The Bulga complex in the NSW Hunter Valley is made up of South Bulga and two open-cut operations. The South Bulga longwall operates in the 4.5m thick Whybrow seam.
With three panels left to mine, the operation effectively runs out of recoverable reserves in early 2003. Final blocks E6 and E7 will be extended by around 250m which extends the life of South Bulga by around five months.
Recoverable reserves at South Bulga measure 5.4Mt ROM at the end of June 2001. Beltana hosts recoverable reserves of 20.8Mt ROM. Longwall mining at Beltana is scheduled to commence in April 2003, two months after the completion of mining in South Bulga. The shearer, AFC, surface belt system and continuous miners will be replaced but the South Bulga roof supports will be refurbished for use at Beltana. The new mine will be mining at 2.8m, as opposed to 2.4m at South Bulga.
Contracting group Roche Mining is developing roadways for the first longwall panel, with 200m of development having been completed by mid-September. The first two of the longwall panels have been drilled to 500m centres and development approval is expected by December this year.
Beltana's panel lengths average around 1900m, but exploration work continues in the adjacent block with a view to increasing panel length.
According to newsletter Coal Trade, production costs are expected to be even lower than at South Bulga due to a range of factors. As a punch longwall Beltana does not require any mains development which will help reduce manning levels from 180 currently at South Bulga to only 126. The mine is targeting productivity levels of around 40,000 tonnes per person per year.
Equipment, including the shearer will have more capacity. The longwall conveyor will also be upgraded to cope with higher capacity.
This calendar year South Bulga should produce 4.36Mt ROM, while 2002 production is expected to drop off to 4Mt ROM. In 2003, when Beltana starts production, underground production of 4Mt to 4.4Mt is targeted. The changeover to Beltana will result in a two month production outage. By 2004, at full capacity Beltana is planned to produce over 5Mt.
In South Bulga's last panels, rib bolting has been introduced for gate roads, undertaken with CRAM "roll over" rigs on 12CM30s. Targeted development rate with super units is 6m per hour or 26m per shift.
South Bulga is also continuing trials of inertial navigation technology to check the three-dimensional position of the shearer. This is part of an ACARP funded project, which is feeding into the Longwall Automation project. Initial results have been able to track the shearer over a panel length to within 100mm of its position.
Mine electrical engineer Peter Henderson said the technology was aimed at reducing the amount of time it took to manage face alignment.
