‘Demand will only grow’: High quality OTR tyre recycling feedstocks fuelling greener tyres and a greener supply chain
As thermal conversion tyre recycling and refining technology transforms stockpiles into valuable commodities, Kal Tire’s Mining Tire Group is shifting end-of-life tyres and the tyre side of reclamation from environmental challenge to circular opportunity.
When a mining tyre is recycled by way of thermal conversion, the list of recovered outputs is simple but valuable: alternative fuel, steel and carbon black. Nearly a decade ago, Kal Tire’s Mining Tire Group began its journey of developing the technology to give those base elements their highest and best use, and promote a circular economy. Today, Kal Tire’s mining tyre recycling facility in northern Chile uses heat in the absence of oxygen to process ultra-class scrap tyres in thermal reactors. A full load, five 63-inch tyres, generates 6,500 litres of alternative fuel, 4,000 kilograms of steel, 8,000 kg of carbon ash, all for reuse in new materials, plus enough synthetic gas to fuel the plant for several hours. Every day, demand grows for such a circular solution to the challenge of mining tyres – and that high-value feedstock.
That’s why Kal Tire recently took their solution a step further, developing specialised technology to refine one of its key outputs, carbon ash, to create recovered carbon black (rCB).
“Tier 1 tyre manufacturers and compounders are taking strides to reduce the carbon footprint of tyres, and that means demand for high-quality recovered carbon black,” says Terry Galvin, VP, recycling services, Kal Tire’s Mining Tire Group. “Developing a secondary refining process was the only way to ensure the rCB would meet our own standards as well as the quality requirements of tyre manufacturers.”
Just as Kal Tire had to develop the OTR tyre thermal conversion recycling technology and equipment to bring mines a practical and sustainable solution to the challenge of scrap tyres, the company has also invested in research and development to refine its carbon ash into high quality rCB, to meet the specifications required by tyre manufacturers and compounders.
Working with a Canadian firm, Kal Tire and engineers designed a bespoke reactor for its upgrading line in Chile where teams heat, mill, dry and package. It’s a new process that purifies and upgrades the carbon ash.
“We have developed a very efficient method,” says Galvin. “The only emission is the synthetic gas that we use to fuel the reactors.”
A full load of carbon ash going into the refining process is 8,000 kilograms, derived from the conversion of five 63-inch tyres, with the upgrading process consisting of heating, milling, pelletising and cooling.
With four years of successful operations recycling end-of-life tyres underway, Kal Tire now has a healthy stockpile of carbon ash to begin refining.
“The output quality meets, and in some cases, exceeds the quality specifications required by tyre manufacturers and compounders, so it’s been incredibly rewarding for our team to be a part of the continued development of rCB as a commodity for the future,” says Galvin. “With both recycling and refining, we continue to demonstrate our commitment to solutions at the top of the recycling hierarchy.”
Reaching initial targets for yield quality was just the beginning. To continue to ensure yields are managed and optimised, the Chile facility unites a team of petroleum, chemical and thermal conversion engineers.
“There is world-class technology at work here, but it’s also the people – a whole team of passionate, experts – behind all of these great results.”
In 2023, the recycling facility received International Sustainability and Carbon Certification (ISCC) PLUS certification verifying that feedstocks are circular. That certification was renewed in 2024, and again in 2025. The ISCC program demonstrates to downstream markets that Kal Tire’s outputs (reclaimed oil, steel, carbon ash and syngas) are 100% derived from waste materials and traceable.
“More and more organisations are prioritising sustainable supply choices and they’re also looking for proof,” says Galvin. “Third-party validation from ISCC provides downstream markets confidence that these are genuinely sustainable, circular materials. It’s exciting to consider the impact we are making with the end-of-life tyres we’ve recycled in Chile, and now the carbon ash we’ll be refining, helping our customers to create a greener and more transparent supply chain.”
While Chile, home to some of the world’s largest copper mines, was selected as the first region for a facility to begin using Kal Tire’s thermal conversion and refining technology – the broader goal is to help other mining regions understand that there is a viable, scalable solution to address the longstanding challenge of mining tyre stockpiles.
“Mining companies are actively seeking sustainable alternatives.”
Today, in many mining regions, the primary options for scrap tyres are stockpiling or shredding to create rubber crumb. Unfortunately, these solutions lead to landfilling at some point in the future and, in most cases, once a tyre leaves the mine site, traceability is lost.
“Maintaining chain of custody from the mine site to its next use in a recycled product is key. That transparency allows mines to report back to stakeholders with confidence. They want to see that chain of circularity and meaningful reuse.”
In Chile, the introduction of tyre recycling legislation brought a collaborative approach among stakeholders, including mines and Kal Tire, to develop this long-term solution beyond shredding.
“Any region that can bring the right stakeholders to the table has a chance to create its own circular success story – and beyond incentives and policy, progressive reclamation gives mines a strategic path forward in pursuit of sustainable solutions to end-of-life tyres,” says Galvin.
Progressive reclamation is an approach that sees mines planning for reclamation throughout the life of a mine – not just at closure. By drawing on reclamation reserves now, mines can get a head start on the significant process of tyre recycling, often one of the more resource-intensive tasks during reclamation.
“Tyre recycling doesn’t have to come out of a mine’s operating budget,” says Galvin. “It fits within the remediation or reclamation budget. By accessing those funds now, it’ll be more manageable and more cost-effective than waiting until years down the road.”
With proven technology, a source of funding and demand from downstream markets, tyre recycling is more feasible than ever, but it takes time and commitment across the board.
“Getting input and action from all the stakeholders – government, tyre manufacturers, offtake partners, environmental groups – is critical,” says Galvin, of Kal Tire’s experience in Chile. With such a rich mining history, the country’s stockpiles once represented an enormous environmental challenge. Now, however, Chile is benefiting from the chance to become an exporter of high-demand, high-quality circular outputs. “That demand is only going to grow.”
