A seminar organised by the Australian Industry Group (Ai Group) for industry and waste management experts in Newcastle earlier this month put on show many imaginative and effective approaches to the waste crisis that is confronting businesses both locally and across the developed world.
While the challenges are enormous, speakers with a cross-section of interests and expertise perceived an optimistic future for the re-use of wastes into new materials and products. They were all confident that for every recycling problem to be solved, an engineering solution could be applied. The challenge for policy makers is to ensure that good engineering solutions are financially sustainable.
Brett Allan, General Manager Supply Chain and Strategic Sourcing at the locally based global mining consumables and services provider,Molycop, observed: “The age of cheap and abundant materials has come to an end. Many of the world’s major mines are going deeper and providing lower yields. Recycling is no longer a feel-good option, it is a necessity.” Molycop is re-using two waste streams in its steel-making process for railway wheels and axels and grinding media:
- Injecting pelletised rubber from scrapped car tyres into their Electric Arc Furnace at 1550 degrees Celsius as a replacement for coke (a very polluting substance to make). The rubber is cheaper, has a higher heat content and creates less waste.
- A mixture of wire from scrap tyres and mattress springs is compressed into bales and used as steel feedstock.
The inventor of the rubber pellet process (called Thermal Micronising) is Laureat Professor Veena Sahajwalla from the SMaRT Centre at the University of NSW. Professor Sahajwalla is a world expert on the re-use of industrial wastes and is working with several Hunter organisations on re-use opportunities.
The SMaRT Centre is operating a number of Microfactories to identify the most cost-efficient way of extracting valuable materials from e-waste. Australia is a big consumer of electronic devices and generates more e-waste per capita than all but four other countries worldwide. In 2016-17 we produced around half a million tonnes of e-waste, and this category of waste is growing fast. Simply disposing of e-waste has been very costly.
However, all devices contain valuable and increasingly scarce materials such as Lithium, Cobalt, Nickel and Aluminium. While the tonnages are small, the value is very high. Professor Sahajwalla noted: “The challenge for scientists and remanufacturers is to drill down to the elemental level and then find a process for the recovery of that element.”
Tim Askew from the Hunter Joint Organisation of Councils (JO) described the work they are undertaking to advance the “Circular Economy” approach to waste. This follows the push-back from China on accepting waste from Australia for recylcing. They are conducting a study which:
- Identifies waste material flows, nature and destinations;
- Mapping which organisations are doing what in the recycling space;
- Identifying what recycled products Local Councils can buy to provide baseload demand for the recycled product makers; and
- Collaborating to facilitate large-scale projects.
Hunter JO welcomed the NSW Government initiative NSW Circular announced on 9th October to support recycling projects and activities across the State.
Tom Woods, Managing Director of TW Woods, described how they had designed and built a construction waste sorting plant for a client in Western Australia. Using the best equipment available, TW Woods has been able to build a very robust plant that will have a long working life. It mechanically sorts bricks, gravel size concrete, soil, steel and plastic. Only timber is manually sorted.
Ai Group contributed to the discussion in a number of ways. Our preliminary survey of regional manufacturers identified key waste streams of one-way pallets, oily waste, rubber hoses and soft plastics. These all have potential for recycling and reuse. Taking account of the cost of disposal, oily waste became the highest value option for recycling and reuse.
Ai Group also floated ideas for the harvesting and reprocessing of one-way pallets to get more value from new pine wood.
Many ideas were generated in the panel session and Ai Group looks forward to participating in identifying circular economy projects which require application of engineering solutions.
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