Summary:
The Dawson deposit is located towards the south eastern corner of the basin, with structural disturbance and faulting increasing to the north, and depositional complexity, shown by an increase in split seams, to the south. The Dawson opencast operation extracts coal from the Baralaba Coal Measures, which contain seven main seams. All except two seams have been mined.
Dawson Mine is located in the Bowen Basin, approximately 200 km south-west of Gladstone, Queensland, on the eastern limb of the Mimosa Syncline. The project targets five coal seams (A, B, C, D, E in order of geological age from youngest to oldest) belonging to the late Permian-aged Baralaba Coal Measures (BCM). The seams dip broadly to the west at around 10° with several splits and coalescences. Interburden lithologies are predominantly alluvial floodplain facies consisting of lithofelspathic sandstone, siltstone, coal, and tuff (Leisemann et al., 1992). Underlying the BCM is the Kaloola Member (KM), which is characterised by abundant tuffs and thin, tuffaceous, non-economic coals interbedded with deltaic and prodeltaic siltstones and sandstones. The Kaloola Tuff, which is a stratigraphic marker horizon equivalent to the Yarrabee Tuff elsewhere in the Bowen Basin, is typically located within the E seam floor at a variable depth (Gonano, 1980).
The main regional structures in the Dawson Mine area are NNW-trending, thin-skinned, low-angle thrusts representing the southern part of the Jellinbah Thrust Belt, albeit with diminished complexity and severity (Sliwa et al., 2008). A subordinate minor thrust system varying in strike from WNW to EW is also present and is possibly the result of reactivation of basement fault systems during compressional tectonism. Minor EW normal faults are also observed but tend to lack lateral continuity. Large crossbedding structures are frequently encountered due to channel deposition and lateral migration discordant to seam structure. Other structures typical of a compressive tectonic environment and present in the Dawson Mine area include bedding plane shears, low-angle reverse faults, and thrust ramps with minor seam displacement. Locally within the pit 6-8 area, faults are NW-to-NNW trending thrusts.
Summary:
Dawson mine is a large open-cut coal mining operation in Queensland that historically had been operated as a strip mine, with multiple draglines exposing coal in a westerly direction and dumping spoil to the east. In response to a shortage of dump space, insufficient progress with progressive rehabilitation and the ongoing disturbance of land, the operation made changes to address these increasing closure liabilities. This included backfilling depleted open pits, which involved changing the fleet for this part of the mine to truck and shovel.
Highwall mining is a low cost, low impact mining method to extract otherwise uneconomic coal at the end of an open cut pit life. It has been extensively used in the USA and Australia including at Glencore’s Newlands and Ulan mines and Anglo American’s Dawson mine.
Summary:
Dawson Coal plant is the largest coal handling and preparation plant (CHPP) in Australia. The raw coal system will accept coal from three separate mine sources delivered by an overland conveyor system, with the CHPP processing at 2000 tonnes per hour in two stage mode and up to 3400 tonnes per hour in single stage mode. The state-of the-art plant contains dense medium cyclones, spirals and flotation circuits. The product coal will then be loaded via high capacity automated reclaimers to a new rail load out facility.