Ahead of a prefeasibility study expected this quarter on a restart of the Kiena mine complex in Quebec, miner Wesdome Gold Mines (TSX: WDO) has announced the results of bulk sample processing from the high-grade Kiena Deep A zone. The processing results slightly exceed the grades suggested in the December 2020 resource for the underground complex and confirm the continuity of the high-grade A and A1 zone mineralization.
The Kiena mill processed 7,032 tonnes of the bulk sample, recovering 6% more gold than predicted by the mineral resource. Feed grades of 15.7 g/t gold where ahead of model grades of 14.7 g/t gold and, with recoveries of 98.2%, produced 3,479 gold oz.
“We are very pleased with the results of the bulk sample that confirmed the continuity of the high-grade gold mineralization of the A zone, but more importantly demonstrated a 6% positive reconciliation in the number of ounces recovered from the bulk sample compared to the resource block model. This is very positive and provides confidence in the resource estimate for future mining,” Duncan Middlemiss, Wesdome president and CEO, said in a release.
To obtain the bulk sample, Wesdome blasted 66 rounds. The company also completed a geotechnical assessment, and mapped, photographed and sampled the faces from each round to assess the strike continuity of the high-grade gold in the A zone. Material processed at the mill was sourced from the Kiena A and A1 zones, milled at throughputs of up to 41 tonnes per hour.
Underground exploration is targeting extensions of the A and VC zones at Kiena; Wesdome is also ramping up a surface exploration program at the property.
The December 2020 resource outlined indicated resources of 1.8 million tonnes at 13.8 g/t gold, that contain 795,900 gold oz. and 3.4 million inferred tonnes grading 6 g/t gold, for an additional 656,200 oz. The Kiena Deep A zone contributes 1.3 million indicated tonnes grading 17.5 g/t gold and 325,700 inferred tonnes at 11.5 g/t gold to the inventory.
Kiena has been on care and maintenance since 2013 and includes a 930-metre shaft with a ramp system that extends down to 1,050 metres. Between 1981 and 2013, the site generated 12.5 million tonnes grading 4.5 g/t gold.
A May 2020 preliminary economic assessment on a restart of the mine outlined an eight-year operation, producing an average of 85,931 oz. gold annually at AISCs of US$512 per oz with an initial capital cost estimate of $35 million.
Wesdome expects to make a restart decision shortly after the prefeasibility release, expecting less than six months from a restart decision to production.