Summary

Deposit type

• Sedimentary

Summary:

The Poitrel coal deposit is located within the Rangal Coal measures and includes the well-known Leichardt and Vermont seams. At Poitrel the seams split and coalesce within the deposit and the faulting has been well mapped with 3D seismic.

The main economic target at Poitrel is the Leichardt Seam, which is typically five metres thick with a bright basal 0.5 metre section which splits off the seam floor in the north to form the Lower Leichhardt Split (L4 Ply). The Leichhardt Seam is divided into 6 plies:
• Ply 1: upper 0.2m is typically dull, very high ash coal;
• Ply 2: next 0.6m is low ash with a moderate Crucible Swell Number ( CSN);
• Ply 3: next 1.0m is also low ash but has poor CSN. Base of Ply 3 is marked by a stone band, which is not always present across the deposit;
• Below the stone band are Plies 4 and 5 which have moderate CSN’s of 2.5-3.0 and are 1.15 and 1.50 metres thick, respectively; and
• Ply 6 is the Leichhardt 4 seam (formerly the LB Seam) where it coalesces with the Leichhardt Seam. It has a moderate ash but good CSN of 6. Top of Ply 6 is identified by two thin stone bands over most of the deposit (remnants of the L3-L4 parting).

For economic assessment (modelling), Leichhardt Seam is broken into three sections L12, L3 and L4, with a reasonably persistent stone band marking base of L12. Studies indicate duller L12 is more suited to producing PCI / Thermal product than Coking. Brighter L3 is For personal use only more suited to producing a Coking and PCI product. Previous exploration drilling near the western boundary of the Mining Lease revealed Leichardt Seam splitting. L3 ply splits into L31, L32, L33 and subsequent L312, L323.

In parts of the deposit, L4 splits off Leichhardt Seam floor in the north. It is typically 0.6 metres thick, characteristically bright, with raw ash averaging 14.6%. Leichhardt full seam raw ash is typically 17% air dried basis (adb).

The Vermont sequence is made up of the Vermont upper and lower seam sequence (V1, YT, V2, V3, VL and VLL).

The Vermont Upper 1 (V1) Seam is typically 1.6 metres thick, and like L4 is a bright seam with coking potential, with raw ash is typically 15%. Midburden between L14 and V1 varies in thickness from 15 to 20 metres, and averages 18.9 metres.

The transition between Rangal Coal Measures and Fort Cooper Coal Measures is generally clearly marked by the Yarrabee Tuff, a basin-wide marker bed comprised of weak, brown tuffaceous claystone. At South Walker Creek the Yarrabee Tuff band divides Hynds Seam (HY-HB), and at Poitrel divides the Vermont Seam (V23 - VL).

Dimensions
The main economic seams are L13, L4 and V1. These seams are consistent throughout the Poitrel lease but the L4 seam splits into L4U and L4L in central areas and the L3 component of the L13 splits into 3 plies in the far west of the lease. The L13 seam exists from 2-150m depth and is between 20-60m depth in general. The V1 seam exists from 15-195m and is between 50-90m depth in general. The deposit extends along strike for approximately 9.5km and has a maximum width of approximately 4km.

Mining Methods

• Truck & Shovel / Loader
• Dragline

Summary:

Poitrel is an open cut coal mine producing a mix of approximately 65% hard coking coal (“HCC”) and 35% PCI.

Coal is mined using conventional open-cut strip mining methods, employing a mix of truck and/or excavator, and dozer push mining.

General activities undertaken in the mining process at the Poitrel include:
• Land clearing and topsoil removal.
• Overburden / inter burden drilling and blasting.
• Excavator and truck stripping.
• Dozer stripping.
• Excavator and truck parting removal and post stripping.
• Dragline stripping.
• Coal ripping and pushing.
• Coal loading and hauling.
• Pit preparation and dewatering, and
• Reclamation.

Geology and topography of the Poitrel mine area is such that the strip-mining technique has been adopted as the mining method. Initial mining operations commenced on the sub-crop of the Main seam in 1996 and 2006 respectively using fleets of excavators and trucks as the primary overburden removal tools to uncover coal in strips orientated along the strike of seam.

Mining then progresses along strike and down-dip to the lease boundary or to a depth of maximum economic strip ratio, at which point a transition to underground mining may commence. Mining strips and blocks are aligned with current pit voids along strike and extended down dip to the lease boundaries. Allowances are made for permanent access corridors, major transport corridors and major creek corridors between pits. Coal mining is achieved by a fleet of large front end loaders and excavators loading onto bottom dump and rear dump haulers. The haulers run from the pit to the crushing and processing plant along a haul road network. For blending requirements, the haulers are required to stockpile the coal along designated locations.

Overburden stripping at Poitrel will be primarily Cast and Dozer Excavate (CDX) operations.

Typical Open Cut Pit Design
Pit Width (m): 55-65;
Highwall Angle (Degrees): 45-70;
Lowwall Angle (Degrees): 37;
Highwall Berm (m): 10-30;
Stripping Method: Cast Dozer Excavator & Truck and Shovel.

Poitrel Southern Levee & Ramp 10 Box Cut
The Southern Levee Extension Project is now complete including receipt of levee certification. The construction of a water pipeline connecting the northern pits with the mine’s dams has been completed, providing improvements to the site’s water transfer capability.

In 2024, Poitrel achieved production and sales records. The successful completion of the Ramp 10 box-cut has been a critical step in maintaining a balanced life-of-mine strip ratio to ensure long-term operational competitiveness. Performance has been further strengthened through strategic fleet replacement activities.

Comminution

Crushers and Mills

Processing

• CHPP
• Crush & Screen plant
• Desliming
• Centrifugal concentrator
• Spiral concentrator / separator
• Wash plant
• Flotation
• Dense media separation

Summary:

Coal is washed at the modern Red Mountain CHPP, with a capacity is 9.6 Mt (ROM coal).

Poitrel Coal Handling & Preparation Plant consists of the ROM (Run of Mine) dump hopper and crusher, the coal processing plant, product stockpile and train load-out facilities.

ROM coal is either direct fed or stockpiled prior to crushing on various ROM stockpiles. Coal is fed by front end loader or trucks from the ROM stockpiles into a hopper. The required blend of ROM coal is achieved by selecting coal from specific ROM stockpiles. The crushing stations crush all feed to the processing plants. The processing plants are heavy medium plants with fines circuits. The crushing stations crush all feed to the processing plants. The processing plants are heavy medium plants with fines circuits.

Coarse rejects are back hauled to reject disposal dumps. Plant tailings are hauled into the pit (sieves) in Poitrel and pumped into tailings dams at South Walker Creek. The decant water is pumped back to the plant and used in the process water circuits. Product stockpile arrangement comprises an overhead tripper system which has access to all 4 bays of the stockpile area. Coal is reclaimed via reclaimers located in a reclaim tunnel. Dozers are used to manage coal on the stockpile. The standard moisture content of feed is 4%. Metallurgical Coal and Pulverised Coal Injection (PCI) produced is processed and blended to meet product quality specifications. The generic process of beneficiation employed is as follows.

• Raw coal from the operations is fed into hoppers and is crushed by rotary breakers to -50mm. Oversize material from each of the rotary breakers contains mostly stone and tramp materials and is rejected and dumped at specific reject dumps.

• New raw coal handling facilities reduce the size of raw coal into - 50mm in a series of sizers. There are no rejects from this process.

• Raw coal at -50mm reports to the CHPP. All coal is distributed via desliming screens to coarse and fines circuits. In the coarse circuit, dense medium cyclones separate coal and the denser non-coal by passing the material through a dense medium via centrifugal force. Fine coal is cleaned through either classifying cyclones, froth flotation or spirals. In some CHPP, reflux classifiers were added into the fine circuits to further recover the coal fines.

• Coarse rejects are hauled back to disused ramps or pits for disposal. Fine rejects are thickened before being discharged into tailings disposal dams.

In 2023, Stanmore Resources completed maintenance and upgrades of Coal Handling and Processing Plant (CHPP) at Poitrel.

Water Supply

Summary:

Groundwater – Braeside Borefield, this is a Stanmore-owned borefield and is the source of raw water for Poitrel Creek.

In 2024, major upgrades were completed at the Braeside borefield resulting in higher efficiency and control of transfer. Upgrades included a communication tower upgrade, aeration and balance tank replacements, foundation bank stabilisation, aerator and high lift pump upgrades.

Commodity Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
Chief Operating Officer	Leandro Pires		Jun 16, 2025
Maintenance & Engineering Manager	Kyle Hughes		Jun 16, 2025
Maintenance Superintendent	Kailyb Gray		Jun 16, 2025
Mine Planning Superintendent	Tom White		Jun 16, 2025
Technical Services Manager	Ekin Eraydin		Jun 16, 2025