Montagne dOr Study Calls For 237,000 oz/y of Gold

Nordgold and Columbus Gold have reported the results of an independent bankable feasibility study of their Montagne dOr gold project in French Guiana that anticipates development of an open-pit mining operation producing 237,000 oz/y of gold during its first 10 years of operation. The study was funded by Nordgold, pursuant to which it earned a 50.01% interest in the project. Nordgold has also acquired an additional 5% interest as the result of a share purchase agreement dated January 12, 2016 and now holds a 55.01% interest in the project.

The Montagne dOr feasibility study estimates total initial capital costs to develop the project at $361 million, including pre-stripping and contingency and minus surplus tax credit refunds. The after-tax payback period is estimated at 4.1 years. Project development is based on proven and probable mineral reserves of 2.75 million oz of gold contained in 54.1 million mt at a grade of 1.58 g/mt. These reserves are a subset of measured and indicated resources totaling 3.85 million oz in 85.1 million mt grading 1.41 g/mt gold at a cut-off grade of 0.4 g/mt and a $1,300/oz gold price.

The mine production schedule is based on feeding an ore processing facility operating at a rate of 4.5 million mt/y; however, ore would be mined in excess of this rate so that marginal low-grade can be stockpiled and processed at the end of the mine life. The mining plan consists of two years of limited pre-stripping prior to ore processing start-up, 10 years of openpit mining, and two years of low-grade ore stockpile re-handling to feed the mill.

Because of significant rainfall, terrain, and saprolite material, a mixed mining equipment fleet is planned. The initial fleet will consist of two 6.7-m3-capacity excavators loading a fleet of nine 40-mt articulated dump trucks, which will be used for pioneering excavation and most of the saprolite mining. As the open pit expands, a larger mining fleet will be introduced consisting of three 12.0-m3-capacity excavators and 17 91-mt rear dump trucks to perform most of the bulk mining production.

The Montagne dOr plant is designed to treat the range of ore types and blends that will be mined over the life of the project. Unit processes will include primary jaw crushing; single-stage semi-autogenous grinding with recycle to produce an 80% passing 75- grind size; gravity concentration and removal of coarse gold from the milling circuit recirculating load; pre-leach thickening; a leach/ carbon-in-leach circuit incorporating a leach tank and six carbon-in-leach tanks for gold adsorption; an elution circuit treating loaded carbon; electrowinning; and gold smelting to produce dor.

Nordgold CEO Nikolai Zelenski commented, The Montagne dOr is worldclass, high-grade orebody, and the work we have now completed shows a project with robust economics. It meets our criteria for project development as it benefits from straight-forward metallurgy, excellent recovery rates, and a moderate stripping ratio.

The mine will be a major employer in the region and generate significant revenues for the country when fully operational. Montagne dOr is a core part of our long-term growth pipeline, and we look forward to progressing through the permitting process.

As featured in Womp 2017 Vol 05 -