Overview

Mine Type	Underground
Stage	Permitting
Commodities	Coal (metallurgical)
Mining Method	Bord-and-pillar Continuous
Mine Life	...
Snapshot	The Groundhog North Project is the world’s largest undeveloped anthracite deposit, located in British Columbia, Canada. The Groundhog Project offers several large potential development areas suitable for multiple joint venture and/or partnership development opportunities. The massive Groundhog North project (100% Atrum) has been the subject of multi-decade historical exploration work and contains an existing JORC Resource estimate of over 1 Bt (156 Mt Measured, 453 Mt Indicated and 407 Mt Inferred). In 2016, PFS for the starter mine of Groundhog North complex was completed.

Deposit type

• Sedimentary

Summary:

The Bowser Lake Group comprises a 3,500 m thick sedimentary succession in the Groundhog project area and consists of the following formations:
- The Devil’s Claw Formation;
- The McEvoy Formation;
- The Currier Formation; and,
- The Ashman Formation

Currier Formation
The approximately 1,000 m thick Currier Formation overlies the Ashman Formation and is the primary coal bearing formation of the Groundhog Coalfield. It is deltaic in origin and records a change from the underlying Ashman Formation to alternating marine and non-marine deposition. The formation consists of alternating beds of shale and sandstone with lesser amounts of siltstone, conglomerate and coal. Prior to 1991 the Currier Formation was referred to either as the Groundhog Sequence or Groundhog Unit.

Coal Seam Geology
The coal-bearing Currier Formation consists of alternating beds of shale and sandstone, with lesser amounts of siltstone, conglomerate and coal. Strata are generally arranged in coarsening-upward units ranging from 30 to 60 m thick in the lower part of the formation. Within Groundhog tenure areas, the thickness of the coal-bearing unit, locally known as the Currier Formation, is approximately 600 m thick.

Coal occurrences indicate the base of the Currier Formation.

Target Coal Seams
At least 21 known coal seams occur within the Currier Formation on the Groundhog property. These are broken into four horizons starting with the Davis Horizon at the top followed by the Discovery, Duke and Trail Horizons. Seams within these horizons are given a letter starting with an ‘A’ at the top and additional letters for each new seam down stratigraphy. Coal seams range in thickness from tens of centimetres to more than 7 m, and typically range from 0.5 to 3.0 m for the seams considered amenable to mining. Atrum geologists introduced the new coal seam nomenclature following an extensive correlation exercise which evaluated each drill hole independently with drill core photos, drill logs and geophysical logs. As the correlation exercise developed it became apparent that there were more coal seams than previously thought in Groundhog North and that two coal seams (Discovery B and Discovery C) were both being called Seam 70 in previous correlations. The Discovery B and Discovery C coal seams vary in their quality and thickness but typically one or both of the coal seams are greater than one metre in thickness at any point. In previous correlations it was assumed that Seam 70 split and had a large parting in areas where both coal seams are strongly represented; however, upon closer examination made possible by the close drill hole spacing in the BSA, it was proven not to be the case.

Economic targets at Groundhog include the near-surface Discovery B seam, and the lower Duke E and Trail B seams. Mining studies have shown the Duke E seam is the most rewarding first target for mining, as it is the thickest target, with a working section averaging 2.2m, it produces higher product yields, and is shallowly emplaced in several areas across Groundhog North.
Successive drilling campaigns have identified three main target seams which are economically viable as mining targets:
-Duke E seam (average 2.2m thick) is the primary mining target, with product yields ranging from 60% to more than 75%
-The shallow Discovery B seam (average 1.5m thick) yields approximately 50% which remains economic
-The deepest economic target is the Trail B seam (~2m thick) , representing an opportunity for further exploration

The Duke E seam is of particular interest due to its higher yield producing a very low ash product. The Discovery B seam outcrops in several areas across the mining complex, creating an attractive mining target for low cost entry to production.

Mining Methods

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Comminution

Crushers and Mills

Processing

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Production

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