Sahelian fires up Poura gold mine

Having successfully revived the past-producing Poura underground mine, owner Sahelian Goldfields (SHGI-C) has joined the ranks of gold producers and re-established Burkina Faso as a gold-producing nation.

The Toronto-based company is currently crushing stockpiled ore, which will be sent through the milling circuit shortly.

Run-of-mine ore will first be placed through a crushing, milling and flotation circuit to produce a concentrate. Dor bars will be produced on site using the carbon-in-leach process, although the economics of this method will be compared with those of producing only a concentrate during the test period.

Full-scale production is targeted for the fall, after which the mine is expected to yield 45,000 oz. per year at total operating costs of US$180 per oz.

Proven and probable minable reserves stand at 420,000 tonnes grading 11 grams gold per tonne, equivalent to 141,634 contained ounces of gold. The reserves were calculated using a cutoff grade of 4 grams, with higher-grade assays cut to 30 grams.

The area of blocked-out reserves is 2 km long by 300 metres deep, whereas previous development only extended to the 250-metre level. A total of 2,000 metres has been developed underground so far, leaving another 1,300 metres before full-scale mining is reached. The ore will be mined by a number of methods, but chiefly through cut-and-fill techniques.

“[Poura] is the only gold mine in Burkina Faso to see the light of day,” noted Sahelian President Guy Charette. “Since taking over the project, we have increased development rates to 300 metres per month and managed to turn it into a viable operation inside of nine months, while saving a number of jobs in the process.”

Poura last operated in 1995, having produced over 600,000 oz. gold from a combined open pit and underground operation in its lifetime. In early 1997, Sahelian struck a deal with Ashanti Goldfields (ahd.u-t) to acquire the latter company’s option to earn 90% in the 11-sq.-km mining licence for Poura, the surrounding 500-sq.-km exploration permit and the mine facilities. The deal required Sahelian to issue 3 million shares and 2 million warrants to Ashanti.

The Burkina Fasan government’s 10% interest in Poura remained unchanged.

Sahelian has since completed a feasibility study, thereby allowing it to exercise its option on the properties. An underground development and rehabilitation program formed the basis of the study, which was carried out by consulting firm A.C.A. Howe International. Project financing was provided by a US$14.6-million non-refundable grant from SYSMIN, a European-based development agency. In order to keep the grant in good standing, Sahelian hired 340 Burkina nationals, nearly all of whom are expected to continue working at Poura indefinitely.

Gold mineralization at Poura occurs as free grains in a steeply-dipping, north-south-striking quartz vein averaging 2 metres in width. The zone is structurally controlled and enclosed by competent andesitic and dacitic volcanic rocks of Birimian age. The system is described as being similar in character to the lode gold deposits of Canada’s Abitibi greenstone belt.

Exploration in 1997 also extended the strike of the mineralization by 700 metres to 2.7 km. The extension, said Charette, was not included in the reserve calculations because grades of lode gold deposits can only be determined by development. Drifting is continuing into the extension, and ramping has reached the 332 level, where several drill stations have been developed for an underground drilling program.

“There is still no foreseeable limit on the zone’s length,” added Charette.

“It is also intriguing that there are currently no examples of similar deposits extending for such a length, but no more than 300 metres deep.” Although underground drilling has only recently begun, one hole intersected the gold-bearing structure at a depth of 440 metres. The drill results are not considered economic, but do indicate the continuance of the system.

Charette said it is highly probable that the vein pinches near the 300 level and swells again at depth. This, he noted, explains why previous owners failed to find any depth extensions.

A total of 6,000 metres of drilling are planned. A surface exploration program will get under way in the coming months to follow-up a number of targets outlined by previous work.