Focused on Growing Production
Phase 1: 250,000 - 350,000 ounces annual production by leveraging existing mill and land package
Phase 2: 400,000 to 500,000 oz annual production, will require another mill expansion
Sabodala Gold Mine
The Sabodala Gold Mine that anchors Teranga's West African operations is located in a region of Senegal that has only recently been opened for mining and exploration. The region is emerging as a significant new gold camp, with more than 10 million ounces of resources already discovered. The Sabodala gold project is the only large-scale gold mine to come into operation in Senegal.
Construction and development of the Sabodala mine and plant occurred throughout 2008, at a cost of approximately US$330 million. With full commissioning occurring in early 2009, the mine's first gold was poured in March 2009. In its first full year of operation, production totalled 172,140 ounces of gold at a cash cost of US$528 per ounce.The first year of operation benefited from the excellent performance of the processing plant and the availability of well oxidized near-surface ore which enabled mill throughput to exceed nominal capacity by 11 percent, at 2.24 million tonnes.
Mining at Sabodala is undertaken by open pit truck and shovel methods. The recently expanded mill is capable of processing 3.5Mtpa of hard ore or almost 6.0Mtpa of soft ore. The conventional carbon-in-leach plant includes primary and secondary crushing, a SAG and two ball mills and leach tanks to produce dore bars of gold (90% gold / 10% silver). Power at Sabodala is provided by a 36MW heavy fuel oil power station located on the mine site.
As of December 31, 2012, the Sabodala gold mine had proven and probable reserves of approximately 1.6 million ounces of gold included in measured and indicated resources of 2.9 million ounces of gold and inferred mineral resources of 1.7 million ounces of gold.
Over $500 million has been invested to date.
2013 and Beyond - Focused on Growth
• Est.2013 production 190,000-210,000oz; total cash costs of $650-700/oz.
• Est.2014 production 200,000-250,000oz; depending on timing of Gora
• Increasing tonnes mined and milled by 24% and 37% from 2012 results
• Maximizing cash margins now that the hedge is extinguished
• Using our balance sheet to fund organic growth and minimize dilution
• Systematically advancing our project pipeline within our 1,200km2 regional land package and investigating the ~50 anomalies we have discovered
• Focused on growing profitable production through exploration, J.V.s and acquisitions of other properties; leveraging off our existing infrastructure
Mining of the Sabodala pit is carried out by owner-operated conventional truck and shovel equipment. The workforce comprises 129 operators with an additional 15 for vacation allowance.
The mine plan uses four cut-off grades for production assumptions. The highest cut-off grades are preferentially processed in descending order. All material above the incremental cut-off grade will be mined and stockpiled and is scheduled to be treated at the end of the mine life. Mining phases are sequenced to maximize gold production annually.
The mining schedule attempts to balance the annual truck hours required to deliver ore to the Run-of-mine (ROM) pad and waste to the waste dumps with the available loading capacity. Ore produced in excess of process plant requirements is selectively stockpiled throughout the life of the operation.
Processing
Metallurgical test work on the Sabodala ore has shown it to be a medium to hard silified breccia with fine-grained gold, mainly associated with pyrite but with some liberated gold also present.
Gold extractions in the 85-90% range at an optimal grind size of 75um (80% passing size) were readily achieved in the laboratory with some potential enhancement with gravity concentration. In anticipation of actual closed circuit grinding resulting in improved liberation, it was decided to defer installation of a gravity circuit. A simple crush, semi-autogenous-ball milling-crushing (SABC), carbon in leach (CIL) circuit was designed to treat a minimum of 2 Mtpa with a predicted recovery of 91.4%.
Preliminary tests on Niakafiri ore showed it to be very similar to Sabodala but, both in view of its greater oxide content and in consideration of other potential satellite orebodies, some initial tests were carried out to determine amenability to heap leaching. The oxide ore appears to be heap leachable with 90% recoveries obtained on agglomerated ore at an 8mm crush size, although further optimization work is still required.
Climate
In Kédougou, the nearest town to Sabodala, highest monthly average temperatures are between March and May, 31ºC to 40ºC. The lowest monthly average minimum temperatures range between December and January, from 17ºC to 26ºC. There is a distinct tropical wet season from May to October, with the most rain falling from August and September, and a dry season from December to April. Mean annual rainfall at the Sabodala project is estimated to be 1,130 mm.
It is possible to operate in Senegal on a year-round basis, but the schedule allows for a reduced mining rate and for predominantly fresh ore to be processed in the wet season.
Administration
The main camp is located approximately three kilometres from the mine and two kilometres from the plant. The SGO village was designed to house up to 585 employees and has been recently expanded to accommodate 700 people for the proposed near mine exploration program and increased capacity mining and milling operations. Sufficient capacity exists in the fuel farm to accommodate the expanding mining fleet.
Teranga currently employs close to 1,085 people with all contractors included.
Infrastructure
Teranga provides for the majority of its own infrastructure needs. Power is generated at the site using low speed, heavy fuel oil ("HFO") generators. A 30MW 5+l engine HFO power plant was constructed by Mineral Deposits Limited ("MDL"). Water supply to service the processing plant and mine comprises two surface water storage dams from local catchment areas. These dams are designed to store adequate water from seasonal rainfall events to provide for mine production needs on a year-round basis. A water pipeline was constructed to carry water from the local river, but due to sufficient natural supply, will likely never be required. There are sufficient waste disposal areas and a second tailings storage area will be constructed. The Company constructed a plant and supporting facilities at the site, including offices, shops and warehouses. Existing port facilities at Dakar are utilized for unloading of all equipment, spares and consumables for the mine. A significant proportion of the personnel involved in the mining operations have been sourced from the local villages, surrounding regions and Dakar.
Access to the Sabodala gold project from Dakar is by approximately 650 kilometres of sealed roads to Kédougou, with another 96 kilometres of a combination of sealed and surfaced roads. A 1,250 metre sealed, public airstrip, capable of handling light to medium sized aircraft, lies at the north end of the mining concession.
There are three villages on the mining concession. Sabodala village is approximately two kilometres south of the Sabodala mine pit and is very close to the Niakafiri deposit. Faloumbo village is to the north northeast of the Sabodala mine pit and the Dambankoto village is occupied by just a few families formerly from Faloumbo.
Regional Geology
The Sabodala deposit is located within the Senegalese portion of the Kédougou Kenieba Inlier, a major Proterozoic Birimian Inlier along the northeastern margin of the Archaean Leo Man shield. Within the Inlier metamorphic grade attains greenschist facies, with formation of metamorphic biotite and locally amphibolite grade near major intrusions. The Inlier is bounded on its western side by the Hercynian Mauritanides mobile belt considered to be Pan-African in age, and on all other sides by flat-lying Neoproterozoic Cambrian sediments of the Taoudenni Basin. Lateritic weathering combined with duricrust formation is considered to be still active and laterite has developed since the Cretaceous. The terrain is covered, to a large degree, by laterite.
The Kenieba Inlier in Senegal is interpreted as an accretion of northeasterly trending Birimian age volcanic terrains. The Inlier is divided into three main stratigraphic units. The western one, the Mako Supergroup (Saboussire Formation in Mali), hosts the Sabodala deposit within a north trending zone of intense shearing and silicification associated with gold and minor sulphide mineralization. The Senegal Tombo Shear Zone (“STSZ”) separates the Mako Supergroup from the rest of the Inlier and is considered to be west dipping and flattening in dip at depth, forming the sole of an imbricate thrust system. One of the splay faults of the thrust system is the mineralized Sabodala Shear Zone.
The Diale Dalema Supergroup (Kofi Formation in Mali) and the Diale Supergroup (Keniebandi Formation in Mali) make up the remainder of the Inlier and are further subdivided in the southeast part of the Inlier by the regionally important Senegalo Malian Shear Zone. These formations are host to a number of significant gold mines in nearby Mali, including Yatela, Sadiola and Loulo.
Local Geology
The Sabodala deposit is situated in the Mako Volcanic Belt. Locally the volcanics are intruded by subvolcanic dolerite and gabbro sills and dykes and also quartz feldspar porphyry and unfoliated rhyolite dykes. Interflow sediments parallel the layering in the sequence. There are excellent outcrops of the volcanics to the east of the deposit, which indicate a general north northeasterly striking sequence dipping steeply to the west. The lowest unit of the volcanic stratigraphy consists of magnesium-rich (komatiitic) basaltic rocks including massive, variolitic textured flows. Interflow carbonaceous and siliceous sediments, that are discontinuous along strike, have variable thickness between 0.2 metres and 1.0 metres.
The Sabodala Shear Zone is approximately 2 km wide and is identified by a subtle magnetic trend that extends through the 7 km long permit and transects volcanic stratigraphy.
For more information on Property Geology, please click here.