to factors that are regionally specific, with many of these factors being influenced by State Government policy, programs and regulations.
Legislative frameworks are a key driver for promoting recycling infrastructure and market development activities for products made from recycled materials. In areas where the cost of landfill is high, i.e. a waste levy is in place, there is incentive to recover materials and avoid disposal costs. Resource recovery exemptions and the introduction of the requirement for pre-treatment or sorting of wastes prior to landfilling in some states also contribute to driving recovery rates upward.
Other factors include the introduction of specifications for the use of recycled products and green purchasing policies to support the development of markets for recycled products along with product stewardship and industrial ecology programs.
It can be done - a local success story
The Sydney Industrial Ecology Network (SIEN, facilitated by Edge Environment) a NSW EPA Waste Less, Recycle More initiative funded from the waste levy, has successfully modified the practices of demolition contractors in the Sydney CBD, increasing resource recovery rates from building defit churn from a standard practice of 20% recovery to an industry-wide target of 80%.
This was achieved through workshops, investment in establishing new markets for resources, development of guidelines, demonstration projects, negotiations of policy and awareness raising activities.
The SIEN is continuing to explore alternatives to resource disposal along with product stewardship. (A report from the Governor Macquarie Tower Defit Trial is available at http://bit.ly/1P7u6K6)
What else can be done to maximise recovery of these readily recycled materials?
Efficient processing pathways for source separated materials are already well developed so the opportunity lies in the recovery of mixed waste and the residual fraction from source separated processing facilities.
STEINERT’s range of magnetic separation and sensor sorting solutions are ideally suited to maximise the recovery of high value raw materials such as metals, wood, plastic or paper from a mixed waste stream. Alternatively, should a higher order use for residual materials not exist, STEINERT’s range of sorting machines can also be utilised to prepare materials for energy recovery processes in place of fossil fuels i.e. refuse derived fuel.