Papua New Guinea

Wafi-Golpu Project

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Categories

Overview

Mine TypeUnderground
StagePermitting
Commodities
  • Copper
  • Gold
  • Silver
Mining Method
  • Block caving
Mine Life... Lock
SnapshotIn April 2023, Newcrest and its Wafi-Golpu Joint Venture partner Harmony Gold signed a Framework Memorandum of Understanding (MOU) with the Independent State of Papua New Guinea. The MOU represents a substantial step forward in progressing towards the signing of a Mining Development Contract for Wafi-Golpu and confirms the parties’ intent to proceed with the project, subject to finalising the permitting process and approvals of both the Newcrest and Harmony Gold Boards. The MOU is a pivotal milestone towards the development of one of the world’s premier undeveloped coppergold deposits.

Owners

SourceSource
CompanyInterestOwnershipInvestor's Info
Newmont Corp. 50 % Indirect
Harmony Gold Mining Company Ltd. 50 % Indirect
The Wafi-Golpu JV is owned 50% by the Newcrest Mining and 50% by Wafi Mining Limited, whose ultimate holding company is Harmony Gold Mining Company Limited.

On November 6, 2023, Newmont Corporation completed the acquisition of Newcrest Mining Limited to create the world’s leading gold company with robust copper production.

Contractors

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Deposit type

  • Epithermal
  • Vein / narrow vein

Summary:

Wafi–Golpu is a complex, multiphase mineralised system, comprising:
- Golpu porphyry copper–gold deposit;
- Wafi epithermal gold deposit;
- Nambonga porphyry gold–copper deposit.

The upper portions of the porphyry systems were overprinted by the high-sulphidation epithermal mineralisation at Wafi.

Golpu
The Golpu deposit extends over about 800 m north–south by 500 m west–east, and was drill tested to more than 2,000 m depth.

Porphyry-style veins are preserved within the clay alteration at the top of the Golpu deposit. These veins have had the copper–iron sulphides removed, leaving only a skeleton of quartz. Irregular molybdenite veins are preserved stable remnants of the porphyry mineralising event.

The dominant copper–gold-bearing sulphide species vary laterally and vertically within the deposit from an inner bornite (plus chalcopyrite) core, to chalcopyrite as the dominant copper sulphide, and grading out to a pyrite-only shell on the mineralisation margin.

The proportion, by volume, of disseminated copper–iron sulphides varies from trace to as much as 10%. Pyrite increases from near absent in the core to 10% on the margin in a reverse relationship to chalcopyrite. Disseminated sulphides are typically located at the site of relict iron-bearing phases including primary phenocrystic hornblende and hydrothermal alteration-derived biotite– magnetite.

The Hornblende Porphyry (Livana Porphyry) is the main mineralised porphyry. Other porphyries act either as weak mineralisers (e.g., Golpu Porphyry) or as benign hosts (wall rock) from adjacent mineralising porphyries. The mineralisation style in benign (wall rock) porphyries can change due to rheological contrast and chemical variations. Quartz vein stockworks occur on the intrusive margin in sedimentary rocks. Significant zones of quartz flooding may be present. The porphyry system is mineralised with gold, copper, silver and molybdenum:
- Gold, copper and silver trend from highest grade in the Hornblende Porphyry (Livana) core to background levels at the mineralised edge;
- Molybdenum content is low in the gold and copper maxima, but increases outwards to a maximum at the copper margin and declines to background beyond the copper mineralisation limits.

Wafi
The Wafi deposit has a surface area of approximately 1,100 m x 800 m and was drill tested to about 600 m below surface. A number of zones, including the A, B, NRG and Link Zones, were defined. The NRG Zone is the nonrefractory portion of the A Zone, and the Link Zone is a more discrete, higher-grade zone characterised by both high sulphidation and low sulphidation mineralisation. It is unclear if the high sulphidation and intermediate sulphidation events at Wafi are independent, or are a continuum of a single event.

The high sulphidation gold event alteration overprints the Golpu porphyry-style alteration and mineralisation, with the diatreme carrying fragments of the earlier porphyry alteration. The high sulphidation event was interpreted to have remobilised pre-existing porphyry-related copper from the phyllic–argillic-altered upper porphyry and deposited this as zoned enargite–tennantite– covellite–chalcopyrite mineralisation. Most of the gold in the high sulphidation overprint was introduced in association with pyrite.

The low sulphidation Link Zone, which occurs on the diatreme margin, between and below the Zones A and B high sulphidation gold mineralisation, is characterised by pyrite with lesser quartz (quartz–sulphide–gold style) veins, which are overprinted by more than one generation of pyrite– sphalerite–galena–carbonate veins (carbonate–base metal–gold style). Selective sampling shows the gold in this zone is related to the arsenian pyrite of the quartz–sulphide-style veins, while the multi-stage lowarsenic carbonate–base metal veins are not well gold-mineralised.

Advanced argillic alteration contains primary copper mineralisation as chalcocite, but gold occurs within pyrite or as electrum associated with pyrite–enargite–tetrahedrite. Mineralisation appears to broadly follow the metasedimentary and volcanic host rocks stratigraphy (i.e., 40–50° to the east, and northeast), and is often sub-parallel to bedding. The copper–gold-bearing lenses occur in kaolinite–chalcocite–pyrite and vuggy quartz ± covellite ± enargite bands that may reach 20 m in thickness.

Nambonga
The stock is a low-grade copper and gold mineralised system, and extends over an area of approximately 200 m x 200 m and to a vertical extent of at least 800 m.

Much of the mineralisation is associated with silicification, either pervasive or as veins. Quartz stockwork veins that may be as wide as 10 mm and stockworks overprint the porphyry, especially in the upper levels.

Mineralisation consists of disseminated and vein-style copper–gold mineralisation and structurally-controlled base metal mineralisation in steeply-dipping lodes. Chalcopyrite is the dominant copper sulphide mineral. Chalcopyrite and pyrite form anhedral grains ranging that can reach 0.2 mm in width, and tend to occur as centrelines to quartz veins. Magnetite forms anhedral grains that can be 0.4 mm wide, and is generally present in the margins of the quartz veins or in the wall rock adjacent to quartz veins. Minor magnetite, pyrite and chalcopyrite are disseminated through the host rock.

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

CommodityUnitsAvg. AnnualLOM
Copper kt 1614,520
Gold koz 2667,445
Gold Equivalent koz 32,359
All production numbers are expressed as payable metal.

Operational metrics

Metrics
Annual ore mining rate  ....  Subscribe
Plant annual capacity  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
Tonnes milled, LOM  ....  Subscribe
* According to 2020 study.

Production Costs

CommodityUnitsAverage
Cash costs (sold) Copper USD  ....  Subscribe
All-in sustaining costs (sold) Gold USD  ....  Subscribe
All-in costs Copper USD  ....  Subscribe
Assumed price Copper USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2020 study / presentation.
** Net of By-Product.

Operating Costs

Currency2020
UG mining costs ($/t milled) USD 4.16 *  
Processing costs ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2020 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Expansion CapEx $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
Total CapEx $M USD  ......  Subscribe
Total OpEx $M USD  ......  Subscribe
Total Taxes $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax IRR, %  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Nov 1, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 1, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 1, 2023

Total WorkforceYear
...... Subscription required 2020

Aerial view:

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