A large mystery sinkhole that developed in July at Lundin Mining’s Minera Ojos del Salado operation in Chile will be filled in as it also continues to pump out water that has seeped into the mine, according to a company official.
A senior executive for a local unit, Luis Sanchez, told Reuters that an investigation is in the “decisive stages” and that a technical body is “receiving all the information to be able to draw conclusions” from the 36-metre-diameter sinkhole that opened up at the Alcaparrosa underground copper mine, part of the Candelaria operation.
He noted that, regardless of the outcome of the probe, it will fill the hole with material like sand and rocks that have the same characteristics as a river bed. It will also fully seal the impacted section of the mine.
Initially, about 300-330 litres per second of water leaked into the mine. Following sealing work, that has dropped to about 10-30 litres per second.
“We are observing a positive development in the recovery of the levels in the aquifer and this means that we can look positively at this solution and we can say that we are not facing irreparable damage, as some authorities have indicated,” Sanchez told Reuters.
Lundin Mining has reportedly spent $10 million so far to resolve the sinkhole issue. Sanchez declined to indicate to the news service how much it would cost to fill in the hole.
It was first detected on 30 July and confirmed by Lundin on 1 August. The mine is located about 665 kilometres north of Santiago.
Lundin owns 80% of the operation, with the balance held by Japanese group Sumitomo.