Coal is mined from within the Bulli seam.

Coal is extracted at Tahmoor Coking Coal by a longwall shearer and conveyed to the surface by a series of conveyors.

The area immediately in front of the coal face is supported by a series of hydraulic roof supports, which temporarily hold up the roof strata and provides a working space for the shearing machinery and the face conveyor. After each slice of coal is removed, the hydraulic roof supports, the face conveyor and the shearing machinery is moved forward.

Mining activities during the reporting period have been conducted in accordance with the approved Mining Operation Plan (MOP) and Subsidence Management Plan (SMP) approvals. Extraction of Longwall 31 was completed on 17 August 2018. Longwall 32 extraction commenced on the 30 October 2018.

Longwall 32 has commenced mining and four further longwalls are proposed within the Western Domain of the Tahmoor North Mining Domain:
- Longwall West 1 , proposed start 8/11/2019 - proposed completion 20/8/2020;
- Longwall West 2, proposed start 19/05/2020 - proposed completion 28/4/2021;
- Longwall West 3, proposed start 10/6/2021 - proposed completion 21/12/2021;
- Longwall West 4, proposed start 31/1/2022 - proposed completion 9/6/2022

Tahmoor’s Coal Preparation Plant is made up of three main sections:
a) Crushing and Screening: The Run of Mine (ROM) feed is normally in the size range of 0 to 250mm. The feed is sized to 100 mm using a divergator. The +100mm reports to the primary crusher and is crushed to 100mm top size. The combined product reports to the raw coal sizing screen and material over 50mm is crushed in the secondary crusher to 50mm maximum. The product from this operation is de-slimed over 2 de- sliming screens to 0.5mm.

b) Primary and secondary cyclones: The +0.5mm raw coal reports to 4 x 900mm diameter dense medium cyclones with the product drained and rinsed of magnetite and dried in centrifuges. The coking coal is conveyed to the coking coal stockpile (500,000 tonne capacity). The reject from the primary cyclones is pumped through two 800mm diameter secondary cyclones. The product from this operation is drained and rinsed before being conveyed to the steaming coal stockpile (100,000 tonne capacity). The reject from the secondary cyclones is conveyed to the reject area for emplacement and rehabilitation.

c) Flotation circuit: The de-sliming underflow (minus 0.5mm) reports to the flotation cells, and aided by the use of reagents, the fine coal is separated from the fine reject material. The fine coal is dried using drum filters and is mixed with the coarse coal from the cyclone product reporting to the coking coal stockpile. The fine reject is dried using a belt press filter and mixed with the coarse reject before being conveyed to the reject area.