JOHANNESBURG (miningweekly.com) – Aim-listed copper miner Weatherly International’s Tschudi mine, in Namibia, has produced 2 257 t of LME Grade A copper cathode in the quarter ended June 30.

Production for the first full quarter of operations was more than 50% of design capacity.

The mine’s production guidance was reaffirmed at 1 000 t/m, or 70% of design capacity, for the September quarter, but output was expected to increase to 1 400 t/m in December.

As such, the company’s production guidance for the full year remained at 10 000 t.

"The ramp-up at Tschudi is proceeding according to the revised schedule and, by the end of this calendar year, Weatherly will be operating a new 17 000 t/y copper mine in the best mining country in Africa, producing some of the highest-quality copper cathode in the world,” CEO Craig Thomas enthused.

With over one-million tonnes of full-scale heap leaching experience now gained for Tschudi material ranging from 12 m to 60 m depth, the company had greater confidence in predicting leach rates and acid consumption rates and, below the shallow leached cap, these rates remained consistent with feasibility study assumptions.

“It is now clear that practically all of the ore, which was planned to be treated, would still be economically treated,” the company noted.

The material which leached significantly slower on the heap and which consumed more acid than originally expected, contained about 3% of the planned copper metal to be stacked over the current life of the Tschudi project.

“More than 80% of that material will have been mined by the end of the year,” it added.

The remainder would be mined relatively slowly over the following four years as pit pushbacks were developed, while the leach cap ore would not impact on Tschudi’s production rates once design capacity was achieved.

Cathode quality remained above expectations, exceeding LME Grade A requirements and plant operating efficiencies were also exceeding initial expectations. 

Cathode assays of 99.998% copper and electro-winning current efficiencies of 92% to 94% were routinely achieved.

Meanwhile, Weatherly delivered 2 760 t of copper cathode to metal trader Orion Merchant Services at a weighted average price of $5 929/t.
 
The first of two new primary mining areas at the company’s Otjihase pit was also now in production and access to the second higher-grade primary mining area was expected to be complete by the end of the September quarter. 

Otjihase ore tonnages had improved and ore supply was expected to be more consistent going forward.