PERTH (miningweekly.com) – An updated prefeasibility study (PFS) into the Jervois copper-silver project, in the Northern Territory, has lengthened the project’s life expectancy, says owner KGL Resources.

A 2014 PFS estimated that the two-million-tonne-a-year project would have an initial mine life of seven years, producing about 21 000 t/y of copper and one-million ounces of silver concentrate a year, at a capital cost of A$189-million.

Cash costs for the project had initially been estimated at $1.51/lb.

While an updated PFS, released this week, maintained the capital expectation of A$189.5-million, the project’s mine life had been extended by nearly one-and-a-half years, while C1 cash costs had dropped to $0.88/lb.

“Jervois is confirmed as a robust, midlevel-scale mining project with initial production of more than 20 000 t/y of copper, one-million ounces of silver a year, plus lead and zinc, with a mine life of more than eight years,” said KGL MD Simon Milroy.

“In 2015, we increased and upgraded the mineral resource, simplified the metallurgical processing and reduced the operating costs.”

Milroy noted that the additional studies now indicated that Jervois could be among the lowest cost of the world’s probable new mines.

“The PFS benefited from the upgrading of the mineral resource and increases in silver, lead and zinc tonnage. With 12 km of strike length, all current orebodies remain open and the potential for substantial new discoveries is demonstrated by the recent intersection at the Rockface prospect in an area that is not included in the current mining inventory used in the PFS.”

The updated PFS was based on a copper resource of some 26.7-million tonnes, grading 1.12% copper and 16.6 g/t silver, while a 3.8-million-tonne lead/zinc resource was also defined, grading 0.72% copper, 3.7% lead, 1.2% zinc and 67.5 g/t silver.

A definitive feasibility study was planned for the first quarter of 2016, subject to funding, while first production had been slated for the fourth quarter of 2018.