Peak Downs coal mine located in the Bowen Basin of Central Queensland is Australia’s biggest coal mine by recoverable coal reserves.

The open-pit coal mine has been producing high-quality hard coking coal since 1972. It has been owned and operated by Australia’s biggest coal producer and exporter BHP Billiton Mitsubishi Alliance (BMA), a 50:50 joint venture between BHP Billiton and Mitsubishi, since 2001.

Peak Downs that lies within the mining lease ML 1775 is one of the seven coal mines operated by BMA in the Bowen Basin. The remaining six mines are Goonyella Riverside, Broadmeadow, Daunia, Peak Downs, Saraji, Blackwater, and Caval Ridge.

Location and geology

The Peak Downs metallurgical coal mine is situated within the western branch of the northern Bowen Basin in central Queensland, approximately 30km south of Moranbah.

The mine targets coal seams located within the terrestrial Moranbah Coal Measures (MCM) that comprises sandstones, siltstones, mudstones, claystones, and coal, and extends more than 300m-deep beneath the surface.

Peak Downs coal reserves

The Peak Downs coal mine was estimated to contain 718 million tonnes (Mt) of recoverable coal reserves, including 379Mt of proved and 339Mt of probable reserves as of June 2019.

The measured and indicated coal resources at the mine were estimated to be 519Mt and 863Mt, respectively.

Production at the Peak Downs coal mine

The Peak Downs coal mine produced approximately 11.8Mt of metallurgical coal in the year ending 30 June 2019, compared to 12.6Mt in the previous year.

Mining and coal handling

Peak Downs is an open-cut coal mine using draglines, trucks, and shovels for overburden removal and coal extraction.

The mining fleet includes Liebherr 996B, Liebherr 9800 and Hitachi EX5600 excavators, apart from Caterpillar 793, 797 and 797f dump trucks, and Liebherr T 282 C ultra-class haul trucks.

The run-of-the-mine (ROM) coal is sent to an on-site coal handling and preparation plant (CHPP) for processing. Approximately 2.5 million tonnes per annum (Mtpa) of ROM coal from the Peak Downs mine is also sent through an 11km-long overland conveyor to the CHPP at the nearby Caval Ridge coal mine.

The overland conveyor system that commenced operation in October 2018 was constructed as part of the £155m ($204m) Caval Ridge Southern Circuit (CRSC) project in order to utilise the latent capacity of the Caval Ridge CHPP.

Coal transportation

The coal output of the mine is transported by rail to BMA’s own Hay Point Coal Terminal near Mackay, as well as the Dalrymple Bay Coal Terminal at the Port of Hay Point, RG Tanna Coal Terminal at the Port of Gladstone, and the Abbot Point Coal Terminal near Bowen, for shipping.

Contractors involved

Thiess, a subsidiary of CIMIC Group, was contracted to provide mining services as well as FleetCo hire equipment and maintenance services for Peak Downs and Caval Ridge coal mining operations for a period of three and a half years starting from December 2017.

Thiess was required to remove 90 million bank cubic metres (bcms) of overburden at Peak Downs and 45 million bcms of overburden at Caval Ridge, as part of the £256m ($340m) contract awarded in October 2017.

National Heavy Haulage (NHH), a subsidiary of National Group, was contracted to deliver five Liebherr T 282 C dump trucks to the Peak Downs mine site in September 2018, while National Plant and Equipment (NPE), another subsidiary of National Group, delivered a Hitachi EX5600 excavator to the mine site in January 2019.