Copper Mine NPV

Tintina Resources announced that its Preliminary Economic Assessment (capital budgeting analysis) of the company's Black Butte Copper Project in central Montana resulted in an IRR of 30.5 percent, an NPV of $218 million at a cost of capital of 8 percent, and a 3.6 year payback. The company announced a post-tax NPV of $110 million, but infortunately appears to have used the same 8 percent cost of capital. A pre-tax valuation should use a pre-tax interest rate, while a post-tax valuation should use a post-tax interest rate.