Name: Twangiza mine.

Controlling Company: Banro Corporation (100%).

Location: Twangiza is located 45 km south-southwest of Bukavu, in South Kivu province, in the Democratic Republic of Congo. 

Brief History: The Twangiza gold deposit was discovered by Miniere des Grande Lac (MGL) in the 1950s. The company followed the occurrence of alluvial gold deposits upstream from the Mwana river to the present-day Twangiza deposit. MGL tested the deposit through 8 200 m of trenching and 12 100 m of adits on seven levels, collecting 17 400 samples. In the mid-1970s, Charter Consolidated undertook detailed exploration, including the excavation of numerous close-spaced adits into the mineralized zone.

In 1996, Banro acquired control of the Twangiza property, and undertook a $9-million exploration programme the following year, which included 10 490 line-kilometres of airborne geophysics, 1 613 samples from 16 adits and 8 577 drill core samples from 9 122 m of core drilling along 800 m of strike. This represented less than 20% of the identified mineralised trend.

Brief Description: Twangiza consists of six exploitation permits covering 1 164 km2 in the highly-prospective 210-km-long Twangiza-Namoya gold belt.

The operation became Banro's first producing openpit gold mine when it entered production in October 2011. With a mill throughput of 1.7-million tons a year at full capacity, expected production is 120 000 oz/y of gold, with an expected mine life of seven to eight years from currently-defined reserves.

Mining Method: Openpit.

Products: Gold.

Major Infrastructure and Equipment: Banro Corporation has bought a refurbished gold-processing plant capable of achieving a throughput capacity of 1.3-million tons a year. The refurbished plant comprises a crushing plant, two ball mills, carbon-in-pulp section, a gold room and a laboratory. The process plant uses single-stage crushing, followed by a semiautogenous and ball mill operating in closed circuit with hydrocyclones. A conventional gravity-carbon-in-leach processing facility was designed for yearly throughput of 5-million tons of oxides or 3.75-million tons a year of transitional and fresh ore, or combinations thereof. A valley close to the mine site has been chosen for tailings deposition. Nearby rivers have the potential to generate hydroelectric power for Banro's projects and local communities.

Reserves: Total proven and probable reserves as at March 4, 2011, were 25.58-million tons, with a grading of 1.87 g/t gold.

Geology/Mineralisation: The Twangiza area is underlain by sediments of Proterozoic age that have been intruded by porphyry sills, folded into a series of broad anticlines and synclines and subjected to very low-grade metamorphism. The gold mineralisation at the main Twangiza deposit is hosted within mudstones, siltstones, greywackes and porphyries along the crest of a major anticlinal structure.

Gold mineralisation is of hydrothermal origin and is associated with sulfides, which occur in quartz-carbonate veins, and disseminations throughout the host rocks. Unlike the Twangiza Main deposit, the mineralisation at Twangiza North is associated predominantly with feldspar porphyry sills that have intruded westerly dipping shales and siltstones, with the mineralisation in this lithology being nonrefractory. This mineralisation is open at depth and to the north, where recent regolith mapping has indicated that the gold-in-soil anomalism has been masked by recent colluvial and alluvium material. Other significant gold occurrences on Banro's Twangiza's concessions include Tshondo and Mufwa.

Prospects: A comprehensive upgrade of the metallurgical plant is under way, which includes the introduction of a larger front-end crusher, increases carbon-in-leach tank volumes and the doubling of elution capability.

The completion of the full expansion exercise is planned for the end of the third quarter 2013. This will increase throughput to 1.7-million tons a year, which is about 68% higher than the fourth quarter of 2012 and, together with higher recoveries, is expected to be in the 90% range. Unit costs will reduce further to $500/oz to $600/oz.

Contact Person: Investor relations, Toronto office, Naomi Nemeth.

Contact Details:
Banro Corporation
Tel +1 416 366 2221
Fax +1 416 366 7722
Email info@banro.com
Website: www.banro.com