The approved mining area contains a multi-seam coal deposit consisting of eight economically viable open-cut mineable coal seams. Bengalla currently extracts coal from the Warkworth seam to the Wynn seam (previously to the Edderton) which form part of the Whittingham Coal Measures.

Bengalla is situated on the western limb of the Muswellbrook Anticline with the coal seams generally dipping to the west at approximately 5 degrees. The average strip ratio at Bengalla is approximately 3.5 bank cubic metres (bcm) of overburden to each ROM tonne (t) of coal recovered.

Initial and continuing exploration programmes over mining tenements are planned with borehole spacing at approximately 600m. These boreholes include a mixture of open and cored holes and provide a broad understanding of the lithology, quality, gas and other properties in future areas.

Mining Method: Open Cut – Dragline, truck and excavator (machinery will be progressively upgraded). Mining operations and coal processing 24 hours per day, seven days per week.

The mine is designed as a dragline strip mine with pre-strip undertaken by excavator and truck fleets. The dragline has an operating radius of 105m and a nominal digging depth of 55 m and a dumping height of 55 m.

The mining sequence for the pre-strip fleet at Bengalla begins with topsoil removal and stockpiling, then continues into the cyclic process of drill and blasting of the overburden/interburden, moving the overburden/interburden with loading units and trucks to the OEA to uncover the coal seam. The coal is then mined with loading units and trucks to be transported to the temporary ROM coal stockpile and/or ROM Hopper to be processed. This process is repeated until the lower dragline horizon is reached where a similar process is followed with the main difference of the dragline moving the majority of the interburden from highwall to low wall instead of loading unit and trucks. As each strip is completed, the void created from the mining process is backfilled with the interburden from advancing strips. Once the OEA has reached the final landform height, reshaping is completed and topsoil is then removed from existing stockpiles or directly from the advancing pre-strip and used on the shaped landform to start the rehabilitation process.

The pre-production drilling program was suspended in November 2020 due to business requirements, and will likely resume in H2 of 2021. [Annual Review 2020, p.25]

Coal is transported via haul trucks from the mine to the temporary ROM coal stockpiles and/or the ROM hopper which has an approved capacity of 2600tph (tonnes per hour). The first stage of coal processing involves crushing ROM coal to less than 250mm in size. The crushed coal is then transported along a conveyor to a secondary crushing station where it is reduced to less than 50mm. After crushing, coal can be bypassed to product, direct fed into the CHPP or transported and stockpiled on the raw coal stockpile via conveyors.

CHPP including facilities to wash or bypass coal, 2600tph throughput of ROM Hopper and CHPP, CHPP stockpile capacity of approximately 1,215,000t, train load out capacity of 5,000tph, rejects are loaded into trucks and co-disposed in the OEA.

Bengalla’s CHPP currently has three coal stockpiles in the handling and preparation process. The Raw coal stockpile has a capacity of up to approximately 200,000t and the two product stockpiles hold a combined volume of up to 500,000t. Current approvals is for approximately 1,215,000t CHPP stockpile capacity.

The CHPP is a two stage plant that can change from single stage to two stage washing when required and has an approved capacity of 2,600tph. A combination of dense medium cyclones (DMC) and single stage spirals are utilised to process coal. After processing, the product coal is centrifuged for the purpose of moisture reduction and then stacked onto one of the two product coal stockpiles.

Product (includes bypas ........