14 / 60
12
MODERN MINING
May 2017
MINING News
The results of a Bankable Feasibility Study
(BFS) on the Ngualla rare earth project
(located in Tanzania) and proposed refin-
ery in Tees Valley (located in the UK) have
confirmed that the project has the poten-
tial to become one of the lowest cost and
highest quality rare earth projects world-
wide, says ASX-listed Peak Resources. The
DFS was led by AMEC Foster Wheeler.
According to Peak, delivery of the proj-
ect – in which it has 75 % ownership – is
well timed to benefit from the expected
strong uplift in the demand for permanent
magnet motors required by the rapidly
expanding electric vehicle market, which
has been the main catalyst for significant
increases in the price of lithium and cobalt
since late 2015. Neodymium and praseo-
dymium are expected to generate 90 % of
Ngualla’s future revenue.
The Ngualla deposit is located in
Tanzania, 147 km from the city of Mbeya. It
is one of the world’s largest NdPr deposits,
with a total mineral resource containing
4,6Mt of REO (rare earth oxide). The deposit
is host to a thick blanket of weathered,
high-grade mineralisation from surface.
The project combines mining and
multi-stage processing at Ngualla with
downstream refining at a solvent extrac-
tion separation plant in the UK to produce
a range of rare earth products.
The BFS estimates an operating cost
of US$34,20 NdPr oxide, which Peak says
demonstrates Ngualla’s potential to be the
world’s lowest cost fully integrated rare
earth development project, and a total
pre-production capex (including the UK
refinery) of US$356 million.
Peak has developed and demonstrated
through extensive pilot plant operation a
robust process for Ngualla’s unique ore
to provide confidence in the deliver-
ability and operability of the three main
processing stages – beneficiation, leach
and purification/separation. The pilot
plants together cost approximately A$5
million and comprehensively validate the
operating and design parameters used
in the study.
The annual output target is 2 420
tonnes of neodymium and praseodymium
rare earth oxide (2N min 75 % Nd
2
O
3
); 530
tonnes of mixed samarium, europium
and gadolinium rare earth carbonate; and
3 005 tonnes of cerium carbonate and
6 940 tonnes of lanthanum carbonate.
The study envisages production over
a 30-year mine life based on the weath-
ered Bastnaesite Zone mineralisation at
Ngualla, which comprises only 22 % of the
total Ngualla mineral resource estimate at
a 1 % REO lower grade cut.
Mining at Ngualla will be by open-
pit methods. As the mineralisation is
weathered and at surface, mining will pre-
dominantly (70 %) be free dig requiring
minimal blasting and with low ore to waste
stripping ratios.
An optimal shell was selected as the
BFS positions Ngualla as a world-class development
A 3D perspective of the proposed
processing plant at Ngualla.
basis for the open-pit mine design and
subsequent LOM schedule, which is to be
mined by four initial stages followed by
the ultimate pit design. In line with previ-
ous studies, it is assumed mining is via two
successive 2,5 m mining flitches.
Peak has designed a multi-stage pro-
cessing plant that will be located on site
at Ngualla to produce 28 300 t/a of rare
earth concentrate grading 45 % REO. The
plant comprises a ROM pad to receive
mine production and blend plant feed to
predefined specifications; a comminution
circuit incorporating primary crushing,
grinding and classification; and benefi-
ciation of the ground feed utilising reverse
gangue flotation, regrinding and rare earth
flotation to produce a high grade/lowmass
concentrate. A segmented Tailings Storage
Facility (TSF) will be used for safe disposal
of waste solids and water reclaim.
“I would like to congratulate the Peak
and AMEC Foster Wheeler teams and
our other consultants on the delivery of
a robust and comprehensive BFS,” com-
ments Peak’s Managing Director, Darren
Townsend.
“Our stakeholders can take comfort that
the study has been completed under the
leadership of our Chief Operating Officer,
Rocky Smith and Technical Director, Dave
Hammond, and is based on the Peak
team’s significant rare earth operating
and marketing experience combined with
extensive pilot planting.”