LAS VEGAS (September 25, 2012) – Today at MINExpo in Las Vegas, Michelin unveiled a new line of underground mining Earthmover tires called the XTXL. The demands of underground mining require machinery to operate in extremely arduous conditions of use. Space for maneuvering, loading and unloading is restricted and poorly ventilated, temperatures are high, and driving conditions are precarious because of bumps, holes, rubble, various deposits and sometimes water.
The Michelin XTXL provides a solution for all of these requirements:
X for Radial.
T for Transport.
XL for Xtra Load and Xtra Life.
The MICHELIN XTXL is available in size 35/65R33. Additional sizes of MICHELIN XTXL will be offered in the future for a wide range of underground mining transport machines.
The tire responds to demand for greater productivity that results from machines with greater load capacity. The 35/65R33 XTXL is designed to support transport equipment with up to 60-tonne load capacity.
The new MICHELIN XTXL is ideally suited for the latest-generation underground mining dump trucks, such as the Atlas Copco MT6020 and Caterpillar AD55B.
Beginning in October 2012, the MICHELIN XTXL will be utilized as the exclusive original tire fitment on the Atlas Copco MT5020 and MT6020.
Compared with the 35/65R33 XLDD1 tire that could carry 24,300 kilograms per tire with pressure of 6.5 bar, the XTXL can carry 29,000 kilograms per tire inflated to 8 bar[1].
The tire’s ability to transport increasingly powerful machinery and their payloads is one of the keys to improving mine productivity. The latest generation of vehicles for underground mining can deliver productivity gains of 20 to 30% in terms of ton kilometer per hour. This can mean an additional $500,000 per month in gold ore transported for just $3,000 more in fuel costs[2]
In addition to providing significant productivity gains, thanks to its superior load capacity and longer lasting casing and tread, the MICHELIN XTXL also improves two other crucial aspects of mining operations:
- Safety. The MICHELIN XTXL is more resistant to impact, cuts and scrapes and easier to mount on the rim.
- Respect for the environment. The MICHELIN XTXL uses fewer raw materials while its greater longevity has a direct impact on recycling. In addition, the manufacturing process for Michelin tires has been optimized for greater environmental protection. All Earthmover production plants are ISO 14001-certified and their environmental footprint has been reduced by 22% since 2005.
The robustness of the MICHELIN XTXL is due to a range of features especially designed to stand up to the difficult operating conditions in underground mines:
- Wide tread blocks and a solid center rib provide resistance to aggressions, increasing longevity and protecting the casing.
- Protective ribs on the sidewalls enhancing abrasion resistance.
In terms of design, the XTXL offers an unparalleled combination of load capacity and aggression resistance in its segment. Thicker metal wire in the casing ply enable the tire to operate at higher pressure and increase load capacity by 20%.Several steel-reinforced protective plies offer greater resistance to impact damage and decrease the likelihood of a puncture by 20%[3]. Lastly, a thermal underlay at the base of the tread and cooling elements in the shoulders speed the cooling process to maintain the tire’s working potential and thus aiding productivity.
Reinforced with B2 technology
Michelin’s proprietary B2 technology strengthens the bead area, providing greater endurance and longevity under heavy loads and high-torque conditions.
Both internal bead structure and external contact area are 30% wider, greatly improving the tire and wheel contact points and eliminating rim slip. The improved design allows up to 20% more engine torque to be transmitted to the ground[4]. A tire that slips too much on the rim can be irreparably damaged long before it is completely worn. Eliminating this slipping effect can potentially double the life of the tire[5].
B2 technology also has a direct impact on fuel consumption and emissions of CO2 and other pollutants as well as on the overall environmental cycle, since longevity means fewer raw materials used upstream and less material to be recycled downstream.
Tire maintenance operations are also reduced, which also has a direct effect on mine productivity.
What’s more, B2 technology is fully compatible with traditional rims and requires no additional operations when mounting or dismounting tires.
Thanks to this technology, the MICHELIN XTXL has a high ton per kilometer per hour (TKPH) rating of 250.
[1] For Underground Mining applications.
[2]Interview with Troy Cole, Mining Manager at Stawell Goldmine, Australia, in the February 2008 issue of International Mining
[3]In-house Michelin test, compared with a previous-generation MICHELIN XLDD1 tire and conducted in underground mining conditions.
[4] In-house Michelin test, compared with a tire integrating conventional bead wires.
[5] In-house Michelin test, compared with a previous-generation MICHELIN XLDD1 tire and conducted in underground mining conditions