Quality coal, flexible work practices and low-cost output have positioned Moranbah North to exploit windows of opportunity in coal markets.
It is all systems go at the Moranbah North mine in Queensland, the Bowen Basin’s dazzling new longwall operation which has been in production since mid-January.
Shell Coal Australia subsidiary, Moranbah North Coal (Management) Pty Ltd, has already notched up two significant achievements at the mine: longwall coal production started five months ahead of schedule, and the project came in under the budgeted $500 million price tag. By how much Shell is not saying.
The mine’s progress is being watched by other operators and industry observers keen to monitor results of some technological, mine development and man management innovations introduced at Moranbah North. Already these have yielded positive results.
Place changing, the “American” roadway development method chosen by management, has been shown to be effective, achieving a total of 23.5 km of underground drivage. Steve Newson, Moranbah North’s technical services manager, said management was pleased with the development performance which averaged just under 10km per unit last year, but added that there was a lot more potential in the system.
How the mine handles the thick Goonyella Middle seam will be watched with interest, particularly given the strata control problems nearest neighbour, the North Goonyella mine, has encountered in the same seam. Newson is quick to point out that the two mines are 45km apart — a substantial distance geographically. “We can’t read (conditions) straight across, we can only work on the generalities of thick seam extraction. We’re aware of some of the problems they’ve had and we’ve tried to obviate those problems. But our seam characteristics aren’t quite the same.”
Newson said so far the longwall had encountered no unexpected problems, however, he acknowledged that managing the extraction height shaped as an ongoing challenge. Mining of the first panel, LW101, began at around 3.2m and by the middle of February was nearing the targeted 4.5m extraction height.
“There aren’t too many mines in the world doing 4.5m extraction heights,” Newson said. “That’s really the limit. The problems associated with extracting 4m are more than twice as difficult as 2m. It’s a geometric progression, not an arithmetic progression.
“At 4.3-4.5m extraction if you get, say, a relatively simple problem with a ram on your fore-poles it becomes a major issue to deal with because of the height.”
Keeping the face stable was the main challenge. “As soon as coal starts to spall out at that height you get big spans of unsupported ground. If you’re not careful a relatively small roof control problem can develop into a large cavity in a matter of shifts.”
Moranbah North’s first full year of production is expected to yield up to 4mt, but Newson believes production could be higher depending on what happens with coal markets. As a state-of-the-art mine using some of the most sophisticated and biggest longwall equipment in Australia the mine is, on paper, capable of delivering high-quality coking coal at consistent rates and lower costs. These are factors Newson hopes will stimulate the interest of buyers around the world. Which is why he says being the “new kid on the block” is Moranbah North’s main advantage this year. “We’re highly confident that whatever we sell, we’ll produce — not what we produce we’ll sell. We’re being driven by the market.”
During February, the mine’s first month of commercial production, about 200,000t of raw coal was produced. This will steadily ramp up to the 500,000t-per-month-plus mark by November if everything goes according to plan. And so far the mine’s commissioning has gone smoothly.
Installation of the longwall, by contractors Mastermyne, began on November 23 and all major components were in place underground days before Christmas.
“What we had to do then was couple it all together, both electrically and hydraulically. I call that the spaghetti — kilometres and kilometres of hoses, cables and connectors, valves and filters.”
Three weeks of sequential commissioning of the electrics and electronics followed and on January 19 the shearer was powered up and the cutting drums turned. For the first eight shifts, as the four longwall crews were phased in to two 12 hour shifts, coal was cut at night, while the day shift was used to fine-tune the commissioning process. By early January the mine went to a seven day working week and at press time four longwall crews were working four-on, four-off 12 hour shifts, seven days a week. The rest of the mine’s operators were on five day, 9.5 hour shifts.
The four longwall crews each received a week of OEM training, supplemented by “mining training” provided by International Mining Consultants. Newson said OEM training was like the Ford car handbook that explained how to turn on the ignition and where to put the oil. Mining training taught how to drive the car and how to do it safely.
When Newson spoke to Australia’s Longwalls the night shift was achieving five-and-a-half shears and though the day shift was programmed to cut coal, some windows had been left for modifying shearer control and water pressure control systems. Moranbah North’s staff complement is 175 at present, just short of the predicted 190 required at full capacity and the company will employ the remainder if and when it needs to. This flexibility in managing manning levels is indicative of Shell’s hard won battle to liberate the mine of restrictive work practices and is another reason Moranbah North is setting new benchmark standards for the coal industry.
An ability to switch rosters, reschedule roadway development or simply change mining strategies, have given management unprecedented freedom of choice. “We never went into this saying we will produce longwall coal from Monday to Friday and over the weekend we’ll do (maintenance),” Newson said. “What we wanted from the system was flexibility. What we’re saying now is we have a longwall crew available 24 hours a day. We will work the face as the market and the geology dictates.”
What Newson is most happy with is that the mine’s workforce is pulling together and “has a desire to succeed” — half the battle in anyone’s language.
