TORONTO (miningweekly.com) – With only about $100-million remaining to be spent and a little more than a year to go before production starts in the third quarter of 2017, project developer Pretium Resources on Wednesday said that construction of its high-grade Brucejack mine, in British Columbia, was on schedule and expected to cost less than previously thought.
Upon achieving the 60%-construction milestone, Pretium late last year undertook the cost estimate update, reporting that the project could now be completed for $640.8-million, $106.1-million below the June 2014 feasibility estimate. The company had also made provision for $56-million in working capital for the first three months of operation after commissioning.
Pretium saved $17.7-million in underground development, $24-million by deferring the acquisition of underground mining equipment, $9.5-million in the mill design and build, and $145-million owing to an updated exchange rate between the US and Canada.
However, while certain costs fell, others rose.
Cost increases included the owner’s preproduction cost increasing by $46.7-million, additional environmental monitoring costs of $18.6-million, added winter construction costs of $14.5-million, increased camp support costs of $10.8-million, and increased engineering, procurement and construction management costs of $18.4-million.
At a base case price of $1 100/oz of gold, the Brucejack project generated an aftertax net present value, at a 5% discount rate, of $1.55-billion, and an internal rate of return of 33%. The deposit comprised proven and probable reserves of 16.5-million tonnes grading 14.1 g/t gold and 57.7 g/t silver, containing 7.5-million ounces of gold and 30.7-million ounces of silver.