Name of the Project
RHA tungsten underground mine restart.

Location
Zimbabwe.

Project Owner/s
Premier African Minerals (49%) and the Zimbabwean National Indigenisation and Economic Empowerment Fund (NIEEF), which has a 51% shareholding.

Project Description
The RHA tungsten mine has a significant underground operation, which is currently under care and maintenance.

Premier aims to re-establish production at RHA, with a technical and economic assess­ment proposing two production scenarios: underground production at 6 000 t month to 7 000 t month or underground and openpit mining at 6 000 t a month and 34 000 t a month respectively, with a plant processing rate of 40 000 t a month.

Premier is considering only the first option as a basis for restarting production at RHA. Existing resource estimates in the underground areas of RHA, excluding any openpit resources, indicate a mine life of more than ten years. In the underground production scenario, the mine life modelled has been limited to an initial 15 months of mining, including a month of rehabilitation for the underground mine and three months of development before the start of stoping. The reason for this limit at this time is that the results of drilling currently under way will guide the future underground development and mining rate.

The initial tungsten production is modelled to 2 700 t a month from underground mining, with the company incrementally increasing this to a steady-state production of 6 000 t in month 14. RHA also has sizable historical tailings deposits accumulated during historical production in the 1970s. The potential simultaneous processing of tailings and underground ore has also been examined in house by Premier and has not been independently reviewed.

The company undertook an assessment to determine the tungsten resources contained in the tailings, and conducted a comprehensive sampling programme to determine the size fraction, grade and potential in situ resource. The results of the programme concluded that 86.1% of the material was above 45 µm, which is a suitable size for gravity concentration. The company has estimated that it can produce a tonne of concentrate from the tailings for 59% tungsten. These results have not yet been independently reviewed. Considering these favourable economics, the company has concluded that it should combine the reprocessing of these tailings with underground mining operations as and when they restart.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
Not stated.

Capital Expenditure
The total underground mining costs, according to the economic and technical assessment, is estimated at $1.06-million.

Planned Start /End Date
Not stated.

Latest Developments
Premier African Minerals has commissioned grid electrical power to the RHA tungsten project.

Adequate power is now available from the national grid to enable the company to consider resuming plant operations at the end of January to reprocess historic tailings, CEO George Roach has said.

“We are reassured by the continued commitment of the National Indigenisation and Economic Empowerment Fund to meeting the financial commitment to the funding of RHA.”.  

Roach has further noted that the availability of electrical power has considerably reduced the costs associated with operating the plant. 

Similarly, and by arrangement with MN Holdings, in which Premier has recently acquired a shareholding, the capital plant needed to feed the tailings at RHA is now expected to be potentially available to RHA at net operating cost only.

Supporting the proposed reprocessing of tailings is the already mined and milled historical tailings to the extent that they may be fed directly to the gravity recovery sections of the plant. The added benefits of this are that only a portion of the plant needs to be operating, much lower overall operating costs, better plant availability, reduced maintenance and lower labour requirements.

“Based on the above, I believe it is completely logical that RHA should now look to consider the reprocessing of the tailings dumps as soon as possible,” Roach has said.

Key Contracts and Suppliers
Bara Consulting (technical and economic assessment).

On Budget and on Time?
Not stated.

Contact Details for Project Information
Premier African Minerals, email info@premierafricanminerals.com.