Mining Intelligence and News
Papua New Guinea

Porgera Mine

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Overview

Mine TypeOpen Pit & Underground
StatusActive
Commodities
  • Gold
Mining Method
  • Truck & Shovel / Loader
  • Longhole stoping
  • Longhole open stoping
Backfill type ... Lock
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Mine Life... Lock
SnapshotThe Porgera Gold Mine is one of the world’s top ten gold mines and the second-largest gold mine in Papua New Guinea.

The project suspended production in April 2020 due to the expiration of mining rights. After negotiation, it fully resumed production on 22 December 2023.

Owners

SourceSource
CompanyInterestOwnership
Barrick Gold Corp. 24.5 % Indirect
Barrick (Niugini) Ltd. (operator) 24.5 % Indirect
Zijin Mining Group Co., Ltd 24.5 % Indirect
New Porgera Ltd. (NPL), the new Porgera joint venture company, was incorporated on October 13, 2023.

On October 13, 2023, a new Special Mining Lease was granted to NPL.

On December 22, 2023, Barrick completed the Commencement Agreement, pursuant to which the PNG government and Barrick (Niugini) Ltd. (BNL), the 95% owner and operator of the Porgera joint venture, agreed on a partnership for the future ownership and operation of the mine. Ownership of Porgera is now held in a new joint venture owned 51% by PNG stakeholders and 49% by a Barrick affiliate, Porgera (Jersey) Limited (“PJL”). PJL is jointly owned on a 50/50 basis by Barrick and Zijin Mining Group and therefore Barrick now holds a 24.5% ownership interest in the Porgera joint venture. BNL was appointed as operator of the Porgera mine.

Contractors

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Deposit type

  • Epithermal
  • Vein / narrow vein
  • Breccia pipe / Stockwork

Summary:

Porgera Mine is an epithermal vein-type gold-silver deposit but it shares many characteristics with porphyry copper deposits. Remnant heat from the intrusive rocks drove the boiling and upward migration of hydrothermal fluids and resulted in the emplacement of mineralization. The movement of these fluids was controlled by permeability of the rock mass, which developed in and around faults and tectonic zones of dilatancy. As such, the mineralization tends to occur in tabular bodies and breccia zones, the geometry of which is strongly influenced by the orientation of fault structures and subsidiary fractures. Deposition of ore minerals in epithermal systems is also dependent upon temperature and hydrostatic pressure. These conditions are generally closely related to elevation, with reduction of both temperature and pressure as the fluids migrate upwards.

The Porgera area geology consists of a complex sequence of high-level potassium-rich intrusives and variably altered sedimentary rocks. It has characteristics of different deposit types. Despite its alkalic nature, Porgera shares many similarities with porphyry copper deposits. Rapid emplacement at shallow crustal levels distinguishes it from a typical gabbroic intrusion and the nature of the mineralization is more indicative of an epithermal gold deposit (Richards and Kerrich, 1993).

Mineralization occurs within the Porgera intrusive complex and is closely associated with three dominate structural trends, the RF (Zone VII), the Hanging Wall Shear Zone (Zone VI) and the Footwall Splay Zone (Zone VIII). Mineralization occurs around the margins and within the intrusive bodies. The Footwall Diorite (north of Zone VII) and the Eastern Deeps have contributed significant tonnages at moderate grade (Agnew & Bassotti, 2008).

Gold is suggested to have been transported as a chloride complex in early magmatically derived hypersaline fluids and deposited as disseminate auriferous pyrite during cooling as a result of sulphidation and sericitization reactions with mafic igneous wall rocks.

Precious metal mineralization comprises four types, corresponding to four distinct mineralizing events. From oldest to most recent, these are:
- Auriferous pyrite, sphalerite and galena;
- Coarse euhedral auriferous pyrite;
- Fine-grained anhedral auriferous arsenical pyrite;
- Gold and electrum associated with roscoelite.

The fourth mineralization style is typified by very high grades and the presence of roscoelite is a useful visual indicator of these high-grade zones. The distribution of mineralization is associated with structural activity and, to a lesser extent, alteration. The deposit is a low-silica, high-sulphur system with most of the gold being refractory, likely in solid solution with pyrite grains. The relationship between higher gold grades and sulphide content, however, is not direct.

Gold mineralization occurs as fracture-fillings and as disseminations in and around faults, breccias and dilatant zones. Gold is usually present as submicroscopic grains within the pyrite, with a relatively minor component occurring as free grains. Important accessory minerals include quartz and roscoelite. Cross-cutting relationships indicate the mineralization occurred in several pulses.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

Porgera was placed on temporary care and maintenance on April 25, 2020 until December 22, 2023. Work started on the recommissioning of the Porgera mine on that date and mining and processing are expected to restart at Porgera in the first quarter of 2024.
CommodityUnits2024202020192018201720162015
Gold koz  ....  Subscribe  ....  Subscribe597430495493554
All production numbers are expressed as metal in conc./ doré. ^ Guidance / Forecast.

Operational metrics

Metrics202020192018201720162015
Stripping / waste ratio  ....  Subscribe5.7 15 12.9
Ore tonnes mined  ....  Subscribe5,789 kt
Waste OP  ....  Subscribe21,907 kt17,956 kt20,867 kt
Total tonnes mined  ....  Subscribe27,697 kt20,762 kt24,219 kt16,924 kt22,139 kt
Tonnes processed  ....  Subscribe5,558 kt4,501 kt5,891 kt5,705 kt6,323 kt
Daily milling capacity  ....  Subscribe16,100 kt15,600 t15,200 t
Daily mining rate  ....  Subscribe45.9 kt62.1 kt

Production Costs

CommodityUnits20242020201920182017
Cash costs Gold USD 810 / oz   791 / oz  
Cash costs Gold USD 796 / oz **   781 / oz **  
Total cash costs Gold USD  ....  Subscribe 848 / oz  
Total cash costs Gold USD  ....  Subscribe  ....  Subscribe 838 / oz **  
All-in sustaining costs (AISC) Gold USD  ....  Subscribe 1,013 / oz   1,097 / oz   1,003 / oz  
All-in sustaining costs (AISC) Gold USD  ....  Subscribe  ....  Subscribe 1,003 / oz **   1,083 / oz **   993 / oz **  
All-in costs Gold USD  ....  Subscribe 1,013 / oz   1,097 / oz   1,003 / oz  
All-in costs Gold USD  ....  Subscribe 1,003 / oz **   1,083 / oz **   993 / oz **  
^ Guidance / Forecast.
** Net of By-Product.

Operating Costs

Currency20202019201820172016
OP mining costs ($/t mined) USD 4.18  3.6  4.03  4.53  5.51  
UG mining costs ($/t mined) USD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe
Processing costs ($/t milled) USD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe  ....  Subscribe

Financials

Units2020201920182017
Capital expenditures M USD  ....  Subscribe 95   131   116  
Sustaining costs M USD  ....  Subscribe 95   131   116  
Revenue M USD  ....  Subscribe 848  
Operating Income M USD  ....  Subscribe 238  
EBIT M USD
EBITDA M USD  ....  Subscribe 326  

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required May 21, 2024
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....................... Subscription required ....................... Subscription required Subscription required May 21, 2024
....................... Subscription required ....................... Subscription required Subscription required May 21, 2024
....................... Subscription required ....................... Subscription required Subscription required May 21, 2024
....................... Subscription required ....................... Subscription required Subscription required May 21, 2024

Aerial view:

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