Bucyrus will supply Whitehaven Coal’s North Narrabri mine with a 300-m longwall with a capacity of 8 Mt/y. A special feature of the 146 Bucyrus roof supports is that they can be retrofitted for Longwall Top Coal Caving (LTCC) at a later date. Located in the Gunnedah Basin of New South Wales, Australia, the mine will take delivery of the system next October, with operations expected to start in Early 2011, subject to Stage 2 planning approvals from the NSW state government. Bucyrus is the only western supplier with substantial experience with LTCC.
The contract was awarded to Bucyrus following detailed competitive tender process for the design, construction, installation and commissioning of the longwall. The system will have full face automation using Bucyrus’s inertial measurement system based on IMAR 3D gyroscopes. Initial production from the mine is 700,000 t/y, using continuous miners. Development crews are expected to reach the coal seams late this year. Second stage development aims to have the longwall installed in early 2011 to ramp up to 6 Mt/y of low-ash thermal coal and pulverized injection coal. The maximum production is expected to be 8 Mt/y.
A decision on the use of the LTCC mining method is subject to ongoing feasibility studies, which will be subject to mining conditions experienced, in particular the caving characteristics of the coal seam. If LTCC is selected as the preferred mining method, the equipment can be easily retrofitted with the with additional LTCC components.
The seam has a height of 9 m, but initially, the mine is targeting the bottom 4.5 m as this is low-ash, low-sulphur coal. The mine is considering using Longwall Top Coal Caving (LTTC) as this technique allows extraction to a total seam height of more than 10 m by using a longwall shearer to cut the bottom 2.8 – 3 m and then caving the top coal up behind the roof supports onto a rear AFC. This would, however, require a major upgrade of the proposed wash plant because of the lower-grade coal.
With a potential 80,000 Mt of thick coal in Australia, mine operators are showing a great interest in Longwall Top Coal Caving (LTTC). A Bucyrus LTTC longwall which was jointly developed under licence from Yankuang. is in successful service at the Austar mine in the Hunter Valley, New South Wales, Australia.
Bucyrus will supply the Narrabri mine with 146 two-leg 1,378-t roof supports, each capable of retrofit for LTCC, a 3,500 t/h PF 6/1242 armoured face conveyor powered by 2 x 1,200 kW with 2 KP-65 CST gearboxes, a Bucyrus Electra® 3000 evo shearer with installed power of 2,075 kW, as well as a beam stage loader and all hydraulics, electrics and infrastructure.