Economic Prefeasibility Studies of Mining in the Ahtna, Inc. Selections in the Wrangell-St. Elias National Park and Preserve, Alaska

Mining and processing cost analyses were conducted on basaltic copper, polymetallic vein, and iron skarn deposit types that are found on Ahtna, Inc. selections in the Wrangell-St. Elias National Park and Preserve. Resources and recoverable metal values (RMV) needed to make these deposits economically viable were modeled. Methods for estimating ore grades and required RMV are presented.

Economic modeling for basaltic copper deposits indicated the RMV necessary for a 15% Discounted-Cash-Flow Rate-Of-Return (DCFROR) for an underground mine ranged from $152/st for a 10,209 stpd operation to $224/st for a 1,276 stpd operation. Economic modeling for polymetallic vein deposits indicated the RMV necessary for a 15% DCFROR for an underground mine ranged from $155/st at 2,189 stpd to $394/st at 273 stpd. Economic modeling for iron skarn deposits indicated the RMV necessary for a 15% DCFROR for an underground mine ranged from $163/st at 6,191 stpd to $259/st at 774 stpd.