Along the structurally disturbed north-eastern edge of the Bowen Basin, the coals range in rank from anthracite to low volatile bituminous, and deposits tend to exhibit a complex structure. Coals in the central part of the basin are medium to high volatile bituminous and include the best coking coals. Structural deformation in these deposits is generally relatively mild.

Coal-bearing horizons have been preserved at many stratigraphic levels throughout the Bowen Basin, but deposits of economic importance are restricted to four groups.

Group II coal measures, also of Early Permian age, occur as several unconnected deposits located around the northern and western margins of the basin. These include the Collinsville Coal Measures in the north, the Rugby Coal Measures south-west of Moranbah, and a group of deposits in the Clermont area, including the Blair Athol and Wolfang Basins, which are structural outliers of the Bowen Basin. The Calen Coal Measures, which occur near the coast north of Mackay, are also considered to be of similar age.

Wolfang Coal Measures of Lower Permian age, essentially flat lying, but with steep dips near faults along the western margin of the deposit. The main seam of economic interest, the Wolfang seam, averages 38m in thickness in the initial mine area. A further five relatively thin unnamed seams of variable thickness and distribution also occur, but these contain less than 5% of the planned mining reserves.

Clermont Open Cut is a truck and shovel operation. The major seam mined is the Wolfang seam, typically between 35-40 metres

Pit wall designs are based on specific pit slope geotechnical design sections for the western pit wall and geotechnical guidelines for the remaining walls to ensure stable final pit slopes. Roadways included in the east and west pit walls provide in-pit haulage access for a haul back mining method, while also improving geotechnical stability of these pit walls. Other specific geotechnical measures to ensure pit wall and waste dump stability have been included in the mine plan and mining costs.

The pit is overlain by up to four separate basalt flows with total thickness up to 90m in the north and thinning to the south. The basalt represents 40% of the overburden waste and is highly variable in rock mass strength. The remainder of the overburden waste is relatively weak being made up of claystone, gravels, Permian coal measure sediments and minor volumes of basal conglomerates and metamorphic rock types.

Pit development to the south of the box-cut involves benching of east-west strips in a step wise sequence, uncovering coal as the strips progress to pit bottom. Pit access from the surface is via the advancing waste faces and in-pit waste dump faces.

The low Run of Mine strip ratio (3.2:1) and minimal processing (90% coal does not require washing) combined with the high quality coal, means the mine has a first quartile margin position in the seaborne thermal coal market.

All ROM coal feed will be crushed and sized at Clermont prior to being transported to the existing Blair Athol product stockyard via a 13.3 km overland conveyor of a nominal 2900 t/h capacity.

About 2.3% of ROM coal will be washed subject to market conditions with the remainder directly
bypassed.

The wash plant capacity will be around 300 tonnes per hour, utilising dense media cyclone and spiral gravity separation. Non-coal reject will be placed in impoundments and then buried with overburden waste.

After processing at Clermont, coal is transported by an overland conveyor to the stockpile and rail loading facilities at the nearby Blair Athol mine. The coal is exported primarily through the Dalrymple Bay Coal Terminal.