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Liberia

New Liberty Mine

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Summary

Mine TypeUnderground
StatusActive
Commodities
  • Gold
Mining Method
  • Longitudinal stoping
  • Transverse stoping
  • Transverse open stoping
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SnapshotThe New Liberty Gold Mine is Liberia’s first and largest commercial gold mine. The operation consists of two worked-out open pits, an underground mine with three separate portals, and a large processing plant with tailings dams. All ore mined in the region is processed through the New Liberty plant, which operates with an industry-standard flowsheet.

Mining focuses on the steeply dipping, deeper ore beneath the worked-out open pits, extracted by underground operations accessed through four different portals (Larjor, Larjor-WW, Kinjor, and Marvoe) developed into the sides of the open pits. The open-pit operations, which began in October 2014, were completed in June 2022. Underground mining began in August 2020.

The mine is operated by a private company, so some data on its activities is not publicly available.

Owners

SourceSource
CompanyInterestOwnership
Government of Liberia 5 % Indirect
Avesoro Holdings Ltd. 95 % Indirect
Bea Mountain Mining Corp. (operator) 100 % Direct
Avesoro Resources Inc. holds its interests in the New Liberty Gold Mine through its subsidiary Bea Mountain Mining Corporation (“Bea”). Avesoro Resources is a subsidiary of Avesoro Holdings Ltd.

According to 'An Act to Ratify the First Amendment to the Restated and Amended Mineral Development Agreement by and Between the Government of Liberia and Bea Mountain Mining Corporation', approved on September 14, 2023, the Government of Liberia shall receive, free of charge, an equity interest in the company's operations equal to five percent (5%) of its authorized, issued, and outstanding share capital at any given time, without dilution.

Contractors

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Deposit type

  • Orogenic
  • Vein / narrow vein

Summary:

The New Liberty Property hosts a typical Upper Archean to lower Proterozoic style of metallogeny, characteristic of greenstone-hosted lode gold mineralisation, where deposits are often referred to as orogenic, and characterised by the presence of gold-quartz veins and disseminated mineralisation. Gold mineralisation is hosted in moderate to steeply dipping quartz-dominated shear zones with associated extensional vein systems. This model is consistent with Archean orogenic gold deposits described by Hagemann and Cassidy (2000), Richards and Tosdal (2001), Goldfarb et al. (2001) and Roberts et al. (1989).

The New Liberty deposit is hosted in sheared and altered ultramafic rocks. The gold mineralisation is associated with disseminated sulphides. The disseminated sulphide host bodies are more continuous than a typical quartz-hosted vein. The orebody is in a highly sheared and mylonised schist belt which trends east-southeast.

The average dip of the orebody is approximately 60°, with local variations in dip ranging from near vertical to around 40°. The orebody consists of a number of veins, generally parallel to each other. Mineralisation can occur in more than one of the veins, creating the potential for multiple parallel stopes in some parts of the deposit.

The widths of the mineralised zones range from 2 m to 30 m, with an average width of 10 m.

Within the ultramafic unit, silicification is found proximal to the mineralisation, within the immediate hangingwall and rarely in the footwall gneisses. Other alteration styles associated with the mineralisation include the presence of phlogopite as well as chlorite within the mineralised zone, and an associated sulphidic bleaching of the rocks linked with the destruction of magnetite.

These features point to a pathway for the mineralising fluids which was active over a long period of time. The deposit shows the classic signs of sulphidation, with iron sulphides (mainly pyrrhotite) replacing the magnetite and it has a low sulphide content with sulphides forming between 0.1% and 1% of the mineralised zones.

Multi-element analyses of cores have highlighted a clear association between gold and arsenic, sulphur, nickel and tungsten in the mineralised zones. Enhanced values of magnesium, sodium, potassium, rubidium and barium occur along the margins of the mineralisation. It is hypothesised that the gold-bearing metamorphic fluid may include a granitic component in its evolution.

The vast majority of the mineralisation at the Project is hosted within the altered parts of the sheared ultramafic rocks. Pyrrhotite, gersdorffite and arsenopyrite are the main sulphides with occasional pyrite and rare chalcopyrite or pentlandite. Metallurgical tests of the mineralised sections carried out by Lakefield Research Limited (Lakefield, 1999b) indicated that the gold is free in form. Gold mineralisation occurs in zones of variable thickness, with average widths of 10 m, and is nearly continuous along 2 km of strike.

Reserves

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Mining Methods

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Required Heavy Mobile Equipment

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AV - Autonomous

Comminution

Crushers and Mills

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Processing

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Commodity Production

CommodityUnits20242023201820172016
Gold koz  ....  Subscribe  ....  Subscribe1107664
All production numbers are expressed as metal in doré.

Operational metrics

Metrics20242023201820172016
Ore tonnes mined  ....  Subscribe1,352 kt1,166 kt996 kt
Plant annual capacity  ....  Subscribe  ....  Subscribe1.1 Mt
Tonnes processed  ....  Subscribe  ....  Subscribe1,411 kt1,144 kt842 kt
Stripping ratio  ....  Subscribe  ....  Subscribe16.1 11.1 9
Waste OP  ....  Subscribe  ....  Subscribe21,797 kt12,935 kt8,965 kt
Total tonnes mined  ....  Subscribe  ....  Subscribe23,149 kt14,102 kt9,961 kt

Production Costs

CommodityUnits20182017
Cash costs (sold) Gold USD 862 / oz   918 / oz  
All-in sustaining costs (sold) Gold USD 1,120 / oz   1,427 / oz  

Operating Costs

Currency2017
OP mining costs ($/t mined) USD  ....  Subscribe

Mine Financials

Units20182017
Revenue M USD 140.3   95.2  
After-tax Income M USD -40.3   -20.8  

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Jul 29, 2025
....................... Subscription required ....................... Subscription required Subscription required Jul 29, 2025
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Workforce

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