Coppabella mine is an open-cut operation located 140km south-west of the Mackay region close to the Nebo and Moranbah townships in Australia. The mine includes four pits – Johnson, South, Creek and East Pits.
The Coppabella mine began operating on 1 June 1998 within 15 months after the discovery of coal. It currently runs at an installed production capacity of 4.8Mtpa. It produced 2.4Mt coal and 2.9Mt run of mine (ROM) in 2009.
The site operated under a mining contract for nearly ten years. In June 2008, the mine became a 100% owner-operator operation after a joint venture led by Macarthur Coal acquired it. Macarthur Coal holds a 73.3% stake in the mine and also carries out the mining operations. Other parties to the joint venture include CITIC Australia Coppabella, KC Resources (Kawasho Corporation), Mapella (Marubeni Corporation), NS Coal (NS Trading), and Winview (Sojitz Corporation).
The mine contained an estimated 43Mt proven and 20Mt of probable reserves as of 2009. Measured, indicated and inferred resources at the mine have been estimated at 64.6Mt, 122Mt and 16.6Mt respectively.
The mine lies within the eastern part of the Queensland Bowen basin on the south-western edge of the Carborough syncline. The south-east section of the deposit has been affected by a cretaceous-aged granodiorite intrusion that has changed the direction of the synclinal flank upwards.
A north-east dipping Permo-Triassic strata encloses the economic coal measures of Fort Cooper and Rangal. Although the surface of the strata is flat to slightly wave-like, the sediments hosted within the Carborough Syncline are folded and characterised by a major north to north-west striking fault system. One particular fault set is split into two distinct open-pit operations.
The Fort Cooper coal measures form the basal unit of the deposit. The measures, about 350m in thickness, consist of tuffaceous sediments with thick high-ash coal seams. The unit, however, is considered uneconomical within the deposit.
The Fort Cooper coal measure is overlain by the Upper Permian Rangal coal measures that include low-to-medium ash coal seams up to 150m in thickness. The seams of economic value within the deposit include the Leichhardt seam with the Vermont and Phillips seams. The Philips seam is extremely thin and contains high content of ash. Towards the north-west part of the deposit, the Liechhardt seam is divided into Leichhardt Upper (two plies) and the Leichhardt Lower (four plies).
The Rangal Coal measures are overlain by a non-coal bearing unit termed as Triassic Rewan formation.
The Triassic Rewan formation, consisting of sandstones and siltstones, constitutes the overburden during the mining operations.
The mining process is conventional, using dragline with truck and shovel and hydraulic excavators. The P&H 4100 electrical shovel is used for pre-stripping operations and removing overburden. In order to facilitate the process, the overburden is first drilled and blasted.
A Marion 8200 dragline is used on the final pass to coal in the central region. The exposed coal is mined using hydraulic excavators.
Mined ore is transported by coal trucks to the stockpile or to the ROM from where it is fed to the coal handling and preparation plant (CHPP).
Coal is processed in a 4.8Mtpa CHPP. To maximise plant output the coal is blended properly before it is fed to the CHPP. Raw coal is crushed in a three-phased crushing system to reduce the fine coal generation. Cleansing of coarse coal is done in a dense medium cyclone that has a 1,300mm diameter. The fine coal is cleaned in 24 banks of triple start spirals. Ultra-fine coal is recovered with two Jameson flotation cells.
The processed coal is sent to the product stockpile before it is loaded and delivered for export to the Dalrymple Bay Coal terminal.