Chile’s state-owned copper giant Codelco is seeking approval to restart parts of its flagship El Teniente mine less than a week after a deadly collapse killed six workers and forced a full suspension of operations, according to sources familiar with the matter.
The accident, triggered by a 4.2-magnitude seismic event last Thursday (July 31), halted production at the world’s largest underground copper mine.
Codelco has formally requested Chile’s National Geology and Mining Service (Sernageomin) to allow a partial reopening of the mine, pending approval of safety and technical evaluations, two sources told Reuters.
The cave-in, which was triggered by the earthquake, occurred more than 900 meters underground and initially trapped five miners.
Their bodies were recovered over several days by a rescue team of more than 100 people, including veterans of Chile’s 2010 San José mine rescue. The body of a sixth miner, who was killed at the time of the collapse, was recovered earlier.
“We deeply regret this outcome,” said O’Higgins Region Prosecutor Aquiles Cubillo on Sunday, confirming the final recovery. He offered no additional details on the cause of the collapse, which remains under investigation.
Operations at El Teniente were formally suspended by Sernageomin, Chile’s geology and mining agency, shortly after the incident.
It also instructed Codelco to submit four comprehensive technical reports before any restart can be authorized. The reports must include: an analysis of the collapse’s cause, a recovery plan, an assessment of current fortification systems, and a wider structural evaluation.
While underground mining has stopped, Codelco has maintained limited activity at El Teniente. The company is conducting ongoing maintenance at the processing plant and smelter, including operations at the smelter’s anode furnaces every two hours to keep critical equipment in operable condition.
Codelco said it had responded to three separate information requests from Sernageomin and Chile’s Labor Inspectorate, but added that it could not yet estimate the financial or operational impact of the suspension.
Scrutiny on safety standards
Mining Minister Aurora Williams ordered the temporary cessation of activities at the mine over the weekend. Meanwhile, Energy and Mining Minister Diego Pacheco said on Sunday that Codelco would commission an international audit to understand what went wrong.
“We’re going to commission an international audit to determine what we did wrong,” Pacheco said. While no formal complaints had been received about the safety conditions of the site, he pledged that a full investigation and appropriate corrective measures are underway.
El Teniente, located about 100 kilometers south of Santiago in the Andes mountains, is a cornerstone of Codelco’s operations and Chile’s mining economy.
It produced 356,000 metric tons of copper in 2024, nearly 7 percent of the country’s total output. The mine has operated for over a century and contains a labyrinth of more than 4,500 kilometers (2,800 miles) of tunnels.
The seismic event that triggered the collapse, while relatively mild by global standards. has raised questions about the structural integrity of older sections of the mine and the adequacy of current fortification systems.
A blow to expansion efforts
The accident is a significant setback for Codelco as it seeks to modernize its aging infrastructure and boost production after years of underinvestment.
The collapsed area is believed to be part of the Andesita section of the mine, a relatively small but strategically important component of El Teniente’s broader expansion, which includes the Andes Norte and Diamante projects.
The Andesita development is intended to help offset declines in older zones and maintain output levels through the next decade. Its disruption will likely ripple through Codelco’s project pipeline, which is already under pressure due to rising costs.
Though Chile boasts one of the world’s safest mining sectors – a fatality rate of just 0.02 percent in 2024 – the string of incidents at Codelco sites has drawn concern from unions and regulators alike.
The industry’s worst accident remains the 1945 fire at El Teniente, which killed 355 miners and stands as one of the deadliest mining disasters in history.
Securities Disclosure: I, Giann Liguid, hold no direct investment interest in any company mentioned in this article.
