NGEx weighs up autonomous haul trucks for Josemaría copper-gold-silver project

One of the few “construction-ready” copper-gold-silver projects yet to be funded has contemplated the use of autonomous haul trucks in its latest economic study.

The prefeasibility study for the Josemaría project in San Juan province, Argentina, showed ore would be mined using conventional open-pit methods and assumed the latest in autonomous haul truck technologies.

The PFS outlines the development of a 150,000 t/d milling operation able to produce 125,000 t/y of copper, 230,000 oz/y of gold and 790,000 oz/y of silver at a C1 cost of $1.26/Ib ($2,778/t) of copper-equivalent over a 20-year mine life.

The initial capital cost came in at $2.75 billion, with the post-tax net present value (8% discount) slightly below at $2 billion. All of these calculations used an average $3/Ib copper price.

The PFS was prepared and managed by SRK Consulting with input from Ausenco Engineering Canada, Knight Piésold, BGC Engineering, Merlin Geosciences and Gino Zandonai.

NGEx said the plan for Josemaria saw ore trucked from the open pit to a primary crusher, which crushed the material before it was sent to the process plant. The 150,000 t/d comminution circuit design considers high-pressure grind roll crushing followed by ball mill grinding. Conventional sulphide flotation would follow the comminution stage and is expected to produce a gold and silver-rich copper concentrate.

“Groundwater for the process plant would be supplied from nearby aquifers to the plant site, and power would be supplied via 250 km of power line construction to connect to the Argentine national grid,” NGEx said.

Concentrates would be trucked from the plant to the port of Caldera in Chile, approximately 380 km by road from the Josemaría plant site, requiring the construction of 57 km of new road to connect to the public highway.

NGEx CEO,  said: “The PFS shows robust economics and confirms the great potential of Josemaría. Long-term copper fundamentals are strong, and the global project pipeline is at multi-decade lows. We believe that this scarcity will lead to premium valuations for companies with construction-ready projects.

“We plan to work towards fast-tracking Josemaría towards production by starting work on a feasibility study, securing water rights, and advancing our environmental permitting plans.”