Premier African Minerals (LON:PREM) is finalising the plant design and flow sheets for its RHA tungsten mine in Zimbabwe after new metallurgical test work proved successful.
Cumulative wolframite (tungsten) concentrate grades ranged between 62.3% and 63.5% WO3 and recoveries between 82.9% and 77.3%, Premier said.
George Roach, chief executive, added: "Determination of the concentrate grade and process recovery is a significant milestone in the development of the RHA mine.
"The fact that these positive results were achieved on a mini pilot scale allows us to finalise the flow sheet and plant design and proceed to order."
Premier will now update May 2013’s conceptual mining study resource to include the latest test results, he added.
The metallurgy consisted of investigative work on a 200kg bulk sample as well as a mini pilot run on 800kg of bulk sample.
Most aspects of the proposed flow sheets and plant design have been finalised, it added, while Appropriate Process Technologies has provided the plant design at an instantaneous process rate of 16tph.
The quotation is at a considerable discount to the US$2.79m estimated in the concept study, Premier added.