The underground mine production rate is estimated to average 1,000 tpd. A fleet of 5.4 cubic-metre load-haul-dumps ("LHDs") and 27 cubic-metre trucks has been selected as the primary underground production equipment. At peak operation, the underground will have approximately 42 pieces of mobile equipment (including production, development and support equipment) and have a ventilation capacity of approximately 350 m [ 3 ] per second.
At peak operation, the underground will require a workforce of 187 persons (staff, hourly and contract employees).
Both mine areas will deliver material to a central gyratory crusher for primary reduction and delivery to the processing plant.
Metallurgy and Processing
Metallurgical testing has been conducted over a period of almost three years at SGS Canada Inc. in
. Based on the results, BBA has developed a conventional flow sheet including:
- primary crushing and grinding;
- gravity recovery;
- whole-ore leaching followed by a carbon-in-pulp circuit;
- electro-winning and smelting to produce gold doré; and
- a cyanide destruction circuit.
Major equipment for the processing facility includes a 54'' x 75" gyratory crusher, a 36' by 20', 15 MW dual pinion drive semi-autogenous grind ("SAG") mill and a 26' by 40.5', 15 megawatt ("MW") dual-pinion drive ball mill. Mill feed will be ground to a P
size of 75 microns before entering a leaching circuit for final metal recovery. Equipment has been sized for the 80
percentile of expected ore hardness. The average leach time is 30 hours.
Metallurgical recoveries for gold and silver over the life of the mine are expected to average 90.4% and 64.1%, respectively. One tailings pond is envisioned, and will be located approximately three kilometres northwest of the plant.
It is estimated that 89 people (staff and hourly employees) will be required for the process plant operations.