Waste to Energy: Inside WM New Zealand’s Tyre Recycling Facility in Wiri

“We provide end-to-end tyre collection and recycling services, handling both pneumatic (air-filled) and solid tyres. We collect from a wide range of vehicles, including road vehicles like cars, trucks, buses, motorcycles, scooters, and trailers, as well as agricultural machinery and off-road vehicles such as quad bikes and 4WDs,” says Sunny.

Starting with around 10,000 tonnes of tyres processed in its first year, the facility has now doubled that number in the 2023/2024 financial year.

WM New Zealand’s tyre recycling process transforms tyres into Tyre Derived Fuel (TDF), a high-energy alternative to coal.

“We collect and shred tyres into chips for use as TDF. We currently supply TDF to Golden Bay Cement.”

“Imported coal is expensive, and by supplying TDF we offer a lower-cost fuel while keeping more value within New Zealand.”

The recycling process follows three key stages: collection, transport, and processing.

“We collect used tyres from across the North Island, including Auckland, Northland, Bay of Plenty, and Waikato,” Sunny says. “Depending on the load size, we use appropriately sized trucks to help reduce emissions. The tyres are then transported to our recycling facility in Wiri.”

“Our production team starts by sorting the tyres by type and size. The tyres are then fed onto a conveyor and into the shredding system, which includes two sets of industrial blades—a primary and a secondary shredder.”

“First, the primary shredder breaks them down, and then the secondary shredder further reduces them to the target size.”

“After shredding, the material is screened to ensure it meets specific size requirements, usually 75mm x 75mm or smaller, as determined by Golden Bay Cement for kiln use.”

“TDF needs to fall within a precise size range to be accepted. Generally, the process starts with reducing the tyres to around 50mm x 50mm pieces, or even 25mm x 25mm pieces, depending on the volume and quality needed. If the product doesn’t meet specifications, it’s redirected via a return conveyor back through the shredding process. Smaller tyres, like passenger tyres, may only need two shredding cycles, while larger truck tyres, might require up to five passes to achieve the required size and quality.”

“Once approved, the final product is deposited on the production floor, where conveyor-mounted scales track output and inventory. Lastly, transport partners collect the TDF from the site and deliver it to its end destination, completing the recycling loop.”