Highlights
- Mineralogical variability studies show that the composites
tested achieved similar recoveries (i.e. both by weight and grades
of niobium and tantalum) to the partially optimized rougher
flotation process established during the previous phase 1 and 2
metallurgical programs.
- Over 90% of the composites tested achieved rougher recoveries
which exceeded 96% tantalum and 92% niobium within the
tantalum/niobium circuit only.
- The amount of tantalum and niobium metals reporting to the
flotation feed is relatively constant at about 81.4% for tantalum
and 80.6% for niobium
- The Mineral Resource update underway at AMEC will include
results of exploration in 2012, as well as 34 drill holes
(totalling 8,715 m) of infill drilling completed in 2011 and not
included in the previous resource.
VANCOUVER, March 27, 2013 /PRNewswire/ - Commerce
Resources Corp. (TSXv: CCE, FSE: D7H, OTCQX: CMRZF) (the
"Company" or "Commerce") is pleased to provide a further update on
recent work completed at its Blue River Project since release of
the National Instrument (NI) 43-101 compliant Mineral Resource
update (Commerce news release July 6,
2012) for the Upper Fir Deposit. Newly completed
mineralogical variability studies show that the partially optimized
flotation flow sheet which formed the base of the metallurgical
analysis in the Preliminary Economic Assessment (Commerce news
release November 3, 2011), and which
was further optimized during Phase 2 test work (reported
December 3, 3012) shows good
applicability across the range of mineralogies tested.
The geological, engineering, metallurgical and
environmental programs carried out in 2012 provide broad support to
the advancement of exploration and development at the Company's
wholly owned Blue River Project,
east-central British Columbia. The
new metallurgical results continue to strengthen the foundation of
broadly based technical knowledge developed in 2012, and after
completion of the mineral resource update currently in progress by
independent consultants AMEC Americas Ltd. ("AMEC"), will be
sufficient to support the initiation of a pre-feasibility study
(PFS).
"We are pleased with these new results from what
has been a significant amount of work accomplished in the past
year. These metallurgical results provide additional upside to the
positive test work previously reported in the PEA, a major
milestone in our progress to develop the Upper Fir. The
post-PEA metallurgical results reinforce Commerce's belief that we
are in the process of building a very important long-term source of
conflict free and ethical tantalum which could potentially supply
10% of the current world's market for the long term." says
Dave Hodge, Commerce's President.
"We will be extremely interested in the upcoming resource update
from AMEC which will be based on all work to date."
The Blue River Property is host to the Upper Fir
Tantalum and Niobium Deposit, which was discovered in 2002 and
which has been the focus of the Company's activities since 2005. In
fiscal 2012 Commerce spent approximately $3.8M on the Property.
Metallurgical Test Work in 2012
Metallurgical work in 2012 has continued to update and optimize the
process flow sheet described in the NI 43-101 compliant Preliminary
Economic Assessment ("PEA") study completed by AMEC on the Blue
River Project (effective date of September
29, 2011; see Commerce news release of November 3, 2011). The process flow sheet
for the recovery of the tantalum and niobium described in the PEA
was developed in 2011 based on Phase 1 studies.
In April 2012,
Commerce commissioned Acme Metallurgical Ltd ("Acme Met") of
Vancouver, BC to initiate a Phase
2 investigation. This was designed to follow-up the successful
results of the earlier program which had tested flotation as the
preferred method to remove the larger portion of fine slimes and
carbonatite minerals early in the process. Subsequent process steps
could then focus on material containing Ta and Nb.
Phase 2 testing optimized the use of desliming
and carbonate rejection flotation, as well as chemical reagent
dosages to increase the efficiency of rougher/cleaner Ta/Nb
flotation. This work enabled finalization of the process flow sheet
developed in Phase 1 which was based on composite samples BS-2F and
BS 2G. All Phase 2 work was conducted on these same composites and
all tests were conducted at a grind size of 80% passing 130
microns. These results were reported in a news release dated the
3rd of December 2012.
Mineralogical Variability Testing
A total of 767 samples of drill core rejects from the Upper Fir
deposit were combined into thirty-six composites (selected to
represent five different end member mineralogies within the
deposit) and subjected to flotation testing. This variability
testing, initiated in April 2012 and
completed in January 2013, had the
primary objective of determining the composites' response to the
partially optimized flotation procedure established during the
Phase 1 and 2 metallurgical programs completed in 2011 and 2012 and
previously reported.
Key Areas of Variability Investigation and
Results:
Desliming and Mass Rejection
- The majority of the composites are amenable to the standard one
stage cyclone desliming process with rejection of 17.2% of the
weight as slimes, containing 7.2% of the tantalum and 6.9% of the
niobium. Variation of the weight rejected is minimal between
composites with no significant effect from grind sizes or
mineralogy.
- The total carbonate mass rejection is proportional to the
amount of carbonate and phosphate materials in the feed, with the
average weight of carbonate concentrate floated and rejected for
all composites being 53.2% of the mass, with losses of 11.4% for
tantalum and 12.5% of niobium. Metals losses were directly
proportional to the weight of concentrate removed and independent
of head grades.
Carbonate Concentrate Cleaning
- Cleaning of the carbonate concentrate was not performed during
this testing campaign, however, the scavenger stage of flotation
represented about 40% of the total weight floated, containing about
two thirds of the metal losses. This is indicative of mechanical
losses due to strong scavenging action and entrainment.
- It is strongly recommended that cleaning of the concentrate be
kept in the flow sheet to reduce these losses. Recycling the
cleaner tails to the Ta:Nb flotation feed might account for 2% to
6% of the metals in the feed.
Feed to Tantalum:Niobium Flotation
- Though the weight of material left after slimes and carbonate
removal does vary with the type of mineralogy, it overall averages
29.5%. The amount of metals reporting to Ta:Nb flotation
nevertheless remains fairly constant at about 81.4% for tantalum
and 80.6% for niobium. Losses of metals to that point are
proportional to the weights removed and thus statistically
inversely proportional to head grades.
- Within the Ta:Nb rougher and cleaner flotation circuit only,
over 90% of the composites achieved rougher grade Ta:Nb recoveries
which exceeded 96% for Ta and 92% for Nb.
Magnetic Separation
- The final stage of magnetic separation also increased the final
concentrate grade with minimal loss of the Ta and Nb minerals. This
supports results from Phase 2 work in which approximately 50% of
the final concentrate mass was removed with minimal Ta/Nb
loss.
Acme Metallurgical Recommendations
Acme Met recommends that further optimization work be undertaken as
follows:
- The carbonate flotation stage appears to require a lower dosage
of the oleic acid collector as tantalum and niobium minerals
are likely trapped and entrained with the tight froth generated by
the over dosage of oleic acid.
- The balance of flotation reagents diamine acetate (Duomac T- as
collector) and fluosilicic acid (H2SiF6 as pH
modifier/silicates depressant) in the Ta:Nb cleaning circuit should
be investigated as metals losses are mostly observed between pH 4
to 3.
- A fifth and sixth stage of cleaning should be investigated to
achieve a grade of 35% combined Nb-Ta oxides.
- Locked cycle tests should be completed to provide clear
indication of reagents consumption as each stage.
- Full assaying of final concentrate products, particularly for
sulphur and rock-forming elements, could provide additional
information which would help orient further investigations.
Upcoming Mineral Resource Update
A Mineral Resource Update and subsequent technical report which
will incorporate all data from 2005 through 2012 is currently
underway by AMEC with completion targeted for the second quarter of
2013. This work will build from the previous Mineral Resource
Update technical report (effective date June
22, 2012) in which AMEC compared results from the 34 holes
totalling 8,715m drilled in 2011, after the closure of the resource
database to the updated resource model and found them to be
reasonably consistent with the geology predicted by the model.
2011 PEA Outcomes
The Preliminary Economic Assessment ("PEA) was prepared to define
an overall proof of concept for further development of the Blue
River Project. The PEA (effective date September 29, 2011) indicated that the deposit
can be developed economically as an underground mine and
recommended future studies to support a pre-feasibility level
assessment of the project. The assessment included geological
and mineral resource modeling, preliminary mine planning, a
description of metallurgical test work and process design, a
summary of environmental baseline work to date, and estimates for
capital and operating costs. As well, it determined the
economics to develop the project as an underground mine with
process facility, and included an estimate of the direct cash costs
to produce tantalum contained in a technical grade oxide
product.
Property
The Blue River Project is located near the village of Blue River, which is approximately 250 km
north of the city of Kamloops and
approximately 90 km south of the town of Valemount. The Project comprises 105,373
hectares (1,000 km2) of mineral claims.
Power transmission lines, rail, and paved and gravel roads are all
adjacent to, or within the property boundaries. Transalta
Corp.'s 18 MW Bone Creek run-of-river hydroelectricity project near
the project was commissioned in June
2011.
NI 43-101 Disclosure
Ms. Jenna Hardy, M.Sc., P.Geo.,
Commerce Resources Corp., is a Qualified Person as defined by
National Instrument 43-101, read and approved the disclosure of the
technical information in this news release.
About Commerce Resources Corp.
Commerce Resources Corp. is an exploration and development company
with a particular focus on tantalum, niobium and rare metal
deposits with potential for economic grades and large tonnages. The
Company is specifically focused on the development of its Upper Fir
Tantalum and Niobium Deposit in British
Columbia and its Ashram Rare Earth Element Project in
northern Quebec.
On Behalf of the Board of Directors
COMMERCE RESOURCES CORP.
"David Hodge"
David Hodge
President and Director
Tel: 604.484.2700
Email: dhodge@commerceresources.com
Neither 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.
Forward-Looking Statements
This news release contains forward-looking information which is
subject to a variety of risks and uncertainties and other factors
that could cause actual events or results to differ from those
projected in the forward-looking statements. Forward looking
statements in this press release include that our results will be
sufficient to support the initiation of a pre-feasibility study;
that we are in the process of building a very important long-term
source of tantalum which could potentially supply 10% of the
current world's market for the long term; that we will be able to
enhance even further the quality of the resource; and that prices
for our potential products are conservatively estimated and may
trend upwards. These forward-looking statements are based on
the opinions and estimates of management and its consultants at the
date the information is disseminated. They are subject to a
variety of risks and uncertainties and other factors that could
cause actual events or results to differ materially from those
projected in the forward-looking information. Risks
that could change or prevent these statements from coming to
fruition include changing costs for mining and processing and their
impact on the cut off value established; increased capital
costs; changing forecasts of mine production rates; the
timing and content of upcoming work programs; geological
interpretations based on drilling that may change with more
detailed information; potential process methods and mineral
recoveries assumption based on limited test work and by comparison
to what are considered analogous deposits that with further test
work may not be comparable; the availability of labour, equipment
and markets for the products produced; market pricing for the
products produced; and despite the current expected viability of
the project, conditions changing such that the minerals on our
property cannot be economically mined, or that the required permits
to build and operate the envisaged mine can be obtained. The
forward-looking information contained herein is given as of the
date hereof and the Company assumes no responsibility to update or
revise such information to reflect new events or circumstances,
except as required by law.
SOURCE Commerce Resources Corp.
