Pretium Resources has received a positive NI 43-101 compliant preliminary economic assessment (PEA) for the high-grade gold and silver resources identified to date at its Brucejack project in northern British Columbia. Project planning assumes initial development of a 1,500-mt/d underground mine based on a mining inventory of 6.6 million mt at an average mill feed grade of 10.5 g/mt gold and 87.3 g/mt silver. An additional 2.26 million mt grading 3.35 g/mt gold and 36 g/mt silver would be mined from small open-pits following completion of underground mining.
The base case for the Brucejack PEA assumes metal prices of $1,100/oz for gold and $21/oz for silver. Gold-silver doré would be produced using a combination of conventional bulk sulphide flotation, gravity concentration and cyanidation, with gold and silver recovery by the Merrill-Crowe process. Production would average 173,200 oz/y of gold and 1.12 million oz/y of silver during the first 10 years of operation and 135,000 oz/y of gold and 918,000 oz/y of silver over a total mine life of 16 years.
Capital cost to develop the Brucejack high-grade project is estimated at $281.7 million, and estimated operating costs are C$158.36/mt milled for underground mining and C$68.77/mt milled for open-pit operation.
Pretium expects to initiate an updated Brucejack PEA during the fourth quarter of 2011, following completion of its 2011 drilling program. Concurrent with preparation of the updated PEA, the company anticipates it may proceed with a prefeasibility study or advance directly to a full feasibility study.