SEMAFO: Over 95% Gold Recovery at Siou in Both Oxide and Sulphide Rock
January 28 2013 - 9:02AM
Marketwired Canada
SEMAFO Inc. (TSX:SMF)(OMX:SMF) announced today that metallurgical test work
performed on high-grade Siou zone samples revealed gold recovery rates of over
95%. Testing on the Siou zone, located approximately 15 kilometers from the Mana
mill, was conducted using a standard carbon-in-leach ("CIL") process and results
represent higher recovery rates than any deposit found at Mana to date.
"We are thrilled with the recovery results at Siou. The exceptionally high
recovery rates within the sulfide mineralization demonstrate that non-refractory
mineralization also occurs outside the Wona-Kona complex," said Benoit
Desormeaux, SEMAFO's President and Chief Executive Officer. "As part of our
objective to focus exploration on organic growth at Mana in the vicinity of the
mill, we intend to add the Siou zone to the 2012 resource estimate and to
reserves in 2013. We hope to begin ore extraction from the zone in late 2014 or
early 2015."
Following the delineation program completed in the third quarter of 2012, a
series of Siou mineralized intervals across the main zone were selected for
testing in order to establish the metallurgical characteristics of the deposit.
Based on visual core description and drill hole assay results, the deposit was
already known to contain significant amounts of free visible gold grains
although rarely larger than 0.5 millimeters. In addition, no relationship
between the sulfide content and gold grades could be identified. Finally, gold
was almost exclusively associated with quartz veins.
Delineation drilling and permitting at Siou remain a priority for the
Corporation in 2013 in an effort to fast-track the deposit towards production.
Two core rigs are currently active on the Siou zone, both along strike and at
depth to establish the continuity of the mineralization. More comprehensive
information about the metallurgical test work can be found in Appendix I of this
press release.
Sylvain Duchesne P. Eng., SEMAFO's Mineral Processing Engineer and a Qualified
Person under NI 43-101 has reviewed and approved the technical information
related to this news release.
About SEMAFO
SEMAFO is a Canadian-based mining company with gold production and exploration
activities in West Africa. The Corporation currently operates three gold mines:
the Mana Mine in Burkina Faso, the Samira Hill Mine in Niger and the Kiniero
Mine in Guinea. SEMAFO is committed to evolve in a conscientious manner to
become a major player in its geographical area of interest. SEMAFO's strategic
focus is to maximize shareholder value by effectively managing its existing
assets as well as pursuing organic and strategic growth opportunities.
CAUTION CONCERNING FORWARD-LOOKING STATEMENTS
This press release contains forward-looking statements. Forward-looking
statements involve known and unknown risks, uncertainties and assumptions and
accordingly, actual results and future events could differ materially from those
expressed or implied in such statements. You are hence cautioned not to place
undue reliance on forward-looking statements. Forward-looking statements include
words or expressions such as "demonstrate", "objective", "growth", "intend",
"hope", "priority", "towards", and other similar words or expressions. Factors
that could cause future results or events to differ materially from current
expectations expressed or implied by the forward-looking statements include the
ability to demonstrate that non-refractory mineralization also occurs outside
the Wona-Kona complex, the ability to focus exploration on organic growth at
Mana in the vicinity of the mill, the ability to add the Siou zone to the 2012
resource estimate and to reserves in 2013, the ability to begin ore extraction
from the zone in late 2014 or early 2015, the ability to bring the deposit
towards production, the ability to execute on our strategic focus, fluctuation
in the price of currencies, gold or operating costs, mining industry risks,
exploration uncertainties, permitting risks, uncertainty as to calculation of
mineral reserves and resources, delays, political and social stability in Africa
(including our ability to maintain or renew licenses and permits) and other
risks described in SEMAFO's documents filed with Canadian securities regulatory
authorities. You can find further information with respect to these and other
risks in SEMAFO's 2011 Annual MD&A and 2011 Annual Information Form as updated
in our 2012 First Quarter MD&A, 2012 Second Quarter MD&A and 2012 Third Quarter
MD&A and other filings made with Canadian securities regulatory authorities and
available at www.sedar.com. These documents are also available on our website at
www.semafo.com. SEMAFO disclaims any obligation to update or revise these
forward-looking statements, except as required by applicable law.
Appendix I
The selected samples of the Siou mineralized zone ensured both spatial and grade
representation as well as enabled the comparison of oxidized and fresh rock
characteristics. Each individual sample represents one kilogram of coarse reject
of the original reverse-circulation drill sample.
Based on this information, the mineralized zone was divided into four quadrants
as follows:
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Total Weight CIL Calculated CIL
Area Description (Kg) Head Grade Recovery
---------------------------------------------------------------------------
MSO Oxidized part of the south half 10 4.77 g/t Au 98%
of the zone
MSS Sulfide part of the south half of 8 7.54 g/t Au 98%
the zone
MNO Oxidized part of the north half 8 3.16 g/t Au 95%
of the zone
MNS Sulfide part of the north half of 10 6.70 g/t Au 96%
the zone
---------------------------------------------------------------------------
TOTAL 36 5.57 g/t Au 97%
---------------------------------------------------------------------------
The samples were collected and sent to the SGS laboratories in South Africa to
perform metallurgical tests. Work conducted on the samples included the
following tests.
-- Bond Ball Working Index (BBWI)
-- Lixiviation Carbon-in-Leach (CIL)
-- Gravity Recoverable Gold (GRG)
-- Specific Gravity (SG)
-- Acid-Base Accounting (ABA) - Results pending
-- Mineralogical Study - Results pending
Lixiviation results indicated excellent gold recovery using standard CIL
processing. Lixiviation parameters used to conduct the tests were similar to
those used in Mana's CIL process (grind, cyanide consumptions, pH etc.). Overall
CIL laboratory test work showed consistent recovery above 95% for all
mineralization types including oxides and sulphides, which indicate a high
proportion of free gold within the mineralized samples. In addition, results
demonstrated recovery consistency throughout the mineralized deposit including
between oxide and sulfide mineralization types.
Siou's GRG results were similar with regard to free gold by demonstrating
excellent gold recovery potential of between 75% and 87% via gravity
concentration alone for MNO and MSS samples, respectively.
Test work was also performed to evaluate a combination of two processes, gravity
concentration followed by CIL to determine if combined recovery rates would
improve compared to the CIL process alone. Overall results showed no significant
gain.
BBWI performed on various samples is typical of Wona results, with values
between 7.1 kWh/t and 11.5 kWh/t on soft oxide mineralization and between 14.0
kWh/t and 16.8 kWh/t on medium-hard sulphide mineralization.
Composite samples were also taken to perform trace metal analyses with overall
results showing no refinery concerns.
FOR FURTHER INFORMATION PLEASE CONTACT:
SEMAFO
Robert LaValliere
Vice-President, Investor Relations
Cell: +1 (514) 240 2780
robert.lavalliere@semafo.com
Sofia St Laurent
Communications & Investor Relations
Tel. local & overseas: +1 (514) 744 4408
North America Toll-Free: 1 (888) 744 4408
sofia.stlaurent@semafo.com
www.semafo.com
Maria Bang
Brunswick Group Stockholm
+46 (8) 410 32 189
mbang@brunswickgroup.com