Capstone Mining has completed a prefeasibility study for the phase V expansion (phase V PFS) of its high-grade Minto copper-gold mine in the Yukon, Canada.

According to the study, conducted by SRK Consulting, proven open pit and underground mineral reserves in the mine have increased to 12.9 million tons grading 1.53% copper, 0.60g/t gold, and 5.2g/t silver, for a contained 435 million pounds of copper, 247,000oz of gold, and 2.2 million ounces of silver.

Phase V PFS has targeted 400 million pounds of copper in concentrate to be produced over a ten-year mine life.

The mine life can be extended to 2020 with an average of 43 million pounds of copper production a year.

Capstone Mining president and CEO Darren Pylot said underground mining would begin in the second quarter of 2011, resulting in an extended mine life, processing of higher-grade ore earlier in the mine life and continued improvement with respect to environmental considerations.