Nevsun Resources expects to begin commissioning the new zinc flotation plant at its Bisha operations in Eritrea midway through the second quarter of 2016, with commercial production to follow later in the year. Nevsun currently produces copper concentrates from the Bisha deposit’s copper-enriched supergene zone, which overlies a primary sulphide zone containing both zinc and copper.
The zinc flotation plant will enable processing of primary copper-zinc-gold-silver ore at rates of up to 2.4 million mt/y, producing copper concentrate from the existing copper flotation plant and zinc concentrate from the new zinc flotation plant.
Based on its current open-pit mine plan, Nevsun expects Bisha to produce an average of 225 million lb/y of zinc and 53 million lb/y of copper in concentrates through 2025. The company is forecasting that costs to complete the zinc flotation plant will come in at about $80 million, significantly under the budget of $100 million.
As the total tonnage of copper and zinc concentrates produced by Bisha going forward is expected to be similar to total copper concentrate tonnage produced in 2015, there has been no need to add transport or shipping infrastructure capacity.
As of year-end 2014, proven and probable reserves in the Bisha deposit’s primary zone totaled 21.6 million mt grading 1.08% copper, 5.66% zinc, 0.70 g/mt gold, and 45 g/mt silver.