Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Gravity separation
- Agitated tank (VAT) leaching
- Inline Leach Reactor (ILR)
- Carbon in pulp (CIP)
- Elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 5.5 years (as of Jan 1, 2019) |
July 30, 2021 - Thor Explorations Ltd. is pleased to announce the first gold pour from its Segilola Gold Mine located in Osun State, Nigeria. The pour took place this morning, July 30, 2021.
October 5, 2021 - Thor Explorations Ltd. is pleased to announce commercial production has been achieved at its wholly owned Segilola Gold Mine located in Osun State, Nigeria. The process plant is now consistently operating in-line with its design throughput capacity of 715,000 tonnes per annum. |
Latest News | Thor Explorations Announces Commercial Production at Its Segilola Gold Mine in Nigeria October 5, 2021 |
Source:
p. 2
The Segilola Project is 100% owned by Segilola Resources Operating Limited (“SROL”), which is a 100% owned subsidiary of Thor Explorations Inc..
Deposit Type
- Vein / narrow vein
- Orogenic
Summary:
Segilola is an orogenic-style lode gold deposit which occurs within a regional-scale shear zone.
Host rocks comprise an overturned sequence of high-grade amphibolite-facies metasediments intruded by a large, possibly differentiated, granodiorite sill-like body. The mineralisation is developed within a series of steeply dipping, tabular, very continuous, latestage quartz-pegmatite veins that do no exhibit any form of significant deformation such as folding or faulting. The geological and mineralogical characteristics of the mineralised veins are consistent throughout both the strike and down dipextents of the known resource.
Drilling results demonstrate that gold mineralisation occurs in fractured pale to dark grey coloured smoky quartz veining, sheared pegmatite, and silica/chlorite/carbonate alteration. The mineralisation is hosted in three steeply dipping vein sets or lodes; the Hanging Wall Lodes (Lodes 100 and 300) and the Footwall Lode (Lode 200). Together these form an elongate mineralised zone striking 010º and dipping 60º to 70º towards the west within a single shear zone, primarily in biotite gneiss. The currently drilled mineralised zone is approximately 2,000 m in strike length, between 70 m and 200 m in depth, and between 2 m and 20 m in true thickness.
The mineralogy of the Segilola deposit is characterised by its general simplicity and consistency. The gold is entirely non-refractory and commonly occurs as visible particles within either pegmatitic quartz-feldspar veins or foliated biotitic selvedges to the veins. There are no significant trace element associations such as silver with gold. However, metallurgical assaying indicates slightly elevated copper (250 ppm to 300 ppm) and mineralogical studies suggest a gold-tellurium association.
Two styles of gold mineralisation are observed:
• Narrow, 1 m to 3 m thick Hanging Wall Lodes within silicified biotite schists (DGS). These lodes locally contain 5 µm to 20 µm grains of visible gold and are developed in the hanging wall to the main (footwall) lode. These lodes appear to have different controls to the footwall lode and have a more vertical continuity over shorter strikelengths.
• Wide, up to 15 m, ‘footwall’ mineralisation within a characteristically grey-green, strongly silicified zone of biotite schists and gneisses (SZQ1).
The mineralised lodes generally comprise highly silicified fine-grained, foliated biotite gneiss typically intruded by both discordant and concordant pegmatitic quartz-feldspar veins.
Shearing, fracturing, and alteration influence the location of gold mineralisation. This relationship has generated multiple zones of gold mineralisation hosted by shears now represented by chlorite and calcite alteration, together with quartz veining and pyrite development.
Minor sulphides, typically pyrite, are associated with the lodes. Macroscopic observations show that sulphide grains and blebs are often aligned with foliation, commonly following either biotite-rich laminae or near pegmatite boundaries. There is also, however, a common generation of pyrite occurring along fractures or as quartz-pyrite tension gashes, highly discordant to the foliation. A cursory examination suggests most of these do not contain pyrrhotite. These either relate to a late episode of mineralisation, or to remobilisation of sulphides.
Native gold is visible in both altered wall rock and in quartz-feldspar veins. It occurs with petzite (a silver gold telluride), within pyrite, and quartz veins. The typical size of native gold blebs is approximately 10 µm. Gold, either as native grains, flakes and blebs occurs together with gold-on-pyrite in alteration zones, along tension gashes, hair-like fractures, joints, and minor faults.
Summary:
The Segilola Gold Project will be operated primarily as a contract mining operation with all mobile equipment to be provided, operated, and maintained by a mining contractor(s) over the life of the Project. Conventional open pit mining methods using excavator and truck fleets will be used. Thor will provide fixed installations including contractor area establishment, workshops, offices, and first aid facilities.
There are four well defined weathering horizons present, allowing the material to be mined according to classification as residual soil, oxide rock, transitional rock, and fresh rock. The vast majority of material is fresh rock.
Drilling rigs operated by the contractor will be Epiroc T45/50 class top-hammer drills with the capability to drill holes from 89 mm to 140 mm in diameter. Ore blasting will be done on five metre benches, while waste blasting will be conducted on 10 m benches where possible. A set of blast patterns ranging in powder factor from 0.43 kg/m3 to 1.07 kg/m3 will be applied depending on the material type.
Narrow ore zones will require the implementation of careful blasting techniques to minimise dilution and maximise ore recovery, namely the use of “Blastmaster” bench planning to optimise blast shapes/geometry and sequencing, choke firing where possible to minimise ore movement, blast initiation timing to control movement, the use of blast movement indicators, and a refinement of blast design parameters based on results obtained.
Blasting will be done with pumped emulsion as water is expected in the blast holes.
The mining contractor will use 200 t hydraulic excavators (12.5 m3 bucket capacity) and 90 t payload rear dump trucks. Excavators will be in backhoe configuration to allow flexibility for mining both ore and waste.
Waste mining will be performed using a double-bench method, where possible, in order to reduce ancillary equipment costs, taking a full 10 m cut with each pass. Ore mining will be on two 2.5 m flitches to reduce the chance of dilution whilst still providing a sufficient bench height for the required production rates.
Grade control drilling and mining of the ore will only take place during dayshifts so that the Thor technical department can guide excavations to minimize ore dilution and loss.
The production equipment will be supported by ancillary equipment such as dozers and graders to achieve level graded floors, smooth out blast heave, and provide face cleanups. Water carts will be employed for dust suppression, using water sourced from pit dewatering and other storage dams when necessary.
A total of 75% of the Run of Mine (ROM) is planned to be re-handled due to the substantial stockpiling planned. This will be done using a front-end loader (FEL), such as a Caterpillar 988, with 6.4 m3 bucket capacity. The ROM pad and stockpile area will be located adjacent to the processing plant at the southern end of the west waste dump. All waste rock from the pre-strip period and initial months of mining will be used to create the flat area for the ROM pad and ore stockpiles. The front-end loader may need to be supplemented by a truck from the mining fleet when ROM pad hauls exceed 200 m.
Open pit dewatering requirements have been assessed based on limited groundwater information. The assessment has estimated the inflow into the open pit from groundwater sources could range from 60 m3/day to 600 m3/day. The contractor costed the provision of 3 Sykes HH160i pumps, which can each provide 350 m3/h capacity with a head of 100 m).
Sub-horizontal drains will be used to promote passive drainage of the pit walls, typically installed from benches in the pit walls, with a horizontal spacing of 10 m to 30 m between drains. Drilled diameters will be 75 mm to 100 mm, with a 50 mm diameter high-density polyethylene (HDPE) of unplasticised polyvinyl chloride (uPVC) slotted screen installed.
Flow Sheet:
Processing
- Gravity separation
- Agitated tank (VAT) leaching
- Inline Leach Reactor (ILR)
- Carbon in pulp (CIP)
- Elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The plant is designed to operate 365 day/year, 24 hours/day, with a design utilization of 91.3%, for a nominal ore throughput of 81.3 tph and design ore throughput of 84.5 tph. Production throughput utilises 86.6% of design utilization, resulting in an average LOM annual production of 625,000 tpa.
The process plant was initially designed for a ROM throughput of 500,000 tpa. During the DFS study, to better align with the mine design and optimise project economics, the process plant throughput capacity was increased to 650,000 tpa. This increase in size of the processing facility also allows for operating flexibility and future expansion capacity.
The ROM pad will be located at the south east corner of the plant site. ROM with a nominal top size of 600 mm will be delivered by haul trucks from the open pit mining operation and will either be dumped directly into the ROM bin, or stockpiled on the ROM pad. If oversize rocks bridge the static grizzly, a mobile rock ........

Production:
Commodity | Units | Avg. Annual (Projected) | LOM (Projected) |
Gold
|
koz
| 66 | 393 |
All production numbers are expressed as payable metal.
Reserves at February 4, 2019:
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
In-Situ (OP)
|
3 Mt
|
Gold
|
4.2 g/t
|
405 koz
|
Indicated
|
In-Situ (OP)
|
3.03 Mt
|
Gold
|
4.5 g/t
|
441 koz
|
Indicated
|
In-Situ (UG)
|
0.1 Mt
|
Gold
|
9.4 g/t
|
28 koz
|
Indicated
|
Total
|
3.12 Mt
|
Gold
|
4.67 g/t
|
469 koz
|
Inferred
|
In-Situ (OP)
|
0.33 Mt
|
Gold
|
6.8 g/t
|
73 koz
|
Inferred
|
In-Situ (UG)
|
0.35 Mt
|
Gold
|
7.9 g/t
|
90 koz
|
Inferred
|
Total
|
0.68 Mt
|
Gold
|
7.4 g/t
|
162 koz
|
Corporate Filings & Presentations:
Document | Year |
...................................
|
2020
|
...................................
|
2019
|
...................................
|
2019
|
...................................
|
2019
|
...................................
|
2019
|
Press Release
|
2017
|
Technical Report
|
2016
|
- Subscription is required.
News:
News | Date |
Thor Explorations Announces Commercial Production at Its Segilola Gold Mine in Nigeria
|
October 5, 2021
|
Thor Explorations Announces First Gold Pour at Its Segilola Gold Mine in Nigeria
|
July 30, 2021
|
Thor Explorations: Successful Turning of the Mills and Commencement of the Commissioning of the Segilola Gold Plant
|
July 19, 2021
|
Thor Explorations Announces Its Admission to Trading on AIM & First Day of Dealings
|
June 22, 2021
|
Thor Explorations Announces Updated Mineral Resource and Mineral Reserve Estimates for the Segilola Gold Project and Improved Life of Mine Plan
|
March 29, 2021
|
Thor Announces Remaining In Pit Drill Results at Segilola, Nigeria and Exercise of Options
|
December 10, 2020
|
Thor Announces Encouraging Initial In-Pit Infill Drill Results at Segilola, Nigeria
|
October 13, 2020
|
Thor Announces Construction Update at Segilola Gold Mine
|
August 10, 2020
|
Thor Announces Strong Initial Segilola Infill Drilling Results and Segilola Exploration Plan for Q3 2020
|
July 22, 2020
|
Thor Announces Signing of EPC Contract Financing Update for the Construction and Financing of the Segilola Gold Project
|
June 4, 2019
|
Thor Explorations Ltd. Files NI 43-101 Technical Report for Previously Announced Definitive Feasibility Study for the Segilola Gold Project
|
March 21, 2019
|
Thor Explorations Completes Robust DFS for the Segilola Open Pit Gold Project and Positive PEA for the Supplementary Segilola Underground Gold Project
|
February 4, 2019
|
Excellent Preliminary Metallurgical Test Work Results for Thor’s Segilola Gold Project
|
May 18, 2018
|
- Subscription is required.