PERTH (miningweekly.com) – Gold miner St Barbara is expected to restart gold production at its Simberi operations, in Papua New Guinea (PNG), later this month.

The miner this week told shareholders that it had completed the laying of the deep sea tailings placement (DSTP) pipeline, and that wet commissioning of the process plant at Simberi was conducted in preparation for the on-schedule commencement of full processing over the coming week.

Simberi remains on track to meet its 2022 production guidance of between 60 000 oz and 70 000 oz.

Mill operations were suspended last year as St Barbara worked to replace the DSTP pipeline, and while the mill was shut down, Simberi established a 130 000 t oxide ore stockpile on run-of-mine pads and implemented multiple processing plant upgrades. These upgrades include the replacement of cyanide mixing and storage tanks, refurbishment of the rope conveyor, installation of downcomers in the carbon in leach (CIL) circuit to promote slurry mixing, a new lime circuit and several process control enhancements to CIL and thickener circuits.

A new mine plan has been developed to deliver oxide material to the mill, with substantial pre-stripping work conducted over the last six months.

St Barbara in December last year announced a binding scheme implementation deed to acquire fellow-listed Bardoc Gold, with Bardoc shareholders to receive 0.3604 new St Barbara shares for every one Bardoc share held.

Based on the closing price of St Barbara shares on the ASX on December 17, the transaction values Bardoc at approximately A$157-million and each Bardoc share at A$0.530. Following the takeover, St Barbara shareholders would hold 87% of the enlarged company, with Bardoc shareholders holding a 13% share.

St Barbara said at the time that the acquisition of the advanced Aphrodite and Zoroastrian underground deposits, which lie immediately adjacent to the rail line that runs to the Leonora processing plant, provides the opportunity to accelerate St Barbara’s Leonora province plan.

St Barbara’s ongoing prefeasibility study of growth initiatives at Leonora has identified openpit mining as the preferred development option for the Tower Hill deposit, which has facilitated the declaration of a substantially increased mineral resource estimate of 1.2-million ounces.

The combined mineral resource across Gwalia Underground, Tower Hill and the refractory Harbour Lights deposit provides a substantial foundation for a low-cost expansion of the existing Leonora processing plant from 1.4-million tonnes a year to 2.1-million tonnes a year.

Following the acquisition of Bardoc, St Barbara was proposing to spin-out Bardoc’s South Woodie Woodie manganese project, in Western Australia, into a separately listed vehicle.

The takeover offer is subject to an independent expert concluding that the deal was in the best interest of Bardoc shareholders, as well as court and shareholder approvals.