Positive early assessment for Mina Justa

Preliminary economic studies on the Mina Justa copper project in southwestern Peru have indicated an open-pit mine could be feasible.

Chariot Resources (CHD-T), which owns a 70% interest in the project, commissioned the study by consulting firm GRD Minproc. Minproc modelled the economics of a start-up heap leach operation with follow-on construction of a mill.

Minproc concluded the project had a pre-tax net present value of US$364 million, based on an 8% discount rate, with an internal rate of return of 28%. The initial capital cost to bring the heap leach operation on stream would be around US$236 million.

The mine would exploit an oxide resource of 121 million tonnes at 0.62% copper and a sulphide resource of 21 million tonnes grading 2% copper. A preliminary pit design puts the stripping ratio at 2.5. Three-fifths of the resource is currently only inferred, and more drilling will be needed before a full feasibility study can be done.

Minproc estimated the production costs at US$1,520 per tonne (US69 per lb.), a figure that did not include any by-product credits. Chariot plans to produce both silver and a magnetite concentrate from Justa, as well as an average 70,000 tonnes copper annually.

Chariot owns 70% of the Marcona copper project, of which Justa is a part. Korea Resources Corporation and LG-Nikko Copper are joint venture partners.