Material Handling Conveyors Go Green

Giant mining tires and conveyor belts are made of high-performance rubber and, due to perceptions that recycled rubber cannot effectively replace virgin rubber in tangible amounts, these materials have, historically, presented a sustainability challenge within the tire and rubber industry.

Waste off-the-road mining tires (wOTR) pose significant sustainability challenges due to the high costs and logistical complexities that come with them. In some cases, only 6 tires can be shipped on a single transport truck. These are highly engineered products, comprised of natural and synthetic rubber compounds, numerous reinforced protection ply layers, and steel belts. A single haul truck tire can weigh up to 5 metric tonnes (11,000 pounds), stand 15 feet tall, and contain enough steel to make a small car. However, tough as they are, like all tires, these tires wear out, and in Canada alone, thousands of them need to be replaced annually. With no national or international mining tire recycling programs or commercially viable recycling opportunities currently available, worn-out tires represent one of the largest sources of industrial waste generated by mining operations.

While some companies are actively repurposing retired OTR tires for temporary uses like building retaining walls or civil engineering projects, around 80% of companies either stockpile or dispose of these tires in landfills. This has created an enduring challenge, OTR tires do not biodegrade due to their chemically inert constituent materials. Whether they are left on-site or placed in landfills, OTR tires are not going anywhere.

The Teck team undertook a lot of research. They looked at vendors capable of downsizing a 5-ton, 15 ft high giant mining tire. They studied the technologies available to reclaim or regenerate the rubber. Technologies — devulcanization, waterjet, thermal conversion (pyrolysis), micronization, as well as other tier 2 and tier 3 options to recycle giant mining tires. These were researched and then ranked in terms of which options were the most environmentally friendly — zero waste and discharge, energy used to recycle, GHG friendly. Ultimately devulcanization and waterjet technologies were two the team chose to pursue.

It was important to find the most environmentally friendly and sustainable way to transport the tires. This was accomplished by implementing backhauls or trucks that were going back empty and by using rail to transport materials. This accomplished, the team also set out to upcycle the rubber crumb so that it was not merely being used as landscape mulch or for making rubber mats. Their objective was to displace virgin rubber being imported and ultimately this rubber crumb was reclaimed using devulcanization and partially replaced virgin materials.

The goal was to develop a technology that would reclaim the waste into a quality rubber which end users would buy, compound and permanently adopt and, using the Tyromer technology to develop tire-derived polymer (TDP), and remarkably, they did just that.

Collaborating with strategic partners, Teck worked with Liberty Tire to mechanically separate OTR tires, recycle steel components, and provide the residual crumb rubber. Teck then upcycled this rubber crumb using Tyromer’s devulcanization technology to bring the spent crumb rubber back to life.

Fenner Dunlop then integrated the team’s TDP into new conveyor belts, after compounding and rigorous testing phases. These belts were put to work and monitored at one of Teck’s mining operations in BC, but getting to that stage was no mean feat. Convincing both management and maintenance personnel required persistence and technical guarantees from the manufacturer because a lot is riding on these tires.

After all, a premature failure causing downtime at Canada’s largest open-pit copper mine would be costly, and impact adoption and any future pilots.

After the initial pilot, the initiative expanded with belts being tested at multiple Teck sites and, depending on the application, monitored for abrasion resistance and performance. The success of these initial efforts provided confidence to develop a new fire-retardant compound to expand the product line. This required CSA certifications from a third party, and the end result, after stringent testing, was the manufacture of a 3,368 ft conveyor belt weighing 63,318 lbs, installed at one of Teck’s mining operations.

The success of their CSA-C fire-retardant belt has encouraged a third-party mining company to purchase and install a conveyor belt at one of their operations in Canada.

Teck’s innovative but careful approach to the task they set themselves is what enabled them to work collaboratively with industry giants like Michelin, Fenner Dunlop and Continental, shifting perceptions within the conservative tire and rubber sector. Proving that regenerated rubber can indeed replace virgin rubber in substantial quantities is a game changer, reducing the environmental footprint of mining operations and promoting circular economy principles in industrial manufacturing.

In addition to achieving sustainability objectives and contributing to the circular economy, Teck’s innovative pilot projects have set new industry standards and proven the concept of transforming waste into valuable resources. These efforts help prevent deforestation associated with rubber cultivation by providing a sustainable domestic alternative to imported rubber, contributing significantly to Canada’s manufacturing sector’s reduced reliance on foreign materials.

Sometimes “What goes around comes around” is a dire warning, but coming from Teck Resources Limited, it’s a very hopeful start.