Flooding at Ivanhoe copper mine was self-induced, study suggests

Seismic activity that disrupted output at a massive copper mine in the Democratic Republic of Congo appears self-induced, according to preliminary findings released by operator Ivanhoe Mines Ltd.

The incident last month, which flooded parts of the Kamoa-Kakula mine, began in an area where a “mature percentage” of ore had already been extracted, the company said in a Wednesday filing.

“Current thinking postulates that blocks of ore, earmarked for secondary extraction, started to yield in a cascading fashion, which resulted in stress redistribution onto regional pillars,” according to the preliminary geotechnical findings.

The setback has cast uncertainty on a project touted as one of few across the mining world to be built ahead of schedule and on budget. Ivanhoe’s Kamoa-Kakula had swiftly risen up the ranks of global copper mines, establishing the Congo as one of the top countries for production of the critical metal used in everything from wiring to electric vehicles.

Ivanhoe co-chairman Robert Friedland expressed confidence in the mine’s future on Thursday, calling the incident a “bump in the road.” But if studies confirm the disruptions were the result of over-mining, the company may be forced to rethink its plans.

The finding’s recommendations suggest “a likely reduction” in total reserves at all the deposits, meaning the company will have to reduce mining rates and spend more, said Bank of Nova Scotia analyst Orest Wowkodaw in a Thursday note, adding the report indicates the seismic activity “appears self-induced by mining.”

“We don’t think Kakula is lost by any account,” the note added. Still, the findings suggest a revised operating plan for the entire complex that is “likely based on lower mining rates, lower reserves, and higher costs, but still very economic due to grade.”

(By Jacob Lorinc and James Attwood)