In almost any form of mining, abrasion is an ongoing asset-protection issue. Abrasion can rapidly destroy loading and haulage equipment tires, for example, leading to premature and costly replacement, not to mention the potential for vehicle accidents. The same applies to the steel plating on haul truck bodies; if not protected, abrasive material often can rapidly wear down the plating to a point where rebuilding or replacement is necessary long before expected.
Consequently, equipment fleet owners have a high level of interest in finding effective, economical wear-protection solutions. Here are two approaches that offer the prospect of better tire and truck-body service-life longevity.
Sidewalls: A Truck Tire’s Point of Vulnerability
Haul truck fleet operators, for example, have long contemplated the possibility of adopting the same remedy—chain sets—used to protect the tires of loading and utility equipment such as wheeled dozers and graders. Fitting a suitably patterned, durable set of traction chains to a truck’s drive wheels could provide more grip and deflect abrasion away from the tread. But there still remains the risk of tire-sidewall damage from sharp rocks.
With wheeled loaders, dozers and graders it is accepted practice to protect their tires from sidewall damage with a tight-meshed set of chains. However, while tire sidewall protection chains have been tried, under extreme conditions, on trucks, the long haulage distances involved make this solution impractical and short-lived.
Some 70 years ago, responding to the needs of newly arrived, pneumatic-tired mining loaders, Germany-based RUD-Erlau developed the concept of a tire protection chain (TPC), and since has gone on to grasp what it claims is more than 65% of the world market
for TPCs and traction chains in heavy industrial applications. RUD-Erlau was well aware of the vulnerability of truck tire sidewalls and asked its research and development team to tackle the problem.
The team’s first instinct was to create a product based on steel-alloy elements. However, success only came when the focus turned to a combination of metal and nonmetal materials. The result is Sideflex, in which a sturdy set of replacement lug nuts and extensions mounted on a truck wheel support a simple steel ring to which is attached a fanned array of overlapping shield plates that cover the entire sidewall of the tire, deflecting rock fragments away.
Although the mounting components are made of steel, the Sideflex shield is composed of a sophisticated engineering polymer that has found many applications in the automotive and other industries. This material has a unique memory capability that enables the shield plates to flex and deform upon impact and then return to their original shape without any loss of integrity.
The Sideflex assembly is lightweight and low-profile, according to RUD-Erlau, which reports that the product already has undergone many months of extensive field trials in a local quarry, and continues to perform well under the site’s harsh conditions.
Tacking Extra Service Life onto Truck Bodies
The decision to extend the life of one of the largest copper and gold mines in Papua New Guinea has resulted in a significant haulage fleet upgrade, with 25 new 250-mt trucks put to work hauling copper ore from the mine to the crusher. To extend the service life of haul truck bodies for this new fleet, the mine selected Keech Australia’s Keeplate wear material to line the truck bodies.
Keeplate is manufactured from chromium carbide beading welded onto a 250 grade steel base and is available in a range of thicknesses.
Keech Australia’s Michael Scott, who works directly with a number of mines in Papua New Guinea, said the installation of Keeplate can significantly increase the life of the bodies, buckets and blades of mines equipment on which it is used. Other applications for Keeplate include dozer mouldboards, shovel and loader buckets, skid plates and high speed chutes.
When it came to choosing the most appropriate thickness for truck tray liners, consideration was given to overall weight of the liner plates along with the impact conditions. “You don’t want to add too much weight to the tray, particularly when the trucks are used for downhill loads. At the same time, you want the plates to be thick enough to provide maximum protection, so it’s a matter of balancing these two issues to find the right Keeplate for the job,” said Scott.
Keech reports its Wearpact system, a patented ground engaging tool designed for underground loader buckets, also is proving popular in Papua New Guinea.
Manufactured from high-impact and wear-resistant steel, Wearpact features multiple retentions to prevent the castings from coming loose, but installation and removal can be quick, due to a hammerless wedge retainer system.
“The Wearpact system is designed for full bucket nose protection and a clean upper lip plane finish. There is no intrusive casting inside the bucket to hinder loading or dumping operations. The system also provides the option of moving from semi-spade to full-spade by simply changing the castings,” said Scott. “It’s been manufactured to wear from the bottom up, which gives a greater wear-away to throw-away ratio, thereby reducing the overall cost for the mining operator.
“We’re currently fitting the system to a fleet of underground loader buckets in a large copper and gold mine in the highlands region of Papua New Guinea following a successful trial of the system.
“Given that the Wearpac system is also suitable for surface loaders, it has huge potential to improve operations at a large number of mines across Papua New Guinea,” he said.