Canada’s Banro Corp, which operates the Twangiza and Namoya gold mines on the Twangiza-Namoya gold belt in the DRC’s South Kivu and Maniema provinces, reports that its gold production for 2015 was 183 369 ounces with revenue for the year a record US$157 million, a 25 % increase over 2014. Gross earnings from operations were US$56 million, a 91 % increase over 2014. The company says it expects gold production in 2016 to total between 210 000 and 230 000 ounces.
Over the period, the Twangiza processing plant processed 1,71 Mt of ore (compared to 1,36 Mt during 2014) achieving 101 % of the design capacity. The design capacity of 1,7 Mt/a was based on the processing of oxide material while Twangiza’s processing achievement includes the continued processing of harder non-oxide material. Ore was processed during 2015 at an indicated head grade of 3,03 g/t Au (compared to 2,70 g/t Au during 2014) with a recovery rate of 80,9 % (compared to 83,0 % during 2014) to produce 135 532 (compared to 98 184 during 2014) ounces of gold.
The process plant of the Namoya gold mine in the DRC (photo: Banro Corp).
During 2015, Namoya produced 47 837 ounces of gold from a total of 1,41 Mt of ore, stacked and sprayed on the heap leach pads, at an indicated head grade of 1,88 g/t Au.
During the first two quarters of 2015, Namoya – which achieved commercial production at the beginning of this year – implemented a number of process design changes which converted the hybrid CIL/heap leach circuit into an agglomerated heap leach. Following the commissioning of the agglomeration drum in the first quarter of 2015, Namoya implemented process upgrades to increase throughput and stacking capabilities which came online in stages from late in the second quarter to the end of the year.
These upgrades led to daily stacking rates that incrementally increased and stabilised; however, the utilisation of the processed circuit in the second half of the year was restricted due to the lack of ore delivery from mining operations. This led to stacked ore volumes being supplemented by low grade ore stockpile material which decreased the average head grade of ore stacked.
Ore delivery from mining operations at Namoya in the third quarter was adversely impacted by low excavator availability. The situation improved in September with the commissioning of the first component of the larger mining fleet. The remainder of the larger mining fleet, the Cat 777s, were commissioned in phases throughout November with the full mine fleet operational in early December.