Mining Intelligence and News
Namibia

Okanjande/Okorusu Mine

Click for more information

Categories

Overview

Mine TypeOpen Pit
StageRestarting
Commodities
  • Graphite
Mining Method
  • Truck & Shovel / Loader
Production Start... Lock
Mine Life... Lock
SnapshotOkanjande/Okorusu Project consists of the Okanjande graphite deposit and the Okorusu processing plant. The previously producing Okanjande graphite Mine, active from 2017 to 2018, is located on the Property. The Okanjande graphite Mine is currently under care and maintenance and is planned to be restarted after executing a process plant relocation, several brown fields expansion projects, modifications and refurbishment activities.

In August 2023, the Company announced the results of a new preliminary economic assessment (“PEA”) that confirmed the economics of the relocation of its processing plant to the Okanjande mine site in Namibia. The PEA, dated July 31, 2023, was prepared by CREO Engineering Solutions and confirms the viability of moving milling operations directly to the Okanjande mine site.

Owners

SourceSource
CompanyInterestOwnership
Northern Graphite Corp. 100 % Indirect
Northern Graphite Corporation (“Northern” or the “Company”), acquired 100% ownership of Imerys Gecko Holdings (Pty) Ltd, which in turn owned 100% interest in Imerys Gecko Graphite (Namibia) (Pty) Ltd and Imerys Gecko Okanjande Mining (Pty) Ltd.

The companies were rebranded to Northern Graphite Holdings (Namibia) (Pty) Ltd (“Holdings”), Northern Graphite Okanjande Mining (Pty) Ltd (“NGOM”) and Northern Graphite Processing (Namibia) (Pty) Ltd. (“NGP”).

Collectively, Holdings, NGOM and NGP are referred to as “Northern Graphite (NG) Namibia” as they operate as one under joint management and control.

Contractors

Lock

- subscription is required.

Deposit type

  • Metamorphic

Summary:

The Okanjande deposit fits the description of a crystalline flake graphite deposit in a paragneiss. The original rocks at the Okanjande deposit were arkoses, feldspathic quartzites and ortho-quartzites that have been subjected to high grade metamorphism to become feldspathic-quarzitic gneisses and graphitic quartzites.

The Okanjande deposit is a massive deposit with shallow dipping layers to the southeast. Its surface extent is approximately 900m northeast to southwest and up to 820m from northwest to southeast. The mineralization extends from surface and has been defined by drilling up to a depth of 90m below surface. The mineralization is open at depth.

Mineralization
The mineralogical investigations revealed that the graphitic samples generally contain similar minerals, although they vary significantly in both proportion and texture.

The major silicate minerals of the graphitic gneiss at Okanjande are quartz and K-feldspar. The most common mica is muscovite, comprising between 2% and 8% of the rock.

Sulphide mineral content in the samples varies between 2% and 7%. Pyrite and pyrrhotite are the most commonly occurring sulphide minerals, with approximately equal proportions. Other sulphide minerals were identified in trace amounts, including chalcopyrite, molybdenite and covellite (only observed in weathered rock). Sulphides occur in irregular patches or clusters of up to 20mm across, or in veins associated with quartz, and a small proportion of the sulphide is associated with graphite flakes.

Five sulphate minerals (barite, gypsum, jarosite, sidorotil and melanterite) were identified. Barite occurs in small quantities and is the only primary sulphate mineral, while the other minerals are as a result of weathering and oxidation of sulphide minerals. Jarosite can make up more than 10% of the weathered rock and some of the jarosite particles are closely associated with graphite flakes.

Sidorotil and melanterite are soluble iron sulphate minerals which occur in minor amounts in the weathered rock, commonly along joints and fractures. Sulphate minerals may occur at depth in fresh mineralisation due to oxidation along joints, faults and shears.

Rutile content in the Okanjande deposit samples is between 0.2% and 1.3% with an average of 0.8%. Rutile particle size is between 0.05mm and 0.40mm, with an average of 0.20mm. Rutile grains are commonly enclosed in gangue minerals and most have no association with graphite. A small proportion of rutile has inclusions of graphite, zircon and sulphides. SEM analysis indicates that some rutile grains are high in vanadium occurring in solid solution within the rutile structure.

The graphite content of the analysed samples ranges between 3% and 18% TGC. The average flake size ranges between 500µm and 800µm. More than 85% of the graphite flakes occur as straight undeformed, well-crystallised, euhedral flakes, and free of interlaminated gangue minerals in unaltered mineralized material. Only 3% to 12% of the graphite flakes are interlaminated with gangue minerals. Most of the flakes that are interlaminated with gangue minerals are very large flakes that occur in the form of books. A small proportion of the flakes (<5%) occur as tiny flakes or grains enclosed in the feldspar or muscovite grains.

In the western part of the deposit, approximately 15% of the graphite flakes in weathered rocks at depths below the observed levels of oxidation have altered textures. The altered graphite flakes are associated with localised shear stresses at depth along a zone trending northeast to southwest. Altered graphite flakes are curved, bent or broken, reducing flakes to smaller sizes. Graphite flakes with this texture are interlaminated with gangue minerals and are commonly rimmed with muscovite.

Reserves

Lock

- subscription is required.

Mining Methods

Lock

- subscription is required.

Comminution

Crushers and Mills

Lock

- subscription is required.

Processing

Lock

- subscription is required.

Production

CommodityUnitsAvg. AnnualLOM
Graphite kt 31311
All production numbers are expressed as concentrate.

Operational metrics

Metrics
Daily mining rate  ....  Subscribe
Annual mining capacity  ....  Subscribe
Annual ore mining rate  ....  Subscribe
Annual milling capacity  ....  Subscribe
Stripping / waste ratio  ....  Subscribe
Waste tonnes, LOM  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
Total tonnes mined, LOM  ....  Subscribe
Tonnes milled, LOM  ....  Subscribe
* According to 2023 study.

Production Costs

CommodityUnitsAverage
C1 cash costs Graphite USD  ....  Subscribe
All-in costs Graphite USD  ....  Subscribe
Assumed price Graphite USD  ....  Subscribe
* According to 2023 study / presentation.

Operating Costs

Currency2023
OP mining costs ($/t mined) USD 4.17 *  
OP mining costs ($/t milled) USD  ....  Subscribe
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2023 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Expansion CapEx $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
Working capital $M USD  ......  Subscribe
Closure costs $M USD  ......  Subscribe
Total CapEx $M USD  ......  Subscribe
OP OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 132
G&A costs $M USD 19.5
Total OpEx $M USD  ......  Subscribe
Income Taxes $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe
Net Income (LOM) $M USD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
Pre-tax NPV @ 8% $M USD  ......  Subscribe
After-tax NPV @ 8% $M USD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe
After-tax IRR, %  ......  Subscribe
Pre-tax payback period, years  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Required Heavy Mobile Equipment

Lock

- subscription is required.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Jun 9, 2024
....................... Subscription required ....................... Subscription required Subscription required Jul 31, 2023
....................... Subscription required ....................... Subscription required Subscription required Jul 31, 2023
....................... Subscription required ....................... Subscription required Subscription required Jun 9, 2024

EmployeesYear
...... Subscription required 2023

Lock

- subscription is required.