Following the recent mineral resource upgrade at its Longonjo NdPr project in Angola, ASX-listed Pensana Metals (Pensana) has appointed the international engineering company Wood Group to execute a Preliminary Feasibility Study (PFS) for the expedited development of the project.
The study will focus on the delivery of an open-pit mine and 1,5 Mt/a flotation operation producing 95 000 tonnes of NdPr ((neodymium/praseodymium) concentrate for export to China via the recently upgraded Benguela rail line and the Atlantic deep-water port of Lobito.
RC drill rig operating at Longonjo.
The project lies just 4,3 km from the sealed national highway and rail line that run from the port at Benguela, 200 km to the west, to the provincial capital of Huambo, 60 km to the east.
Discussions with potential financiers have commenced and it is expected that a financing package will be finalised to coincide with the completion of the PFS (scheduled for September 2019).
Pensana is of the view that given the work that has been completed to date and the relative simplicity of the operation, it should be possible to move immediately to Front End Engineering Design (FEED) and Engineering Procurement Construction Management (EPCM) following the completion of a favourable PFS.
“The development concept is very straightforward,” commented Dave Hammond, Chief Operating Officer of Pensana. “We are looking at a low capital cost, shallow open-pit and flotation operation producing a high-grade concentrate for export to China via the adjacent major rail and port infrastructure.
“Last month’s substantially increased mineral resource estimate has enabled us to bring forward the PFS. Our aim is to get into production and build our customer base at a time when EV and wind turbine manufacturers are driving the increasing demand for NdPr magnets for electric motors and Chinese rare earth processors are looking for additional low-cost feedstock.”
Initial development studies will focus on the highest grade and quality portion of the mineral resource estimate – the near surface weathered zone mineralisation.
The weathered zone consists of a thick blanket of soft, friable NdPr mineralisation that occurs over an area of approximately 700 x 700 m to typical depths of 20 m. Such material is amenable to ’free-dig’, shallow open-pit mining with a very low waste to mineralisation ratio.
Pensana has already demonstrated an effective processing route for this style of mineralisation to produce a high-grade mineral concentrate using flotation techniques. The company is working with Chinese technical institutes to further optimise the concentrate production process flowsheet.
The high-grade weathered zone subset represents less than 10 % of the total mineral resource estimate and at a 0,65 % NdPr lower cut off includes 22,9 Mt at 4,16 % REO (Rare Earth Oxide).
Subsequent studies will focus on an expansion of this initial operation to treat additional NdPr mineralisation from this large deposit.