B2Gold’s expansion study for its El Limon gold mine in Nicaragua found the potential for a higher annual processing rate and mine life increase of 10 years with the inclusion of the inferred mineral resource from the El Limon Central deposit.

The company released its findings on Tuesday, alongside an additional announcement that it had signed a renewed two-year collective agreement with the mine’s labour unions.

The expansion study was prompted by B2Gold’s February 2018 announcement of a new El Limon Central open-pit inferred mineral resource of 5,130,000 tonnes at a grade of 4.92 grams per tonne on the El Limon property. The study looked at the potential of combining the remaining underground resources from El Limon with the new open-pit.

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The study recommended expanding the existing plant at the mine by upgrading the crushing system, cyclones and leach circuit, as well as adding a pebble crusher and a new thickener. Completing these upgrades would result in an processing rate of 600,000 tonnes per year, a significant increase from the plant’s current rate of 485,000.

The upgrades would also grant access to a third stage of milling, which could be used to reprocess old mine tailings at the end of mine life. The company said that would give El Limon an additional 11 years to process the tailings.

The annual gold production for the expanded El Limon mine is estimated at 75,000 ounces of gold per year for the 10 years of mining, for a sum of 750,000 ounces. With processed tailings taken into account, B2Gold projects the mine’s total gold production could be 985,000 ounces over 21 years or more.

B2Gold estimates that the recommended upgrades would cost US$35 million and would take 16 months to complete.