Illawarra Coal's assets are located in the southern portion of the Sydney Basin within the Southern Coalfield.

The full sequence of Triassic to Permian sedimentary units are present within the Illawarra Coal's areas, including the Permian Shoalhaven Group, Illawarra Coal Measures and the overlying Triassic Narrabeen Group and Hawkesbury Sandstone.

The economic coal seams relevant to the Illawarra Coal's areas are hosted within the Illawarra Coal Measures. The general description of the most relevant units is provided below:

- Bulli Coal is the uppermost coal unit in the Illawarra Coal Measures. It is extensively worked in the northern portions of the Southern Coalfield. The Bulli Seam is the main economic coal seam for the Bulli Seam Operation - Appin mine and West Cliff Colliery (now Appin North). It averages approximately 2.6 m thick across Appin, gaining a maximum thickness of approximately 4.1 m. The Bulli Seam thins to approximately 1.4 m in the south eastern part of West Cliff and also south west of Appin. Overall, the coal thickness for the Bulli Seam is generally consistent across Bulli Seam Operation in the mined out areas and planned areas of longwall mining;

- The Loddon Sandstone is generally between 7 m to 10 m thick;

- Balgownie Coal consists of high ash coal and carbonaceous shale and is generally less than 1 m thick;

- Lawrence Sandstone is 7 m to 11 m thick;

- Cape Horn Coal is a carbonaceous shale to bright coal, typically less than 0.5 m thick;

- Eckersley Formation consists of thin coals, minor carbonaceous shale, laminites and black shales;

- Wongawilli Coal ranges between 7 to 11 m thick and consists of inter-banded tuffs, carbonaceous shales and coal. The basal 4 m contains coal of economic potential and is currently mined at the Dendrobium Mine. The Wongawilli Coal is subdivided into 13 individual plies and 12 partings units and into three working sections. The working sections are based on mining experience and are the most relevant division of the seam. The Second Machine Band working section is generally the target of mining at Dendrobium;

- Wongawilli Seam is present within the Appin and West Cliff (now North Appin) areas, although a viable working section is not interpreted to occur in the area;

- American Creek Seam is a thin coal inter-bedded with carbonaceous claystone; and,

- Tongarra Coal is a thin coal inter-bedded with carbonaceous siltstone and claystone.

The structure over the Illawarra operation area is relatively well defined based on the geological data available. Seam dips over the area are generally low (1° to 3°). There are localised variations in seam structures. Relatively steeply dipping strata occurring at the Dendrobium Mine between Areas 2 and 3 where dips reach 7° - 8° in an area associated with a small scale fault. The localised steeper dip zones are also often associated with underlying igneous intrusions and domes.

Faulting has been identified across the and Dendrobium Operation. The faults have been identified by 3D seismic, 2D seismic, underground mapping, underground drilling, de-gassing intra-seam holes and, to a lesser extent, interpreted from floor contours generated from drill-hole data. The faults are predominately extension normal faults, although low angle thrust faults have also been identified (such as Maingate 12 at Dendrobium).

Faulting affects the Bulli Seam Operation area more significantly than at the Dendrobium Operation. Fifty-one faults have been interpreted at the Bulli Seam Operation area to a level of confidence that allows them to be incorporated in the geological model. The throw on the Appin faults average approximately 20 m, although the maximum throw is 90 m; approximately 13 faults have throws of greater than 5 m. As the average thickness of the Bulli Seam is less than 2.7 m, a throw of more than 2 to 3 m can adversely impact the potential for eventual economic extraction. This was demonstrated at West Cliff where LW 22 to 24 were constrained due to faulting. The Appin mine plan has been laid out to avoid the significant faulting identified by exploration to date.

At the Dendrobium Operation only four faults are incorporated into the Dendrobium Operation geological model. Of these, only two are located within the current mine plan:

- Elouera Fault - identified in the old Elouera underground workings, affecting the southern boundary of the Illawarra operation area, displacement of up to 20 m;

- WW1 Fault - Small displacement fault (less than 5 m) identified in the northwest mains workings, between Areas 2 and 3. There are a number of features that have been interpreted as probably faulting but to a lesser degree of confidence.

As well as the four modelled faults, there are a number of interpreted fault structures for the Dendrobium Operation. Most of the predicted structures are understood to be minor and not expected to affect mining operation due to their limited throw.

Igneous intrusions are present at both the Bulli Seam Operation and Dendrobium Operation.

The Bulli Seam Operation has igneous dykes varying from near vertical and thin (less than 0.3 m), which are boggy and soft and easy to mine, to more significant dykes of 4 to 5 m in width which are very hard (up to UCS of 270 MPa) and more difficult to mine. Through geological studies and operating experience, the igneous dykes are understood and have been observed to have narrow contact margins. Hard and wide dykes are being intercepted in the current mining area.

At the Dendrobium Operation Tertiary igneous intrusions, in the form of sills and dykes, post-date the sedimentary strata in the area which hosts the coal. Sills and dykes have been identified through a combination of surface mapping, vertical drilling, in seam drilling, aeromagnetic survey and from mining.

Extensive igneous sills have been identified in the Wongawilli Seam and have had significant impacts on the extent of economic coal at the Dendrobium Operation.

Additionally, there is a swarm of dykes known as the Dendrobium Dyke Zone located directly north of Dendrobium Area 2. The Dendrobium Dyke Zone currently defines the northern limit of the Dendrobium Mine design for Areas 2 and 3.

Illawarra Metallurgical Coal operates two underground metallurgical coal mines, Appin mine and Dendrobium mine, and West Cliff and Dendrobium coal preparation plants.

Illawarra Metallurgical Coal produces premium-quality, hard coking coal for steelmaking and energy coal. The product is processed at the coal preparation plants before being transported to the PKCT for distribution to domestic and international customers.

Appin Mine
Appin Mine underground longwall mining operations have transitioned wholly to AA7 and AA9 following completion of longwall mining activities at Appin North (West Cliff Area 5) in early 2016. Appin Mine extracts coal from the Bulli Seam within the Southern Coalfield.

Appin Mine underground longwall mining operations are accessed from three surface locations: Appin North, Appin West and Appin East.

Longwall (LW) 708B commenced mining on 24 April 2020 and had retreated 2260 m, to finish on 3 January 2022. LW709 commenced on 22 February 2022 and as of the end of the reporting period had retreated 601 m with an estimated completion in July 2023.

Extraction of LW904 commenced on 20 May 2021 and had retreated approximately 2026 m as of the end of June. LW904 was completed 9 August 2022.

Ore and Product Stockpiles
No coal is stockpiled at Appin West, as ROM coal is transported underground to Appin East or the West Cliff Coal Preparation Plant (WCCPP). The Appin West coal storage bins are currently under care and maintenance.

Appin East has a total raw coal stockpiling capacity of up to 50,000 tonnes. The stockpile is recovered with front-end loaders and transferred directly into the coal haulage trucks for transport by road to either the WCCPP or Dendrobium Coal Preparation Plan (DCPP).

Appin North operates six primary coal stockpiles for both clean coal and raw coal.

Dendrobium Mine
Dendrobium Mine extracts coal from the Wongawilli Seam (also known as the No 3 Seam) of the Southern Coalfield. Three mining areas make up the approved mine plan for Dendrobium and are named Areas 1, 2 and 3 (including 3A, 3B and 3C). Longwall mining during the reporting period was undertaken in Area 3A (Longwall (LW) 19) and Area 3B (LW17 and LW18). The mine primarily produces hard coking coal and is approved to produce up to 5.2 million tonnes per annum until 31 December 2030. Dendrobium Mine is comprised of a number of sites as detailed below.

Kemira Valley Coal Loading Facility (KVCLF)
Coal is transported from the underground workings to the KVCLF via a conveyor network, reaching the surface via the Kemira Valley Tunnel (KVT). The coal is then fed through a coal sizer, into a rill tower and deposited onto a 140,000-tonne capacity stockpile. Coal is loaded onto trains via an enclosed rail-loading chute

Kemira Valley Rail Line (KVRL)
The private KVRL is used to transport the coal from the KVCLF to the Dendrobium Coal Preparation Plant (DCPP).

Ventilation Shaft 1
The fan housings associated with Ventilation Shaft 1 were decommissioned in October 2008 and relocated to Ventilation Shaft 3. This shaft now provides intake air to the underground workings. The Ventilation Shaft 1 site layout is shown in Plan

Ventilation Shaft
2/3 Site (ML 1566) Construction of Ventilation Shafts 2 and 3 commenced during 2006 and was completed in 2008. Ventilation Shaft 2 (downcast) and 3 (upcast) provide ventilation to the current and future underground workings in Area 3.

Mineral processing facilities include the West Cliff Coal Preparation Plant (WCCPP), the West Cliff Emplacement Area and the Dendrobium CPP (located at the Port Kembla Steelworks).

Appin Mine
The majority of ROM coal from Appin Mine is directed to the WCCPP for processing. The CWEA is used to emplace coal wash from the WCCPP and DCPP (if beneficial reuse options are not available). ROM coal is transported to the WCCPP by:
• coal trucks from the Appin East site, along Appin and Wedderburn Roads; and
• bulk coal winder at Appin North, transported underground from AA7 and AA9.

ROM coal from Appin Mine may also be transported to the DCPP via Mt Ousley on an ‘as required’ basis to maintain work continuity and maintain reduced stockpile sizes at the Appin sites. Clean coal from the WCCPP is trucked to BlueScope Steel (Port Kembla Steel Works) coal handling facilities or to the Port Kembla Coal Terminal (PKCT) for distribution.

All coal produced at the Bulli Seam Operations (BSO) is processed at the West Cliff Coal Preparation Plant, which incorporates:
- Dense medium drum;
- Primary dense medium cyclone (“DMC”);
- Secondary DMC;
- Froth flotation cells;
- Thickening cyclone; and,
- Horizontal belt filters.

ROM coal is reclaimed and conveyed to a rotary breaker that reduces the top size of the coal. The sized coal is screened into fine and coarse material which is stored in separate coal bins prior to processing in the West Cliff CPP.

The West Cliff CPP comprises a range of components that can be generally classified into three major circuits, the coarse coal, small coal and fine coal circuits.

Each of these circuits include components that separate coal materials on the basis of size (e.g. screens) and on the basis of material type (e.g. cyclones, flotation cells, jig/drum). Each circuit has links to each of the other circuits for recycling of undersize or oversize material.

The small coal and fine coal circuits also include components that are used to dewater coal products (e.g. centrifuges) and the fine coal circuit includes components that are used to dewater coal and coal wash (e.g. thickeners, filters and tailings presses).

Dendrobium Mine
Processing of the RoM coal produced at Dendrobium Mine is undertaken at the DCPP. Coal wash is emplaced at the Appin Mine Coal Wash Emplacement Area (CWEA), directed to beneficial reuse, sold as a low-grade thermal coal or used as engineered fill under Operational Purpose Deductions (OPDs).

The Dendrobium CPP has the capacity to process up to 5.2 Mtpa of sized ROM coal.

The Dendrobium CPP incorporates:
- Heavy medium drum;
- Primary dense medium cyclone (“DMC”);
- Secondary DMC;
- Froth flotation cells;
- Drum filters;
- Horizontal belt filters; and,
- Media fluid bed dryer.

The Dendrobium CPP comprises a range of components that can be generally classified into three major circuits, the coarse coal, small coal and fine coal circuits. Each of these circuits include components that separate coal materials on the basis of size (e.g. screens) and on the basis of material type (e.g. cyclones, flotation cells, jig/drum). Each circuit has links to each of the other circuits for recycling of undersize or oversize material.

The small coal and fine coal circuits also include components that are used to dewater coal products (e.g. centrifuges) and the fine coal circuit includes components that are used to dewater coal and coal wash (e.g. thickeners, filters and tailings presses).