NEW BRUNSWICK – Vancouver-based Trevali Mining Corp. has received a positive preliminary economic assessment for the Halfmile-Stratmat zinc-lead-silver project in the Bathurst Mining Camp. The base case study outlined a new 3,000-t/d concentrator at the Stratmat site that will be treat underground ore from both the Stratmat and Halfmile deposits.
Test mining in 2012 recovered 100,000 tonnes of material from the Halfmile underground mine. (Image: Trevali Mining)
Developed with a stand-alone mill, the project has a pre-production capex of $231 million, with a post-tax internal rate of return of 19% and a post-tax net present value of $99 million at an 8% discount. The mines would have a life of 13 years with peak annual production of about 117 million lb. of zinc, 35 million lb. of lead, 2 million lb. of copper, and 766,000 oz. of silver.
An alternate PEA was also done with ore being pre-concentrated using a dense media separator and final processing at Trevali’s Caribou mill. This option has a pre-production capex of $156 million, with a post-tax IRR of 25% and a post-tax NPV of $116 million at an 8% discount.
The Halfmile deposit has measured and indicated resources of 7.8 million tonnes grading 2.35% lead, 6.94% zinc and 36 g/t silver. There is also an inferred resource of 6.5 million tonnes grading 1.51% lead, 5.62% zinc, and 23 g/t silver.
The Stratmat deposit has an indicated resource of 4.7 million tonnes grading 2.1% lead, 5.3% zinc, and 49 g/t silver plus an inferred resource of 2.4 million tonnes at 2.1% lead, 4.8% zinc, and 39 g/t silver.
Detailed information from the Halfmile-Stratmat PEA are available in the Nov. 6, 2017, news release posted at www.Trevali.com.