Carlisle Goldfields Reports Positive Metallurgical, Environmental, and Grindability Results from MacLellan Mine Project
TORONTO, ONTARIO -- (Marketwire) -- 12/19/11 -- Carlisle Goldfields Limited (TSX: CGJ) ('Carlisle' or the 'Company') announces positive scoping-level metallurgical, environmental, and grindability results from its 100%-owned MacLellan Mine Project in northwest Manitoba near the town of Lynn Lake.
Highlights:
-- Achieved gold and silver recovery of 98% and 92%, respectively using
conventional Carbon-in-Pulp (CIP) leach processing techniques, including
a flotation leach circuit.
-- Tailings waste material is not acid-generating and is in fact acid
neutralizing.
-- The bond rod and ball mill work indices were 15.1 and 12.4 kWh/t,
respectively.
'I am extremely pleased with these initial results,' stated Bruce Reid, President and Chief Executive Officer of Carlisle. 'They demonstrate that high gold and silver recoveries are achievable using conventional Carbon-in-Pulp processing techniques. Furthermore, test work shows that this ore's tailings are not acid generating but, are in fact, acid neutralizing. In addition, I am pleased to report that the grindability test work was favourable for all methods tested.'
Metallurgical Results
Initial metallurgical testing of composite samples indicates that the MacLellan Mine Project gold and silver mineralization is amenable to many conventional processing techniques, the results are summarized below:
Projected Recovery
Circuit Gold Silver
Gravity 41.5% 11.5%
Whole Ore Flotation 88.4% 83.8%
Whole Ore Leach 96.0% 52.1%
Gravity and Flotation 88.7% 78.3%
Gravity and Leach 95.1% 48.9%
Flotation and Leach 97.5% 92.1%
Gravity, Flotation and Leach 97.5% 90.7%
Initial metallurgical test results indicate that leaching achieves excellent gold recoveries of up to 96%. Cyanide and lime consumption are both moderate to low, and averaged 0.9 kilograms per tonne of material ('kg/t') and 0.4 kg/t, respectively. Preliminary leach kinetic studies also suggest that a Carbon-in-Pulp process is likely to be the most suitable technique for treating the MacLellan Mine Project ore.
When combined with other processing techniques, the most favourable conceptual flow sheet for gold and silver recovery was derived through the flotation and leaching of the flotation tail, which achieved gold and silver recoveries of 97.8% and 92.1%, respectively. Whole ore leaching and gravity followed by leaching also demonstrated strong potential for conceptual flow sheet designs.
This scoping-level testing will be followed up by more detailed metallurgical and mineralogical studies for the development of an optimized processing flow sheet as part of a preliminary feasibility study that the Company expects to initiate and complete in 2012. Future test work will have an emphasis on improving silver recoveries.
Environmental Testing
Flotation tailings produced from the metallurgical testing process were determined to have a low potential for acid generation and are in fact acid-neutralizing. The Company plans to conduct additional test work to determine how best utilize the acid neutralizing nature of the tailings from the MacLellan Mine Project.
Grindability Testing
Composite samples were also subjected to grindability testing and the results are summarized in the following table:
Parameter Index
Bond Abrasion Index 0.158
Bond Rod Mill Work Index 15.1 kWh/tonne
Bond Ball Mill Work Index 12.4 kWh/tonne
The results indicate that the composite samples tested are in the medium to hard range. The Company plans to conduct additional grindability test work to further characterize the mineralized material from the MacLellan Mine Project.
Sample Preparation
The preliminary metallurgical test work program was conducted by SGS Mineral Services under the supervision of Senior Metallurgist, Sarath Ratnayake, and Lead Metallurgist, Jake Lang.
The preliminary test work was completed using a bulk sample of approximately 220 kilograms ('kg'), comprised of 43 mineralized core samples taken from the centre of the MacLellan Mine Project orebody.
The samples were stage-crushed to -3/4', blended and a 5 kg test charge was split out for the Bond Abrasion Index Test. The remainder was stage crushed to -1/2', blended and a 15 kg test charge was split out for the Bond Rod Mill Work Index Test and 75 kg was separated for metallurgical testing. The 75 kg test charge was then stage crushed to -6 mesh, blended and a 10 kg test charge was split out for the Bond Ball Mill Work Index Test. The rest was crushed to -10 mesh, blended and split out into 2 kg test charges. The average grade of the composites for metallurgical testing was 2.01 grams of gold per tonne of material ('g/t Au') and 3.59 grams of silver per tonne of material ('g/t Ag').
QA/QC
This news release was supervised by Rick Adams, P. Eng., Chief Operating Officer, who is a qualified person as defined by National Instrument 43-101 ('NI 43-101') with more than 40 years of experience in mine development and operations. All technical information contained in this news release has been reviewed and approved by Rick Adams. All the information contained herein is in compliance with NI 43-101.
Exploration programs are carried out under the supervision of Peter Karelse, P.Geo., Vice President of Exploration, who is a qualified person as defined by NI 43-101 with more than 25 years of experience in gold exploration and development.
About Carlisle: Carlisle Goldfields Limited is a Canadian-based gold exploration and development company, focused on development of its mining leases and claims in the Lynn Lake Greenstone Belt of Northern Manitoba, covering approximately 20,000 hectares which include the former MacLellan Gold mine and two other former producing gold mines as well as numerous other historically identified Gold Zones all within close proximity of the town of Lynn Lake.
In mid-2010 (see News Release dated July 26, 2010), Carlisle announced a NI 43-101 compliant Resource Estimate on the MacLellan Gold Property in Lynn Lake, Manitoba, which included Total Open Pit and Underground Resources having increased to 5.3 million tonnes containing 658,200 ounces of AuEq (Gold Equivalent) at an average grade of 3.85 g/t AuEq (3.59 g/t Au and 19.3 g/t Ag) in the Measured and Indicated categories and 4.4 million tonnes containing 506,200 ounces of AuEq at an average grade of 3.56 g/t AuEq (2.9 g/t Au and 42.4 g/t Ag) in the Inferred category. The current Measured and Indicated Categories represent 55% of the total resource tonnage.
This press release does not constitute an offer to sell or solicitation of an offer to buy the securities in any jurisdiction. The Common Shares and other securities of the Company have not been and will not be registered under the United States Securities Act of 1933 and may not be offered or sold in the United States absent an applicable exemption from the registration requirements.
Except for statements of historical fact contained herein, the information in this press release may constitute 'forward-looking information' within the meaning of Canadian securities law. Other than statements of historical fact, all statements are 'Forward-Looking Statements', including drilling plans and anticipated dates for reports, that involve various known and unknown risks and uncertainties and other factors. There can be no assurance that such statements will prove accurate. Results and future events could differ materially from those anticipated in such statements. Readers of this press release are cautioned not to place undue reliance on these 'Forward-Looking Statements'. Except as otherwise required by applicable securities statutes or regulation, Carlisle expressly disclaims any intent or obligation to update publicly forward- looking information, whether as a result of new information, future events or otherwise.
Neither IIROC nor the TSX accepts responsibility for the adequacy or accuracy of this release.
Contacts:
Carlisle Goldfields Limited
Bruce Reid
President and Chief Executive Officer
647-500-4495
br@carlislegold.com
Carlisle Goldfields Limited
Carl McGill
Vice President, Corporate Development
416-278-8406
cmcgill@carlislegold.com
Carlisle Goldfields Limited
2702 - 401 BAY STREET
TORONTO, ONTARIO, CANADA
info@carlislegold.com
www.carlislegold.com
