JOHANNESBURG (miningweekly.com) – A recently completed drilling and bulk sampling programme at TSX-listed Tsodilo Resources’ 100%-owned BK16 kimberlite project, in the Orapa kimberlite field (OKF), in Botswana, has returned positive results.

The $1.7-million programme was completed on time and within budget and focused on bulk sampling of the 6 ha BK16 kimberlite, one of the few untested kimberlites in the OKF.

A small parcel of previously recovered diamonds from BK16 indicates that this kimberlite contains a high proportion of Type IIa white diamonds, all grading as D-colour with no or only faint levels of fluorescence.

The BK16 kimberlite has an estimated volume of some 16.2-million tonnes made up of the main kimberlite phases VK2 (5.4-million tonnes), VK3 (9.4-million tonnes), and CB (1.5-million tonnes) to a depth of 250 m from the base of the Kalahari surface. The volume figures are in the process of being updated using the latest large diameter drilling (LDD) hole logs.

"There is still work to do on BK16 to assess its full potential but the work that Mike de Wit and his team in Botswana has accomplished is nothing short of being first-rate,” said CEO James Bruchs.

He added that control of the LDD programme by the company's geological team has resulted in a product that has an abundance of coarse chip material with fragments over 10 cm in length from some holes.

“From the day we were awarded the prospecting licence the work has been has been non-stop. Tackling big projects like this, which would normally be set aside for mid-sized or major companies, is nothing new to us but it is always gratifying when we reach this level; our staff is to be commended,” Bruchs highlighted.

This stage of the evaluation programme will define the grade and diamond content of the two main kimberlite phases, VK2 and VK3, of BK16 in support of an economic assessment. It will also provide a first pass valuation of the diamonds that will be recovered from these samples.

The 243 samples from the LDD programme, totaling some 2 008.9 t, will be treated through the company's 10 t/h dense media separation plant, which is situated just outside Letlhakane.

In addition, the plant will also treat up to 1 500 t of a mixture of pre-1976 and 2000 historical tailings that were removed from the BK16 site and deposited next to the plant.