Tasman Precipitates Heavy Rare Earth Element Concentrate and Provides Flowsheet Development Update for Norra Karr Project, Sw...
09 Juli 2014 - 2:45PM
Marketwired Canada
Tasman Metals Ltd. ("Tasman" or the "Company") (TSX
VENTURE:TSM)(FRANKFURT:T61)(NYSE MKT:TAS). Mr Mark Saxon, President & CEO, is
pleased to announce the precipitation of a heavy rare earth element (REE) rich
concentrate as part of the hydrometallurgical testwork program underway on the
100%-owned Norra Karr heavy REE project in Sweden. Preparation of this
concentrate is the final step in defining the Norra Karr flowsheet, and marks a
significant milestone in the Company's metallurgical programs. An update on
recent beneficiation progress is also provided.
Beneficiation and hydrometallurgy testwork has been completed by various
internationally recognized laboratories and delivered data of a quality suitable
for the Norra Karr Pre-Feasibility Study (PFS) which remains in progress.
Norra Karr is one of the most significant heavy REE deposits in the world, with
a simple and predictable REE mineralogy. Previous testwork has shown that the
only REE-bearing mineral with significant abundance at Norra Karr is the
zirconosilicate eudialyte. Eudialyte is weakly magnetic (paramagnetic) and
dissolves rapidly in weak acid at low temperature. This simplicity has allowed
for an uncomplicated flowsheet to be developed, that can be achieved with
standard mining/processing equipment and widely available chemicals.
Highlights
-- Crushing and grinding characteristics of the Norra Karr mineralized
material are now well known. A grind size of 60 micron has been chosen
which provides adequate liberation of the REE-bearing mineral
(eudialyte) that can easily be achieved through standard commercial
equipment;
-- Extensive testwork and optimization of single-stage magnetic separation
has been completed by equipment manufacturer Metso Minerals and
metallurgical laboratories of the Geological Survey of Finland (GTK).
This optimization has increased REE recovery in beneficiation to in
excess of 86% in less than 35% of the original mass, such that flotation
is no longer deemed necessary as was envisaged under the Norra Karr
Preliminary Economic Assessment (PEA) published June 2013. Magnetic
separation shall use standard commercial equipment and does not require
process chemicals;
-- Extensive hydrometallurgical research has been completed by ANSTO
Minerals which has tested/optimized a process of sulphuric acid
leaching, leach solution purification, REE solvent extraction and
precipitation of an REE-concentrate. Sulphuric acid was chosen due to
its relatively low cost, and its widespread availability in Sweden. A
railway line which passes only 25km from Norra Karr already transports
bulk sulphuric acid;
-- Under the hydrometallurgical process developed, leaching is undertaken
at ambient temperature and pressure. High temperature roasting is not
required to dissolve eudialyte;
-- The improved magnetic separation has significantly reduced the amount of
sulphuric acid-consuming gangue minerals within the eudialyte-rich
mineral concentrate. As a result, sulphuric acid consumption per tonne
of ore has fallen to 85 kg/tonne from the 150 kg/tonne envisaged in the
PEA;
-- A heavy REE enriched oxalate has been precipitated by ANSTO during
continuous testing with a grade of approximately 45% REE. The high value
heavy REE dysprosium (Dy) contributes 4.8% of the REE content. This
oxalate can be easily calcined to a high grade REE-oxide (REO) subject
to customer requirements;
-- Despite Norra Karr being a high-grade zirconium (Zr) and hafnium (Hf)
deposit, under the metallurgical process being modeled for the PFS, the
recovery of Zr is not being considered. Zr shall pass with Hf and
niobium (Nb) to a by-product that shall be stockpiled for potential
future recovery;
"Tasman staff and their consultants have worked hard to optimize the processing
conditions for the Norra Karr deposit for our Pre-Feasibility Study" said Mark
Saxon, Tasman's President and CEO. "We have extensively tested our metallurgical
process and have achieved the significant milestone of precipitating an
attractive high purity heavy REE product. Eudialyte was once believed to be a
difficult mineral to process, but due to the excellent work by Tasman's team,
robust process pathways are now available. We congratulate our team on the
milestones they have achieved and are proud to have taken the project from
discovery to this significant milestone."
With the guidance of Tasman's PFS consultants, samples used in testwork were
carefully chosen from drill core to be representative of the Norra Karr deposit,
both in grade and ore type distribution. A 5 tonne sample was homogenized then
crushed and ground to the target P80 size at a facility in Germany. This bulk
sample has a total rare earth oxide (TREO) grade of 0.61% and has provided a
consistent material source for all testing. Where possible, registered REE
standards have been inserted to ensure assay quality, and mass balance
calculations have consistently been completed to confirm results.
Magnetic Separation Tests
Due to the paramagnetic nature of eudialyte, magnetic separation has been the
focus for beneficiation research. Following multi-laboratory testing of magnetic
separation equipment, the Metso Minerals continuous HGMS was chosen as most
promising for optimization. Metso has worked with the metallurgical division of
the Geological Survey of Finland (GTK) to undertake both batch and continuous
testing under a wide range of operating parameters (flow velocity, magnetic
field strength, load density, grind size). The optimum operating conditions have
been determined, which have been applied repeatedly under continuous tests, the
results being both stable and predictable.
Recovery in single pass magnetic separation consistently exceeded 86% recovery
in 35% of the original mass. Size-by-size assaying and Mineral Liberation
Analysis (MLA) has demonstrated that approximately 70% of the 14% REE lost to
the tailings stream is in the fine grained (below 20 micron) fraction, which
should be recoverable by a combination of hydrocyclone separation to recover the
fine particles and small volume magnetic separation scavenging step.
Mineralogy of the mineral concentrate from the HGMS is comprised predominantly
of the paramagnetic minerals eudialyte (16.0%) and aegirine (56.9%), with minor
contribution of the felsic minerals feldspar (11.1%), nepheline (6.0%) and
zeolite (4.9%). The very low content of nepheline and zeolite in this mineral
concentrate is significant, as both minerals are soluble in sulphuric acid and
therefore increase acid consumption.
Hydrometallurgy Tests
ANSTO Minerals in Australia were engaged by Tasman in 2013 to optimize and
finalize the Norra Karr hydrometallurgical flowsheet that had been initiated by
other parties. ANSTO are an acknowledged world leader in REE hydrometallurgy,
and were chosen due to their experience in similar projects. Work was initiated
on a poorer quality mineral concentrate, but moved to the higher quality
material described above in 2014.
ANSTO's work has defined a stable and repeatable hydrometallurgical process that
has been applied in continuous operation through to precipitation of an REE
oxalate. ANSTO's extensive experience with silica management has allowed for any
process-related issues to be quickly resolved.
In previous testwork, various acids were trialed, each giving certain process
benefits. ANSTO has used only sulphuric acid for leaching due to its low cost,
and widespread availability in Sweden. A railway line which passes only 25km
from Norra Karr already transports bulk sulphuric acid that is produced in
copper smelting in Sweden and Finland.
Due to the improved mineral concentrate and ANSTO's superior process control,
sulphuric acid consumption (including residual acid) in leaching has been
reduced to 85 kg per tonne of ore. This is a very significant reduction, as PEA
financial modeling indicates sulphuric acid is the single largest processing
cost.
Following leaching, purification of the leach solution via chemical and pH
control was completed to remove various impurities including silica, iron and
manganese. The concentration of REE's in solution was increased using
conventional solvent extraction, which were then precipitated in oxalate form
through the addition of oxalic acid. The composition of this REE-oxalate is
provided in Table 1 below. This oxalate is strongly enriched in the high value
heavy REE's, which contribute 44% of the material.
The recovery of REE's achieved in the hydrometallurgy stage (leaching to
precipitation) is approximately 90%, with heavy REE (not including yttrium)
recovery consistently exceeding light REE recovery.
"The results described above come at an important stage of the development of
Norra Karr, and will be incorporated into the PFS models" said Mark Saxon,
Tasman's President and CEO. "Norra Karr is unusual in its heavy REE enrichment,
and furthermore has the unique advantage of lying within a first world
mining-friendly country with easy access to road, rail, power, process
chemicals, skilled labor and the large European market."
----------------------------------------------------------------------------
Element Weight % REE in Oxalate Solid REO as % of TREO
----------------------------------------------------------------------------
La 4.94 10.7 LIGHT REE
--------------------------------------------------------------
Ce 10.75 23.2
--------------------------------------------------------------
Pr 1.46 3.1
--------------------------------------------------------------
Nd 6.76 14.5
--------------------------------------------------------------
Sm 1.65 3.5
----------------------------------------------------------------------------
Eu 0.27 0.6 HEAVY REE
--------------------------------------------------------------
Gd 1.66 3.5
--------------------------------------------------------------
Tb 0.35 0.7
--------------------------------------------------------------
Dy 2.19 4.6
--------------------------------------------------------------
Ho 0.49 1.0
--------------------------------------------------------------
Er 1.29 2.7
--------------------------------------------------------------
Tm 0.18 0.4
--------------------------------------------------------------
Yb 1.14 2.4
--------------------------------------------------------------
Lu 0.15 0.3
--------------------------------------------------------------
Y 12.21 28.6
----------------------------------------------------------------------------
Total REE 45.48 100 %
----------------------------------------------------------------------------
----------------------------------------------------------------------------
Light REE % 55.1
----------------------------------------------------------------------------
Heavy REE % 44.9
----------------------------------------------------------------------------
Table 1: Composition of REE-oxalate precipitated by ANSTO Minerals from
Norra Karr project, with REO relative abundance (when converted to oxide)
Norra Karr lies 15km NNE of the township of Granna and 300km SW of the capital
Stockholm in mixed forestry and farming land, and is secured to Tasman with a
25-year Mining Lease. The short time taken from discovery to Mining Lease
granting demonstrates the efficiency and advantage of operating in a
jurisdiction with a strong and transparent Mining Act and a long term
association with resource industries. The project is proximal to road, rail,
power and operating ports, plus skilled personnel, minimizing the need for
offsite infrastructure to be built by the Company.
Tasman's Qualified Person, Mr. Mark Saxon, President and Chief Executive Officer
of Tasman and a Fellow of the Australasian Institute of Mining and Metallurgy
and Member of the Australian Institute of Geoscientists, has reviewed and
verified the contents of this news release.
About Tasman Metals Ltd.
Tasman is a Canadian mineral development company focused on critical metals
including Rare Earth Elements (REE's) and tungsten (W) in Scandinavia. Tasman is
listed on the TSX Venture Exchange under the symbol "TSM" and the NYSE-MKT under
the symbol "TAS". REE and tungsten demand is increasing, due to the metals'
unique properties that make them essential for high technology and industry.
Since over 95% of REE and 80% of tungsten supply is sourced from China, the
European Commission promotes policy to develop domestic supply of critical
metals to ensure the security of industry. Tasman receives research funding from
the European Commission.
Tasman's exploration portfolio is uniquely placed, with the capacity to deliver
strategic metals from politically stable, mining friendly jurisdictions with
developed infrastructure and skills. The Company's Norra Karr and Olserum
projects in Sweden are two of the most significant known heavy REE resources in
the world, enriched in dysprosium, yttrium, terbium and neodymium. The Company
is now focused on the safe, sustainable and responsible development of its
Scandinavian mineral portfolio.
On behalf of the Board,
Mark Saxon, President & CEO
The TSX Venture Exchange nor its Regulation Services Provider (as that term is
defined in the policies of the TSX Venture Exchange), the NYSE - MKT nor the
Frankfurt Stock Exchange accepts responsibility for the adequacy or accuracy of
this news release.
Cautionary Note to U.S. Investors Concerning Mineral Resources and Reserves. In
this news release, the definition of "mineral resources" is that used by the
Canadian securities administrators and conforms to the definition utilized by
CIM in the "CIM Standards on Mineral Resources and Reserves - Definitions and
Guidelines" adopted on August 20, 2000 and amended December 11, 2005.
The standards employed in estimating the mineral resources referenced in this
news release differ significantly from the requirements of the United States
Securities and Exchange Commission (the "SEC") and the resource information
reported may not be comparable to similar information reported by United States
companies. The term "resources" does not equate to "reserves" and normally may
not be included in documents filed with the SEC. "Resources" are sometimes
referred to as "mineralization" or "mineral deposits." While the terms "mineral
resource", "measured mineral resource", "indicated mineral resource" and
"inferred mineral resource" are recognized and required by Canadian regulations,
they are not defined terms under standards in the United States and normally are
not permitted to be used in reports and registration statements filed with the
SEC. The terms "mineral reserve," "proven mineral reserve" and "probable mineral
reserve" are Canadian mining terms as defined in accordance with National
Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101")
and the CIM - CIM Definition Standards on Mineral Resources and Mineral
Reserves, adopted by the CIM Council, as may be amended from time to time by the
CIM. These definitions differ from the definitions in the United States
Securities and Exchange Commission Industry Guide 7 ("SEC Industry Guide 7")
under the Securities Act of 1933. Under Canadian rules, estimates of inferred
mineral resources may not form the basis of feasibility or prefeasibility
studies, except in rare cases. Disclosure of "contained ounces" in a resource is
permitted disclosure under Canadian regulations; however, the SEC normally only
permits issuers to report mineralization that does not constitute "reserves" by
SEC standards as in place tonnage and grade without reference to unit measures.
The estimation of measured, indicated and inferred mineral resources involves
greater uncertainty as to their existence and economic feasibility than the
estimation of proven and probable reserves. U.S. investors are cautioned (i) not
to assume that measured or indicated resources will be converted into reserves
and (ii) not to assume that estimates of inferred mineral resources exist, are
economically or legally minable, or will be upgraded into measured or indicated
mineral resources. It cannot be assumed that the Company will identify any
viable mineral resources on its properties or that any mineral reserves, if any,
can be recovered profitably, if at all. As such, information contained in this
news release and the documents incorporated by reference herein concerning
descriptions of mineralization and resources under Canadian standards may not be
comparable to similar information made public by United States companies in SEC
filings.
Cautionary Statements. Certain statements found in this release may constitute
forward-looking statements as defined in the U.S. Private Securities Litigation
Reform Act of 1995. Forward-looking statements reflect the speaker's current
views with respect to future events and financial performance and include any
statement that does not directly relate to a current or historical fact. Such
statements reflect the current risks, uncertainties and assumptions related to
certain factors including, without limitations, competitive factors, general
economic conditions, customer relations, uncertainties related to the
availability and costs of financing, unexpected geological conditions, success
of future development initiatives, imprecision in resource estimates, ability to
obtain necessary permits and approvals, relationships with vendors and strategic
partners, the interest rate environment, governmental regulation and
supervision, seasonality, technological change, changes in industry practices,
changes in world metal markets, changes in equity markets, environmental and
safety risks, and one-time events. Should any one or more of these risks or
uncertainties materialize, or should any underlying assumptions prove incorrect,
actual results may vary materially from those described herein. Forward-looking
statements cannot be guaranteed and actual results may vary materially due to
the uncertainties and risks, known and unknown, associated with such statements.
Shareholders and other readers should not place undue reliance on
"forward-looking statements," as such statements speak only as of the date of
this release.
FOR FURTHER INFORMATION PLEASE CONTACT:
Investor Information
Tasman Metals Ltd.
Jim Powell, V.P. - Corporate Development
+ 1 (647) 478 8952
jpowell@tasmanmetals.com
Tasman Metals Ltd.
Mariana Bermudez
+1 (604) 685 9316
info@tasmanmetals.com
www.tasmanmetals.com
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