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Thunder Bay mine developer investigating mineral estimate blunder

Clean Air Metals goes back to the basics to study miscalculation before beginning recount
(Clean Air Metals photo)

Clean Air Metals is digging into the details behind a serious miscalculation in the resource estimate of one of its mineral deposits outside Thunder Bay.

The northwestern Ontario mine developer announced this week it has started a review of a discrepancy recently discovered concerning the amount of metals thought to be in the ground at its Current deposit, which is part of its Thunder Bay North Project. The project is a platinum, palladium, copper and nickel property, 40 kilometres north of the city.

Last month, Clean Air pulled its resource estimate and a preliminary economic assessment for a proposed $367-million ramp-access underground mine after revealing there was an error in the mineral calculation. The company said at that time that the reduction could be in the range of 20 to 50 lower than what was originally reported in 2021.

A pre-feasibility study for the proposed mine study was underway and the results of the latest drill results were being tabulated when the error was found.

In a news release, Clean Air said it’s working with SLR Consulting, with the cooperation of Nordmin Engineering, “to determine the nature, cause, and extent” of the discrepancy.

There appear to be no issues with the metal content resource estimate at the nearby Escape deposit, which runs parallel to the Current deposit.

Clean Air gave no approximate date on the when the review will be completed.Once it's finished SLR will undertake a new resource update of both deposits.

The release said the review work involves studying the geological framework, plus "the modelling approaches, mineralogy, geochemistry and mineral assemblages employed as controls on mineralization in preparing the geological interpretation."

"The parties are engaged in a robust process to reconcile the mineral resource at the Current Deposit,” said Abraham Drost, Clean Air’s CEO, in a statement.

“The continued collaboration of the parties towards resolution of the discrepancy is appreciated and recognizes the efficacy of disclosure requirements under NI 43-101."

A recognized industry expert, Todd McCracken of BBA E&C has been appointed by Clean Air as an owner representative to assist management and the company board of directors with the technicals issues under review.