Construction and demolition (C&D) waste will need to do the heavy lifting if Australia is to reach an 80 per cent average recovery rate from all waste streams by 2030, according to Daniel Webber, CDE Regional Manager for Australasia.
Daniel calculates the sector should be aiming for more than 90 per cent recovery as hitting national targets proves problematic for other waste streams.
C&D is a large proportion of the waste generated in Australia through infrastructure development and building activities, so there are strategies already in place for it to be recovered and recycled.
The major hurdles in achieving the more than 90 per cent recovery, as Daniel sees them, will be tackling the dirty, or heavily contaminated, materials and reaching regional areas. To achieve that will require technology and capital.
“At the moment, the really dirty materials aren’t viable to process,” Daniel says. “But CDE is investing heavily into waste and recycling technology to tackle difficult contaminants, such as plastics and masonry, so we can recover more resources.
“In regional areas it’s not the tech, it’s the capital that we need to overcome. How can we deploy recycling systems that are well suited to the volumes of waste that regions will have?”
CDE’s wet processing solutions are used across a range of materials within the waste recycling sectors. In construction and demolition waste alone, the company has assisted customers worldwide to reuse more than 100 million tonnes of waste material.
Daniel says the aim is to maximise high value recycled sand and aggregates which can then be used as a replacement for natural materials in a range of construction applications including concrete and asphalt production.
He says there’s a growing demand for sand and aggregates from a sustainable source as natural reserves decline.
Sand required for the construction industry needs to have been exposed to wave action. It’s the constant thumping of waves that gives it sharp edges and makes it ideal as a binding agent. Sand in the middle of a desert, or dune sand, has been exposed to wind which softens its edges and makes it unsuitable.
“While the world has a lot of sand, not a lot of sand is able to be used in the construction industry,” Daniel says. “We are running out of stone and sand as virgin materials. Sand is being carted almost 200 kilometres from Goulburn to meet Sydney’s demand. Bacchus Marsh in Melbourne has almost run out and they’re looking to regional areas.
“If we can take C&D waste and make those materials, it’s a powerful circular economy example.
“But it’s not about sending waste materials back as a B-grade product. As a technology provider our challenge is to make it an A-grade product. To make it as good as virgin materials to go back to its highest possible end use.”
Engineering and technology are evolving to overcome some of the constraints in dealing with heavily contaminated C&D waste and soils containing hydrocarbon and per- and poly-fluoroalkyl substances (PFAS).
CDE is also making inroads in delivering solutions for regional areas. It recently developed a C&D processing system for Waters Excavations in Mildura, in Victoria’s north-west, about 550 kilometres from Melbourne.
Owner Michael Waters says the system, capable of processing up to 80 tonnes of waste an hour, is not massive, but is versatile.
The brief was to design a plant capable of producing three types of aggregates and two sands that could be used back in the local construction industry. And it needed to process a range of different materials.
One of the plant’s main features, Michael says, is the ability to scrub aggregates of clay and float off lightweight contaminants such as leaves, sticks and light plastics.
“It’s been a real success,” he says. “I’m blown away with the level of contaminants we were able to remove from the waste stream and how clean the end products were.”
It’s a solution that could be replicated throughout regional Australia, which would have huge environmental benefits, Daniel says.
Any regional area with a road sweeping contractor, a hydra excavation business or a batch plant, already has three potential feedstocks for a C&D waste processing facility.
“If you’re starting to get a few of those services and contractors within a town and regional cities, the chances are there’s material that can be recycled that is probably going to landfill,” Daniel says. “If engineering partners like us can make a solution that is flexible in the materials it can handle, then the sky’s the limit.”
For more information, visit: www.cdegroup.com
.png){kind=small}
