Antofagasta has cut its 2026 group copper guidance to 625–655 thousand tonnes after intense July weather and intermittent power outages forced an orderly shutdown at Los Pelambres [E2][E3]. The mine was offline for roughly five days before beginning a gradual restart, with the interruption handled as a controlled operating response [E3]. Only weeks earlier, the company had retained a 650–700 thousand tonne range [E4]. The physical ledger therefore changed sharply between the July production report and the August half-year results [E2][E4].
At the midpoint, the old range implied 675 thousand tonnes and the new one 640 thousand, a 35 thousand tonne reduction derived directly from the two published ranges [E2][E4]. That arithmetic is a change in annual guidance, not a disclosed tally of copper lost during the five-day outage. Antofagasta did not publish an exact tonnage attributable solely to those offline days in the material on this record [E2][E3]. Five lost plant days matter; assigning them a fabricated cargo weight would turn an operating interruption into false precision.
The cut lands against first-half group production of 285,000 tonnes [E1]. That leaves the second half carrying most of the annual volume even at the bottom of the revised range, while Los Pelambres works through its ramp [E1][E2][E3]. Centinela belongs in a separate column: the company ties its lower output mainly to grades and the mine plan, not to the July Los Pelambres weather event [E2]. Combining the two would make one storm responsible for tonnes the company attributes elsewhere.
Cash moved in the opposite direction. First-half EBITDA reached $2.8405 billion, with stronger realized copper prices, by-product credits and cost control supporting earnings and lowering net cash cost [E1]. Those gains can soften what fewer tonnes do to the income statement, but they do not send concentrate back through a stopped mill. Antofagasta’s August results therefore show a profitable half and a smaller production year living on the same page [E1][E2].
The interruption also exposed the mine’s dependence on local infrastructure beyond the orebody itself. Repairs to pipeline platforms and water-management systems formed part of the work around the restart, while intermittent power was among the causes of the shutdown [E3]. The record supports a Los Pelambres operating constraint tied to severe weather and power interruptions; it does not establish a nationwide Chilean grid failure or a global copper deficit [E3]. The commodity consequence begins with fewer reliable plant hours at one large operation, not with a country-sized blackout inferred from them.
There is a strong finite-interruption counter-case. Los Pelambres shut down in an orderly way, restarted gradually, and the company reported no material damage to key equipment [E3]. Antofagasta also kept its growth projects intact while narrowing the group production range [E2]. On that reading, July took several valuable days from the operating calendar without rewriting the mine’s longer-term capacity.
Quarter-three Los Pelambres production will settle which ledger deserves more weight. A clean ramp and output consistent with 625–655 thousand tonnes would make July a bounded weather charge inside a still-manageable year [E2][E3]. A weak quarter or another guidance cut would show that the five-day stoppage carried consequences beyond the calendar itself [E2][E3]. Prices can repair EBITDA after tonnes disappear; the mill still has to make the tonnes.