Rio Tinto has declared force majeure on shipments of copper cathode from its Kennecott operation in Utah after an earthquake in March.
The declaration was made as the Utah facility continues to reopen after being hit by a 5.7 magnitude earthquake on 18 March.
The facility's mine, concentrator and tailings have resumed operations.
"We are working to restart Kennecott's smelter after the emergency shutdown in response to the earthquake and with our customers to minimize any disruption in supply," Rio Tinto told Argus today.
Kennecott accounts for approximately 11pc of copper production in the US, according to Rio Tinto.