Silver Bear Resources Plc has shared a National Instrument 43-101 (“NI 43-101”) mineral resource update for Vertikalny deposit within the Mangazeisky Silver Project, Republic of Sakha (“Yakutia”) Russia.
Infill channel sampling has improved Silver Bear’s knowledge of grade distribution in the Vertikalny deposit. The additional sampling has converted 1.8 million oz of contained silver resource to the Measured resource category; and Silver Bear now has a good understanding of the local variability within the near-term open-pit resource, which will provide an excellent basis for short-term mine planning.
President and CEO of Silver Bear Resources, Graham Hill, commented: “I am very pleased with this significant upgrade of the Vertikalny Inferred resources to the Measured and Indicated category, of which 1.8 Moz is now classified as Measured, at a very high average grade of 1572 g/t Ag. This upgrade based on recent grade control trenching, once again confirms that this high grade is present right from the start of ore mining and will kick-start Silver Bear into an operating, dynamic company. As construction progresses at site, we continue to stock pile ore in anticipation of silver production early in 2018. We look forward to this being the start of our ongoing development as we look at future project opportunities both within and beyond our current exploration area.
In addition, the drilling work on the Infill and Metallurgical campaign announced in November is progressing well and planning for the balance of exploration is 2018 is well advanced with some very interesting targets.”
Resource Estimation Assumptions and Methods
Key Assumptions used to estimate the Mineral Resources are:
The Mineral Resource has been estimated with dimensional block models of: 10 m x 10 m x 1 m (x, y, z), with minimum sub-block dimensions of 2.5 m x 2.5 m x 0.25 m (x, y, z).
The estimate was constrained to the mineralised zone using wireframe solid models. The wireframes were sub-domained to isolate the strongly mineralised main zone from the silver mineralisation associated with wall rock alteration.
Grade estimates were based on 0.7 m composited assay data.
The interpolation of the metal grades was undertaken using ordinary kriging.
In order to demonstrate that the deposit has reasonable prospects for economic extraction, a cut-off grade of 200 g/t silver has been applied for resources contained within an open pit shell at Vertikalny Central. A 350 g/t silver cut-off has been applied for the underground resource.
A pit shell wireframe was used to constrain the open pit Resource in order to demonstrate that the blocks have reasonable prospects for economic extraction. The pit shell uses the following assumptions:
- Silver price of US$19 /Troy oz.
- Mining recovery 95%.
- Waste dilution 30%.
- Mining cost of US$2.53 /t.
- Processing cost of US$52 /t.
- General and administration costs of US$40.6 /t.
- Royalty of 6.5%.
- Overall silver recovery of 88%.