OTR Tyre Recycling for Australian Mining: Processing Haul Truck Tyres

By:     Conor Murphy

The Scale of the Australian Mining Tyre Problem

OTR tyre recycling for Australian mining presents waste management challenges that no other sector comes close to matching. A Caterpillar 797F haul truck, the workhorse of large open-cut mines in the Pilbara, Bowen Basin, and Hunter Valley, runs on six tyres each measuring approximately 4 metres in diameter and weighing around 5,300 kg. A single tyre change produces over five tonnes of rubber waste. A fleet of 100 such trucks, typical at a large iron ore mine, generates hundreds of these giant tyres every year.

Even at more modest mining scales, the OTR tyre waste stream from Australian mining is extraordinary by global standards. Iron ore, coal, gold, copper, and bauxite operations all generate OTR tyre waste from haul trucks, loaders, scrapers, graders, and ancillary equipment. The combined annual weight across the sector runs into many thousands of tonnes.

The physical scale creates problems at every stage of the waste chain. Standard collection vehicles cannot transport large haul truck tyres without specialist equipment. Standard processing facilities cannot handle OTR tyres without dedicated cutting and size reduction machinery. The remote locations of many Australian mines add another layer of difficulty, with transport distances to processing facilities that make conventional collection economics extremely difficult to justify.

Gradeall International has developed and supplied OTR tyre processing equipment specifically for the mining sector, with the OTR tyre sidewall cutter, OTR tyre splitter, and the broader tyre recycling equipment range designed and built for the size and structural demands of OTR mining tyre processing. With nearly 40 years of manufacturing experience and equipment in over 100 countries, including major mining nations, Gradeall’s OTR equipment is designed for the reality of mining tyre processing rather than theory.

The Challenge of Haul Truck Tyre Dimensions

Understanding the engineering challenge of processing mining haul truck tyres requires an appreciation of their physical properties. These are not simply large versions of car tyres; they are fundamentally different in construction, materials, and the mechanical forces required to process them.

Dimensions. Large haul truck tyres for 240-tonne class trucks (Caterpillar 797, Komatsu 960E) use tyre sizes in the 59/80R63 range, with loaded tyre heights approaching 4 metres. Even medium-scale mining truck tyres in the 27.00R49 range are over two metres in diameter and weigh over 900 kg each.

Construction. Mining OTR tyres feature multiple steel-belt layers and a steel-reinforced sidewall construction, making them significantly more robust than highway truck tyres. The steel content as a proportion of total tyre weight is high, and the gauge of the steel reinforcement requires cutting equipment with substantially greater force capacity than equipment designed for highway truck tyres.

Volume when intact. A single intact large-haul truck tyre occupies a large volume of storage and transport space. Multiple intact large OTR tyres quickly exceed any practical storage capacity at a mine site, driving the need for on-site volume reduction before collection can be organised.

On-Site Processing: The Practical Solution for Remote Mines

For mines more than a few hundred kilometres from a tyre processing facility, reliance on third-party collection of whole intact OTR tyres is often economically unviable. The transport costs of moving large, low-density rubber objects over long distances exceed the processing economics at the receiving facility. This creates a compelling case for on-site processing at the mine site to reduce tyre volume before collection.

On-site volume reduction through sidewall cutting and splitting transforms intact OTR tyres into sections that pack more efficiently onto transport vehicles and are manageable by downstream processing equipment. A single intact 59/80R63 haul truck tyre that would occupy the majority of a flatbed trailer becomes, after sidewall cutting and splitting, several flat sections that load efficiently and transport at much lower cost per tonne.

Gradeall’s OTR tyre sidewall cutter. The OTR tyre sidewall cutter removes the sidewalls from large OTR tyres, separating the relatively flexible sidewall sections from the heavier tread band. This significantly reduces the tyre’s height profile and separates it into sections that can be handled individually. For very large tyres, sidewall cutting is the first step in size reduction before further processing.

Gradeall’s OTR tyre splitter. The OTR tyre splitter cuts the tread band section of the OTR tyre into smaller pieces, further reducing the volume and making sections manageable for handling, storage, and transport. The combination of sidewall cutting followed by splitting produces OTR tyre sections that can be collected and transported to processing facilities much more efficiently than whole tyres.

Operating at mine sites. Equipment deployed at mine sites for OTR tyre processing must be suited to the operational environment of a working mine. This means robustness against dust and vibration, compatibility with mine site power supply specifications, operator safety design consistent with mining safety management systems, and the ability to handle the largest tyre sizes the mine operates. Gradeall’s OTR equipment is designed for industrial operating environments, including mine sites; site-specific deployment requirements should be discussed with Gradeall at the specification stage.

Processing Routes for Australian Mining OTR Tyres

After on-site size reduction, the sections of processed OTR tyres need a destination. The available processing routes for Australian mining OTR tyre sections:

Shredding to crumb rubber. OTR tyre sections fed to shredding equipment produce crumb rubber and recovered steel. The high steel content of OTR tyres means steel recovery is a significant by-product revenue stream from OTR processing. The crumb rubber from OTR tyres can be used in the same applications as crumb rubber from car tyres, though the different compound formulation of OTR tyres (typically less synthetic rubber and a different carbon black specification) may affect properties in specific applications.

Pyrolysis. OTR tyre sections are suitable feed material for pyrolysis reactors that accept pre-processed tyre material. The pyrolysis route produces oil, recovered carbon black, and steel from the OTR rubber. For mines near emerging pyrolysis facilities, this route may become increasingly viable.

Civil engineering field. Cut sections of OTR tyre sidewalls and tread bands can be used as fill material in certain civil engineering applications. Whole-tyre baling to PAS 108 is not applicable to large OTR tyres, but engineered use of cut tyre sections in drainage, erosion control, and embankment applications has been investigated. Site-specific engineering assessment is required for these applications.

Landfill (where permitted). Processed tyre sections can be disposed of at a landfill in jurisdictions where this is permitted. Several Australian states restrict or prohibit whole tyre landfill; processed sections may be accepted depending on state regulations. Landfill should be the last resort after all viable recycling routes have been assessed.

The Regulatory Context for Mining Tyre Management

Australian mining operations are subject to both state environmental regulations (administered by state EPAs) and mining-specific safety and environmental requirements (administered by state mining departments and resources regulators such as the Department of Mines, Industry Regulation and Safety in WA).

Mine environment plans and mine closure plans submitted to state resources regulators typically include waste management provisions covering OTR tyre disposal. Mines with environmental authorities or approvals from the EPA may have conditions specifically addressing tyre stockpile management, maximum storage volumes, and required disposal routes.

The Tyre Stewardship Australia scheme covers OTR tyres within its PCTE conversion framework; large OTR tyres have high PCTE conversion factors reflecting their rubber mass. TSA recycler payments for accredited processors handling OTR tyres reflect this higher PCTE value.

Environmental compliance at mine sites requires that tyre stockpiles remain within approved storage limits, that waste tyre movements are documented with appropriate waste transport records, and that disposal routes are through authorised parties. Non-compliant disposal, including burning tyres on-site (a practice that occurs at some remote operations due to collection cost), is an environmental offence with potentially severe consequences for mine operators and their environmental approvals.

“Mining OTR tyres are among the most demanding material handling challenges in the tyre recycling industry,” says Conor Murphy, Director of Gradeall International. “The physical scale requires purpose-built equipment; you cannot process these tyres with equipment designed for highway trucks. We’ve been developing OTR processing equipment for mining applications for many years, and our range covers from medium-scale mining tyres through to the largest haul truck sizes.”

Contact Gradeall International for OTR tyre processing equipment for Australian mining operations, including the OTR tyre sidewall cutter, OTR tyre splitter, and associated handling equipment.

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