PERTH (miningweekly.com) – ASX-listed gold miner St Barbara has upwardly revised its 2017 production targets for its Gwalia mine, in Western Australia, after the mine produced above expectations during the first half of the current financial year.

St Barbara on Wednesday increased production expectations at Gwalia from between 245 000 oz and 265 000 oz for the 2017 financial year, to between 255 000 oz and 265 000 oz.

The Gwalia mine produced 70 925 oz of gold during the December quarter, compared with 67 118 oz in the previous quarter, owing to a higher average mined grade, which resulted from the presence of high-grade shoots. Mined tonnes at Gwalia decreased during the quarter, owing to a combination of precision blasting, giving lower dilution early in the quarter, and delays with blasting key stopes in December, resulting from a change in explosive suppliers.

St Barbara said it would take a final investment decision on the Gwalia extension project in March.

A feasibility study to increase ventilation at Gwalia was completed last year, and estimated that some A$70-million to A$75-million will be required to provide additional ventilation to mine between 1 800 m and 2 000 m below the surface.

A further A$15-million to A$20-million in capital will be required for the past aggregate fill project, which will involve mixing paste from surface with waste crushed underground for stope fill and will allow waste to be disposed of underground, boosting truck productivity.

Meanwhile, the Simberi project, in Papua New Guinea, delivered 28 057 oz of gold during the quarter, which was also up from the 25 249 oz delivered in the September quarter.

St Barbara noted that total material movement at Simberi hit record highs during the quarter, at four-million tonnes, up 12% on the previous record set in the September quarter.

Despite the increase in production at Simberi, St Barbara has maintained the mine’s 2017 production outlook at between 95 000 oz and 105 000 oz.