African Copper soars on Dukwe drilling

Shares in London-based explorer African Copper (ACU-T, ACU-L) soared by as much as $1, or 79%, to $2.27 in Toronto on Jan. 20, after the release of further high-grade delineation drill results from the Dukwe copper project in Botswana.

The northernmost hole in the recent 12-hole program tested the Mapanipani North lens footwall and yielded 9.33 metres running 3.54% copper. The company says it coincides with previously sunk hole no. 46BD2, which cut 9.33 metres of 6.44% copper.

The new footwall zone extends along 200 metres of strike, 300 metres vertically, and ranges in true thickness between 10 and 30 metres. It remains open to the north and at depth.

Meanwhile, drilling on the hanging wall returned a 14.5-metre interval of 3.49% copper. Other intersections include 2.95 metres of 6.73% copper and 3.52 metres of 5.7% copper, both are contained in a 86.6-metre section of 0.92% copper. Another 38.9-metre interval averaging 1.18% copper includes 3.05 metres of 4.57% copper.

The drilling generally tested at depths between 140 metres and 625 metres. The intervals do not represent true widths.

Drilling at the northern (69.3 metres of 1% copper) and southern (37.4 metres of 1.08% copper) ends of the lens (600 metres apart) also indicates the continuity of a high-grade zone surrounded by a halo of lower-grade material.

“The deepest hole in the current program cut the deposit at a depth of approximately 475 metres below surface providing the company an opportunity to expand the Mapanipani lens,” said African Copper chief executive David Jones.

A resource estimate for the 600-metre-by-2,000-metre Mapanipani North zone is expected shortly.

Mapanipani North is one of 5 continuous sections that make up the 4.4-km-long Dukwe deposit. The sections are slightly displaced along post-mineral faults. The deposit is home to an oxide reserve totalling 5.1 million tonnes grading 1.85% copper to a maximum depth of 175 metres. This reserve overlies another 13 million tonnes of inferred sulphide resources averaging 3.85% copper. The estimates employ a cutoff grade of 1.5% copper and a minimum mining width of 2 metres.

African Copper’s six drill rigs have now turned their focus to tracing to the south the copper horizon at the Mapanipani and Bushman lenses.

Dukwe was initially envisaged as an open-pit followed by underground mining. The company is now looking at underground mining only via a twin ramp system one ramp for a conveyor system, the other for men and materials. During the initial years of operation, supergene material would be hauled to surface by truck from above the 125-metre level.

Ore would be sent to a 350-tonne-per-hour, three-stage crushing circuit feeding a 3,000-tonne-per-day ball mill and sequential sulphide and oxide floatation circuits. The circuit is expected to spit out around 22,680 tonnes of copper-in-concentrate annually. Metallurgical testing on sulphide material indicates recoveries between 88% and 93%, yielding concentrates containing 27% to 30% copper.

The plan carries an estimated price tag of around US$37 million. Preliminary operating cost for crushing, grinding and flotation ring in at US$10 per tonne, with another US$5 per tonne for general and administration costs.

African Copper expects all mine permits to be granted by the end of February; construction could conceivably follow in the second quarter.