1.2.3.1.4 Carmichael Coal Mine and Rail Project


Adani Mining is the proponent of the Carmichael Coal Mine and Rail Project in the north-eastern Galilee Basin, about 160 km north-west of the town of Clermont (Figure 12). The Carmichael Project proposes the development of a large scale thermal coal mine on mining lease application (MLA) 70441, which incorporates EPC 1690 (Adani Mining) and some parts of neighbouring EPC 1080 (Waratah Coal). The site is also covered by MLA 70505 (Carmichael East) and MLA 70506 (Carmichael North). Adani Mining has received consent from Waratah to lodge MLA 70441 as it includes parts of Waratah’s EPC 1080 (Adani Mining, 2013). Considerable mining-related infrastructure and coal processing and handling facilities are proposed for MLA 70441 and in nearby areas off-site. Capital investment for the life of operation is estimated at $16 billion, with the integrated coal and rail project expected to have an operational life of 60 years. A 90 year mine life was originally planned in the EIS documentation (Adani Mining, 2012), but was subsequently revised to 60 years in the Supplementary EIS (Adani Mining, 2013).

The total coal resource at Carmichael is estimated at 10.15 Gt (reported in accordance with the JORC Code). This includes 1.16 Gt of measured resource, 3.24 Gt of indicated resource and 5.74 Gt of inferred resource (Adani Mining, 2012). The black coal deposits at Carmichael are of Late Permian age, similar to the other advanced coal projects in the central-eastern Galilee Basin such as Alpha and China First. Previous exploration and feasibility studies have shown that the coal deposit underlies almost the entire area of EPC 1690 (Adani Mining, 2013).

There are five main coal seams in the project area. These have a mean thickness of 28 m and a maximum cumulative thickness of 50 m. Consistent with the widely accepted coal nomenclature for the Galilee Basin; the coal seams are designated as A-B, C, D, E and F (Table 9).

Table 9 Composite stratigraphy of the Carmichael Coal Project in the Galilee subregion


Geological age

Lithology

Stratigraphy

Thickness

Cenozoic

Clay and mudstone

40 to 100 m

Triassic

Mudstone and siltstone

Rewan Group

Late Permian

Sandstone

Bandanna Formation

Late Permian

A-B coal seam

Bandanna Formation

12 to 18 m – resource seam

Late Permian

Sandstone and siltstone

Bandanna Formation

10 m

Late Permian

B coal seam splits

Bandanna Formation

1 to 2 m

Late Permian

Siltstone and mudstone

Bandanna Formation

60 to 70 m

Late Permian

C coal seam (carbonaceous)

Bandanna Formation

3 to 4 m

Late Permian

Siltstone and sandstone

Colinlea Sandstone

2 to 20 m

Late Permian

D1 coal seam

Colinlea Sandstone

4 to 6 m – resource seam

Late Permian

Sandstone

Colinlea Sandstone

5 to 30 m

Late Permian

D2/D3 coal seam

Colinlea Sandstone

8 to 10 m – resource seam

Late Permian

Siltstone and mudstone

Colinlea Sandstone

10 to 20 m

Late Permian

E coal seam

Colinlea Sandstone

1 to 3 m – resource seam

Late Permian

Sandstone and siltstone

Colinlea Sandstone

5 to 10 m

Late Permian

F coal seams

Colinlea Sandstone

1 to 5 m – resource seam

Early Permian

Sandstone

Joe Joe Group

Source data: Adani Mining (2012)

The A-B and C seams are interpreted to belong to the Bandanna Formation, whereas the lower three seams are in the Colinlea Sandstone. The current coal resource estimate does not include the C seam due to high ash content and heterogeneous thickness (inferior raw coal). The coal seams are known to sub-crop along the eastern boundary of the project area, and dip gently to the west at relatively low angles (2 to 6°) (Adani Mining, 2012). There are four main easterly trending geological faults that cross-cut the coal seams and off-set their continuity, with vertical displacement of between 20 and 40 m.

As reported for other Galilee Basin coal deposits, overburden at Carmichael includes poorly consolidated to unconsolidated Cenozoic sediments such as sand, gravel and clay (Table 9). These have a mean thickness of 74 m, but may be over 100 m thick in some places. In the west of the project area the coal seams are overlain by up to 400 m of weathered Triassic rocks, comprising the Dunda beds and the predominantly fine-grained Rewan Group (Adani Mining, 2012). Interburden between coal seams includes some sections of predominantly sandstone and siltstone, with other sections consisting mostly of finer-grained rocks such as mudstone. These are also of variable thickness, with some being less than ten m thick (e.g. the strata separating seams E and F), and others over 60 m thick (between the B and C seams).

Even by world standards, the proposed Carmichael mine will be a massive development and, if it reaches its expected full production capacity by about mid-2020, it will be Australia’s largest coal mine (Adani Mining, 2013). The proposed maximum annual production rate of 60 Mt will be sourced from a combined open-cut and underground mining operation (Figure 15). The project has been designed to achieve this production objective within approximately the first ten years of operation, and aims to maintain a steady annual production rate for the following 15 years (Adani Mining, 2013). Annual production rates from the open-cut operations alone are expected to remain steady at around 40 Mt for over 25 years (from about 2024 to 2050). Underground mining, which will operate concurrently with open-cut mining, is expected to last for about 40 years, starting around 2020 and finishing in 2060 (Adani Mining, 2013).

Key components of the proposed Carmichael mine and its on-site infrastructure include:

  • open-cut mining operations will be progressively developed across six separate pits, and will aim to produce 40 Mt of coal per year. Simultaneous mining operations will occur in up to six pits at a time, and the total strike-length of open-cut pits is likely to exceed 30 km (Figure 15)
  • three independent underground longwall mines will operate concurrently with the open-cut operations. These will mine two seams over a 45 km north to south area, with 300 m longwall panels, an expected panel length of 5000 m and an extraction face three to five metres high
  • mine infrastructure area (MIA), which includes a rail balloon loop
  • coal handling and processing plant (CHPP) with maximum processing capacity of 74.5 Mt of raw coal per year
  • out of pit waste rock dumps – the expected volume of overburden and interburden to be removed for mining is estimated at over 13 billion bank cubic metres (bcm). Where possible, waste rock will be permanently stored in mined open-cut voids
  • mine water management dams.

Figure 15

Figure 15 Carmichael mine plan and associated infrastructure areas in the Galilee subregion

Source data: derived from Figure 2.2 in Queensland Coordinator-General (2014)

Adani Mining (2013) indicated that the overall mine concept and infrastructure components are unlikely to change from the plans outlined in the Supplementary EIS, although further refinement of planned mining operations may occur based on updated geological exploration and geotechnical data.

Off-site infrastructure that may be developed to support the mining operations includes quarry pits, a workers accommodation village and associated facilities, a heavy industrial area and a new airport with a 3000 metre long airstrip. Adani Mining proposes for the bulk of the 3500-strong operational workforce to access the site via a fly-in/fly-out roster (Adani Mining, 2012). Water supply infrastructure is also required for extraction, storage and delivery of up to 12.5 GL/year.

The large scale of the mining operations at Carmichael requires a significant investment in equipment and plant. Open-cut operations propose to mainly use conventional truck and shovel equipment for stripping overburden and extracting coal, probably in combination with bucket wheel excavators, draglines and continuous haulage systems (Adani Mining, 2013, although exact mining details were not yet finalised in the Supplementary EIS). The three underground longwall mines will require standard equipment such as hydraulic shields for roof support, coal shearers to cut the coal from the working face, and conveyor systems to transport coal to the surface ROM pads (Adani Mining, 2013).

The west to east flowing Carmichael River transects the central part of the proposed mining area. A 51 hectare exclusion zone has been proposed to provide a protected corridor around the Carmichael River (Figure 15). This corridor has a minimum width of 500 m either side of the centre of the river to minimise impacts to the river and associated riparian zone.

All coal mined at Carmichael is expected to be transported via privately owned railway connecting to existing rail infrastructure near Moranbah in the Bowen Basin (the Goonyella and Newlands rail system) (Adani Mining, 2012). Coal will then be shipped to international markets (mainly India) via the coal export terminal at either Abbott Point or Hay Point. The development of this 189 km long greenfield rail link forms part of the integrated Carmichael development project. The rail system may consist of sections with dual gauge and narrow gauge tracks, as well as reception and departure lines at each end, and an 18.7 km long balloon loop loading line (Queensland Coordinator-General, 2014).

In May 2014 the Carmichael Project obtained conditional approval to proceed (Queensland Coordinator-General, 2014). In late July 2014, environmental approval was also received from the Australian Government under the EPBC Act. As of August 2014, the remaining stages in the overall pre-mining approval process are granting of the current mining lease applications that cover the proposed Carmichael development, and issuing of an environmental authority (EA) to conduct mining related activities. If the ML and EA are granted, construction of the first open-cut pit is planned to commence in 2015 (based on the schedules in Adani Mining, 2012), with the first underground workings starting around 2018 or 2019. Mining operations will initially begin in the northern sector of the lease, with the southern part to be developed in later stages. If construction goes to schedule, first coal production is expected from open-cut pits in 2016, and from longwall operations in about 2020.

Activities associated with construction, maintenance, rehabilitation and decommissioning of mine operations and infrastructure may occur as needed throughout the operational life of the project. Final decommissioning and rehabilitation is scheduled to start in 2071 (Queensland Coordinator-General, 2014).

Last updated:
5 January 2018
Thumbnail of the Galilee subregion

Product Finalisation date

2014
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ASSESSMENT