Awaba Colliery may not be Centennial Coal’s biggest contributor in terms of Mtpa, but mine operators have proved that they are a valuable asset.
Awaba Colliery is an underground coal mine, 1 km south of Awaba Township and 5.5 km south west of Toronto.
In September 2005 Awaba Colliery planned to finish production at the end of February 2006.
The operation was to complete primary development work and undertake a minimal amount of pillar splitting as production units retreated.
The operation was re-assessed as a result of a change to colliery management, and the potential to extend the life of the operation was realised.
A significant area of old pillar panels existed at the colliery, which had the ability to be mined by secondary extraction methods.
There were also a number of small, previously discounted blocks of coal, which had the potential to be accessed and mined by conventional pillaring.
A successful extension to the mining operation was calculated to add two million tonnes of saleable product to the life of the mine.
This would extend the mine’s life by more than two years, and see the operation completed at the end of 2008.
At projected operating costs, and if current market prices were maintained, this would generate an additional $25 million of revenue for Centennial Coal.
The initial assessment of underground workings showed that access to the old panels could be re-established, and a secondary extraction system successfully undertaken.
The condition of targeted panels determined the extent of preparation work required and played a large part in determining the project’s feasibility.
A small amount of capital was required for specialised equipment, and refurbishment of existing machinery.
The extension was treated as an incremental project, so that it could be discontinued part way through the life of the project if need be.
A key to the success of the project was ensuring the plan had the support of the workforce.
A forum for regular communications kept workers informed in the planning process, and in ongoing work.
Communication was an important part of the process as workers concentration on preparation work would result in fewer resources allocated to general production.
Open communication was also important to retain the workforce, as recruitment costs and loss of skilled personnel would decrease the company’s profit margins.
Mine management decided to undertake partial secondary extraction using mobile roof supports.
This would give an increased level of safety to underground operators.
While the majority of equipment was available at the colliery, the mine was able to take advantage of surplus equipment available within the Centennial Coal group.
An integral part of the mining design was dictated by the mine’s geological conditions.
Teralba Conglomerate is the dominant roof lithology in the Main-South area of the mine.
This feature requires careful consideration when designing a mining system.
Teralba Conglomerate has significant spanning capability, and has the potential to fail over large spans with little or no warning.
Sink holes were also appearing on the surface of the mine, causing concern for management.
Such openings increase the potential for the mine to flood in times of heavy rain.
A considerable amount of effort was spent on designing the most appropriate mining system for the project as a result of these challenges.
After the successful completion of the project’s first year, the secondary extraction stage is about to commence.
The first year of the project saw a number of coal remnants successfully mined, with tonnage above what was initially budgeted.
An 8% increase in production is budgeted for the second year of the project, which is correlated against a reduction in travel time and improved familiarity with the mining process.
Judges for the Prospect Awards were thoroughly impressed by the use of automation to control production machinery in the Beltana mine.
Beltana has achieved what is said to be excellent productivity and an innovative approach to automation.
Beltana started longwall production in 2003 after the closure of the adjacent South Bulga mine.
South Bulga was a strong supporter of automation but technologies did not exist to allow the mine to take advantage of automation.
The initial driver for automation at South Bulga was to remove the workforce from dusty work zones.
Beltana used outdated equipment first used at South Bulga and still produced 7.05 Mt Run of Mine according to 2005 production figures.
The second highest producing mine in the country produced 4.8 Mt.
2005 annual production figures for all underground longwall mines shows the productivity that Beltana has been able to achieve, and since then Beltana has remained one of Australia’s most productive mines.
Beltana also shows a commitment to occupational health and safety standards.
In 2006 Xstrata Beltana was highly commended in the New South Wales Minerals Council Safety Innovation Awards.
The accolade was awarded to Xstrata West Wallsend Beltana Mining for designing a user-friendly continuous miner.
The innovative design is said to reduce injury risk to workers operating shuttle cars in underground parts of the mine.