Published in September 2008 Australian Longwall Magazine
For a Queensland mine the Cook Colliery has been around for a long time. It was developed by BHP in the late 1970s before being in the hands of Centennial and Xstrata and several other owners. It has experienced a variety of mining methods from longwall to continuous miner to pillar extraction. But it was not until start-up coal miner Caledon Resources bought the mine in late 2006 that what looks to be a perfect marriage was made.
When Caledon bought Cook from Xstrata for $45.6 million it was assessing a number of mining methods to extract the coal from the traditionally reluctant mine, but for Caledon chief operating officer Peter Seear, the Magatar continuous haulage system was the lead contender from day one.
“We settled on Magatar because it was by far the best integrated total solution. It did everything without us having to reinvent the work of its inventors – the South Africans,” Seear said.
While Caledon was comfortable in its choice, the move was risky. Australia has had a disastrous history with continuous haulage. Plus the Magatar system had been tried nowhere else in the world. Originally Caledon was going to be the second mine to put Magatar in, but when the first unit left Canada for South Africa it sunk in the English Channel en route (along with a number of very expensive motorbikes which were light enough to float to shore and were picked up by some very lucky beachcombers). Caledon suddenly jumped the queue and became the Magatar trailblazers.
The South Africans are only now putting their Magatar into action at a Total-owned mine.
Before bringing the Magatar system to Australia, Caledon had to face industry-wide criticism, and more importantly the perceptions of its own workforce.
“When it was first mentioned we were going to do continuous haulage I was sceptical as anyone else. I thought it was just another attempt to introduce it again when I had seen it go in at Wambo and not work. It was good when the floor was good but when it hit bad conditions it fell to pieces,” Cook mine manager Marek Romanski said.
Seear said those perceptions had to be overcome from the very start.
“The difference at Cook was that we actually went to South Africa to seek out help. The South Africans have been working on continuous haulage for decades so instead of trying to come up with an Australian approach to continuous haulage, we actually fully embraced the South African approach,” Seear said.
“The best way of cross-pollinating the South Africans’ ideas was to expose all our own people – planning, mining engineers, ventilation engineers.” During 2007 Caledon had Magatar people and experts from South Africa on the ground at Cook while the equipment was being manufactured to help run through the panel design, mine layout and all the operational considerations, such as cutting sequences.
“We had a huge amount of help from the South Africans showing us how they mine. And that really broke down a lot of barriers before the hardware arrived. People onsite embraced the South African ideas – they could see the benefits, they could see the South Africans had made various continuous haulage systems incredibly productive and safe.
“So we broke the back of convincing our own people before the hardware arrived and that really was the key to making it work – making sure you’re not forcing this down on people but actually having your own people embracing it and saying this is the way forward.
“You can see now the sort of support it gets onsite – people prefer to operate on Magatar than the shuttle car section,” Seear said. This was certainly true of the operators underground questioned by Australian Longwall Magazine in July, who spoke of the ease of operating and the elimination of manual handling.
The small company approach at the mine was also evident. “Everyone is important to us and are treated as a part of the company,” Romanski said, adding that most people have a personal interest in the success of the operation with the company’s share scheme. The mine is also willing to try new innovations without having to negotiate a large bureaucracy.
Cook has had multiple onsite visits from almost every major Australian mining company. Seear said visitors came away impressed. “For example, CEO of Global Coal and ex-chief operating officer of Rio Tinto operations Steve Bywater said ‘I was very impressed by the Magatar system at Cook’. He is someone that has been in mining operations all his life and he came away saying ‘my god, that is the solution’.”
The mine has also had international visitors, including those from South Africa and Norway, and a Chinese contingent is expected to visit to view strata management.
The Magatar linear continuous mining system centres on a flexible belt haulage system – the Flexiveyor – which is a series of cascading conveyor belts mounted on wheels which provide a continuous link between the continuous miner and the permanent panel conveyor.
A rapid advancing belt system means a belt advance is possible in 20 minutes. Romanski said while each car is independent, whatever the first car does the rest follow. That independence relates directly to safety as the cars will not move from the first car’s path and warn before moving. “It can take 90-degree turns and follows the continuous miner where you want it to. The system is simple with each of the 16 cars having their own power, motor, hydraulics etcetera,” Romanski said.
The Magatar extends 220m of roadway before a belt move is required – averaging a move about every four to five shifts. A panel takes about three months to complete.
The Magatar system increases safety through eliminating traffic and heavy lifting and to date the reliability has made for a good working environment.
“It also allows us to unlock the cutting and loading potential of the bolter miner and makes it truly continuous. Because there is always a conveyor at the back of the bolter miner, it can effectively cut whenever it wants to. That is where the productivity benefit comes from,” Seear said.
He also pointed out the mining conditions the system can negotiate. “It is especially good on weak floor because the mining system passes over that piece of floor twice – once as it mines it and then again as it reverses out. We have been able to mine in conditions that you couldn’t possibly put shuttle cars into.” In the current section the Magatar had to climb roadways with very unusual grades including a local stretch of 1:5.8, tackling boggy and water-soaked conditions.
The biggest challenge...click here to read on.
