PERTH (miningweekly.com) – Gold major Newcrest is hoping to complete an updated prefeasibility study (PFS) on its Wafi-Golpu joint venture, in Papua New Guinea, by the end of 2014, the Australian company reported on Tuesday.

The project, which is being developed with South Africa’s Harmony Gold and comprises the Golpu and Wafi deposits, has a mineral resource of about 28.5-million ounces of gold, 9.1-million tonnes of copper and 50.6-million ounces of silver.

Newcrest, which published its September quarter production report, said work were under way to evaluate access options and reduced capital expenditure development options for Wafi-Golpu.

A 2012 technical PFS confirmed Golpu as a world-class deposit, with cash costs expected to be at the bottom of the industry curve and a mine life of more than 20 years.

Subject to the completion of the updated PFS, Newcrest expects Golpu will be mined using a block cave bulk underground mining method, with an indicative processing plant capacity of between 20-million tonnes a year to 30-million tonnes a year.

Meanwhile Newcrest has reaffirmed its full year production guidance for the 2015 financial year, despite a 12% production decrease during the three months to September.

Gold production during the first quarter declined by 12% on the three months to June, to 561 731 oz, as mining during the quarter was characterised by lower gold grades at the Gosowong, Cadia Valley and Lihir operations, as well as major planned shutdowns at the mill area and Autoclave 4 at the Lihir plant.

The Cadia Valley operations, in New South Wales, delivered 153 119 oz of gold during the quarter as well as 17 535 t of copper, which was in line with the June quarter production.

Newcrest reported on Tuesday that a 14% increase in mill throughput at Cadia Valley was offset by the lower gold grades and recoveries.

Mine production at Cadia East continued to ramp up during the quarter under review to 3.2-million tonnes, and the Cadia East Panel Cave 2 started commercial production at the start of this month.

“It is pleasing to see Cadia East Panel Cave 2 achieving commercial production so early in the financial year, which positions Cadia East well to continue to increase its contribution to the company,” said Newcrest MD and CEO Sandeep Biswas.

Meanwhile, the Lihir operation, in Papua New Guinea, delivered 153 826 oz of gold during the quarter, compared with the 174 601 oz delivered in the three months to June.

Gold production decreased owing to a 14% decrease in average gold grades during the period, which was associated with an increased proportion of plant feed sourced from stockpiles.

At the Telfer operation, in Western Australia, gold production reached 134 771 oz, while the Gosowong project, in Indonesia, added 67 676 oz of gold to the portfolio. The Hidden Valley operations produced a further 27 286 oz of gold during the quarter and 281 247 oz of silver, while Bonikro, in Cote d’Ivoire, delivered 25 052 oz of gold.

For the full 2015, group gold production is expected to be in the range of 2.2-million to 2.4-million ounces.