Tahmoor Mine lies in the southern part of the Permo-Triassic Sydney Basin, within which the main coal bearing sequence is the Illawarra Coal Measures.

Coal is mined from within the Bulli seam. The Bulli seam coal is predominantly a hard-coking coal.

Longwalls are extracted within Tahmoor North (Western Domain) at a depth of approximately 450 m in 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 (2021) have been conducted in accordance with the approved Mining Operation Plan (MOP) and Extraction Plan approvals.

Extraction of Longwall West 2 (LW W2) was completed on 17th June 2021, and LW W3 extraction commenced on 13th September 2021 and was completed on the 21 st March 2022.

Tahmoor Coal Pty Ltd commenced mining of the final longwall in the Picton area, Longwall West 4 (LW W4) in May 2022.

- Longwall West 1, actual start 15/11/2019 - actual completion 06/11/2020;
- Longwall West 2, actual start 05/12/2020 - actual completion 17/06/2021;
- Longwall West 3, actual start 14/08/2021 - actual completion 21/03/2022;
- Longwall West 4, actual start 05/16/2022 - actual completion September 2022.

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.

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