PERTH (miningweekly.com) – Copper/gold miner Oz Minerals has seen first-quarter production affected by wet weather conditions and Covid-19-related production interruptions.

The miner on Friday reported that copper production in the three months to March had reached 30 322 t, down from the 32 169 t delivered in the previous quarter, while gold production declined from 58 306 oz to 48 773 oz.

Despite the fall in quarterly production, Oz Minerals has maintained its full-year production guidance of between 127 000 t and 149 000 t of copper, and between 208 000 oz and 230 000 oz of gold.

All-in sustaining costs for the quarter rose from 159.6c/lb to 174.4c/lb, while C1 cash costs increased from 90.9c/lb to 118.1c/lb.

“The strong copper price environment continues to support robust operating cashflow during a period of reinvestment back into the business with our brownfield expansion projects at Carrapateena and Prominent Hill underway. Our financial position remains strong with A$210-million cash balance at the end of the quarter and significant liquidity available,” said CEO and MD Andrew Cole.

“The first quarter, as previously flagged, saw a softer start to the year with elevated Covid-related workforce and supply challenges as we transitioned to “living with Covid” across Australia. Our South Australian assets were also impacted by a rainfall event in January resulting in highway and rail closures and subsequent supply disruption, in particular at Prominent Hill which had no site access via road for nearly three days and limited access for 12 days. Covid- and weather-related issues had a combined production interruption of circa 370 000 t ore mined across Carrapateena and Prominent Hill.

“Workforce absenteeism due to Covid remains elevated particularly at Prominent Hill and remains a risk to operational productivity. The assets continue to actively manage resources to maintain safe and productive operations and to minimise disruption,” said Cole.

“Despite the slower start to the year, group production and costs guidance remain on track for 2022 with a stronger operational performance expected over the balance of the year as Covid diminishes in the community.

“At Prominent Hill our agile approach to project development identified the opportunity to increase the capacity of the hoisting shaft from 6-million tonnes a year to 6.5-million tonnes a year for an additional A$2-million. Work is underway to assess whether underground mining rates can be increased to fully utilise the increased hoisting capacity. An update to this assessment, including any operating cost benefit, is expected in the second half of 2022.”

Cole noted that at Carrapateena, a milestone of 100 000 t of copper in concentrate produced was achieved on April 4, and the process plant continued its strong performance with a total of 1.1-million tonnes milled. The cave continued its progress towards breakthrough to the surface.

“Our Carajás East Hub strategy continued to advance with an accelerated program underway to deliver a prefeasibility study for Santa Lúcia in the fourth quarter of 2022 while follow-up drilling during the first half of 2022 at the Grota Rica and Tapuia exploration targets, after initial encouraging results in 2021, will help understand further satellite opportunities,” Cole said of the company’s operations in South America.