DNI Reports Additional Bioleaching Results, Including Specialty Metals and Rare Earth Elements From Its Black Shale Projects, Alberta
TORONTO, Sept. 8, 2011 /CNW/ --
DNI METALS INC. (DNI : TSX-Ven)(DG7 : Frankfurt)
TORONTO, Sept. 8, 2011 /CNW/ - DNI Metals Inc. (DNI:TSX-Ven)(DG7:FSE) is pleased to announce consolidated results from a series of
bioleaching R&D studies which conclude DNI's initial testwork on
surface samples from its Alberta polymetallic black shale projects,
Athabasca Region, Alberta.
The bioleaching studies were carried out by Alberta Innovates Technology
Futures (AITF, formerly the Alberta Research Council) to specifications
formulated by DNI and Dr.Corale Brierley, of C.L.Brierley Consultancy
LLC, Denver, who has been assisting DNI during the past two years as
its bioleaching consultant, in formulation of DNI's bioleaching
testwork programs.
The studies were implemented in several iterative stages commencing in
late 2009, and were completed at the end of 2010. The studies
collectively confirmed that suitable bioleaching organisms are
indigenous to the shale and can be readily extracted, cultivated and
adapted to the shale's chemistry. The studies also confirmed that a
broad suite of metals can be collectively extracted from the shale,
with high recoveries for Ni/U/Zn/Co/Cd and lower recoveries for
Mo/V/Cu/Li which might be enhanced through optimized leaching
parameters. Results from the above studies are consistent with results
from concurrent bioleaching testwork previously announced by DNI
carried out by the Bureau de Recherches Géologiques et Minières (BRGM),
France, (press Apr28/2010), and simple sulfuric acid leaching tests
conducted under DNI's direction at Canadian analytical facilities
(press Mar4/2010).
Two sets of surface samples (#BK003 and #BK456) were tested, both of
which were collected by DNI during its 2009 surface trench sampling
from a 9.5m thick mineralized exposure of Second White Speckled Shale
at the Buckton South Zone located approximately 9km to the south of the
Buckton Mineralized Zone. Sample BK003 represents material collected
over 2m of true width, and sample BK456 is a composite sample collected
over approximately 4m of true width beneath sample BK003. The Buckton
South Zone either represents the southerly projected extension of the
Buckton Mineralized Zone, or is a separate similar mineralized Zone
which has not yet been drilled (cored) by DNI, although 12m-23m
thicknesses of the Speckled Shale Formation are reported in downhole
logs from approximately twenty historic oil/gas wells throughout a
100-150 square kilometer area.
The earliest parts of the testwork, completed in late 2009, consisted of
successful harvesting of bio-organisms from the shale, their culturing
and subsequent adaptation. Acid mobility tests, completed in early 2010
to collect baseline data to assess sulfur reagent consumption during
leaching, reported ranges of 7.4-12.3kg and 89.7-102.9kg of acid
consumption per tonne of mineral feed for sample BK003 and BK456,
respectively. The acid consumption results define too wide a range to
be conclusive and will be re-tested during future work.
A set of bench scale batch amenability leaching tests (BATs) were
carried out in duplicate on approximately 200gm aliquots from each of
the two samples to test amenability of the shale samples to leaching
and to determine the amount and suite of metals which might be
extracted (recovered) from the shale via bioleaching. The BAT tests
entailed leaching during 38 and 27 days of incubation for samples BK456
and BK003, respectively, utilizing the indigenous bio-organisms
previously harvested from the shale.
Test results for sample BK456 are tabulated below, consolidated from the
iterative studies as calculated by DNI based on analyses, weights or
volumes of the various solid and liquid fractions from the leaching
tests as reported by AITF. Previously announced results from similar
bioleaching tests completed by BRGM and the Acid Leaching tests carried
out under DNI's direction at Canadian analytical facilities are also
tabulated for comparison.
____________________________________________________________________
| Calculated Metals Extractions (recoveries) |
|____________________________________________________________________|
| |Bioleaching - AITF | Bioleaching - |Acid Leaching - DNI| |
| | (ARC) | BRGM | | |
|__|____________________|_______________|___________________| Best |
| | Sample BK456 ((1)) |Sample 09ASH004| Sample 09ASH004 ( |Recovery|
| | | ((2)) | (3)) |Achieved|
|__|____________________|_______________|___________________| |
| | per |per Solids|Biotic|Abiotic |36hr-30C| 24hr-50C | |
| |Solutions| |Tests | Tests | | | |
|__|_________|__________|______|________|________|__________|________|
|Mo| 34% | 30% | 16% | 3% | 28% | 51% | 51% |
|__|_________|__________|______|________|________|__________|________|
|Ni| 85% | 89% | 88% | 87% | 89% | 70% | 89% |
|__|_________|__________|______|________|________|__________|________|
|U | 100% | 94% | 88% | 82% | 84% | 67% | 100% |
|__|_________|__________|______|________|________|__________|________|
|V | 8% | 12% | 6% | 8% | 34% | 51% | 51% |
|__|_________|__________|______|________|________|__________|________|
|Zn| 100% | 85% | 84% | 84% | 88% | 70% | 100% |
|__|_________|__________|______|________|________|__________|________|
|Cu| 65% | 66% | na | 49% | 53% | 57% | 66% |
|__|_________|__________|______|________|________|__________|________|
|Co| 91% | 91% | 88% | 83% | 86% | 69% | 91% |
|__|_________|__________|______|________|________|__________|________|
|Cd| 100% | 98% | na | na | 93% | 71% | 100% |
|__|_________|__________|______|________|________|__________|________|
|Li| 25% | 22% | na | na | 45% | 58% | 58% |
|__|_________|__________|______|________|________|__________|________|
(1) Sample BK456 is a weighted composite of samples# 09ASH004, 09ASH005
and 09ASH006. Calculated metal extractions tabulated show results based
on aggregate metals extracted in all solution fractions as a percentage
of the head grade, compared with extractions calculated based on the
difference between head grade and aggregate metals remaining in all
solid (tails) fractions. Calculated extractions for U and Cd of 104%
and 102%, respectively, are stated as 100%; (2) BRGM test results
reiterated from DNI press Apr28/2010 and tabulated as rounded figures.
Abiotic test results from leaching in acidic conditions without
addition of bio-organisms shown for comparison with the biotic test
results; (3) DNI Acid Leaching results reiterated from DNI press
Mar4/2010, showing comparative results from tests conducted at
different temperatures leach duration.
To the extent that all of the leaching testwork completed to date
represent initial tests, the recoveries tabulated above represent
minimum recoveries achievable and are initial results to be optimized
during future additional testwork. The best recovery achieved to date
for the various metals is shown as a benchmark on which DNI is relying
for planning purposes, and as a benchmark of interim recoveries which
future work will endeavor to enhance.
Results for sample BK003 are not tabulated above given that they did not
meet acceptable mass balance thresholds and can only be regarded in
qualitative terms indicating that the suite of metals of interest can
be extracted from the shale, and that recoveries for Ni/U/Zn/Co/Cd are
considerably better than for Mo/V/Cu/Li.
Following bioleaching, one of the duplicate samples was further leached
in HCl 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. The test results indicate that while a small
fraction (1%-8%) of all dissolved metals, once leached from the shale,
are removed from the leaching solution through re-precipitation, a
considerable portion of Mo-V-Cu (at least approximately 47% of Mo, 58%
V and 19% Cu) once leached from the shale are lost to re-precipitation
correlated with abrupt changes in pH within the leaching solution. The
foregoing processes will be addressed during future testwork intended
to optimize test parameters to enhance recoveries of Mo-V-Cu.
DNI's leaching testwork over the past two years has confirmed collective
recoverability of traditional metals from the shale. The testwork,
however, also reported successful recoveries of additional metals of
value which are incidentally extracted from shale as co-products. These
co-products consist of specialty metals (Li, Sc, Th) and rare earth
elements including critical rare earths (Dy, Y, Tb, Eu and Nd). To the
extent that the leaching tests reported good recoveries of most of the
foregoing metals, they hold potential to add considerable previously
unrecognized value to the mineralized zones identified by DNI at the
Property.
Grades for specialty metals and rare earth elements (REE's) from DNI's
2010-2011 winter drilling program are summarized below (see also DNI
press Jul15/2011 for results for other metals), together with results
from historic drilling and head grades for samples BK456 and BK003
tested during bioleaching studies. Considering the excellent uniformity
of grades among all drill holes across the Buckton Mineralized Zone,
the tabulated results serve to characterize grades which can be
reasonably expected from the Zone.
__________________________________________________________________
|Hole or|Zone Width** (m) | Weighted Average Grade (ppm)*** |
|_______|_________________|________________________________________|
|Sample#| From-To |Width|Ce |Dy|Er|Gd|La|Nd|Pr|Sm|Y |Yb|Th|Sc|Li |
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|___|
|11BK01*| 46.6-66.9 |20.3 |85 |na|na|na|57|79|na|11|51|5 |10|12|56 |
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|___|
|11BK02*| 67.0-89.8 |22.8 |82 |na|na|na|50|73|na|10|51|5 |11|12|59|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|11BK03*| 41.2-61.0 |19.9 |77 |na|na|na|49|47|na|9 |40|3 |13|11|56|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|11BK04*| 54.5-68.0 |13.5 |73 |na|na|na|41|58|na|9 |39|4 |10|12|53|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|11BK05*| 61.9-74.5 |12.6 |74 |na|na|na|48|42|na|9 |41|4 |11|11|58|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|7BK01* |132.9-148.2|15.3 |84 |na|na|na|58|39|na|9 |62|6 |10|11|55|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|7BK03* |75.0-101.2 |26.2 |98 |na|na|na|66|45|na|10|74|7 |10|12|56|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|7BK05* | 76.8-95.2 |18.4 |90 |na|na|na|55|36|na|8 |55|6 |10|12|56|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|BK456* | na | 4 |111|16|9 |20|72|94|25|17|98|9 |8 |17|53|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|BK003* | na | 2 |55 |5 |2 |6 |25|28|9 |5 |22|2 |9 |7 |68|
|_______|___________|_____|___|__|__|__|__|__|__|__|__|__|__|__|__|
|m=metres; Eu 1-4 ppm; Tb 1-3 ppm |
|__________________________________________________________________|
___________________________________________________________________________________________
|Hole or|Zone Width** (m) | Weighted Average Grade (lb/st)*** |
|_______|_________________|_________________________________________________________________|
|Sample#| From-To |Width| Ce | Dy | Er | Gd | La | Nd | Pr | Sm | Y | Yb | Th | Sc | Li |
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|11BK01*| 46.6-66.9 |20.3 |0.17| na | na | na |0.11|0.16| na |0.02|0.10|0.01|0.02|0.02|0.11 |
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|_____|
|11BK02*| 67.0-89.8 |22.8 |0.16| na | na | na |0.10|0.15| na |0.02|0.10|0.01|0.02|0.02|0.12|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|11BK03*| 41.2-61.0 |19.9 |0.15| na | na | na |0.10|0.09| na |0.02|0.08|0.01|0.03|0.02|0.11|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|11BK04*| 54.5-68.0 |13.5 |0.15| na | na | na |0.08|0.12| na |0.02|0.08|0.01|0.02|0.02|0.11|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|11BK05*| 61.9-74.5 |12.6 |0.15| na | na | na |0.10|0.08| na |0.02|0.08|0.01|0.02|0.02|0.12|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|7BK01* |132.9-148.2|15.3 |0.17| na | na | na |0.12|0.08| na |0.02|0.12|0.01|0.02|0.02|0.11|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|7BK03* |75.0-101.2 |26.2 |0.20| na | na | na |0.13|0.09| na |0.02|0.15|0.01|0.02|0.02|0.11|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|7BK05* | 76.8-95.2 |18.4 |0.18| na | na | na |0.11|0.07| na |0.02|0.11|0.01|0.02|0.02|0.11|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|BK456* | na | 4 |0.22|0.03|0.02|0.04|0.14|0.19|0.05|0.03|0.20|0.02|0.02|0.03|0.11|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|BK003* | na | 2 |0.11|0.01|0.00|0.01|0.05|0.06|0.02|0.01|0.04|0.00|0.02|0.01|0.14|
|_______|___________|_____|____|____|____|____|____|____|____|____|____|____|____|____|____|
|m=metres; lb/st=pounds per short ton; Eu 0.002-0.008 lb/st; Tb 0.002-0.006 lb/st |
|__________________________________________________________________________________________|
*Drill holes 11BK01-11BK05 drilled by DNI. Drill holes 7BK01, 7BK03 and
7BK05 are historic hole. Drill holes tabulated are from drilling over
the Buckton Mineralized Zone. Samples BK456 and BK003 are surface
trenching samples tested during bioleaching tests. **All holes are
vertical and widths reported are true widths; Drill core sampled at a
standard 0.5m interval; Data for historic holes based on DNI's
verification analytical program which re-sampled historic drill core at
lengths averaging 3.8m; Zone width represents true thickness of the
flat-lying Second White Speckled Shale Formation which hosts the
polymetallic mineralization within its contacts. ***Analyses are
weighted averages over the entire intercept of the Speckled Shale
Formation based on lithogeochemical characterization; Data for historic
drill holes from DNI's verification analytical program; lb/st=pounds
per short ton; na=not available; Analyses by Activation Labs, Ancaster,
ON; REE analyses by ICP or MS after total sample digestion; In addition
to analytical blanks and standards utilized by Actlabs as part of its
analytical quality assurance and quality control ('QA/QC') protocols,
DNI's QA/QC parameters consist of duplicate analyses as follows: one
matrix-matched analytical blank per 10 samples, one duplicate analysis
of pulverized pulp per 10 samples, and one duplicate subsample from
coarse fraction per 10 samples.
Considering the uniformity of grades among all drill holes across the
Buckton Mineralized Zone, the tabulated results above serve to
characterize grades which can be reasonably expected from this Zone
which holds potential for hosting 1.4-1.5 billion short tons of
polymetallic mineralization extending over 26 square kilometers and is
open in three directions. If amortized over the Buckton Mineralized
Zone, the apparently modest grades tabulated are significant and
represent an immense in-situ metallic budget of recoverable specialty
metals and REE's ranging in the millions of pounds for any given metal.
Sufficient drilling has been completed over a portion of the Buckton
Mineralized Zone to classify a portion of it to an inferred resource
relating to base metals and Uranium. A similar study relating to
specialty metals and REE's will follow later in the year.
Calculated recoveries of specialty metals and REE's based on results
from the AITF bioleaching testwork studies are summarized below for
sample BK456.
______________________________________________________________________
|Calculated Bioleaching Recoveries for Specialty Metals* - Sample BK456|
|______________________________________________________________________|
| |Ce |Dy |Er |Eu |Gd |La |Nd |Pr |Sm |Tb | Y |Yb |Th**|Sc |Li |
|_________|___|___|___|___|___|___|___|___|___|___|___|___|____|___|___|
|per |77%|92%|88%|83%|88%|66%|66%|58%|91%|97%|90%|90%|100%|51%|25%|
|Solutions| | | | | | | | | | | | | | | |
|_________|___|___|___|___|___|___|___|___|___|___|___|___|____|___|___|
|per |68%|92%|92%|86%|90%|70%|78%|76%|83%|92%|92%|64%|74% |57%|22%|
|Solids | | | | | | | | | | | | | | | |
|_________|___|___|___|___|___|___|___|___|___|___|___|___|____|___|___|
| *calculated by DNI based on analyses, weights or volumes as reported|
| by AITF|
| ** Calculated extraction of 111% (per solution) for Th stated as 100%|
|______________________________________________________________________|
Despite the general availability of commodity price quotes for specialty
metals and REE's, given lack of transparency in their respective
commodity markets, assessment of the economic impacts that these metals
might have as co-products on future development DNI's polymetallic
shales cannot be determined at this time. The grades and incidental
recoverability of these metals are, however, material to any potential
production scenario envisaged by DNI for continuing exploration and
development of the six mineral systems identified at the Property as a
long term source of a variety of metals. The foregoing results compel
DNI to broaden scope of its future testwork to actively focus on
specialty metals and REE's recoveries alongside the base metals of
interest which have so far been DNI's primary focus.
General Update of Work In Progress:
A resource study over a portion of the Buckton Mineralized Zone is
nearly completed and will be announced shortly. Plans are to augment
and amend the study with a stand-alone resources study to estimate
specialty metals and REE's resources, and related metallic budget
hosted within the resources being delineated over a portion of the
Zone.
Bioleaching testwork is in progress on composite samples from the past
winter's drilling. This work will substantially repeat work completed
to date on surface trenching samples, and is slated for completion at
the end of the year. Other work is in its planning stages to expand and
optimize leaching parameters.
Permitting applications have been submitted in advance of a planned
winter drilling to probe projected extensions of the Buckton
Mineralized Zone and to commence initial drilling over the Buckton
South Zone which may represent its southerly extension or an entirely
separate similar Zone.
DNI continues to focus its efforts on its polymetallic black shale
Properties in Alberta, and on its carried interest in the diamond
discovery on its Attawapiskat Property, Ontario.
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. All detailed data
underlying test results reported herein are included in Alberta Mineral
Assessment Report#MIN20100017.
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: 60,100,284
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 MDS&A's, all of which are available from SEDAR
and on its website.
To view this news release in HTML formatting, please use the following URL: http://www.newswire.ca/en/releases/archive/September2011/08/c9665.html
DNI Metals Inc. - Shahe Sabag, President & CEO or Denis Clement, Chairman - 416-595-1195
email ir@dnimetals.com. Also visit www.dnimetals.com