Turning used mining tyres into a resource

Kal Tire is developing a mining tyre recycling facility in Chile that could end up being an opportunity that also emerges in Australia.

Tyres are one of the final frontiers of waste management at mine sites.

Somewhere at every mine there will likely be dozens, if not hundreds of tyres piled up in a waste dump after reaching the end of their operating lives.

Imagine if mining companies had no need for these piles of waste and they could instead convert them into a resource for reuse.

This reality is emerging in Chile where Kal Tire will commission its first thermal conversion tyre recycling facility at Antofagasta in the fourth quarter of 2019.

Chile, a jurisdiction that Kal Tire has operated in for more than 20 years, represents a prime location for the Canadian company to launch the initiative.

The South American country is home to many of the world’s largest copper mines, which have disposed of an estimated 500,000 tonnes of scrap tyres in recent decades.

Chile’s government first acted on this environmental concern in 2012, starting discussions to introduce tyre recycling legislation.

From 2021, the legislation will become law, with 20 per cent of all mining tyres to be recycled to start with, before this percentage progressively ramps up in the following years.

In spite of Chile’s moves, Kal Tire had ambitions to develop a solution that allows recycled tyres to be recovered for use in other products or reused for the same purpose, for example, steel to steel or fuel oil to fuel oil.

Thermal conversion, which uses heat in the absence of oxygen to decompose organic materials and turn tyres into steel, carbon black and oil, offered the ideal technology for these aspirations.

By 2015, Kal Tire was developing a relationship with the Chilean Government and started to design its first thermal conversion facility with engineering partners in Italy.


Kal Tire’s tyre conversion facility, designed in Italy.


Four years later in May this year, the company broke ground at the Antofagasta site where a 20,000-square-metre plant with the capacity to recycle 20 tonnes of tyres each day is being constructed.

Kal Tire director of recycling services Scott Farnham views mining tyres as the last key waste stream that mine operators need to find a management solution for.

“Mining companies don’t pile their garbage up but with tyres it has been okay up until now because there has not been a solution,” Farnham says.

“We really want to get a circular economy going with mining tyres. Scrap tyres are a valuable commodity because of what is in the tyre. This process (thermal conversion) can extract the materials.”

A 63-inch mining tyre, for example, comprises four key materials after thermal conversion – carbon black (1600 kilograms), steel (750 kilograms), oil (1900 litres) and gas (350 cubed metres).

The oil can be upgraded to diesel, which could potentially fuel the mining trucks that had the tyres previously running on them.

Carbon black also has many uses, the main being used in the production of tyres and plastics. Another use that stands out to Farnham is its value as an ingredient in rechargeable batteries, an emerging driver of mining machinery.

“For me, personally, I see electrification of transportation, whether it’s skate boards or mining trucks, as the future,” Farnham says.

“We want to add value to waste streams and battery material is going to be in high demand, and lots of it.

“Every major manufacturer is releasing a half dozen new electric models – it is amazing. The potential to be part of that supply chain is very interesting.”

An independent study has also shown that Kal Tire’s solution for the production of recycled carbon black, steel and diesel generates significantly lower carbon emissions compared with the output of conventional materials.

Australia may not have official plans to introduce mining tyre recycling legislation, but the country’s mining industry does present a similar opportunity to Chile, given the scale of local mines and the number of tyres being used.

A growing push for Australian mining companies to become more sustainable is also expected to increase the focus on initiatives such as tyre recycling.

Kal Tire Australia managing director Darren Wilson believes it isn’t just the development of government legislation that will push Australian mining in this direction, but also the growing need to be more socially responsible.

“It will certainly help customers be more sustainable, in terms of the requirements they are going to have, whether it is legislation or corporate responsibility within their own organisations and the communities they work in,” Wilson says.

“We can potentially provide them with not only a solution around sustainability, but also a value add back in either fuel or carbon black.

“We won’t be coming to the market here with something that is a hypothetical either, so we are starting to make the Australian market aware that there is a solution for mining tyres when there hasn’t been before.”

Traditionally, shredded mining tyres have sometimes been shipped to countries with less restrictive emissions standards to be burned and then used as tyre-derived fuel to replace coal.

In other cases, used tyres have simply gone to ground as landfill with no other alternatives being available.

Kal Tire’s recycling program provides not only an improvement on these methods, but also an alternate way to power mining operations in the future.

“If we can send the materials of mining tyres back to the mine in place of something they are already buying – like diesel with recovered diesel – how good a story is that,” Farnham concludes.

This article also appears in the October–December edition of Safe to Work.

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