Namibia

Rosh Pinah Expansion Project

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Overview

Mine TypeUnderground
StageFeasibility
Commodities
  • Zinc
  • Lead
  • Silver
Mining Method
  • Longhole open stoping
  • Transverse open stoping
  • Longitudinal open stoping
Backfill type ... Lock
Mine Life... Lock
SnapshotAppian said it plans to restart the Rosh Pinah 2.0 mine expansion project which will nearly double the mine’s annual ore throughput to 1.3 million mt, increasing zinc equivalent production to 170 million lb/y, on average and improve safety and environmental performance.
Related AssetRosh Pinah

Owners

SourceSource
CompanyInterestOwnership
Appian Capital Advisory LLP 90 % Indirect
Rosh Pinah Zinc Corporation (Pty) Ltd. (operator) 100 % Direct
The Rosh Pinah Mine is owned by Rosh Pinah Zinc Corporation (Pty) Ltd. (“RPZC”). Trevali owns a 90% interest in RPZC and is operationally responsible for the management of RPZC, with the remainder held by PE Minerals (Namibia) (Proprietary) Limited (“PE Minerals”), Jaguar Investments Four (Proprietary) Limited (“Jaguar”) and an Employee Empowerment Participation Scheme (“EEPS”).

On June 27, 2023, Trevali Mining Corporation ("Trevali" or the "Company") completed the sale of its 90% interest in the Rosh Pinah Mine located in Namibia to funds advised by Appian Capital Advisory LLP (jointly "Appian"). In accordance with the share and asset purchase agreement between the parties, Appian purchased the issued and outstanding shares held by Trevali in GLCR Limited ("GLCR") and assumed certain capital loans owed to Trevali by subsidiaries of GLCR (collectively, the "Transaction").

Contractors

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Deposit type

  • SEDEX
  • VMS

Summary:

Deposit types
The Rosh Pinah mine has been historically interpreted as being predominantly a reworked SEDEX type deposit comprising a primary banded sulphide exhalite, part of which was carbonatized with associated remobilization and enrichment of sulphides. The secondary carbonate mineralization carries the higher, economic, base-metal values.

The emplacement of the Spitskop Volcanic Complex and related mafic edifices at approximately 752 Ma to 741 Ma drove hydrothermal plumbing along the rift-fault system of the Rosh Pinah Graben. Hydrothermal fluids leached base metals from the basin-fill siliciclastics which were derived mainly from the erosion of a Paleoproterozoic, 2.0 Ga to 1.7 Ga, calcalkaline island arc in the hinterland (Frimmel et al. 2004).

The base-metal bearing brines were exhaled onto the sea floor from the present-day Western Fault bounding the Rosh Pinah Graben, during a period of sediment paucity and / or high sea-level. Exhalation was accompanied by silicification and hydraulic brecciation of the footwall. The primary mineralization was deposited at, or below, the sediment / seawater interface as stratiform, inter-banded, massive sulphide and cherty argillite (micro quartzite). Time between exhalative pulses determined the variation in ratio of content, of chert- exhalite and background argillitic sediment.

At some stage following primary SEDEX style mineralization deposition, the hydrothermal fluid chemistry changed to carbonitic, either due to introduction of primary volcanogenic carbonate fluids or as the plumbing system tapped carbonate sediments elsewhere in the sedimentary package. Carbonatization of the more porous, arenitic hangingwall and footwall took preference. On-going base-metal exhalation was supplemented by remobilization of primary mineralization into the hydrothermal carbonate.

Orogenesis at approximately 545 Ma, as a result of transpressive continental collision of the Rio de la Plata and Kalahari cratons, caused complex folding and faulting of the deposit. Fold style is west verging, asymmetric to overturned with steep plunges. Competency interplay caused considerable disharmony within the ductile units of the mineralized zone, both primary and secondary carbonate being squeezed into fold hinges.

There has been a major shift in thinking by RPZC in the last couple of years on the Rosh Pinah mineral deposit type from a predominantly SEDEX deposit to a hybrid of VMS – SEDEX. This approach was adopted based on new evidence and understanding.

The major mineralization types are described in detail below.

Microquartzite and argillite
The primary mineralization type is a silicified, grey to dark grey, fine-grained and laminated unit locally called microquartzite mineralization. It consists of alternating millimetre to centimetre wide bands of sulphides (sphalerite, pyrite and galena + minor chalcopyrite) and is believed to represent a classic sedimentary-exhalative (SEDEX) style although ongoing interpretations are supportive of a volcanogenic massive sulphide (VMS) origin similar to the nearby Gergarub and Skorpion deposits. The argillite mineralization would be similarly derived but diluted with background benthonic argillite.

Arkose / breccia
The mineralization occurs as breccia matrix and veins in silicified arenite lithologies (locally referred to as breccia mineralization) or as disseminated base-metal sulphides (locally referred to as arkose mineralization) and can reach economic grades. In places, the arkose / breccia mineralization gives indications of primary sulphide exhalations into an arenitic host. The breccia mineralization is commonly found in the immediate footwall to the ore equivalent horizon (OEH).

Carbonate
Carbonate mineralization is purely remobilized and provides the major economic component of the resource. Carbonate has replaced the arenites, both in the hangingwall and footwall of the mineralized horizon and a continuous range is observed from slightly carbonatic arenite (textures such as large, ghost feldspar grains occur) to pure carbonate, with all original textures lost. The carbonate has scavenged, concentrated, and remobilized BMS from the primary microquartzite mineralization. A near-total base metal enrichment of the carbonate mineralization gives rise to massive mineralization. When the carbonate has been leached out of the carbonate mineralization and the quartz grains and sulphides remain, the mineralization is locally referred to as sugary quartz ore.

Lens characterization
The deposit is hosted by a thick package of turbidites comprising hinterland and contemporaneous volcanic clastics deposited in a Neo-Proterozoic rift basin during the early part of the evolution of the Gariep Terrane of southern Namibia. Metals scavenged from a primary argillite mineralization were concentrated by late hydrothermally- driven carbonate alteration, providing a carbonate host to the economic deposit. Basin inversion led to oblique continental collision and complex deformation of the deposit, resulting in two phases of disharmonic overfolding with associated faulting and shearing.

The deposit is consequently presented as a series of discrete carbonate and exhalite lenses located on second-phase fold hinges or steeply plunging fold limbs connected by a partially attenuated exhalite-dominated OEH.

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
Lead M lbs 24238
Silver koz 3033,080
All production numbers are expressed as payable metal.

Operational metrics

Metrics
Daily ore mining rate  ....  Subscribe
Annual ore mining rate  ....  Subscribe
Annual processing capacity  ....  Subscribe
Waste tonnes, LOM  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
* According to 2021 study.

Production Costs

CommodityUnitsAverage
Total cash costs Zinc USD  ....  Subscribe
All-in sustaining costs (AISC) Zinc USD  ....  Subscribe
Assumed price Lead USD  ....  Subscribe
Assumed price Zinc USD  ....  Subscribe
Assumed price Silver USD  ....  Subscribe
* According to 2021 study / presentation.
** Net of By-Product.

Operating Costs

Currency2021
UG mining costs ($/t milled) USD 27.1 *  
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2021 study.

Project Costs

MetricsUnitsLOM Total
Expansion CapEx $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
Closure costs $M USD  ......  Subscribe
Total CapEx $M USD  ......  Subscribe
UG OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 129.8
G&A costs $M USD 78
Total OpEx $M USD  ......  Subscribe
Total Taxes $M USD  ......  Subscribe
Royalty payments $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe
Net revenue (LOM) $M USD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
Pre-tax NPV @ 10% $M USD  ......  Subscribe
Pre-tax NPV @ 8% $M USD  ......  Subscribe
After-tax NPV @ 8% $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 Mar 31, 2021
....................... Subscription required ....................... Subscription required Subscription required Mar 31, 2021
....................... Subscription required ....................... Subscription required Subscription required Oct 4, 2023

Aerial view:

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