De Beers completes sample

De Beers Canada Exploration has collected additional mini-bulk drill samples from two of the highest-value pipes at the Kennady Lake joint venture in the Northwest Territories. The wholly owned subsidiary of De Beers Consolidated Mines (DBRSY-Q) hopes to recover a larger number of diamonds to increase the confidence level of its scoping study model.

Last year, the subsidiary tabled a study that examined both open-pit and underground mining options. Open-pit mining was proposed for the 5034 and Hearne pipes, and for a high-grade zone within the top 140 metres of the Tuzo pipe. However, the project fell short of the critical mass to achieve the 15% rate of return needed to proceed to the feasibility stage.

Joint-venture partner Mountain Province Diamonds (MPV-T) says it would only take a 15% increase in diamond values to put the project over the minimum threshold.

Situated 120 km southeast of Lac de Gras, Kennady Lake comprises a portion of the AK-CJ claims, held 51% by De Beers, 44.1% by Mountain Province and 4.9% by Camphor Ventures (CFV-V). De Beers can increase its interest to 60% by advancing the project to commercial production.

This past winter, De Beers recovered 307 tonnes of kimberlite from three large-diameter reverse-circulation (RC) holes into the high-grade northern part of the Hearne pipe, plus 550 tonnes from four holes into the high-grade eastern lobe of the 5034 pipe.

Hearne was modelled at 7.2 million tonnes grading 1.71 carats per tonne at an average value of US$65 per carat, or US$111 per tonne, whereas 5034 contains an estimated resource of 12.5 million tonnes grading 1.64 carats per tonne at US$63 per carat, or US$103 per tonne.

The third pipe incorporated in the scoping study, Tuzo, contains 14.9 million tonnes grading 1.22 carats per tonne at US$43 per carat, or US$52 per tonne. An upper, high-grade zone hosts a modelled 1 million tonnes grading 2.7 carats per tonne at US$47 per carat, or US$127 per tonne.

The mini-bulk samples are being processed in Grande Prairie, Alta. Concentrates will be shipped to South Africa for diamond recovery; the diamonds will then be valued in London at the Diamond Trading Co., followed by revenue-modelling in Johannesburg. Final results are expected late summer.

In the meantime, De Beers has begun exploration drilling in the southern half of the AK claims, targeting geophysical anomalies at the head of several indicator mineral trains.

The South African major is also carrying out further drilling in the MZ Lake area, 20 km northwest of Kennady Lake. Last year, a shallow, 35-metre-long hole drilled into a land-based target on the north shore of MZ Lake intercepted a 1.7-metre-thick interval of kimberlite, along with five kimberlite stringers up to 0.7 metre thick.

This spring, De Beers conducted a ground-penetrating radar survey over this area and, in the process, detected a low-lying, shallow dipping structure. The structure will be drilled to determine if it is kimberlite.