Zimbabwe

RHA Mine

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Categories

Overview

Mine TypeUnderground
Commodities
  • Tungsten
Mining Method
  • Longhole open stoping
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Mine Life... Lock
ShapshotRHA moved into production during 2017, which was then suspended on 9 January 2018. In December 2017, due to the lower ore delivery, anticipated grade and operating losses, the Board of Directors decided to place the RHA Tungsten mine under care and maintenance.

Premier’s historic spend is a matter of record and the potential to bring RHA back into production remains good. Premier remains committed to a return to production but on the basis of equitable contribution to the projected costs or an equitable dilution. It is expected that Premier will be able to deploy parts if not all of the plant to other Zimbabwe based projects within the next 12 months if there is no resolution to this impasse.

Owners

SourceSource
CompanyInterestOwnership
Premier African Minerals Ltd. 49 % Indirect
National Indigenisation and Economic Empowerment Fund 51 % Indirect
Premier holds a 49% interest in the RHA Tungsten joint venture, and has operational management control of the RHA Tungsten Mine. Premier’s JV partner is the government-backed National Indigenisation and Economic Empowerment Fund (NIEEF), with a 51% interest.

The plant is owned 100% by Premier.

Deposit type

  • Vein / narrow vein

Summary:

Geology
The geology of Zimbabwe is dominated by Archean rocks which are overlain, in the northwest, by Proterozoic and Phanerozoic metamorphic and sedimentary rocks, in the area of the Project. In this area, phyllites, quartzites and gneisses are the dominant rocks.

The host country-rock comprises high-grade, strongly foliated biotite schists and paragneisses of the Tshontanda Formation belonging to the Precambrian Dete Inlier. The formation trends northeast on a regional scale, paralleling the trend of the Kamativi Inlier, and dips steeply to the northwest.

Mineralisation
RHA mine is situated within the multi-commodity Kamativi Tin Belt and occupies a land holding on a low ridge of approximately 850 m long and 300 m wide standing about 120 m above its surroundings. Historic mine workings are present and are in the form of adits, open pits, caved stopes, trenches, roads, and rock dumps that occupy the surface.

From information received from PAM it was noted that the known mineralised lodes and veins occur within an envelope that extends over a strike of approximately 400 m with a maximum width of 150 m. The lodes are thought to converge to the east of the property. The lodes strike approximately northeast-southwest paralleling the regional trend of Kamativi Inlier.

The host country-rock comprises high-grade, strongly foliated biotite schist’s and paragneisses of the Precambrian Dete Inlier belonging to the Tshontada Formation. The formation trends northeast on a regional scale, paralleling the trend of the Kamativi Inlier, and dips steeply to the northwest.

The tungsten mineralisation occurs in quartz veins and shear zones within a sequence of quartztourmaline and politic (quartz-biotite-garnet) schists that may be intruded by granite intrusions. The primary tungsten mineral of economic interest is wolframite ((Fe,Mn)WO4).

The lodes are defined by tourmaline (boron metasomatism) alteration zones, of which at least ten have been identified in the diamond drill holes. These appear to converge to the east. To the west, they apparently die out forming numerous 1 to 5 cm tourmaline and quartz veins.

The tourmaline lodes may have developed along planes of weakness that opened up above the apex of a granite intrusion. Some of this quartz ‘sweated out’ from the tourmaline schist, while others carried highly fractionated tungsten-rich fluids from the granite and were deposited within the tourmaline lodes.

A later phase of deformation caused shattering of the tourmaline schist and shearing of the quartz veins. High metamorphic grades are evident with localised partial melting of the tourmaline schist and the quartz biotite schist. The schist’s also show evidence of extreme deformation and mylonite bands are common. These lodes are steeply dipping to the northwest at 80° to 90°. Parts of seven separate lodes were exploited in the past. The most productive of these was Lode 2.

The mineralised quartz veins are identifiable and exhibit strike continuity within the existing underground development, the wolframite mineralisation does not show the same level of consistency. Tungsten grades show extreme variability and range from sub-economic to more than 300kg per ton over short strike distances.

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

Production Costs

Commodity production costs have not been reported.

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Nov 15, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 15, 2023

Aerial view:

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