1.2.2.1.1 Currently operating coal mines

The Stratford Mining Complex is an open-cut mining operation owned by Stratford Coal Pty Ltd, which is a wholly owned subsidiary of Yancoal Australia Ltd (Yancoal). The Stratford Mining Complex commenced in 1995 with production of coal at the Stratford Main Deposit (AEMC, 2011), which continued operations until 2003. Other pits mined in the complex include Roseville Pit, Roseville West Pit and Bowens Road North Open Cut Pit although Roseville West Pit (in operation since 2009) and Bowens Road North Open Cut Pit (operating since 2003) are now the only pits in operation. Additionally, small quantities (up to approximately 0.2 Mt/year) are recovered from the coal handling and processing plant rejects (Stratford Coal, 2012b, p. 2–1).

Conventional open-cut mining processes are used at the Stratford mining complex (Stratford Coal, 2012b, p. 2–1 to 2–3). Due to there being steeply dipping, thin coal seams, the mine uses relatively small mining equipment that has the ability to selectively mine thin seams (Yancoal, 2013, p. 1). Mining methods include vegetation clearance and topsoil removal that will be used in rehabilitation, overburden removal by excavator and haul truck and drilling and blasting of consolidated overburden. Overburden is then removed by excavator and truck and rock is stored for progressive mine void filling. Exposed coal is excavated and loaded into haul trucks for transport to stockpiles before being moved to the coal handling and preparation plant (Stratford Coal, 2012b, p. 2–1 to 2–3).

Approximately 3.3 Mt/year of coal products are produced at the Stratford Mining Complex including thermal and coking coal. Coal is processed at the Stratford Coal Mine coal handling and preparation plant (CHPP), which is owned by Stratford Coal Pty Ltd (Gloucester Coal, 2010a, p. ES-4) and is approved to operate 24 hours/day, seven days/week (Stratford Coal, 2012b, p. 2–1). Coal handling and preparation plant design capacity at the complex is 750 t/hour (Gloucester Coal, 2010a, p. ES-4). The previously mined Stratford Main Deposit Pit is currently used for rock backfill waste and water storage. The Roseville Pit has been backfilled and is undergoing rehabilitation whilst the Roseville Extended Pit is currently being backfilled (Stratford Coal, 2012b, p. 2.1). Product coal is transported via the North Coast Railway to Newcastle for the domestic and international markets (Stratford Coal, 2012a, p. 2–3). Mine waste rock is used for fill behind advancing mining operations or in out-of-pit waste emplacements.

Situated 20 km south of the Stratford Mining Complex (Stratford Coal, 2012a, p. ES-1) (Figure 5), Duralie Coal Pty Ltd is an open-cut mine owned by Yancoal. The Duralie operation started in March 2003, owned by Gloucester Coal Ltd until 2012 when Gloucester Coal merged with Yancoal (Nedlands, 2013). The mine is currently operated by Leighton Mining under contract to Yancoal. Currently the Weismantel Coal Seam and the Clareval Seam are being mined (Duralie Coal Pty Ltd, n.d.). Conventional open-cut mining processes are being performed at Duralie Coal Mine. These include stripping and stockpiling of topsoil for rehabilitation, excavation and removal of weathered overburden and then drilling and blasting of consolidated overburden prior to its excavation and removal. Overburden is stored in stock piles for back filling although any rock that is identified as being potentially acid-forming is additionally treated with limestone within the waste rock emplacement. Coal is transported by rail to the Stratford Coal Mine CHPP (Gloucester Coal, 2010a, p. ES-4; 2010b, p. 2–1).

Combined, the Duralie and Stratford produced and sold approximately 2.0 to 2.3 Mt of coal in 2013 (Yancoal, 2013). The mines produce two key products: a semi hard coking coal and a high ash thermal coal that can be blended with other coals, although the coal is known to have high sulfur levels that can limit its use (Yancoal, 2013, p. 2). Both the mined Weismantel and Clareval seams have consistent thickness of 10 to 12 m, split into four main plies of 0.8 to 7.5 m. Coal is transported by train to the Port of Newcastle for export or domestic use (Duralie Coal Pty Ltd, n.d.).