MMG’s Dugald River underground zinc mine 65 km north-west of Cloncurry in Queensland, Australia is tackling how to recycle End-of-Life (EOL) tyres, with a solution to the age-old problem of sending re-usable materials to landfill. The mine annually generates about 920 EOL tyres from vehicles and trucks. Currently Australia disposes of over 60,000 t of EOL tyres by exporting them. Some 100,000 t are stockpiled in landfill or onsite (mostly by the mining and agricultural sectors) according to global advisory firm, Energy Estate.
With the Council of Australian Governments’ agreed ban on used tyre exportation from December 2021, Australia faces a growing tyre stockpile problem. Dugald River and its mining contractor Barminco have investigated alternative tyre disposal, supporting a joint venture (REVYRE) program with Energy Estate and InfraCo. A proposed recycling process breaks down and repurposes the tyres into a high value polymer product fit for tyre manufacturing and clean high tensile scrap steel.
The REVYRE recycling process “is chemical and solvent free with near zero waste and emissions or by-products making it an environmentally friendly technology.” REVYRE is also looking at renewable energy for its operations. This aligns with its low carbon footprint aspiration while reducing the environmental impact of tyre production. Barminco and MMG say they are proud to support this responsible initiative. A number of REVYRE plants are planned for each Australian mainland state supporting new jobs made possible from the development, construction and operation of the sites. The new plants have the potential to further reduce the carbon footprint burden that came with EOL tyres being previously recycled in Victoria.
The Dugald River team has encountered some challenges with on-site EOL tyre storage as it complies with environmental authority requirements. However, MMG says the team is committed to the smart recycling project and is also looking to reduce other waste streams such as single use plastics.
In the latest REVYRE newsletter from June 2021, the group says it has made considerable progress in the last six months in regards to its facility in the Mount Isa region of Queensland. There is an agreement in place with Economic Development Queensland to acquire to acquire the first Australian site. The site is located within the Nordale Industrial Precinct. REVYRE has received a number of Letters of Intent from major mining companies in the region who have agreed to supply feedstock to the plant once it is operational. The vision for the Mount Isa site, as a flagship for REVYRE in Australia, is that it will deliver on emissions- free solutions for the users of OTR tyres regionally and create re-skilling opportunities, training opportunities and new enduring jobs.
REVYRE has also been selected as a project for inclusion in Beyond Zero Emissions’ Renewable Energy Industrial Precincts (REIPs) proposal for the Hunter and Gladstone regions. The REIPs are designed to support domestic manufacturing opportunities and drive regional economic development through sustainable and renewably powered technologies. The REVYRE plant in the Upper Hunter region will be located within an industrial estate to be developed on the land currently occupied by one of the first coal mines in Australia. This site is owned by Idemitsu Australia Resources (IAR), the large Japanese resources company and the coal mine is scheduled for closure in 2022. The industrial precinct forms part of their redevelopment plans which will transform the existing mine into the Muswellbrook Energy, Training and Industrial Precinct.
REVYRE says it has narrowed down sites based on the following requirements:
- Strategic location close to feedstock supply
- Easy access to a port
- Access to logistic routes
- Repurposing existing industrial sites (where possible)
The current sites will support local mining and industry operations and will generate employment and regional development for the local economies. The update highlighted current priority sites as Mount Isa, Queensland; plus Hunter and Wollongong in New South Wales. Australian “pipeline” areas are listed as the Pilbara & Kalgoorlie in WA; Parkes, New South Wales; Port Pirie in South Australia; and Gladstone, Queensland.
Looking at New Zealand, its Ministry for the Environment has put in place the Resource Management (National Environmental Standards for Storing Tyres Outdoors) Regulation 2021 (NES) that take effect from 20 August 2021.The standards create a method by which all regional councils can manage the environmental and health risks associated with end-of-life tyres stored or discarded outside and is applauded as it provides a consistent, national approach, and thus avoids the need for a region-by-region set of regulations. Tyrewise (the NZ industry-led framework for a mandatory stewardship programme for end-of-life tyres) is strongly supportive of the objectives of the NES as the regulations provide another mechanism for collectors, transporters and processors of end-of-life tyres to ensure they are compliant with the Resource Management Act. REVYRE has a NZ priority site marked as Tokoroa and a pipeline site as Whakatane.
Lastly the group gives its views on the plus side of the REVYRE process versus pyrolysis. They argue that REVYRE is the “only true circular economy rubber resource recovery process available that brings together two award winning tyre recycling technologies for the first time.” REVYRE “does not alter the beneficial material properties of the rubber or steel and does not degrade or dematerialise those materials” so the “economic value and use of resources used to make a tyre – natural rubber, synthetic rubber, water, energy, labour, land use – are all preserved.” No chemicals are used in the process and no toxic by-products produced. It produces “high-purity, high-value rubber powder or TDP that meets the stringent supplier specifications” and “saves carbon emissions, energy and water by substituting new natural or synthetic rubber in tyre production. Due to the quality of the REVYRE products and the high-value to end users, the business case for a REVYRE plant requires no substantial gate fee as the value of the product and significant export market need pays for the cost of processing.“
One of the technologies used in the REVYRE process is Tyromer Inc’s #devulcanisation equipment, which facilitates the transformation of rubber granules into Tyre Derived Polymer (TDP). Tyromer Inc. was founded in Canada and developed its technology out of the University of Waterloo. Recently, the European branch of the company Tyromer Europe (TyrE) announced its newest site in Arnhem, Netherlands. The plant is set to be operational “by mid-2021” and will employ approximately 12 local people. Tyromer says its process uses “a supercritical, carbon dioxide assisted, thermal-mechanical extrusion process” to continuously convert scrap tyre rubber into TDP.
