Overview

Deposit type

• Sedimentary

Summary:

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.

Mining Methods

• Longwall

Summary:

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 transitioned wholly to AA7 and AA9 following completion of longwall mining activities at Appin North (West Cliff Area 5) in early 2016. In FY23 AA9 operations were completed, and operations have transitioned wholly to AA7. 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) 709 commenced on 22 February 2022 and as of the end of the reporting period had retreated approximately 2034 m with an estimated completion in September 2023.

Extraction of LW905 commenced on 25 September 2022 and was completed on 28 February 2023.

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 3C (LW21). 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.

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.

Comminution

Crushers and Mills

Summary:

Appin
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.

Dendrobium
Coal is transported from the underground workings to the KVCLF via a conveyor network, reaching the surface via the Kemira Valley Tunnel. 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.

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

Processing

• Wash plant
• Crush & Screen plant
• Jig plant
• Dry Screening
• Flotation
• Dense media separation
• Dewatering
• Filter press

Summary:

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).

Water Supply

Summary:

Appin mine
Groundwater
Appin West
During the reporting period, groundwater from the Appin underground operations was pumped to the surface at Appin West for treatment via the Appin West Water Treatment Plant (WTP). The treated water is piped underground for reuse, and/or discharged to the environment via LDP 24. The WTP has the capability to blend the treated water if required for reuse underground or to discharge to the environment.

Appin East
During the reporting period, groundwater from the Appin Mine White Panel storage area was pumped to the surface and stored in a 1,400 L tank at Appin East. The water is dosed with sodium hypochlorite to inhibit microbiological growth, before being re-used underground for fire suppression, and mineservices uses (hose-down of mobile and stationary assets, belt maintenance, etc.).

Appin North
Water for underground use is transferred from Brennans Creek Dam (BCD) to the underground operations via a gravity fed pipeline. Water make resulting from strata water inflow is collected in pits and low points in the underground workings where it is mixed with water delivered underground from surface storage. This strata water is brought to the surface either as moisture contained within the coal or as surplus underground water. Groundwater and surplus mine water can be pumped to the surface from Area 5 if required which can be treated at the Appin North WTP (previously temporary WTP prior to January 2023). During the reporting period approximately 24 207.5 ML of water was transferred underground from BCD with 400.8 ML of surplus underground water pumped to the surface to be processed in the Appin North WTPs. The remaining ~508 ML25 of BCD water was used in the West Cliff Coal Preparation Plant (WCCPP), for dust suppression (watercarts), washdown and the truck wash. Excess water in Pond 3 and Pond 4a was periodically used for dust suppression on the active CWEA with the water being filtered through the CWEA before entering the emplacement underdrainage system. Overflow water from P4a entered the emplacement pond system via the overflow pipe to EP2.

The Appin North temporary WTP was decommissioned and replaced with the Appin North WTP in January/February 2023. Both plants treated groundwater pumped to the surface from Area 5. The treated groundwater that meets required limits is then discharged directly to Brennans Creek as permeate via LDP 40. Non-conforming water is discharged into a drainage line that feeds BCD.

The Appin North WTP is able to treat water currently stored in Area 5, as well as underdrainage from the CWEA water management system. It is also planned for the backwash water to be treated following the implementation of Appin North backwash trial.

There were no incidents of groundwater pollution within the report period.

Water Supply and Use
Appin West
Mine water is processed at the Water Treatment Plant (WTP), which has two trains (Integrated Membrane System (IMS) 1 and 2) to produce treated water (permeate). This treated water is supplied to the Appin Mine underground mining operations. Any shortfall in underground supply is supplemented by potable water provided by Sydney Water. Excess permeate is blended with backwash water and discharged to the environment via LDP 24. Potable water is used for site administration buildings, workshops, the bathhouse, fire emergency services, Appin West Gas Extraction Plant, and as a back-up for underground operations.

Appin East
Potable water is supplied by Sydney Water to the Appin East site via a 600 kL surface tank. This tank provides potable water for the bathhouse, workshops, administration buildings, fire emergency services, Ventilation Shaft 2 site, EDL Appin East Power Plant, and nearby mine-owned cottages. Surface water runoff from rainfall is captured in the main surface dam and is reused as supply for the dust suppression on haulage roads and stockpiles, along with the dirty equipment hose down.

Appin North
The Appin North site is primarily reliant on water from Brennans Creek Dam (BCD). Some potable water is trucked to site and stored in a surface tank for use in the bathhouse and office facilities. Most water is sourced from BCD from where it is pumped, following chlorine dioxide treatment, for use in the following areas:
• underground areas for dust suppression;
• WCCPP and associated infrastructure; and
• Appin North Pit Top.

Dendrobium mine
Underground and surface operations at Dendrobium utilise a combination of potable and recycled mine water.

Potable Water Use
Potable mains water, supplied by Sydney Water, is currently used for the longwall hydraulic roof supports (emulsions used underground require high quality water for batching) and surface amenities such as the kitchen and bathhouse facilities. Potable water is also used for fire suppression sprays installed in FY20, which are connected to the fire water tank. Potable water usage for the reporting period for underground was 4.68 ML, which is a 9% increase compared to the previous reporting period. The total potable water used for both underground and surface operations was 56 ML for the reporting period.

Recycled Water Use
Recycled water is sourced from the Nebo Workings and used for various purposes on the surface and for underground operations. In this reporting period, a total of 511.55 ML of recycled water was used. These purposes include:
• Surface Operations:
- Dust suppression along the Portal Road.
- Cleaning of vehicles and equipment in the wash down bay.
- General hose down.
- Cleaning and firefighting.
• Underground Operations:
- Secondary support activities. o Development and production units. o Dust suppression and firefighting supply

Dendrobium Coal Preparation Plant (DCPP)
Industrial water is supplied by Sydney Water mains via the BlueScope Steel water network. Industrial water consumption in FY23 was 246,427 kL, compared to 290,383 kL in FY22.

The stockpile operations reuse water from the sediment dams (No. 4 Area). Industrial water is used to ‘top up’ the systems as required due to water loss on vehicles and to the environment.

Potable water is supplied to the DCPP by Sydney Water mains via the BlueScope Steel water network. Potable water consumption in FY23 was approximately 4,988 kL, which is based on the assumption of 466 litres per person per day.

Water produced from the DCPP is managed through the BlueScope Steel EPL. Illawarra Metallurgical Coal (IMC) advises BlueScope Steel if discharges of water from the DCPP occur.

Production

Personnel

Job Title	Name	Phone	Email	Profile	Ref. Date
Electrical Engineering Manager	Greg Campbell				Jan 2, 2024
Engineering Manager	Ben Patten				Jan 2, 2024
Engineering Manager	Peter Quinn				Jan 2, 2024
Engineering Superintendent	Steve Coffee				Jan 2, 2024
Environmental Superintendent	Chris Schultz	+61-2-4286-3384	Chris.Schultz1@south32.net		Jan 2, 2024
Maintenance & Mine Services Superintendent	James Hutton				Jan 2, 2024
Maintenance Manager	Quinton Wilkinson				Jan 2, 2024
Mine General Manager	Andy Hyslop	+61-2-4629-4752			Jan 2, 2024
Mine General Manager	Simon Thomas	+61-2-4255-4874			Jan 2, 2024
Operations Superintendent	Mark Beale				Jan 2, 2024
Technical Services Manager	Russell Thomas				Jan 2, 2024
Ventilation Specialist	Mark Hockey				Jan 2, 2024
VP Operations	Peter Baker				Jan 2, 2024