The facility, located at Resolute's Syama mine in Mali, is operating at nameplate capacity once again after two and a half months offline.

Welborn conceded the issue "has resulted in a material loss in production from the Syama sulphide circuit in the December 2019 Quarter".

"However, we have worked hard to offset this lost production from other production sources and complete the repairs as quickly as possible.

"As a result, the material loss in sulphide production is likely to have only a minor impact on overall Group production and targeted FY19 production guidance at 400,000 ounces of gold. The lost production in 2019 is more than offset by the additional production we now expect to gain in 2020 by the deferral of the next major roaster shutdown to early 2021."

The facility was shut down early October after a crack was detected in its main external shell. Repairs were completed early December.

"The roaster and all aspects of the Syama sulphide circuit are performing as expected," Resolute said in a statement on Friday.