PERTH (miningweekly.com) – Gold miner Newcrest Mining has reported a 6% increase in gold production and a 3.6% decline in all-in sustaining cost (AISC) for the December quarter, on the back of a strong performance at its Lihir operation, in Papua New Guinea.

Newcrest produced 620 691 oz of gold and 17 581 t of copper during the three months to December 31, compared with 583 745 oz of gold and 21 337 t of copper in the previous quarter.

The increase in gold production was primarily driven by increased output from Lihir and the Telfer operation, in Western Australia, which was partially offset by lower production from the Cadia operation, in New South Wales, following a five-week outage caused by an issue at the semiautogenous grinding mill.

The Cadia operation delivered 128 543 oz of gold and 12 486 t of copper during the period under review, while the Telfer mine produced 132 305 oz of gold and 5 095 t of copper.

Lihir produced 240 423 oz of gold, compared with the 190 570 oz in the previous quarter. The higher output at Lihir was achieved on the back of a 12% increase in milled tonnes and a 15% increase in milled grade.

The improved recoveries at Lihir were achieved despite the impact of a planned 15-day shutdown during the quarter on autoclave 2, premature valve failure on autoclave 3 and premature failure of liners in the high-grade ore of two mills.

Meanwhile, the Gosowong mine, in Indonesia, delivered an additional 68 702 oz of gold during the period, while the Hidden Valley mine, in Papua New Guinea, delivered 17 190 oz of gold and 322 257 oz of silver. Bonikro, in Cote d’Ivoire, delivered 33 527 oz of gold during the three months under review.

“We have had a good quarter in which we maintained our strong focus on safe production and delivered an increase in gold production and lowered our all-in sustaining costs, despite operational challenges at our two largest mines, Cadia and Lihir,” said Newcrest MD and CEO Sandeep Biswas.

“Lihir’s performance was very pleasing, surpassing its 12-million-tonne-a-year target by achieving a record mill throughput, at an annualised rate of 12.4-million tonnes a year, and delivering a significant improvement in its all-in sustaining costs per ounce.”

In fact, Lihir’s 19% decline in its AISC assisted in Newcrest decreasing the group’s AISC by 3.6% during the quarter, to $757/oz.

Looking ahead, Newcrest was aiming to achieve group production of between 2.4-million and 2.6-million ounces of gold and between 80 000 t and 90 000 t of copper for the full year.