JOHANNESBURG (miningweekly.com) – A review of metallurgical testwork has supported the development of a planned process route for gold recovery at the 678 000 oz Mpokoto gold project, in the Democratic Republic of the Congo, developer Armadale said on Monday.

The project would be developed in two phases, with the first phase  seeing the majority of the ore feed weathered and deeply oxidised. The plant would comprise scrubbing, milling and a batch Knelson concentrator to recover the free gold and flotation of the Knelson tailings.  The flotation concentrate would then be intensively cyanided.

The second phase would entail a regrind ball mill grinding the flotation concentrate as the amount of weathered ore decreased and the proportion of transitional and fresh ore increased. A carbon-in-leach (CIL) circuit would also be added to leach the flotation tailings in this phase.

Aim-listed Armadale expected a production rate of about 25 000 oz/y of gold over an initial nine-year mine life and targeted production to start in the first half of 2016, with an average projected operating cost of $647/oz.

Recoveries of between 88% and 90% were expected on the weathered ore and 84% on the transitional and fresh ore, prior to the CIL circuit being added. Further testwork would be completed during the definitive feasibility study to determine the effect of adding the CIL circuit to the treatment of transitional and fresh ores.

“Settling on a final process route for the Mpokoto gold project is another significant step forward in the development path of our low capital expenditure, low operational expenditure operation,” Armdale director Dr Andrew Tunks said.

He added that, with drilling on track to start soon, adding additional tonnages to the current project resource and an agreement in place with Africa Mining Contracting Services to fund, develop, build and operate Mpokoto, the project was rapidly progressing towards first gold production in 2016.