NGEx Resources has reported positive results from a preliminary economic assessment (PEA) of proposed integrated, sequential development of the Josemaría and Los Helados copper-gold deposits, located about 12 km from each other on opposites sides of the Chile/Argentina border. The integrated project has been named Project Constellation.
First production would be from an open pit over a period of seven years on the Josemaría deposit in San Juan province Argentina. In year eight, a six-year production ramp-up would begin for a block cave underground mine at Los Helados in Region III, Chile, during which time material from the two mines would be blended into a single plant feed. Beginning in year 14, once the block cave has reached peak production, plant feed would be sourced exclusively from Los Helados for the remainder of the project life. Including pre-stripping, project life is estimated at 50 years.
Ore from both mines would be processed through a concentrator near the Josemaría mine in Argentina, with nominal plant feed capacity planned at 150,000 mt/d. Primary crushed material from Los Helados underground would be transported via an 8.1-km-long underground conveyor tunnel and a 2.8-km-long surface conveyor that would tie into the Josemaría surface conveyor system.
Production would average about 150,000 mt/y of copper, 180,000 oz/y of gold, and 1.2 million oz/y of silver in concentrate over a period of 48 years, with higher production during the first five years of operation. Life-of-mine production totals are estimated at 7.1 million mt of copper, 8.5 million oz of gold, and 55.6 million oz of silver in concentrate. Life-of-mine recoveries are estimated at 88.3% for copper, 72.7% for gold and 61.4% for silver.
Concentrate would be transported by truck approximately 380 km to a port in Chile.
Initial capital to develop Project Constellation is estimated at $3.08 billion.
Life-of-mine C-1 cash costs, net of by-product credits, are estimated to average $1.05/lb copper, including at-mine cash operating costs, treatment and refining charges, royalties, selling costs, transportation costs, and byproduct credits.