Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Gravity separation
- Centrifugal concentrator
- Intensive Cyanidation Reactor (ICR)
- Filter press plant
- Carbon re-activation kiln
- Leaching plant / circuit
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Carbon adsorption-desorption-recovery (ADR)
- AARL elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 7 years (as of Jan 1, 2021) |
Latest News | Endeavour Mining plc: Annual Financial Report March 28, 2022 |
Source:
p. 22
Company | Interest | Ownership |
Government of Burkina Faso
|
10 %
|
Indirect
|
Endeavour Mining plc
|
90 %
|
Indirect
|
SEMAFO Boungou S.A.
(operator)
|
100 %
|
Direct
|
The Boungou License is held by Semafo Boungou SA. Endeavour, indirectly through its subsidiary Semafo (Barbados) Ltd., holds a 90% stake in Semafo Boungou SA. The remaining 10% interest in Semafo Boungou SA is held by the State of Burkina Faso.
Summary:
The Tawori exploration permit (initially the Boungou exploration permit), which contains the Boungou gold deposit, lies within the Diapaga greenstone belt, a northeast-southwest orientated belt that extends over 250 km in length and over 50 km in width. Endeavour holds four contiguous permits, collectively known as the Tapoa permit group, covering approximately 70 km in strike length along the Diapaga belt.
The stratigraphy at Boungou is relatively simple and quite consistent from hole to hole. The stratigraphy consists of two volcanic flows separated by a volcaniclastic unit. The footwall flow generally progresses upwards from a massive basalt flow to pillowed flows followed by flow breccia and volcaniclastics. The hangingwall is characterized by a medium grained volcanic flow (or sill). All these units are intruded by diorite and/or granodiorite sills, possibly originating from the felsic intrusion located immediately west of the deposit. Late dolerite dykes are also present and appear to be sub-vertical and strike northwest. The Boungou Shear Zone, which hosts the main gold mineralization at Boungou, is located at the contact between the footwall and hangingwall volcanic units, where the volcanic flow top breccias have formed and the volcaniclastics deposited. The contact zone is thought to have served as an area of weakness, focusing the deformation. While the volcaniclastic units are not always present (although the intensity of the alteration can make it difficult to identify), the flow top breccias are interpreted to be ubiquitous across the deposit area.
The Boungou gold deposit can be described as a West African shear zone hosted greenstone gold deposit. The main mineralized lode is interpreted as a flat-lying anticlinal shear that outcrops in the southeast and plunges gently to the northwest. The mineralization has a strike length of approximately 2 km, striking towards a bearing of 315° and an across-strike length of approximately 1 km (towards 45°). The mineralization is gently folded with the fold axis oriented along strike and the limbs dipping gently at approximately 15°.
Gold mineralization is associated with biotite and silica-sericite alteration, along with disseminated sulphides, such as pyrrhotite, pyrite and minor arsenopyrite and chalcopyrite, with occasional free gold. The mineralization is structurally controlled and is hosted primarily within a large shear zone and its associated alteration. Arsenopyrite is almost invariably associated with the presence of gold in assayed samples. The percent arsenopyrite logged can be used as an initial identification of the mineralized lode. Although not common, visible gold has been observed in core in some drill holes.
Summary:
Mining uses a conventional open-pit mining method, with hydraulic excavators in backhoe configuration to mine both the mineralized zone and waste. The majority of the rock requires blasting and only the softer material located within the top 5m to 10m of the deposit is free digging and loaded directly by hydraulic excavators.
Mine production was halted on November 6, 2019 due to a security incident on the main route to Boungou. The Boungou Mine was put on care and maintenance for the rest of the year. On February 6, 2020, the Boungou plant was restarted and began processing the stockpile. Open pit mining restarted in July 2020 with a local contractor undertaking load and haul. Full contract mining with SFTP contractors started on October 15, 2020.
Rock mass characterization indicated a very thin Saprolite/Saprock domain (7 m to 15 m thick) underlain by very strong and competent metabasalts and metavolcanic sediments fresh rock mass domain. Structural fabric (joint and bedding) control pit wall stability.
The average annual rainfall at Boungou is 784 mm, with a wet season from June to September. The geology of the pit comprises metabasalts and metavolcanic sediments with a relatively flat mineralized shear zone. Historical records indicate that dewatering rates peak in August (90000 m3 ). Groundwater contribution is in the order of 5000 m3/month (167 m3/day).
Open pit mine production at Boungou averages approximately 3,600 t/d of ore in bedrock, from the West, East and West Flank pits, that can be blended with ore currently on the Rompad up to 4,000 t/d for processing in the mill.
The production, drilling and blasting operations are carried out on 6m benches on ore and 9m bench on waste. To be able to achieve the best degree of selectivity, ore mining is undertaken on a 2 m flitch. The highly weathered (strongly and moderately oxide) zone is amenable to free digging or soft blasting. Emulsion is used in both wet and dry blasting conditions for efficiency.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
|
|
|
1
|
Pebble crusher
|
|
|
|
1
|
SAG mill
|
|
20' x 12.2'
|
2.3 MW
|
1
|
Vertical mill / Tower
|
|
|
3.3 MW
|
1
|
Summary:
A static grizzly (800 mm), mounted above the ROM bin, will prevent the ingress of oversize material. A rock breaker will be installed to assist in breaking down oversize material, retained on the static grizzly. Ore will be withdrawn from the ROM bin, by a variable speed apron feeder, directly to a vibrating grizzly (75 mm aperture size). Oversize from the grizzly will report directly to the jaw crusher, which will operate in open circuit. Crushed ore from the crusher discharges, together with undersize from the grizzly, directly onto the primary crusher discharge conveyor, which will convey the crusher product to the mill feed bin.
The crushed ore product conveyor will be fitted with a weightometer, to monitor the crushing area throughput and for controlling the apron feeder variable speed drive.
The crushing circuit will be serviced by a single dust collection system, comprised of a series of extraction hoods, ducting and a bag house. Dust collected from this system will be discharged onto the crusher product conveyor.
Crushed ore will be withdrawn from the mill feed bin, by a variable speed apron feeder. The feeder will discharge onto the SAG mill feed conveyor, which will convey the crushed ore to the SAG mill feed chute. The SAG mill feed conveyor will be fitted with a weightometer, used for controlling the speed of the apron feeder and for mass accounting of feed presented to the grinding circuit.
Hydrated lime will be added directly to the SAG mill feed conveyor, via the lime variable speed rotary feeder. The hydrated lime storage silo will have a storage capacity of 60 t, equivalent to 47 days storage at 1.34 Mtpa.
The grinding circuit will be a SATMC circuit, comprised of a single, variable speed, SAG mill and a single fixed speed tower mill. The SAG mill will operate in closed circuit with a pebble crusher, whilst the tower mill will operate in closed circuit with hydrocyclones. The product particle size exiting the grinding circuit (hydrocyclone overflow) will contain 80% passing 63µm material.
To meet the design throughput, and achieve the required leach product size, a 6.10m diameter x 3.72m EGL SAG mill (20ft x 12.2ft; 2.30 MW) and a 3.3 MW tower mill will be required.
Crushed ore, reclaimed from the mill feed bin, will be conveyed to the SAG mill feed chute via the SAG mill feed conveyor. Process water will be added to the SAG mill feed chute, to control the in mill pulp density. The SAG mill will be fitted with discharge grates which will allow slurry to pass through the mill and will also relieve the mill of pebble build-up. The SAG mill product will discharge to a single deck vibrating screen, for size classification.
SAG mill discharge screen oversize will be conveyed to a pebble crushing circuit. Undersize from the discharge screen will gravitate to the SAG mill discharge hopper, where it will combine with discharge from the tower mill, prior to being pumped to the classification hydrocyclone cluster by one of two (duty/standby) variable speed hydrocyclone feed pumps. The classification hydrocyclone cluster overflow will gravitate, via a trash screen, to the pre-leach thickener feed distribution box. The trash screen undersize will constitute the pre-leach thickener feed whilst trash screen oversize will be discharged to a trash bunker.
Oversize from the SAG mill discharge screen will be conveyed to the pebble crusher feed bin, via two belt conveyors. A self cleaning tramp metal magnet will be mounted above the pebble recycle conveyor, to remove any scrap metal and steel media which could potentially damage the pebble crushers.
Processing
- Gravity separation
- Centrifugal concentrator
- Intensive Cyanidation Reactor (ICR)
- Filter press plant
- Carbon re-activation kiln
- Leaching plant / circuit
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Carbon adsorption-desorption-recovery (ADR)
- AARL elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The Natougou mineralization is predominantly hosted in quartz veins and a significant quantity of the gold occurs as visible, free gold. Sulphide minerals comprise pyrrhotite, arsenopyrite pyrite, and minor chalcopyrite. The Natougou quartz vein deposit is considered free milling. A significant component of the gold is amenable to gravity recovery and consequently the proposed process facility will consist of the following process areas:
• Primary crushing and coarse ore storage.
• Grinding, utilizing a SAG Mill, Tower Mill and Pebble Crusher (SATMC) circuit.
• Leach and CIP Carousel circuit.
• Gold recovery and carbon handling circuit (consisting of a cold acid wash followed by a split, Anglo American (AARL) elution circuit and horizontal carbon regeneration kiln).
• High density tailings handling and disposal.
The Natougou project process plant will be designed to process 4,000 tpd (1.34 Mtpa) with an average gold head grade of 4.15 g/t.
Recoveries & Grades:
Commodity | Parameter | 2021 | 2020 | 2019 | 2018 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  | 94 |
Gold
|
Head Grade, g/t
| ......  | ......  | ......  | 5.75 |
Reserves at December 31, 2021:
Cut-off grades for the resources are: oxide at 0.91g/t Au, transition at 0.91g/t Au, sulphide at 1.09 g/t Au;
Cut-off grades for the reserves are: oxide: 1.20g/t Au; transitional: 1.30g/t Au; fresh: 1.30g/t Au.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
0.6 Mt
|
Gold
|
1.95 g/t
|
39 koz
|
Probable
|
9.3 Mt
|
Gold
|
3.61 g/t
|
1,075 koz
|
Proven & Probable
|
9.9 Mt
|
Gold
|
3.51 g/t
|
1,114 koz
|
Measured
|
0.6 Mt
|
Gold
|
2.04 g/t
|
40 koz
|
Indicated
|
10.5 Mt
|
Gold
|
3.95 g/t
|
1,336 koz
|
Measured & Indicated
|
11.1 Mt
|
Gold
|
3.85 g/t
|
1,376 koz
|
Inferred
|
0.1 Mt
|
Gold
|
4.89 g/t
|
14 koz
|
Corporate Filings & Presentations:
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2021
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2021
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2021
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2019
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2019
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2019
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Annual Information Form
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2018
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Press Release
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2018
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Annual Information Form
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2017
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Feasibility Study Report
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2016
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- Subscription is required.
News:
News | Date |
Endeavour Mining plc: Annual Financial Report
|
March 28, 2022
|
Endeavour Reports Record FY-2021 Results
|
March 17, 2022
|
Endeavour Beats 2021 Full Year Guidance; Announces H2-2021 Dividend of $70m
|
January 24, 2022
|
Endeavour Restarts Boungou Mine and Begins Realizing Synergies Following SEMAFO Integration
|
October 15, 2020
|
Closing of Business Combination Between SEMAFO and Endeavour Mining
|
July 1, 2020
|
SEMAFO Obtains Court Approval of the Arrangement with Endeavour Français
|
May 29, 2020
|
SEMAFO Obtains Shareholder Approval of the Arrangement with Endeavour Français
|
May 28, 2020
|
Semafo halts Bongou operations following attack on mine
|
November 8, 2019
|
SEMAFO: Follow-up Drilling on Dangou Returns Promising Results
|
January 21, 2019
|
SEMAFO Pours First Gold at Boungou Mine
|
June 29, 2018
|
SEMAFO: Construction of Boungou Mine 87% Complete
|
March 22, 2018
|
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