Mining & Processing
Basic rock mechanics studies have been performed using data from the adjacent Doyon mine. A geotechnical drilling campaign is underway to help optimize stope dimensions, sequencing and the location of underground infrastructures. The production rate will be 2,200 tpd obtaining 200,000 ounces or 800,000 tpy in order to reach profitability. The mine start-up is scheduled for early 2013 and should be in production for at least 16 years, based on currently identified resources. The current mine plan postpones extraction of the base metal-rich zones until the end of the project to reflect the current deflated base metal prices.
Ore processing will be carried out at the existing Doyon carbon-in-pulp (“CIP”) mill complex. However, the project will be split into two phases.
In the first phase, only the gold mineralization will be treated at the mill. During the first year of operation the Westwood mineralization will be processed at a rate of 700,000 tpa. Subsequently, the tonnage will be increased to a capacity of 800,000 tpa. The Mouska copper circuit will be temporarily converted to a desulphuration circuit. Cyanide destruction capacity will be increased to treat the generated tailings.
In the second phase, the capacity of the existing copper flotation circuit will be increased. A zinc flotation circuit will be added and a new desulphuration circuit will be set up to begin tailings reclamation.
The ore will be hauled to the Doyon mill (two kilometres away) to be crushed and ground. The ore grinding circuit will utilize the existing SAG mill and a 1,000 HP ball mill
The current Mouska flotation circuit will be used for copper flotation in the second phase of the project. Three tanks, Cell (1+2), will be added to increase the retention time and the current copper concentrate thickener (3.6 metres) will be upgraded (6 metres) in order to meet the higher demand. A new circuit will be installed for zinc flotation. The paste backfill plant will be moved closer to the Westwood shaft allowing the paste to be distributed by gravity when required by the underground infrastructure. The Doyon mill produced up to 250,000 ounces of gold per year in the 1990’s. The existing gold recovery circuit will have more capacity than required to recover the annual gold production from Westwood.