PERTH (miningweekly.com) – Gold miner Newcrest Mining has lowered its full-year production guidance on the back of the tailings breakthrough at its Cadia operations, in New South Wales. 

Gold production for the 2018 financial year, which ends in June, has been revised from between 2.4-million and 2.7-million ounces, to between 2.25-million and 2.35-million ounces. The copper production has been revised from the previous estimate of between 80 000 t and 90 000 t, to between 70 000 t and 75 000 t.

Operations at Cadia were suspended on March 9, following an embankment slump at the northern tailings facility, with mining restarting on March 27, followed by processing operations on March 29, at a limited rate.

The operation was expected to return to full production during the June quarter.

Meanwhile, Newcrest has reported that gold production for the March quarter had fallen to 575 791 oz, compared with the 612 695 oz produced in the previous quarter, with copper production down from 22 321 t to 18 862 t during the same period.

“It has been a busy quarter, starting with our acquisition of an interest in Lundin Gold, followed by the release of an updated feasibility study for Wafi-Golpu. Both are Tier 1 asset development opportunities for Newcrest,” said MD and CEO Sandeep Biswas.

“We were also challenged during the quarter with the embankment slump in the northern tailings facility at Cadia. I have been particularly impressed by the efforts of our people at Cadia, who have risen to this challenge and are striving to safely restore the operation to normal production.”

Biswas noted that at the Lihir operation, in Papua New Guinea, Newcrest achieved a record annualised throughput rate of 15-million tonnes a year for the quarter, which exceeded the company’s sustainable target milling rate of 14-million tonnes a year.

Lihir produced 235 626 oz of gold during the quarter, up from the 209 888 oz produced in the December quarter.

Gold production at the Telfer mine, in Western Australia, reached 89 005 oz of gold and 3 438 t of copper during the quarter under review, with gold production down 27% on the previous quarter, reflecting the lower mill feed grade, lower ore tonnes mined, and reduced processing plant availability.

Ore production at Telfer was impacted by wet weather conditions, and higher waste-to-ore ratios.

At Gosowong, in Indonesia, gold production was up from 59 338 oz to 71 410 oz in the three months to March, on the back of higher head grades compared with the previous quarter.

The Bonikro mine, in Côte d’Ivoire, also delivered 36 780 oz of gold during the quarter, compared with the 40 929 oz produced in the December quarter. Newcrest completed the divestment of Bonikro at the end of March.