Ironark Zinc on Monday told shareholders that the review had confirmed a 3.3-million-tonne-a-year operation as the optimum scale of the project, with the initial mine life confirmed at 14 years.

Ironbark noted that in an effort to decrease the risk, underground access to the main orebodies would now be undertaken via twin declines. While this is expected to increase initial development costs, it would also improve mining productivity and enhance safety.

This would result in materially improved metal recovery in the first six years of run rate production, with an additional 90 000 t of zinc metal being extracted from the mine.

“This study represents the first instalment of several reviews currently being undertaken to ensure that the feasibility study for the Citronen project is completely refreshed by taking advantage of the many changes in technologies, standards and pricing that have occurred since the original study work was completed in 2012,” said Ironbark MD Michael Jardine.

“These initial findings, focused on the mining operations, demonstrate the wisdom of this approach and serve to reinforce the magnitude of the opportunity that the Citronen ore deposit represents. These mining study results further de-risk the project by the adoption of updated mining practices, an optimised new mine plan and more efficient production schedule.”

Jardine noted that against the current backdrop of rising zinc prices, the review represented an outstanding project development opportunity, with the project being positioned as one of the next major zinc projects for investment with its long mine life, substantial exploration upside, a granted mining licence in a stable jurisdiction and continued support from base metal traders Glencore and Trafigura.

Offtake agreements with Glencore and Trafigura would see some 70% of concentrate produced at Citronen committed.

Jardine said that in conjunction with the Citronen work stream, the company is also reviewing opportunities to re-engage in domestic exploration, including exploration opportunities within the current Ironbark portfolio, as well as potential acquisitions.