MONTREAL, QUEBEC--(Marketwire - Jan. 28, 2013) - SEMAFO Inc. (SMF.TO)(SMF.ST) 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.
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.
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:
|Area||Description||Total Weight |
|CIL Calculated |
|MSO||Oxidized part of the south half of the zone||10||4.77 g/t Au||98%|
|MSS||Sulfide part of the south half of the zone||8||7.54 g/t Au||98%|
|MNO||Oxidized part of the north half of the zone||8||3.16 g/t Au||95%|
|MNS||Sulfide part of the north half of the zone||10||6.70 g/t Au||96%|
|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.