DNI Announces Positive Leaching Results from Cover Rocks Overlying its Buckton Inferred Resource, Alberta
February 27 2012 - 5:07PM
PR Newswire (Canada)
DNI METALS INC. TORONTO, March 1, 2012 /CNW/ - DNI Metals Inc. is
pleased to announce initial results from its bioleaching testwork
on drill core samples from the overburden cover rocks overlying its
Buckton inferred maiden resource (announced Oct24/2011 and
Jan16/2012) at its polymetallic black shale projects, Athabasca
Region, Alberta. The cover rocks consist of the LaBiche Shale
Formation, also a black shale, with a thin veneer of till which has
been glacially scoured from it. The results being announced are
from the first leaching tests ever completed to determine recovery
of Specialty Metals, Rare Earth Elements and Base Metals from the
overburden cover rocks. The results are from recently completed
bench scale batch amenability bioleaching testwork launched in
2011, carried out by Alberta Innovates Technology Futures (AITF,
formerly the Alberta Research Council), on a 200gm drill core
sample representative of the overburden LaBiche Shale overlying the
Buckton inferred resource. The sample was tested in duplicate to
specifications formulated by DNI. A summary of the best metal
recoveries achieved during the above bioleaching tests, as reported
by AITF, are as follows: Mo-57%, Ni-82%, U-78%, V-10%, Zn-76%,
Cu-65%, Co-80%, Li-41%. Recoveries for Specialty Metals and REE, as
calculated by DNI, based on the difference of metal content between
head sample feed material and final tail residues per analytical
results from AITF's testwork, range as follows: La-13%-20%,
Ce-21%-28%, Pr-28%-34%, Nd-35%-41%, Sm-49%-53%, Eu-55%-59%,
Gd-61%-64%, Tb-60%-63%, Dy-61%-65%, Ho-58%-62%, Er-51%-55%,
Tm-53%-57%, Yb-42%-47%, Lu-53%-57%, Y-56%-59%, Sc-28%-37%,
Th-32%-34%. The above results are from bioleaching of a homogenized
composite drill core sample of the LaBiche Shale overlying the
Buckton resource, representing a 3m long intercept in an archived
historic drill hole which was collected by DNI during its 2009
verification sampling program (Hole 7BK04 from 79.6m to 82.6m). The
interval is geochemically representative* of the LaBiche Shale
which comprises the overburden cover above the Buckton resource.
All of the above results were achieved under test conditions which
are yet to be optimized and, as such, are regarded by DNI as
initial results which future work will endeavor to improve by
further optimizing and refining test parameters. Final tails from
one of the duplicate samples was further leached in HCl following
bioleaching to monitor precipitation of a variety of compounds (eg:
jarosites, sulfates, ferro-compounds) and to assess related metals
re-precipitation from the leaching solution after the metals had
been extracted from the shale. As noted in previous bioleaching
tests conducted at AITF, the test results indicate that a
significant fraction of some of the dissolved metals, once leached
from the shale, are removed from the leaching solution through
re-precipitation. Mitigation of these processes will be addressed
during future testwork intended to optimize test parameters. The
Buckton inferred resource is a near-horizontal tabular zone hosted
entirely within the Second White Speckled (black) Shale Formation,
bounded within its upper and lower contacts. This Formation is
exposed throughout the erosional edge of the Birch Mountains
(eg:Buckton Zone) but is overlain westward by progressively thicker
sequences of other shales and till. Given the uniformity of metals
grades within the Speckled Shale, the Buckton resource has been
laterally delimited based on depth criteria (ie: volume of "waste"
material which would have to be excavated to access the mineralized
zone by open pit) rather than based on continuity of metallic
mineralization which extends well beyond the limits of the current
resource. As previously reported, overburden cover rocks overlying
the Buckton inferred resource have to date been considered to be
"waste" material for the purposes of estimating the Buckton
resource. The results being announced suggest that the overburden
material may represent potential value given that contained metals
and REE are recoverable. The results being announced about
recoverability of Metals and REE from the overburden cover above
the Buckton resource might serve to: (i) enable expansion of
the Buckton inferred resource beyond its current limits to
surrounding areas under thicker overburden cover, and
(ii) provide an additional mineralized zone within the
overburden cover rocks which were previously considered to be
"waste" material. The foregoing represents a significant new
milestone development from the Buckton Zone. The Buckton maiden
resource study for Mo-Ni-U-V-Zn-Cu-Co-Li (announced Oct24/2011) and
the Buckton supplemental resource study for REE-Y-Sc-Th (announced
Jan16/2012) estimated that the Buckton inferred resource is
overlain by 762,678,000 short tons of overburden cover material
consisting of LaBiche Formation shales with a thin veneer of
overlying till glacially scoured therefrom. In addition, the above
studies also concluded that mineralized tonnages ranging 400-679
million short tons with similar grades** as the Buckton inferred
resource can be blocked at a US$7.5 per tonne cut-off, representing
extensions of the Buckton resource which are beneath less than
100m-150m of the surface and which are overlain by 1.4-3.0 billion
short tons of overburden material. These tonnages are not resources
and have currently not been classified as resources. Weighted
average compositions of LaBiche Shale intercepts from all available
drill holes were announced on Dec2/2011 and Dec16/2011. In the
absence of a resource study for the overburden material, and a
separate study to revise the Buckton inferred resource, the above
tonnages estimated by a quantitative resource model can only be
considered to be mineralized material which is a target for further
work whose ultimate quantity and grade are conceptual in nature as
there has been insufficient exploration to define a mineral
resource and it is uncertain whether further exploration will
result in discovery of a mineral resource. DNI's intentions are to
shortly launch a resource study to estimate quantity and grade of
mineralization within the overburden material overlying the Buckton
resource and its projected extensions. Subject to conclusions of
this study, a collateral separate resource study will also follow
to re-asses the Buckton maiden resource to revise it based on
conclusions of the resource study relating to the overburden
material. Plans are also underway to test a suite of composite
drill core samples from overburden intercepts of drill holes
completed by DNI during its 2010-2011 winter drilling program. This
work, scheduled to commence during the summer, is slated for
completion by the end of the year. Plans are also underway for an
expanded leaching testwork program details of which will be
announced once it has commenced. The Qualified Person in connection
with this press release is S.F.Sabag P.Geo, DNI's president and
CEO, who has reviewed analytical results and is responsible for
preparation of this press release. See DNI press Sept8/2011 and
Alberta Mineral Assessment Report MIN20100017 for details of
procedures related to the bioleaching testwork. Bioleaching was
carried out using inoculum previously harvested and cultured by
AITF from DNI's black shale zones. Analytical work carried out by
Actlabs, Ancaster, Ontario, by ICP-MS. The Buckton maiden resource
study and the Buckton supplemental resource study are both
available from www.sedar.com and www.dnimetals.com. lb/t = pounds
per short ton. *Head grades for the drill core sample of the
LaBiche Shale bioleached by AITF are as follows expressed in
ppm(lb/t): MoO(3)-25(0.05), Ni-123(0.25), U(3)O(8)-4(0.01),
V(2)O(5)-431(0.86), Zn-145(0.29), Cu-35(0.07), Co-15(0.03),
Li(2)CO(3)-352(0.70), La(2)O(3)-40(0.08), Ce(2)O(3)-76(0.15),
Pr(2)O(3)-9(0.02), Nd(2)O(3)-35(0.07), Sm(2)O(3)-7(0.01),
Eu(2)O(3)-1(0.003), Gd(2)O(3)-6(0.01), Tb(2)O(3)-1(0.002),
Dy(2)O(3)-5(0.01), Ho(2)O(3)-1(0.002), Er(2)O(3)-3(0.01),
Tm(2)O(3)-0.5(0.001), Yb(2)O(3)-3(0.01), Lu(2)O(3)-0.5-(0.001),
Y(2)O(3)-33(0.07), Sc(2)O(3)-28-(0.06), ThO(2)-12(0.02). **Range of
recoverable grades (lbs per short ton) reported in the Buckton
maiden resource study and the Buckton supplemental resource study
for mineralized tonnages ranging 400-679 million short tons,
representing extensions of the Buckton resource which are beneath
less than 100m-150m of the surface, which can be blocked by the
resource model at a US$7.5 per tonne cut-off: MoO(3):
0.11-0.11, Ni: 0.26-0.26, U(3)O(8): 0.07-0.06, V(2)O(5): 1.02-1,
Zn: 0.54-0.54, Cu: 0.09-0.09, Co: 0.04-0.04, Li2(2)O(3): 0.3-0.3,
La(2)O(3): 0.09-0.08, Ce(2)O(3): 0.14-0.14, Pr(2)O(3): 0.02-0.02,
Nd(2)O(3): 0.07-0.07, Sm(2)O(3): 0.02-0.02, Eu(2)O(3): 0.004-0.004,
Gd(2)O(3): 0.02-0.02, Tb(2)O(3): 0.003-0.003, Dy(2)O(3): 0.02-0.02,
Ho(2)O(3): 0.003-0.002, Er(2)O(3): 0.01-0.01, Tm(2)O(3):
0.001-0.001, Yb(2)O(3): 0.01-0.01, Lu(2)O(3): 0.001-0.001,
Y(2)O(3): 0.11-0.11, Sc(2)O(3): 0.02-0.02, ThO(2): 0.02-0.02. Data
for Mo-Ni-U-V-Zn-Cu-Co-Li based on material under less than
125m of cover. 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. DNI - TSX Venture DG7 - Frankfurt Issued:
66,625,020 We seek Safe Harbour. This announcement includes forward
looking statements. While these statements represent DNI's best
current judgment, they are subject to risks and uncertainties that
could cause actual results to vary, including risk factors listed
in DNI's Annual Information Form and its MD&As, all of which
are available from SEDAR and on its website. DNI Metals Inc.
CONTACT: DNI Metals Inc. - Shahe Sabag, President & CEO
(416-595-1195) orDenisClement, Chairman (416-364-1909) email
ir@dnimetals.com. Alsovisit www.dnimetals.com.
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