The first of Banro's two gold mines, Twangiza has a Mineral Reserve of 1.82 Million ounces of gold.

Twangiza Mine

Twangiza became Banro's first producing open pit gold mine in October 2011, and commenced commercial production in September 2012. With mill throughput currently operating at capacity levels of 1.7 million tonnes per year, Twangiza in 2016 produced 104,438 ounces of gold. The mine has an expected life of 14 years from currently defined reserves.

The property is located 45 kilometres south-southwest of Bukavu in South Kivu Province and consists of six Exploitation Permits covering 1,164 square kilometres in the highly-prospective 210km long Twangiza-Namoya gold belt.

Twangiza is the most advanced of Banro's four properties with a Mineral Reserve of 27.67 million tonnes grading 2.05 g/t Au containing 1.82 million ounces of gold. Measured and Indicated resources at Twangiza are 99.35 million tonnes grading 1.47 g/t Au containing 4.69 million ounces of gold plus an Inferred Resource of 9.83 million tonnes grading 1.17 g/t Au containing 370,000 oz Au. The updated resource calculation used a cut-off grade of 0.4 g/t Au.

The Twangiza deposit is comprised of two resource components - an oxide portion and a transition rock/fresh rock (non-oxide) portion. The current activities involve mining and processing a blend of both oxide and non-oxide material within the reserve pit shell using the existing plant. Exploration activities are focused on growing the oxide resource.

The most recent technical report with respect to Twangiza that has been filed by Banro on SEDAR is dated July 29, 2015 and entitled NI 43-101 Technical Report, Mineral Resource and Reserve Update, December 31 2014, Twangiza Gold Mine, Democratic Republic of the Congo. A copy of this report may be accessed at

Chief Geologist Chris Bawah briefs his team


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 metres of trenching and 12,100 metres of adits on seven levels, collecting a total of 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 during the following year, undertook a US $9 million exploration program, which included 10,490 line-kilometres of airborne geophysics, 1,613 samples from 16 adits, and 8,577 drill core samples from 9,122 metres of core drilling along 800 metres of strike. This represented less than 20 percent of the identified mineralized trend.

Economic Assessment NI 43-101 Technical Report - Twangiza Phase 1 Gold Project, South Kivu Province, DRC - 24 March 2011 (3.2 MB).

Building the lay down area and brick yards at Twangiza


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 mineralization at the Main Twangiza deposit is hosted within mudstones, siltstones, greywackes and porphyries along the crest of a major anticlinal structure. Gold mineralization 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 mineralization at Twangiza North is associated predominantly with feldspar porphyry sills that have intruded westerly dipping shales and siltstones, with the mineralization in this lithology being non-refractory. This mineralization 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 Kibizwa, Tshondo and Mufwa.