Coal-measures in the Bingay Main area are hosted by the Mist Mountain Formation of the Kootenay Group, of latest Jurassic to earliest Cretaceous age. The Mist Mountain Formation is underlain by Jurassic rocks of the Morrissey and Fernie formations. At the crest of the Greenhills Range, east of the Bingay Main property, the Mist Mountain Formation is overlain by the younger coal-measures of the Elk Formation, also of Cretaceous age. Although younger coals are known from the overlying Elk Formation in the Greenhills Range, the Elk coals appear to have been stripped away by erosion within the Bingay Main property. At least 32 coal beds, whose true thickness ranges from 0.3 to 16.2 metres are present. Of these coals, 24 typically are at least 1 metre thick, inclusive of contained bands of rock. Cumulative thickness of these coals is 62.6 metres, within an overall coal-bearing rock thickness of 460 metres; coal thus forms about 13.6% of the coal-bearing rocks at Bingay Main. Bedrock in the proposed mine area consists primarily of siltstone, mudstone and sandstone with interbedded coal seams, which are exposed in the central Bingay Hill and along the east side of the proposed open pit adjacent to the Elk River. The mudstone, siltstone and coal layers appear relatively soft, however coal-bearing erosion resistant sandstone layers form prominent bedrock ridges in the southwestern part of the proposed mining area and along Bingay Creek.

Overburden, generally consisting of coarse sand and gravel is present on the west and north sides of the proposed pit area, and thick silt and clay is located on the north side of the proposed pit area. Thin deposits of silty sand and gravel overlying bedrock are present on the proposed pit’s south and east sides.

The project will produce metallurgical coal at an annual maximum production rate of 2 million clean tonnes. The lifespan of the project is planned for 20 years of coal production at a constant rate, using shovel and truck operation open pit mining method in the first 10-15 years, and then underground mining for the remaining years. The optimal ratio of surface to underground mining is currently being evaluated.

The Bingay Main coal deposit is planned to be mined using the conventional bench-bybench (15 metre) open-pit mining method, which includes excavation of overburden, drilling and blasting of rock, ripping and dozing coal, loading with a hydraulic shovel and a front-end loader, and hauling coal with 100 t capacity trucks and waste rock with 240 t capacity trucks. The strip ratio is variable but is expected to average 6.0 bank cubic meters (BCM) per clean tonne mined (CMT). The entire open pit mine is located in the measured/indicated resource portion of the coal deposit. Auxiliary equipment includes dozers, graders, front-end-loaders, service trucks and general equipment to support and conduct maintenance.

Based on the level of production and the strip ratio, the mining fleet planned for the operation consists of one P&H2800XP electric shovel (or equivalent), one hydraulic shovel, eight 240-tonne capacity haul trucks, four 100-tonne capacity trucks, two diesel electric rotary drills, two large front end loaders and two D10 dozers.

At completion the proposed open pit is expected to encompass approximately 93.4 ha and extend approximately 1300 m in the north-south direction, approximately 1000 m to the east and west, and 250-300 m below the current topographic surface.

The underground operation would commence when the open pit operation is phasing out. The development would be approximately within the open pit area footprint and generally to the north and south at elevation levels between 250 m and 500 m below the surface. The structure of the deposit is suitable for underground hydraulic mining, which uses high pressure water jet to extract coal, a method that has been used in the Elk River valley coalfield for many years.

The entrance into the underground operation will be via portals of two stone drives, which would be located in the floor rock of the lowest coal seam on the axis of the syncline at the open pit floor. The inclination of the stone drives is planned to be 10% to maintain safe tire vehicle operation. Two road headers and four ram cars would be used to haul waste rocks to the surface. When the stone drive distance becomes too long to maintain the efficiency of the ram car operation, the waste rocks would be dumped at the underground transfer points, where front-end loaders will load the rocks onto underground dump trucks or conveyor to haul the waste rocks to the surface. A coal pump system, located at the bottom of the stone drives, would pump all extracted coal flumed down to the coal sump by gravity; a vertical coal slurry pipeline would be also installed.

The underground mining plan is currently in the preliminary stage satisfying the prefeasibility phase of the project. A complete underground study and design is planned to be conducted during open pit operation.

Run of mine (ROM) coal will be stockpiled and fed to a hopper with a 305 x 305 mm grizzly on top to define the maximum lump size going to the breaker. The breaker station would be designed for a maximum capacity of 800 t/hr and will include an interconnecting conveyor, scalping screen, rotary Bradford type breaker, breaker reject conveyor, and a dust collection system. Crushed -45 mm coal from the breaker will be conveyed to a raw coal silo. Oversized rejects will be conveyed to a reject stockpile for further disposal.

The preparation plant would employ three processing circuits: heavy media cyclones for coal in the size range 1.2 – 45 mm; water only cyclones, spirals and classifying cyclones for coal in the size range 0.25 – 1.2 mm; and froth flotation for coal < 0.25 mm.

Coal dewatering will be done mechanically to avoid the use of thermal dryers, to prevent coal from direct contact with flames, and to limit stack emissions of particulate matter and other pollutants. Centermount would employ screenscroll centrifuges, screenbowl centrifuges and hyperbaric filters to achieve the final moisture content.

The processing plant would be constructed north of the mine pit, and would employ a closed water system. All process plant water will be reused or recycled; and no discharge of used water or tailings material into the environment is anticipated. The fine tailings stream would be dewatered by pressure filters and the processed solids will be added to the course refuse material for disposal to the waste rock dumps.