Fortuna Starts Building Lindero Gold Project

Fortuna Silver Mines has started construction of its 100% owned Lindero gold project in Salta province, northwest Argentina. Gold recovered to doré will average 96,000 ounces per year (oz/y) over a mine life of 15 years, with peak production in the first two years of about 137,000 oz/y. All-in sustaining costs of production are estimated at $802/oz.

Initial capital required to develop the Lindero project is estimated at $239 million, including $19 million for an owner- operated mining fleet and $24 million for contingencies. Sustaining capital for the project is estimated at $105 million. The project has an approved environmental impact study and has been granted all major permits for construction.

Lindero will be an owner-operated, conventional open-pit mining operation, producing a nominal 18,750 metric tons per day (mt/d) of ore. Key mining equipment initially will be six 100-mt trucks and two 17-yd3 wheel loaders. Mining costs will benefit from short haul distances from the pit to the primary crusher and waste dumps. Maximum distances are in the range of 2 km. Life-of-mine direct mining costs are estimated at $1.1/mt moved.

Ore will be crushed through a threestage crushing system with high-pressure grinding rolls in the tertiary stage. The crushed product will be agglomerated and cured with a cyanide solution and then conveyed to the leach pad. A mobile conveying and stacking system will be used to stack ore in 10-m-high lifts. The life-ofmine leach pad area is projected at 105 ha, with a maximum height of 100 m. Leaching will be carried out in two stages, with a first stage of 30 days and a second stage of 60 days.

Pregnant solution will be pumped at a rate of 400 m3/h to an SART (sulphidization, acidification, recycling and thickening) plant, where copper content in solution will be precipitated to maintain copper levels below 400 ppm in the solution. The project contemplates an expansion of the pregnant solution flow rate from 400 m3/h to 600 m3/h in year four, with the objective of reducing inventory of gold ounces in the heap at the end of mining.

Following the SART plant, the pregnant solution will go to an ADR (adsorption, desorption and regeneration) plant and then to electrowinning and refining where gold will be recovered as doré bars. Life-ofmine recovery is estimated at 75%.

Project commissioning is planned for the second quarter of 2019. The Lindero porphyry gold system remains open at depth below the current pit shell of reserves and resources, with highgrade drill intercepts bottoming in mineralization. The nearby Arizaro porphyry system, located within the Lindero concession, is a near-term exploration target.

As featured in Womp 2017 Vol 11 -