Lofdal Heavy Rare Earth Deposit: Successful hydrometallurgical test work results in highly efficient process to produce a market ready >98% Rare Earth Oxide product
Press Release
Namibia Critical Metals Inc.
Lofdal Heavy Rare Earth Deposit: Successful hydrometallurgical
test work results in highly efficient process to produce a
market ready >98% Rare Earth Oxide product
Halifax, Nova Scotia October 7, 2021 – Namibia Critical Metals Inc. (“Namibia Critical
Metals” or the “Company” or “NMI”) (TSXV:NMI) is pleased to provide an update on the
development of the Lofdal Heavy Rare Earth project since granting of the Mining Licence in
July this year. The Lofdal Heavy Rare Earth Deposit is one of only two primary xenotime
projects under development in the world. The deposit has the potential for significant
production of dysprosium and terbium, the two most valuable heavy rare earth elements used
in high powered magnets and other high-tech applications. The Project is being developed in
joint venture with Japan Oil, Gas and Metals National Corporation (“JOGMEC”) targeting a
long term, sustainable supply of heavy rare earths to Japan.
The Company has successfully completed hydrometallurgical test work to develop a flowsheet
capable of producing a high-grade rare -earth oxide product from a xenotime flotation
concentrate. The Company’s lead metallurgical consultants at SGS Minerals Services Canada
(SGS) have simplified the final process stage with an acid bake to crack the mineral xenotime,
to purify the pregnant leach solution and to precipitate a rare earth oxalate , which is
subsequently calcined to form a product containing >98% total rare earth oxides (TREO). The
acid bake process and concurrent removal of impurities is highly efficient and resulted in a
95% recovery of Dysprosium and Terbium in the leaching operation of the processing flow
sheet. The high-quality product is practically free of typical deleterious elements like thorium
and uranium (<3 ppm combined U+Th).
Darrin Campbell, President of Namibia Critical Metals stated:
These very positive test results are another big milestone for the Lofdal project and show that
we are on the right path towards establishing that Lofdal can produce a valuable heavy rare
earth product. This will allow us to advance an updated assessment of large -scale and
integrated rare earth production towards a high purity Rare Earth Oxide product in Namibia.
This would result in further value addition in Namibia and puts the country on the global map
of rare earth supply strategies.”
Hydrometallurgical test work and results
Two flotation concentrates produced by processing of bulk samples from the Lofdal d eposit
were tested at the laboratories of SGS in Lakefield, Ontario , to determine the potential for
producing a marketable rare earth product with minimal impurities. Previous
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hydrometallurgical test work had focused on more costly caustic cracking following gangue
acid leach. The comprehensive test work at SGS has demonstr ated the acid bake route is
preferred due to lower reagent costs and higher recovery of the heavy rare earths.
A total of 12 acid bake and water leach tests were completed throughout the test program to
investigate the dissolution of rare earth elements (REE) and the behaviour of gangue minerals
through the addition of sulphuric acid at elevated temperatures (200 -300°C). Optimum
results were achieved using an acid addition of 1250 kg/t H2SO4 at 300°C followed by a water
leach at 20% solids by weight at 25°C. Under these conditions, the tests showed very good
REE recoveries with 97-98% for yttrium, 95% for dysprosium and 94-95% for terbium.
Table 1: Elemental composition of the calcined oxalate
Impurity removal test work using magnesium carbonate and hydrogen peroxide resulted in
maximum precipitation of iron and thorium from the pregnant leach solution while minimizing
REE co -precipitation. An intermediate and impure REE precipitate was produced via the
addition of soda ash (sodium carbonate) solution.
The intermediate REE precipitate was re-leached in sulphuric acid using a two-stage sulphuric
acid process at 50°C to achieve a pulp pH of around 3.5. This step resulted in the production
of a concentrated REE liquor representing 99% of the available REE and also rejected 94% of
the thorium, 85% of the aluminum, and 99% of the remaining iron.
To remove residual uranium and thorium, the re -leach liquor was processed through
sequential ion exchange ( Purolite A660) and solvent extraction ( 0.5% Primene JMT, 2.5%
isodecanol in Aromatic 150ND ) steps to selectively remove uranium and thorium from the
REE liquor. Consequently, 99.9% of the uranium was removed in the IX contacts. A significant
fraction (94%) the thorium was also removed in the IX steps and 75% of the remaining
thorium was removed in the solvent extraction steps. The practically thorium-free raffinate
from the solvent extraction ste p advanced to final REE precipitation with oxalic acid and
calcination of the REE oxalate.
In the REE oxalate precipitation step, all REE were precipitated with minimal co-precipitation
of impurities such as sodium, magnesium, silica and calcium . The final REE oxalate was
calcined and produced a final solid containing 98.1% total rare earth oxides (TREO) or 86.2%
of heavy rare earth oxides (HREO). High leach extractions of ~95% were achieved in the test
% oxide % oxide % oxide
La2O3 2.79 Gd2O3 3.48 SiO2 0.41
CeO2 5.29 Tb4O7 0.91 Al2O3 0.01
Pr6O11 0.55 Dy2O3 7.20 Fe2O3 0.01
Nd2O3 1.89 Ho2O3 1.66 MgO 0.50
Sm2O3 0.87 Y2O3 62.10 CaO 0.22
Eu2O3 0.54 Er2O3 5.29 K2O 0.01
Tm2O3 0.72 TiO2 0.01
Yb2O3 4.25 P2O5 0.01
Lu2O3 0.57 MnO 0.01
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program and REE losses in the REE recovery steps (as shown in Figure 1) are expected to be
minimal.
Figure 1: Hydrometallurgical process flowsheet developed using Lofdal flotation concentrate
While the results are extremely positive, there remains room to optimise these processes
regarding OPEX and CAPEX as well as recoveries. This final optimisation on flotation
concentrate produced from the currently mined bulk samples is planned for 2022.
Planning for further value addition in Namibia
The positive hydrometallurgical test results allow for planning of value addition beyond the
production of a xenotime concentrate at the Lofdal Mine providing for a win-win for the country
and the company.
The addition of a hydrometallurgical plant would create further jobs in the southern Kunene
Region of Namibia, and provides a marketable product for export as the rare earth oxalate
with thorium and uranium levels below 3 ppm would be acceptable for import into Japan
without restrictions or penalties.
About Japan Oil, Gas and Metals National Corporation (JOGMEC)
JOGMEC is a Japanese government independent administrative agency which among other
things seeks to secure stable resource supplies for Japan. JOGMEC has a strong reputation as
a long term, strategic partner in mineral projects globally. The mandated areas of
responsibilities within JOGMEC relate to oil and natural gas, metals, coal and geothermal
energy. JOGMEC facilitates opportunities with Japanese private companies to secure supplies
of natural resources for the benefit of the country’s economic development.
Rare earths are of critical importanc e to Japanese industrial interests and JOGMEC has
extensive experience with all aspects of the sector. JOGMEC provided Lynas with
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US$250,000,000 in loans and equity in 2011 to ensure supplies of the Light Rare Earths
metals suite to the Japanese industry.
The Company currently owns a 95% interest in the Lofdal project with the remaining 5% held
for the benefit of historically disadvanta ged Namibians. The terms of the JOGMEC joint
venture agreement with the Company stipulate that JOGMEC provides $3,000,000 in Term 1
and $7,000,000 in Term 2 to earn a 40% interest in the Lofdal project. Term 3 calls for a
further $10,000,000 of expenditures to earn an additional 10% interest. JOGMEC can also
purchase another 1% for $5,000,000 and has first right of refusal to fully fund the project
through to commercial production and to purchase all production at market prices. The
collective interests of NMI and historically disadvantaged Namibians cannot be diluted below
a 2 6% carried working interest upon payment of $5,000,000 to JOGMEC for the dilution
protection. The JV Agreement is structured such that no NMI equity will be issued and it is
totally non -dilutive to NMI shareholders. To date, JOGMEC, has funded Term 1 and 2
expenditures totaling $6,600,000.
About Namibia Critical Metals Inc.
Namibia Critical Metals Inc. holds a diversified portfolio of exploration and advanced stage
projects in the country of Namibia focused on the development of sustainable and ethical
sources of metals for the battery, electric vehicle and associated industries. The two advanced
stage projects in the portfolio are Lofdal and Epembe. The Company also holds significant
land positions in areas favourable for gold mineralization.
Figure 2: Location of Namibia Critical Metals’ projects highlighting position of gold projects (Erongo, Otjiwarongo and
Grootfontein) in relation to important gold projects within the Navachab-Otjikoto gold belt
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Heavy Rare Earths: The Lofdal Dysprosium-Terbium Project is the Company’s most
advanced project being fully permitted with a Mining Licence (ML 200) issued in 2021. The
project is being developed in joint venture with Japan Oil, Gas and Metals National Corporation
(“JOGMEC”) to provide a sustainable supply of he avy rare earths to Japan, most notably
dysprosium and terbium.
Gold: The Company’s Exclusive Prospecting Licenses (“EPLs”) prospective for gold are located
in the Central Namibian Gold Belt which hosts a number of significant orogenic gold deposits
including the Navachab Gold Mine, the Otjikoto Gold Mine and more recently the discovery of
the Twin Hills deposit. At the Erongo Gold Project, stratigraphic equivalents to the meta-
sediments hosting the recent Osino gold discovery at Twin Hills have been identified and soil
surveys are progressing over this highly prospective area. The Grootfontein Base Metal
and Gold Project has potential for magmatic copper-nickel mineralization, Mississippi Valley-
type zinc-lead-vanadium mineralization and Otjikoto -style gold mineralization. Detailed
interpretation of geophysical data and regional geochemical soil sampling have identified first
gold targets, with the first targets currently being drill-tested.
Tantalum-Niobium: The Epembe Tantalum -Niobium-Uranium Project is at an
advanced stage with a well-defined, 10 km long carbonatite dyke that has been delineated by
detailed mapping and radiometric surveys and over 11,000 meters of drilling. Pr eliminary
mineralogical and metallurgical studies including sorting tests (XRT), indicate the potential for
significant physical upgrading. Further work will be undertaken to advance the project to a
preliminary economic assessment stage.
Copper-Cobalt: The Kunene Copper-Cobalt Project comprises a large area of favorable
stratigraphy along strike of the Opuwo cobalt-copper-zinc deposit. Secondary copper
mineralization over a wide area points to preliminary evidence of a regional -scale
hydrothermal system. Exploration targets on EPLs held in the Kunene project comprise direct
extensions of the cobalt-copper mineralization to the west, sediment-hosted copper, orogenic
copper, and stratabound manganese and zinc-lead mineralization.
The common shares of Namibia Critical Metals Inc. trade on the TSX Venture Exchange under
the symbol “NMI”.
Micheal Archer of SGS is the Company’s Qualified Person and has reviewed and approved the
scientific and technical information in this press release.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term
is defined in the policies of the TSX Venture Exchange) accepts responsibility for the
adequacy or accuracy of this release.
For more information please contact -
Namibia Critical Metals Inc.
Darrin Campbell, President
Tel: +01 (902) 835-8760
Fax: +01 (902) 835-8761
Email: [email protected]
Web site: www.NamibiaCriticalMetals.com
The foregoing information may contain forward -looking information relating to the future performance of Namibia Critical Metals Inc. forward-
looking information, specifically, that concerning future performance, is subject to certain risks and uncertainties, and actual results may differ
materially. These risks and uncertainties are detailed from time to time in the Company's filings with the appropriate securities commissions.