The Asia Miner

OCT-DEC 2015

The ASIA Miner - Reporting Important Issues to Mining Companies in the Asia Pacific Region

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66 | ASIA Miner | October-December 2015 Product News THE Liebherr product portfolio contains a large number of machines for the mining industry with a range of wheel loaders, crawler and mining excavators and crawler tractors that perform a wide range of tasks both effciently and reliably. Liebherr machines can both mine and process many varieties of rock. They can load crushers and sieving plants and transport the extracted material in the quarry. Liebherr customers from Germany to New Zealand confrm that the powerful machines impress with their performance, effciency and high productivity in a variety of quarry operations. Robust designs make the large Liebherr wheel loaders (L550 to L586) well suited to quarrying operations. Using more than six decades of experience, Liebherr has devel- oped and constructed key components for these machines including engines, hydraulic cylinders and electronic components. As a result, Liebherr is able to guarantee manufac- turer quality in every aspect. In addition, Lieb- herr wheel loaders can be set up for intensive mining operations with a variety of equipment options including specialist tyres with tyre pro- tection chains, windscreen guards, and spe- cial rock or HD variant buckets. Liebherr engineers in Austria have devel- oped a clever solution for engine installation by installing the engines in the rear of the machines. The centre of gravity is moved to the rear of the wheel loader so that the diesel engine and the variable displacement pump counterbalance each other. This means that Liebherr can dispense with any ballast, which achieves lower operating weights and higher tipping loads. For example, when handling heavy rock ma- terial, a high tipping load is an advantage as this enables contractors to use larger buckets and move larger loads. The lower operating weight also reduces fuel consumption. Southern Screenworks from Christchurch, New Zealand, were won over by these ad- vantages. The company operates a quarry on New Zealand's South Island with 10 mobile crushing and sieving plants. Directors Brett Swain and Alan King purchased their frst Liebherr wheel loaders in 2007. Three more followed as a result of their positive experience with the machines. Today, a feet consisting of an L564, L566, L576 and L580 moves more than 1500 cubic metres of rock material per day, equivalent to approximately 300 tonnes. "Before we buy a new machine, we compare effciency, perfor- mance and reliability. We opted for Liebherr because other suppliers had nothing on Lieb- herr in terms of these criteria," explained Brett Swain. MARTIN Engineering offers a family of re- sponsive conveyor belt tracking systems that mitigate misalignment, rather than cor- recting it after the fact, even on reversing belts, to promote conveyor effciency and safety. A mistracking belt can contact the mainframe, seriously damaging the belt and the structure, resulting in excessive spillage and even creating a potential fre hazard. Utilizing innovative multiple-pivot, torque- multiplying technology, the Martin Tracker detects slight misalignments initiated by unbalanced loads and fouled rollers, using the force of the belt to immediately adjust its position and realign the path. The trackers minimize risk and material loss, decreasing downtime and operating costs by reducing clean-up and equipment damage. Rollers attached to the end of a sensing arm assembly ride both sides of the belt edge, detecting even slight variations in the belt path. Employing the force of the wan- dering belt, the arms automatically position a steering idler in the opposite direction of the misalignment. Transferring the motion to the steering idler through a unique parallel linkage requires less force to initiate the cor- rection, so fne-tuning of the path can be continuous, active and precise. Martin Engineering's product manager Dan Marshall says, "The biggest issue from a mistracking belt is spillage. If the belt is out of place, it's not handling the load prop- erly and that will cause material to leave the belt. The build-up can be extremely rapid, es- pecially from a high-speed conveyor, which drives up expenses due to wasted material and added clean-up. It also introduces the in- herent risk which is always present when peo- ple are working around a moving conveyor. "The other big issue is having an instanta- neously responsive tracking system, because a misaligned belt can quickly drift over into the conveyor frame and begin abrading the belt and the structure," Dan Marshall says. "If this isn't caught right away, great lengths of valu- able belting can be destroyed and the struc- tural steel itself can be damaged." The multi-pivot design of the Martin system corrects many of the problems exhibited by current trainer systems on the market such as belt switches, vertical guides, v-idlers, crowned pulleys and sensing-roll trainers. Some correction systems have a tendency to overcompensate, requiring a safety tether or lead line to catch the device when the force of the misalignment detaches the unit from the mainframe. Many of these correct mistracking after it has occurred, rather than working to prevent it. By continuously mitigating tracking issues rather than reacting to them, the risk of failure is signifcantly reduced. The Martin Tracker upper unit has guide rolls set 6mm from the belt for high precision when mak- ing adjustments. Belt tracking systems mitigate misalignment Equipment options such as specialist tyres with tyre protection chains or special rock variant bucket set up Liebherr wheel loaders, such as the L566, for tough operations in the quarry. Liebherr machines for quarry use

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