| Mon 9 Feb 2009, 9:00 | | AEA - African Eagle Announces Positive Preliminary Bottle Roll Leach Test |
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AEA
AEA
AEA - African Eagle Announces Positive Preliminary Bottle Roll Leach Test
Results From Dutwa Nickel Project
African Eagle Resources plc
(Incorporated in England and Wales, registered number 3912362)
AIM share code: AFE AIM ISIN: GB0003394813
JSE share code: AEA JSE ISIN: GB0003394813
AFRICAN EAGLE ANNOUNCES POSITIVE PRELIMINARY BOTTLE ROLL LEACH TEST RESULTS FROM
DUTWA NICKEL PROJECT
Preliminary results from bottle roll tests still underway
>90% average nickel recovery from drill samples
Very low sulphuric acid consumption
Heap leach extraction likely to be feasible process route
Scoping study proposals being reviewed
African Eagle Resources plc has received excellent results from acid leach tests
underway at Mintek in South Africa, on drill samples from its Dutwa nickel
laterite project in Tanzania. The results received to date show nickel
recoveries averaging 92%, with very low sulphuric acid consumption, averaging
210 kilograms per tonne.
Mark Parker, Managing Director of African Eagle Resources plc comments: "Whilst
the acid leach tests are scheduled to continue for up to 90 days, these results,
after 68 days, are already very encouraging.
"The metallurgy of nickel laterites is critical to the viability of these
deposits, with two parameters, nickel recovery and acid consumption per tonne of
nickel metal won, being especially important. The results we have received from
Mintek so far are very encouraging as they show that we may be able to use
straightforward, low cost heap leaching to recover the nickel from the ore.
"Taken together, these metallurgical results and the resource estimate of some
340,000 tonnes of contained nickel and 11,000 tonnes of cobalt, (announced in
November), indicate that Dutwa is a highly significant discovery.
"We believe Dutwa has many of the right credentials to make the project
economically viable even at current metals prices: simple and conventional
mining; potential heap leaching with low acid consumption; and the good
infrastructure in the Dutwa area. As the next step in the process, African Eagle
will commission a Scoping Study to investigate these key operating parameters
and to assess the economic potential of the project. We are currently
evaluating proposals for the study from contractors."
The table below shows the cumulative acid consumption and nickel recovery for
the ten 500g samples (5 from diamond drill cores and 5 from reverse circulation
cuttings), after 68 days `bottle roll` acid leaching. Each sample was placed in
a plastic bottle with 2 litres of dilute sulphuric acid and agitated
continuously by rolling on rotating rollers. The recoveries were calculated from
the preliminary solution based extraction curves; the final extractions will be
calculated from the residues when the test is complete.
DH1 DH4 DH6 DH7 DH8 RC25 RC30 RC36 RC55 RC71 Average
Acid 350 200 230 110 200 160 210 300 190 140 210
kg/t
Ni % 96 96 97 86 90 88 94 84 94 97 92
recovery
Mintek is also conducting extensive mineralogical analysis on the samples, using
X-ray diffraction and scanning electron microscopy. These tests will help
African Eagle to categorise potential ore type zoning within the greater
resource and yield information on the likely behaviour of the material in
processing through the identification of the mineral phases present.
Technical terms
A glossary of technical terms used by African Eagle in this announcement and
other published material may be found at www.africaneagle.co.uk/african-eagle-
projects-glossary.html
For further information:
Mark Parker
Managing Director
African Eagle
+44 20 7248 6059
+44 77 5640 6899
Nicola Marrin
Seymour Pierce Limited, London
Nominated Adviser
+ 44 20 7107 8000
Charmane Russell
Russell & Associates, Johannesburg
+ 27 11 8803924
+27 82 8928052
Ed Portman / Gareth Tredway
Conduit PR, London
+44 20 7429 6607
+44 (0) 7733 363 501
About Dutwa
The Dutwa project area lies in the Kilimafedha belt (Swahili for "money hills")
of the Lake Victoria Goldfield. Operationally, the project is favourably
situated, 100km east of the railhead at Mwanza and close to the main Mwanza-
Nairobi trunk road, a major power line and the shore of Lake Victoria.
The Dutwa project area is composed of several prospecting licences covering a
total area of about 750km2. The Company holds 90% interests, with options to
acquire 100%, over most of this ground, including the area of the laterite
discovery, and the remainder is under application.
Greenstones and granites underlie the area. The greenstones, of Archaean
Nyanzian age, are mostly metamorphosed volcanic and sedimentary rocks, with some
banded iron formation in the east. Several large ultramafic bodies intrude the
greenstones and the nickel laterites form a blanket up to 60m thick on top of
these.
African Eagle acquired the Dutwa project for its gold potential, but its
exploration team quickly recognised that there was significant nickel laterite
potential. Geochemical soil surveys carried out by African Eagle over the whole
of the project area identified a promising 5km-long nickel anomaly and a number
of gold anomalies. There is very little outcrop, so the Company conducted
extensive ground magnetic surveys to reveal the underlying structure and
geology. The Company has also compiled historical data, including detailed
geological maps and trench results dating from 1956, when rock chip samples from
the trenches over the ultramafic rocks were reported as yielding up to 1.9%
nickel and 10% chromium.
To investigate the nickel anomaly, the Company undertook trial drilling in June
2008. The results were very encouraging and a 139-hole reverse circulation (RC)
drilling programme was completed to delineate the resource. African Eagle also
undertook a 10-hole diamond drill programme to obtain core samples for
metallurgical testing and density measurements.
In November 2008, African Eagle announced an initial Inferred Mineral Resource
estimate of 31 million tonnes at an average grade of 1.1% nickel and 0.034%
cobalt. At a cut-off grade of 0.5% nickel, this gives Dutwa a contained metal
endowment of some 340,000 tonnes of nickel and 11,000 tonnes of cobalt. The
estimate was prepared by independent consultants SRK Consulting (UK) Ltd in line
with the Australasian Code for Reporting of Mineral Resources and Ore Reserves
(the JORC Code). SRK classified the estimate as an Inferred Mineral Resource in
terms of the JORC code, but noted that the deposit is a continuous mineralised
body of simple geometry, which has been well delineated by the drilling, and
could be promoted easily to Indicated category with more density measurements
and improved knowledge of the metallurgy.
The Company despatched 100 kilograms of mineralised drill core and RC chip
samples to Mintek Laboratories in Johannesburg for investigations into the
mineralogy and metallurgy of the deposit, especially tests of the amenability of
the material to heap leaching. Mintek is carrying out mineralogical
characterisation by X-ray diffraction (XRD), scanning electron microscopy and
polished section work, to determine the nature of the ore body, and extended
`bottle roll` acid leach tests on ten samples, to investigate metal recoveries
and acid consumption. The results received to date, after 68 days leaching, show
nickel recoveries averaging 92% and very low acid consumptions, averaging 210
kilograms per tonne.
As the next step in the process, African Eagle is commissioning a Scoping Study
to investigate the key operating parameters and to assess the economic potential
of the project.
The Company has also completed a trial programme of RC drilling to test a
laterite at its Zanzui project, 70km to the south of Dutwa. Results included
42m at 1.05% nickel (including 6m at 2.80%) and 33m at 0.91% nickel (including
9m at 1.41%).
About African Eagle
African Eagle is a diversified mineral exploration and development company
operating in eastern and central Africa. The Company`s principal advanced
projects are the Mkushi Copper Mines project in Zambia, for which a draft
Feasibility Study was completed in Q4 2008, and the Dutwa nickel laterite
discovery in Tanzania, where the Company announced a significant resource at the
end of 2008.
African Eagle has also defined a gold resource estimated at half a million
ounces at the Miyabi gold project in Tanzania, and is evaluating a second
promising nickel laterite deposit which it recently discovered in Tanzania. The
Company holds a well-balanced portfolio of promising earlier stage gold and base
metal projects, including the Ndola and Mokambo projects in the Zambian
Copperbelt.
Zambia, Tanzania and Mozambique, the sites of African Eagle`s projects, are all
countries which have highly prospective geology, relatively low above-ground
risks and track records of successful major investments in the metals and
minerals industries.
African Eagle specialises in project generation and exploration. To take its
discoveries into production, it seeks to sign up industry partners with records
of successful mine development. These joint ventures and, in time, the revenue
from advanced projects, will finance future exploration and new discoveries.
09 February 2009
Sponsor
Nedbank Capital
Date: 09/02/2009 09:00:01 Produced by the JSE SENS Department.
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