Diamondiferous gravels outlined at Tirisano (September 01, 2003)

An independent resource update has increased the volume of diamondiferous gravels at the Tirisano mine in South Africa, reports Etruscan Resources (EET-T) and Mountain Lake Resources (MOA-V).

South African-based RSG Global now pegs the deposit’s in situ indicated resource at 12.3 million cubic metres averaging 2.8 carats per 100 cubic metres. This new estimate is 18% more volumous than the previous calculation, tabled earlier this year, and is said to comply with National Policy 43-101.

RSG based its estimate on a bottom cutoff screen size of 2 mm, similar to the earlier one, and incorporated subsequent results from drilling and mining. Since November, when mining began, Tirisano has produced 3,500 carats from 126,000 cubic metres — well shy of projected production of 19,200 carats from 600,000 cubic metres annually.

More scrubbers and screeners are being added to the plant so that it can better handle troublesome clay-rich gravels. The additions also will boost the plant’s annual capacity to 960,000 cubic metres, which, in turn, is expected to translate into production of an additional 8,400 carats.

Etruscan operates and owns 51% of Tirisano. The remaining interest is divided among Mountain Lake, with 25%, and minority shareholders of a subsidiary through which Etruscan holds its interest, with 24%.

Meanwhile, Etruscan and partner Semafo (SMF-T) have awarded several more construction contracts at the Samira Hill gold project in Niger. Startup is slated for mid-2004, by which time at least US$27 million will have been spent.

First-year production is pegged at 135,000 oz. at a cash cost of US$177 per oz. Output then falls to an average of 100,000 oz. for each of the mine’s remaining five years, during which costs will average US$203 per oz.

The project comprises the Samira Hill and Libiri deposits, which, combined, host a reserve of 10.1 million tonnes grading 2.21 grams gold per tonne. Both deposits remain open at depth.

Etruscan and Semafo each hold a 40% interest in the project, leaving the remainder to the Niger government.