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LANDAU USES HAUL ROAD MAINTENANCE SOLUTIONS FROM BARLOWORLD - [August 2006]
Anglo Coal’s Landau colliery near Witbank is hoping for a 7 per cent improvement in haul truck suspension life, increased tyre life and a 5 per cent improvement on truck turn around time through a new approach to haul road maintenance.
Stephan Opperman, business improvement manager at Landau, says the order for a Metso mobile crusher and Cat vibrating compactor placed with Barloworld Equipment Middelburg corresponds with a new approach by the mine to road maintenance.
A Metso Lokotrak LT105 mobile crusher crushes sandstone parting material from the opencast pit to build and maintain haul roads at Anglo Coal’s Landau colliery.
“We identified our haul road conditions as an improvement opportunity because of the impact of the roads on truck turn-around times, damage to suspensions and to tyres,” says Opperman. “Availability of haul truck tyres is currently a major problem. Rain also results in deterioration of our roads, impacting production during the summer months,” he explains. “We are thus changing our road building and maintenance strategy to achieve excellent road conditions throughout the year.”
The total length of the haul roads at Kromdraai is about 5km. Traffic includes four off-highway haul trucks carrying 160t loads, two water tankers, two articulated trucks, another two dump trucks for road building, a diesel bowser and two Cat graders, a 14H and a 16H.
A Metso Lokotrak LT105 mobile crusher is being used to crush sandstone parting material from the opencast pit for use as road building material. A Cat CS683E compacter will be used to achieve the correct compaction levels to take the traffic loads and the weight of the trucks. The sandstone will also provide a non slippery road surface in the rainy season, says Opperman.
“Barloworld Equipment offered us a complete fleet solution, together with additional support on road building in terms of knowledge sharing through professional road building experts. We already have good experience with Metso as a brand and we are confident that we will receive good back-up from Barloworld Equipment Middelburg on both the crusher and the Cat compactor.”
The new machines will be maintained by Anglo Coal at Landau, with support from Barloworld Equipment Middelburg in parts supply and major servicing.
Opperman adds that, depending on its success at Landau, the road building technology will be extended to its sister mines.
Barloworld Equipment has produced several studies on the effects of rolling resistance (RR) on mine productivity. RR measures, in theory, the force that must be overcome to roll or pull a wheel over the ground in order to overcome machine inertia. Kenn Smart, applications manager at Barloworld Equipment Mining, says that for off-highway trucks running radial-ply tyres, the following minimum RR figures can be applied:
- Hard, well maintained road 1.5%
- Well maintained road with flex 3%
- 25mm tyre penetration (or flex) 4%
- 50mm tyre penetration 5%
- 100mm tyre penetration 8%
In practice, a 5 per cent increase in RR can result in up to 10 per cent decrease in hauling production and a corresponding increase in production costs.
By lowering RR, says Smart, benefits can be generated in several areas:
- lower fuel consumption per tonne in primary and secondary hauling equipment application
- increased tyre life
- higher equipment availability due to lower maintenance and repair
- better operator proficiency
- higher t.p.h. production rates
- better dust suppression
- less road surface grading required.
FACT BOX – LANDAU COLLIER
Landau Colliery, located about 15km west of Witbank, commenced operations in 1992. But the coal reserves were mined as early as 1926. The mine was then known as Coronation Colliery and mining was underground. Underground mining stopped in 1966, after Coronation had extracted a total of 35-million tonnes of coal.
Today opencast mining methods are used and the no.1 and no.2 seams are mined in a drill and blast operation with one dragline, two hydraulic shovels and four haul trucks. There is a sandstone rock parting between the two seams. The no.1 seam was previously mined by underground mining methods and the pillars are now being extracted from the old underground workings. The no.2 seam is still virgin coal.
Landau consists of two sites, Navigation plant and Kromdraai open cast. The sites are 23km apart, with a rail link to transport mined coal to the plant. The Navigation plant uses dense medium separation methods.
Landau mines 6.5-million tonnes per year and produces 3.9 sales tonnes annually. Most of the coal produced at Landau is exported through the Richards Bay Coal Terminal. A small portion is supplied to the inland market.
As business improvement manager, Stephan Opperman is responsible for identifying improvement opportunities at Landau, developing business cases for improvement projects and managing their execution. He also looks at the end-to-end processes at Landau and identifies bottlenecks in the system which can be improved. He drives innovation at the mine and facilitates new ideas from the workforce.
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