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.
[caption id="attachment_1003720645" align="alignright" width="300"] 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.