Severe wet weather is among a raft of challenges leaving Cannington mine production lagging last year’s output by 20 per cent for the first nine months of the financial year.

Owner South32 said it had temporarily suspended mining activity to ensure safety of the underground operation during the past quarter following the heavy rainfall in North-West Queensland.

The movement of people and critical supplies to site was also disrupted by widespread flooding.

This saw zinc equivalent production decrease by 22 per cent (or 11,700 tonnes) for the past quarter and the operation was unable to rebuild run-of-mine stocks.

When combined with lower mill throughput and and labour constraints in the first half of the 2023 financial year, it left Cannington’s payable zinc equivalent production at 139,800 tonnes for the first nine months of 2022-23.

This is a drop of 20 per cent, or 35,500 tonnes, on where it was at the same time in the previous financial year.

“FY23 production guidance has been reduced by 6 per cent to 195.9kt payable zinc equivalent (silver 11,000koz, lead 102.0kt and zinc 60.5kt),” the company stated.

“The revised guidance reflects an expected 10 per cent reduction in ore processed (to 2,200kdmt), partly offset by higher zinc, lead and silver grades, with the transition to 100 per cent truck haulage providing access to higher grade material.

“We expect run of mine stock availability and more complex underground mining conditions to constrain output in FY24, with production guidance reduced by 8 per cent to 215.3kt payable zinc equivalent (ore processed 2,400kdmt, silver 12,500koz, lead 115.0kt and zinc 62.0kt).

“Due to the lower planned volumes, we have revised FY23 operating unit cost guidance to US$152/t ore processed (from US$141/t).”