Namibia

Otjihase Mine

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Categories

Overview

Mine TypeUnderground
StatusCare and Maintenance
Commodities
  • Copper
  • Silver
  • Gold
Mining Method
  • Room-and-pillar
Backfill type ... Lock
Production Start... Lock
SnapshotOtjihase mine is part of the Central Operation, currently on care and maintenance. The mine was in production until September 2015, producing high quality concentrate sought after for blending.

No production data is publicly available since mine acquisition by Bonohgroup Limited.
Related AssetCentral Operation

Owners

SourceSource
CompanyInterestOwnership
Bonohgroup Ltd. 100 % Indirect
On 1 June 2018, Simon Kirkhope and Andrew Johnson were appointed as Joint Administrators of the Weatherly International plc.

Following no viable third party offers having been received and on the basis that a thorough marketing process had been run and a purchaser had not been found, the Administrators approved and accepted an offer received by Bonohgroup Limited, whose Director, John Sisay, is a person connected with Weatherly International PLC (“the Company”), to purchase the shares the Company held in WNSL, CARN and CARN Holding. CARN which held Berg Aukus and Weatherly (Namibia SL) LTD (St Lucia) “WNSL” which through Ongopolo Mining Ltd (Namibia) “OML” held the Tschudi mine, Central operations and the Tsumeb township and concentrator.

Exchange of contracts took place on 28 July 2020, following this on 2 September 2020 the share sale was completed and the shares in the Company’s subsidiaries were sold to Bonohgroup Limited (is a private company).

Deposit type

  • VMS

Summary:

The Otjihase deposit comprises five sub parallel, spatula-shaped, mineralised zones namely Shoot A, Shoot B, Shoot 2, Shoot 3 and Shoot 4. Shoots A and B are known collectively as the Main Shoot in mine terminology because of their close proximity, but geologically they are separate entities. The shoots consist of massive sulphides composed primarily of chalcopyrite and pyrite, hosted in a magnetite rich quartzite. Of the five, only Shoot A is consistently mineralised and forms the bulk of the mineral resources.

With the exception of Shoot B, which is slightly elevated above the southern margin of Shoot A, the westerly-plunging mineralised shoots occur at approximately the same stratigraphic level and are separated by more than 150m of barren or weakly mineralised quartz-mica schists that dip north westerly at 16°.

The northern margins of the shoots are abrupt, whereas the southern margins are gradational, consisting of thin bands and lenses of mineralisation, or disseminated mineralisation, in the quartz-mica schist country rocks. The footwall contact between the lowermost mineralised band and the underlying quartz-mica schists is usually sharp. The hangingwall contact is often gradational due to the presence of zones of disseminated mineralisation.

Each of the shoots has a gossanous outcrop and extends down plunge for more than eight kilometres. The mineralised shoots are cut by a series of sub-vertical northerly trending normal faults that down-throw the shoots progressively deeper towards the west. The faults separate the deposit into a number of blocks (or compartments) named after the faults that occur along the western margin of each block.

The Otjihase deposit lies in quartz-biotite chlorite and quartz-biotite schists and consists of a shoot of massive and disseminated sulphides about 200m wide plunging to the west at about 6°. The deposit dips to the northwest at about 16°. The shoot thickness varies between 4m and 12m with an average between 6m and 8m. The hanging wall is a quartzbiotite chlorite schist with distinct schistosity which sometimes spalls. It is competent if supported. The declines and other development are usually excavated in competent quartzmica schists.

The mineralisation stretches from near surface to depths of 800m and more and is divided into compartments by north-south trending faults. These faults are water bearing and contain flowing material and are thus difficult to traverse.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

Combined production numbers are reported under Central Operation

Production Costs

Commodity production costs have not been reported.

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

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Aerial view:

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