Mining Intelligence and News

Dartbrook UG Mine

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Mine TypeUnderground
  • Coal (thermal)
Mining Method
  • Bord-and-pillar
Production Start... Lock
Mine Life... Lock
SnapshotDartbrook Mine – a world class asset, targeting first coal in the first quarter of 2024. Dartbrook has excellent infrastructure, a large reserve and resource base, proximity to rail and port facilities, and skilled labour availability

- Excellent Location, infrastructure network in-place
- High quality coal specifications (NEWC)
- 5-year underground mining licence to December 2027, with potential for extension through to at least 2033 (MOD8)
- A JORC compliant underground mining Resource of 1.25 Bt with ROM Reserves of 470 Mt and Marketable Reserves of 370 Mt
- Coal clearance system through the dewatered Hunter Tunnel direct to the CHPP avoids any interaction between operations and the New England Highway
- Multi-seam reserve – underground seam access already developed to multiple seams

Positive outcomes achieved in 2023: Enabled successful completion of Hunter Tunnel dewatering, continued remediation works, and revised Mine Plan.
Related AssetDartbrook OP Project


Tetra Resources Pty Ltd. (operator) 20 % Indirect
Australian Pacific Coal Ltd. 80 % Indirect
27 September 2022 - Australian Pacific Coal Limited (AQC) entered into a binding agreement with Trepang, Tetra and M Resources in relation to a joint venture to see Dartbrook re-commissioned as a coal-producing mine.

On May 1, 2023, the binding term sheet announced in September 2022 has been renegotiated. The key terms of the restructured JV are:

- AQC retains the majority direct working interest which has increased from 50% to 80%.

- Tetra remains a direct JV participant with a 20% working interest and remains the mine Manager and Operator.

- Trepang will no longer have a direct working interest in the JV.

- M Resources will receive a 10% indirect economic interest in the JV through AQC.

AQC holds an 80% joint venture interest (70% economic interest) in the Dartbrook thermal coal project.



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Deposit type

  • Sedimentary


Regional Geology
Dartbrook Mine is located in the northern part of the Hunter Coalfield and west of the Muswellbrook Anticline. The strata of the Permian Whittingham Coal Measures outcrop in the area and dip gently to the west. The underlying marine sediments of the Maitland Group outcrop approximately 3 km east of the site, on the eastern side of the Aberdeen Thrust. The Hunter Thrust, which represents the northern limit of the Sydney basin, is located further to the east (HLA-Envirosciences, 2000).

The Greta Coal Measures occur below the Maitland Group. These seams occur at depths in excess of 1,000 m at Dartbrook Mine (HLA-Envirosciences, 2000).

The Whittingham Coal Measures contain the coal bearing Jerrys Plains Subgroup and Vane Subgroup. Within the basin, these two subgroups are typically separated by the Archerfield Sandstone, which is a massive, well sorted sandstone unit. However, in the vicinity of Dartbrook Mine, there is no vertical separation between these subgroups, as the Bayswater Seam (the base of the Jerrys Plains Subgroup) has coalesced with the Wynn Seam (the top of the Vane Subgroup) (HLA-Envirosciences, 2000).

Four of the five main coal bearing formations within the Jerrys Plains Subgroup (namely the Malabar, Mt Ogilvie, Mt Thorley and Burnamwood Formations) are present at Dartbrook Mine. The coal seams within the Jerrys Plains subgroup generally exhibit a high degree of splitting, and major seams are generally represented by several plies / splits (HLAEnvirosciences, 2000).

Interburden strata within the Jerrys Plains Subgroup generally include interbedded sandstones, siltstones and mudstones with minor claystones and tuffs and occasional conglomerates and thin siderite. These strata are generally coarse-grained in the upper sequence (above the Vaux Seam) and become progressively finer with depth to the Bayswater Seam. Non-coal units in the Vane Subgroup are generally fine to medium grained sandstones (HLA-Envirosciences, 2000).

Local Geological Characteristics
The coal seams at Dartbrook Mine are characterised by gentle dips (ranging from 3 to 6 degrees) to the north-west. Local variations of up to 15 degrees have been identified. These are generally interpreted as being due to clastic wedging, seam splitting and differential compaction (HLA-Envirosciences, 2000).

Dykes and faults are generally well defined due to their presence in historical underground workings at Dartbrook Mine. Faults trend from north-west to south-east, with significant displacements being confined to the Kayuga fault zone, its north-western branch, and the west, north-western fault zone. There are two major dykes at Dartbrook Mine. The Great Wall of China dyke is estimated to be 25 m thick and the Roman Road dyke is approximately 15 m thick. Dykes tend north-east to south-west and have cinder zones of less than 1.5 m. There are seven minor dykes south of the Roman Road dyke. These are generally 0.5 to 2.5 m thick, deeply weathered and of low strength. A number of igneous plugs have been interpreted. The Kayuga plug is approximately 200 m x 400 m in size and its location has been confirmed by exploration activities.

Coal Seam Geology
The target seams for underground mining at Dartbrook Mine are the Wynn, Kayuga, Mt Arthur and Piercefield Seams. To date, mining operations have been undertaken in the Wynn and Kayuga Seams. The Kayuga Seam, one of the uppermost seams, is the target seam for the Modification. At Dartbrook Mine, the Kayuga Seam lies at depths of 20 m (subcrop) to over 300 m.

The Kayuga Seam is characterised by bituminous, high-volatile and low sulphur content coal. The seam occurs as a series of plies and splits which diverge and coalesce across the site.



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Mining Methods


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Crushers and Mills

Milling equipment has not been reported.



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Coal (thermal) Mt  ....  Subscribe
All production numbers are expressed as clean coal. ^ Guidance / Forecast.

Operational metrics

Coal tonnes mined  ....  Subscribe
ROM coal, LOM  ....  Subscribe  ....  Subscribe
Annual processing capacity  ....  Subscribe  ....  Subscribe
^ Guidance / Forecast.
* According to 2023 study.

Production Costs

Total cash costs (sold) Coal (thermal) USD  ....  Subscribe  ....  Subscribe
Assumed price Coal (thermal) USD  ....  Subscribe
^ Guidance / Forecast.
* According to 2023 study / presentation.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M AUD  ......  Subscribe

Heavy Mobile Equipment

Fleet data has not been reported.


Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Dec 12, 2023
....................... Subscription required ....................... Subscription required Subscription required Dec 12, 2023

Total WorkforceYear
...... Subscription required 2023

Aerial view:


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