Gold producer Iamgold has reported a 39% increase in probable reserves at its Essakane heap leach project in Burkina Faso based on the results of a prefeasibility study (PFS).
There are an estimated 4.7 million ounces in reserves at the project. Indicated resources jumped 19% to 5.1 million ounces and inferred resources surged 54% to 0.6 million ounces.
Based on the PFS, it was determined that the life of mine (LOM) increased to eight and a half years from the LOM of five years, which was announced in the 2016 Technical Report.
The study also indicated that the project will have mill throughput of 12 million tonnes per annum and heap leach throughput of 10 million tonnes per annum.
Once heap leach starts operating, average annual production is set to increase by 16% to 480,000 ounces.
Iamgold president and CEO Steve Letwin said: “While we knew that heap leaching had the potential to unlock additional reserves, we were positively surprised at, and benefited from, intercepting higher grades, which account for more than one-third of the 39% increase.
“Essakane is pursuing all avenues for enhancing the value of this already high-performing operation, including targeting additional resources from Essakane’s large, prospective land package.”
In addition, an infill drilling programme was carried out to upgrade targeted lower-grade inferred resources to support the Heap Leach PFS. The programme intersected higher grades than anticipated in several areas.
The company is planning to increase the mine life beyond 2030 through a feasibility study (FS) and the drilling of prospective satellite prospects near Essakane.
The FS is anticipated to be completed in the first quarter of next year.
Iamgold noted that the results may provide potential to highlight further zones of higher-grade mineralisation for processing at the existing carbon-in-leach (CIL) plant.