Granduc Interactive Map
Granduc Interactive Map
Granduc Facts
  • Located in excellent jurisdiction.

  • Preliminary Economic Assessment completed in 2013.

  • Significant exploration potential.

  • Over 62,000 metres drilled since 2010.

  • Infrastructure includes road, ice-free port, and nearby power.

Granduc Project Overview

The Granduc project is located approximately 40 kilometres north of Stewart, British Columbia, and covers a total land area of approximately 33,400 acres.
The property is a copper volcanogenic massive sulphides (VMS) deposit that was mined between 1970 and 1984 by Newmont, then Esso Minerals Canada. The mine was closed in 1984 due to low copper prices. The property was acquired from Bell Resources in 2010 and is 100% percent owned by Castle Resources.

Exploration and drilling completed by Castle Resources since 2010 includes more than 62,000 metres and focused on updating and expanding the NI 43-101 resource. Castle has increased the resource to 1.8 billion pounds of copper, with gold, silver, and magnetite credits.


Rehabilitation of the 17 kilometre haulage tunnel was completed in August 2012.


Several exploration targets on the property have been identified and are drill ready for future development.



In February 2013, the company completed a Preliminary Economic Assessment with the following highlights:
  • Base Case (defined below) initial estimated CAPEX of $494 million including a 16.3% contingency of $69 million with estimated sustaining capital of $239 million over a 15 year mine life.

  • Base Case pre-tax NDV 8% from a discounting start date of Q1 2016 is $489 million with a pre-tax IRR of 20.9%; post-tax NDV 8%of $319 million with a post-tax IRR of 17.8%. Changing the discounting start date to Q1 2013 results in a NPV 8% of $388 million pre-tax and $253 million post-tax, but does not impact the IRR.

  • Life of Mine average operating cash flow is $142 million per year; Peak Life of Mine (Years 2-8 inclusive) is $164 million per year.

  • The project evaluation assumes flat long term metal prices equal to the rolling three year average of $3.65/lb Cu, $28/oz Ag and $1480/oz Au. The benchmark magnetite prices used is $122/tonne. The assumed exchange rate is C$1.00 = US$0.99.

  • The resource used is 11.32 million tonnes in the measured & indicated category grading 1.47% Cu, 0.17 g/t Au and 12.4 g/t Ag and 44.63 million tonnes in the inferred category grading 1.43% Cu, 0.19 g/t Au & 10.7 g/t Ag.

  • Peak Life of Mine (Years 2 – 8 inclusive) annual payable production is forecasted at 72 million lbs of copper, 811 koz silver, 9.5 koz gold and 251,000 tonnes of magnetite.

  • 8,500 tonnes/day underground mining operation.

  • Base Case gross cash operating costs of $2.04/lb payable Cu and net cash costs (inclusive of byproduct credits) of $1.37/lb payable Cu.