part of the solution
one man’s residue is another man’s sand
Did you know that Alcoa has a state of the art global refining research and development group based right here in Australia?
Since 1968 the Technology Delivery Group (TDG) based at Kwinana, WA, has been developing innovative new equipment and processes for cleaner, more efficient production at Alcoa refineries worldwide and consistently helps to solve environmental challenges through new technology.
Alcoa’s leading edge carbon capture is well documented, but did you know that there is a bauxite residue challenge for alumina refineries worldwide? As a leader in sustainability, Alcoa is committed to ensuring sustainability solutions are applied to the management and reuse of bauxite residue (what remains after the alumina has been extracted).
The safe storage of bauxite residue on site is a common practice by alumina refineries globally, but where does it go from there? TDG has been working on the development of alternative uses for bauxite residue for over two decades, with the aim of reducing the size of our residue storage areas and delivering useful products back to the community.
Alcoa’s efforts in residue reuse research are well advanced and we are leading this key sustainability issue for our industry. TDG has examined a range of potential uses for the sand and mud components of bauxite residue, including: as a soil amendment for broad use acre farming and horticultural uses; as a sand for use in cement manufacture; in effluent treatment ponds and septic systems; for trace metal retention from road runoff, rubbish tips and acid mine drainage; in ceramic manufacturing; in plastics manufacturing; and for use as a road base.
Reuse of residue sand is already happening within our operations and is another demonstration of residue being put to a sustainable use. Local sand supplies are declining, so our residue sand reuse is a real benefit to Alcoa and the community.
So watch this space, bauxite residue has the potential to become a valuable resource to WA. In fact, the new Perth Bunbury Highway road network is already helping to pioneer a breakthrough in the transformation of bauxite residue.
Two trials by the WA-based Cooperative Research Centre for Sustainable Resource Processing (CSRP) are using treated residue for road base and nutrient filters.
CSRP CEO, Stevan Green, said that the current programs effectively recast by-products as useful materials.
“We have made some major advances in recent years to develop the technology for converting mining and energy sector residues into potentially valuable construction and agricultural materials”, he said.
In the first trial, more than 2500 cubic metres of sand was extracted from bauxite residue and used as road base to widen the Greenlands Road access to the new highway near Pinjarra.
ReSand® is a concept developed by CSRP which assesses the ecological footprint or impact of sand sourced from recovered material, such as mineral residues, compared with conventionally sourced quarry sand. This gives developers, regulators and the community an assurance that the use of these residue materials is in fact the best outcome for the environment and for society.
Mr Green said the recovery of construction sand from mineral residues would have a range of potential benefits including:
“These benefits can lead to reduced costs, less energy and water use and lower greenhouse gas emissions”, continued Mr Green.
- replacement of increasingly scarce supplies of quarry sand;
- reduction in the clearing of natural bushland for sand quarries; and
- reduction in the demand for expensive waste residue containment facilities.
In the second trial associated with the Perth Bunbury Highway, a demonstration “nutrient trap” has been installed by the side of the new road. The trap collects water run-off and removes nutrients such as phosphates and nitrates, to help prevent algal blooms in the surrounding waterways.
The CSRP worked with Alcoa, the Department of Agriculture and Food WA, Main Roads WA, Southern Gateway Alliance, Wallis Water and other project partners to establish these and other projects.
turning waste into gold
Alcoa has been awarded Gold Status on our recertification with Sustainability Victoria’s WasteWise program. Alcoa was the first industry business to receive WasteWise accreditation back in 1999.
WasteWise is a practical, step-by-step program inspiring Victorians to minimise waste and maximise the efficient use of valuable resources. Business can receive WasteWise certification which acknowledges their commitment to a sustainable future and identifies the organisation as an environmental leader.
Our waste reduction achievements in Victoria now span four sites: Anglesea Power Station, Point Henry Smelter, Portland Aluminium and Alcoa Australia Rolled Products Point Henry.
Victorian Operations General Manager, Arnaud Soirat, said the Gold Status is recognition of our focus on waste minimisation and management.
“The payoff for our efforts has been terrific. There are so many benefits beyond simply the waste reduction itself; environmental impacts are greatly reduced, costs are lower and the community involvement is really inspiring.
“There are more than 1800 employees across our four sites and the support has been outstanding. It seems everyone wants to do their bit and that’s what has made the pretty tough targets of WasteWise achievable,” Arnaud said.
“Waste management practices at Alcoa locations are based on a strong recycling ethos. The use of Material Recovery Facilities at our smelters allows us to control what material, and how much of it, leaves our sites.
“Recyclables such as paper, cardboard, plastics, steel, aluminium and other separated materials are checked and packaged before being sent off to the recycling companies. Critical to the success of these systems, is the engagement of the Alcoa workforce in segregation of waste at the source so that recycling rates can be maximised,” he said.
In Western Australia, our waste minimisation efforts continue also.
Our Pinjarra Refinery is home to our very own large-scale worm farm which is significantly reducing the amount of waste we send to landfill.
At each Alcoa site in Western Australia we have 'worm farm' bins, with the contents then delivered to the Pinjarra worm farm. Each year, on average, our worm farm saves about 140,000 kilograms of kitchen waste from going to landfill. Those wrigglers are not only turning rubbish into garden fertiliser - but also giving us the chance to teach young school children, who tour our operations, about a world of new possibilities in our carbon constrained world.
Meantime at our recycling facility in Yennora, NSW, we recycle about half a billion cans a year. We are in fact the largest recycler of aluminium in Australia – recycling in total about 70,000 tonnes of scrap aluminium every year.
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