Australia-based miner St Barbara is moving as “quickly as possible” to bring forward production from the Simberi sulphides expansion, in Papua New Guinea, MD and CEO Andrew Strelein said on Wednesday.

The ten-year mine plan at Simberi includes the mining of several openpits to exploit the substantial oxide and sulphide ore reserves, with a target of elevating production to about 230 000 oz/y through to 2034, from the current 70 000 oz/y to 75 000 oz/y range.

During the September quarter, St Barbara has selected the preferred flowsheet for the sulphide expansion. This has enabled the project team to investigate options to accelerate the next phases of the project with the aim of bringing forward first production by up to five months, to the September quarter of 2028.

The Simberi team is also considering including more detailed work in the feasibility study and removing the need for a separate front-end engineering design study phase. This would bring forward the final investment decision to the end of the revised, albeit slightly longer, feasibility study.

A revised timeline for the feasibility study has not yet been determined.

Meanwhile, Strelein reported that St Barbara had completed Simberi’s major 18-day scheduled yearly shutdown, during which time it had replaced the 2.8 km overland conveyor belt, reinstalled more than 250 condition monitoring units and other plant refurbishments to improve production and reliability.

Gold production during the quarter of 12 233 oz at an all-in sustaining cost (AISC) of A$3 905/oz was up significantly in the September quarter, compared with the same quarter last year, and in line with expectations.

AISC was impacted by lower production and higher maintenance costs during the shutdown, but in line with guidance predictions.

The full-year 2025 production guidance at Simberi is unchanged at between 65 000 oz and 75 000 oz, at an AISC of between A$3 200/oz and A$3 600/oz.  The average quarterly production for the remaining three quarters is forecast to be between 18 000 oz and 20 000 oz at an anticipated AISC averaging in the range of A$2 800/oz to A$3 400/oz.