The Saraji open-pit coal mine located in the Bowen Basin of Central Queensland is Australia’s fourth-biggest and the world’s tenth biggest coal mine by recoverable coal reserves.
The multi-seam, open-cut mine has been producing up to ten million tonnes per annum of high-quality metallurgical coal for export markets since 1974. It has been owned and operated by BHP Mitsubishi Alliance (BMA), a joint venture between BHP Billiton (50%) and Mitsubishi (50%), since 2001.
Saraji is one of the seven coal mines operated by BMA in the Bowen Basin. The other six mines are Goonyella Riverside, Broadmeadow, Daunia, Peak Downs, Blackwater, and Caval Ridge. BMA also owns and operates the Hay Point Coal Terminal near Mackay in Queensland, on Australia’s east coast.
Location and geology
The Saraji coal mine is located within the western limb of the northern Bowen Basin in Central Queensland, approximately 250km southwest of Mackay and 26km north of Dysart.
Encompassing four mining leases namely, ML1775, ML1782, ML1784, and ML70142, the Saraji mine extends north to south with a strike length of 30 km, and with an average width more than 4 km.
The Saraji mine targets the P, Harrow Creek Upper, Harrow Creek Lower, K and Dysart coal seams belonging to the Moranbah Coal Measures (MCM) of the late-Permian age.
Saraji coal reserves
The Saraji coal mine was estimated to contain a total of 502Mt of recoverable coal reserves, including 442Mt of proven and 60Mt of probable coal reserves, as of June 2019.
The measured and indicated coal resources at the mine were estimated to be 844Mt and 137Mt, respectively.
Production from the Saraji coal mine
The Saraji mine produced 9.78Mt of metallurgical coal in the year ending 30 June 2019, compared to 10.1Mt in the previous year.
Mining and coal handling
Saraji is a conventional strip mining operation using draglines, trucks, and shovels for overburden removal and coal extraction.
The pre-stripping fleets at the mine comprise P&H 2800XP and P&H 4100A electric shovels, while Cat 793C rear dump trucks are used for hauling waste.
Terex O&K RH170 excavators, P&H L-1850 and Cat 994 loaders are used for coal extraction, while the mined coal is hauled in Cat 793 trucks to an on-site coal handling and preparation plant (CHPP).
The processed coal is transported 213km by rail to the BMA’s Hay Point Coal Terminal near Mackay, as well as the Dalrymple Bay Coal Terminal at the Port of Hay Point, for shipping.
Sedgman was awarded an engineering, procurement, and construction (EPC) contract to upgrade the Saraji CHPP in May 2012.
JP Piping Systems was sub-contracted for piping works under the upgrade project by Sedgman in February 2013.
CPH Mining & Civil was engaged for topsoil management, dam construction, dragline pad construction as well as other mining and civil earthworks for the Saraji mine development under BMA’s operatorship.
NRW Civil & Mining was engaged for various civil and earthworks related to the tailings dam and pipeline, as well as access roads at the mine site during 2011 and 2012.
Thiess, in a joint venture with Sedgman, was also contracted for the upgrade of the Saraji coal processing plant in 2005.
JP Piping Systems was subcontracted to install compressed air, fire and water pipelines.
Cordell, a construction company based in Australia, received the contract for upgrading the thickener plant of the Saraji coal mine in 2005.
Sunline Switchboards supplied the motor control centre (MCC), switch rooms and variable speed drive (VSD) cabinets for the Saraji CHPP in 2006.
Saraji East coal project
Saraji East is a single-seam underground coal mine proposed to be developed approximately 30km north of Dysart in Central Queensland within the Isaac Regional Council area.
BMA has applied for two additional mining leases namely ML 70459 and ML 70383 in the Bowen Basin for the proposed project.
The Saraji East project envisages up to 7Mtpa of coal production over a mine life of 25 to 30 years.
A new coal handling and preparation plant (CHPP) has also been proposed to be developed on ML 70142 as part of the project.
The project also includes a conveyor system to deliver raw coal from the underground portals to the CHPP as well as to transport the processed coal to the rail loading facilities located over ML 1775 and ML 70142.
A preliminary environmental impact statement (EIS) for the Saraji East project was submitted in October 2019, while the final EIS is expected to be submitted by June 2020.