The Kestrel Mine lies on the western limb of the gently dipping Talagai Syncline, which plunges southwest between the Capella Block to the north west and the Comet Ridge to the east resulting in an overall regional dip of the stratigraphic sequence to the south and south-east.

At surface an isolated pocket of German Creek Formation (Pud) outcrops near the Kestrel Mine, with the remaining tenement area covered by unconformably overlying Cainozoic aged volcanics and sediments. Tertiary aged Minerva Hills Volcanics (Tr) comprising olivine basalt, trachy basalt, minor agglomerate and tuff are eroded and deposited over the Nogoa River fluvial system as undifferentiated (Cz) soil, sand and gravels and Quaternary aged alluviums (Qa).

The recent Tertiary sequence averages 65 m in thickness and ranges up to 110 m. As many as eight distinct basalt flows can be recognised in the Kestrel Mine area. These are often interbedded or underlain by clay and water bearing sand/gravel beds. The main Tertiary aquifers are the basalts and the basal sand/gravel beds. Airlift water flows of >30 l/s have been measured from these aquifers.

Kestrel Mine is an underground mine which uses the longwall and continuous miner method to mine high quality coking and thermal coal for export.

Longwall mining is a technique which has revolutionised underground coal mining, enabling large scale and efficient extraction of coal in a cost effective and relatively safe manner when compared with other techniques such as board and pillar mining. Mechanical shearers are employed on the longwall panel, traversing across a face cutting coal with the roof supported behind the shearer with hydraulic supports. Cut coal is then transported to surface by a conveyor network. As the mining face advances the hydraulic roof supports are brought forward, the resultant goaf collapsing as earlier mined faces which are no longer supported subside (refer Figure 17). Longwall mining requires relatively benign geological conditions to be economically viable as set up costs for panel layouts are both time consuming and expensive, with the equipment unable to make radical changes in orientation should unexpected geological conditions be intersected.

Continuous mining uses traditional bord and pillar approach of cutting room areas of coal and leaving remnant pillars behind to support the roof and maintain stability with the overlying strata. Coal is collected by shuttle cars and transported to a conveyor for dispatch to surface. This technique enables greater flexibility in areas of more complex geology, although at the expense of lower recovery and extraction rates when compared to a properly operating longwall panel. Pillars can be robbed at a later stage in the mine life to increase recovery of coal.

The original coal handling preparation plant (CHPP) for the then Gordonstone Coal Mine consisted of dense medium baths, dense medium cyclones and conventional froth floatation cells. In 1995 the CHPP underwent an upgrade to increase the daily capacity to 1000 t/h. The upgrade consisted of the addition of two 5 m diameter Jameson cells and an 85 m2 horizontal belt vacuum filter (HBVF) dewatering unit to Module 2 of the plant. Further modifications were made to the coarse coal circuit including the installation of 1000 mm diameter dense media cyclones and banana screens for drain and rinse.