The Tamarack North deposit will be mined using both bulk and selective underground mining methods. The underground mine design framework and execution strategy is the same for both the Ni Concentrate and Ni Sulphate Scenarios.
Long hole mining has been selected as the primary mining method for all areas with the exception of a portion of the MSU, which is better suited to drift-and-fill due to the shape of the deposit.
Bulk Mining
The primary mining method for each zone is transverse long hole open stoping with cemented paste backfill. Stopes are orientated E/W in the Upper SMSU and Lower SMSU and N/S in the 138 deposit. The typical stope size is 15 m wide by 25 m high.
Long hole stopes will be mined in a bottom-up, primary/secondary sequence, with primary stopes designed four stope widths apart, and generally adhere to the following design basis:
• Accessed from a FW drive from waste cross cuts driven with a road header on 15 m spacing;
• Both upper and lower sill drives are driven with a road header from the FW drives, to the extents of the deposit using a road header. In the case where lower stopes have been mined and filled, the upper sill drift remaining from the bottom stope is utilized as the lower sill drift in subsequent levels;
• Stopes will be mined from HW to FW and generally be no longer than 30 m;
• Stopes will be mined in a “primary-secondary” sequence from the bottom levels and advancing upwards, tren ........
