Summary

Mine Type	Open Pit
Status	Active
Commodities	Coal (metallurgical) Coal (thermal)
Mining Method	Truck & Shovel / Loader
Production Start	...
Mine Life	...
Snapshot	The Middlemount mine predominantly produces semi-hard coking coal and low-volatile pulverized coal injection (LV PCI) coal. The Southern Extension Project involves extension of operations at the Middlemount Coal Mine to the south and extension of waste rock emplacement areas. The Project would result in an extension of the approved mine life to 2044.

Deposit type

• Sedimentary

Summary:

The Middlemount resource contains the coal seams of the Rangal Coal Measures and Burngrove Formation of the Blackwater Group. The target seams within the resource consist of the Roper, Middlemount, Tralee and Pisces Upper seams (in descending order) which belong to the Rangal Coal Measures, while the Pisces Lower and Girrah seams belong to the Burngrove Formation and are not considered to have economic potential based on current studies.

Overlying the Rangal Coal Measures are alluvial sediments, inferred to be Tertiary in age, with a thickness of up to 30m. The depth of weathering averages 45m, ranging from 20m in the southeast to over 60m in the central and northern areas of ML70379.

The Middlemount and Pisces seams have been subjected to the majority of the exploration mining works. The Middlemount seam averages 4.0m thick in the area west of the Jellinbah Fault, ranging from less than 2 to over 7 m. The Middlemount Upper working section is a high ash section that is present over most of the Middlemount area – the exception is in the north, where it is less than 0.3m thick. The top section of the Middlemount Lower Section is predominantly dull with some bright banded coal with an average raw coal CSN average of 1 to 1.5. The base section of the Middlemount seam has more bright coal than the top section and the average raw coal CSN is 4 to 5.

The Tralee seam underlies the Middlemount seam. At Middlemount, it ranges in thickness from 0.5 to 1.0m when it occurs just below the Middlemount seam (within 10m). The Tralee seam is divided into three working sections (TL1, TL2T and TL2B, top down) and similar to the Middlemount Lower seam the working section division is predominantly based on coal brightness. Where the seam splits further from the Middlemount seam, the Tralee seam thins to usually less than 0.3m.

The Pisces Upper seam averages 4.8m thick in the area west of the Jellinbah fault, ranging from 2 to over 6 m. Thickening and thinning of the seams is interpreted to be the result due to the same structural effects as noted for the Middlemount seam, while intersections outside this range were similarly excluded from the coal thickness model. The Pisces Upper seam is divided into three working sections (PUT, PUM and PUB, top down) and similar to the Middlemount Lower seam the working section division is predominantly based on coal brightness.

The Middlemount Seam is stratigraphically equivalent to the Leichhardt seam or Elphinstone seam of the Northern Bowen Basin, or the Pollux Seam of the Central and Southern Bowen Basin and the DU and D seam of the south-eastern Bowen Basin at Moura. The Pisces Seam is the stratigraphically equivalent to the Vermont or Hynds Seam of the Northern Bowen Basin and the E seam of the south-eastern Bowen Basin at Moura. The RPM Competent Person is familiar with the characteristics of the Middlemount and Pisces seams throughout the Bowen Basin.

The potential open cut coal area strikes north-northwest and dips to the east at between 3- and 7-degrees; the deposit is approximately 7km long and 2km wide. The resource is limited to the east by the Jellinbah Fault; a major regional thrust fault which is oriented north- northwest and has displacement greater than 300m. This fault is located close to the boundary of ML70379 and ML 70417. The coal seams of the Rangal Coal Measures crop out to the west of the Jellinbah Fault, where the majority of the coal exploration has been completed. The strata present on the eastern or upthrown side of the Jellinbah Fault are from the Burngrove Formation, which are becoming visible in the highwall of the mining excavation.

Exploration drilling and mining has identified that the deposit is complicated by localised thickening of seams in the vicinity of faults. Other than the Jellinbah fault, the deposit contains small-scale (<10m) normal and thrust faults, which is evidenced by the thickened and thinned Middlemount and Pisces seam intersections and by the changes in structural elevations between boreholes.

Mining Methods

- subscription is required.

Comminution

Crushers and Mills

Processing

- subscription is required.

Commodity Production

Commodity	Units	2023	2022	2021	2020	2019	2018	2017	2016	2015
Coal (metallurgical & thermal)	Mt	....	....	....	....	2.7	3.8	3.9	4.1	4.1

Operational metrics

Metrics	2023	2022	2021	2020	2019	2018	2017	2016	2015
Coal tonnes mined	....	....	....	....	3.4 Mt	4.8 Mt	5.3 Mt	5.3 Mt	5.5 Mt
Hourly processing capacity	....	....	....	....
Coal washing plant annual capacity	....	....	....	....		5.4 Mt
Stripping ratio	....	....	....	....			10.6 bcm/t	8.5 bcm/t	7.5 bcm/t

Personnel

Job Title	Name	Profile	Ref. Date
.......................	.......................		May 18, 2024
.......................	.......................		May 18, 2024
.......................	.......................		May 18, 2024
.......................	.......................		May 18, 2024
.......................	.......................		May 18, 2024
.......................	.......................		May 18, 2024

Total Workforce	Year
......	2023
......	2022
......	2021
......	2020