The coal resource at the Duralie Coal Mine (DCM) is located within the Permian aged Gloucester Basin in NSW. The DCM is located in the southern closure of the main synclinal structure of the Gloucester Basin and is associated with the coal bearing strata of the Dewrang Group. The Dewrang Group comprises three main stratigraphic units, namely: Mammy Johnsons Formation; Weismantels Formation; and Duralie Road Formation. The coal seams mined at the DCM include: • the Weismantel Seams; • the Clareval Seams; and • the Cheerup Seams. The underlying basement rocks are principally volcanics of Early Permian (i.e. Alum Mountain Volcanics) and Carboniferous age that were folded during formation of the Gloucester Basin. The Early Permian and Carboniferous volcanic rocks are typically erosion resistant and form the more prominent ridges to the east and west of the DCM.

The Duralie Coal Mine (DCM) is an open cut truck and shovel operation.

The operations extract ROM coal from the Weismantel and Clareval seams at the base of the Gloucester Coal Measures. The deposit forms a synclinal structure with the open cut area located at the southernmost crop line within the main axis of the Gloucester Basin. The operation is now situated on the west limb of the syncline with seams dipping at about 50 degrees east. Mining is undertaken within ML1427 and ML1646 and includes the extension of the Weismantel pit to the north west and the inclusion of the Clareval seam parallel and to the west of the Weismantel seam.

Dips within the deposit vary from a shallow 5 degrees to an almost vertical profile. Consequently, a method of horizontal 3m to 4m benches is used as the primary extraction method. An average of 5m of free dig material is generally experienced at Duralie after which all waste material generally requires blasting.

Mining at the DCM was postponed in October 2018. Since this time periodic rehabilitation and PAF rehandling works have been undertaken. Mining at the DCM recommenced in February 2021 with ROM coal being extracted from the Weismantel Pit.

Mining in the Clareval pit was completed during September 2017. Clearing in advance of mining up to the approved disturbance limit in both Weismantel and Clareval was completed in 2018. No further clearing is proposed for the Duralie Extension Project (DEP).

44,953 tonnes of ROM coal was mined at the DCM during the reporting period (1st July 2020 to 30th June 2021). Approximately 250kt of ROM coal is remaining in the Weismantel pit and is intended to be extracted prior to the end of 2021.

Waste rock (including overburden and interburden) mined during the development of the Weismantel open pit will continue to be placed within the existing Waste Emplacement. Waste rock will also continue to be used to partially backfill the Weismantel and Clareval open pits.

Clareval Open Pit
Mining of the Clareval open pit has been finalised and the pit has been developed to a final depth of -81 m AHD. During the MOP/RMP term, activities at the Clareval open pit will include partial backfilling of the void with waste rock mined from the Weismantel open pit, and placement of potentially acid forming (PAF) material (from existing stockpiles on the Waste Emplacement) within the pit and capping with non-acid forming (NAF) material. Activities will also include ongoing rehabilitation of the southern extent of the Clareval open pit area including re shaping to its final landform design.

Weismantel Open Pit
The Weismantel open pit will be active throughout the MOP/RMP term and will be developed up to approximately Relative Level (RL) -8 m deep. After the cessation of mining of the Weismantel open pit (beyond this MOP/RMP term), the Weismantel open pit will be partially backfilled with PAF material (from existing stockpiles on the Waste Emplacement) and capped with NAF material. Activities will also include ongoing rehabilitation of the southern extent of the Weismantel open pit area including re-shaping to its final landform design.

The Duralie Coal Mine (DCM) is an open cut truck and shovel operation located approximately 20km south of the Stratford Mine facilities, producing ROM coal, which is railed to the Stratford Mining Complex (SMC) and processed at the SMC Coal Handling and Processing Plant (CHPP). Product coal is transported via train on the North Coast Railway to the Port of Newcastle.

Duralie CHP Throughput and Rejects Management
ROM coal is initially handled at the Duralie Coal Handling Plant (CHP). Rock greater than 140 mm is removed from ROM coal using a rotary breaker at the CHP. The separated rock is conveyed to a rejects bin from which it is loaded out and trucked to be buried on site as potentially acid forming (PAF) waste. The ROM coal is then transferred via conveyor to a train loadout bin and railed to the Stratford Mining Complex (SMC) via a shuttle train.

Reject fractions from the ROM coal are generated at the SMC and deposited along with processing waste fractions ........