Seafield Reports Gold Recoveries of Over 90% from Metallurgical Test Work on the Miraflores Deposit, Quinchia District, Colombia
TORONTO, ONTARIO -- (Marketwire) -- 03/26/12 -- Seafield Resources Ltd. ("Seafield" or "the Company") (TSX VENTURE: SFF) is pleased to report the completion of an extensive scoping-level metallurgical testing program for its Miraflores Deposit, Quinchia District, Colombia. This program was designed and supervised by SRK Consulting in Denver (SRK) on behalf of Seafield. Test work was conducted by Inspectorate Exploration & Mining Services, Ltd. (Inspectorate) in Richmond, British Columbia, Canada.
Highlights:
-- All test composites treated were highly amenable to gold recovery by
conventional process flow sheets;
-- All test composite samples contained significant amounts of coarse gold
amenable to gravity concentration. Gold recoveries of 40 to 75% into
gravity cleaner concentrates containing over 2000 g/t were obtained;
-- Three flow sheets were evaluated in Miraflores' metallurgical testing
program:
1. Gravity concentration followed by cyanide leaching of gravity
tailings resulted in overall gold recoveries ranging from 86 to 89%;
2. Gravity concentration followed by gold flotation from the gravity
tailing resulted in gold recoveries ranging from 95 to 97.5%;
3. Gravity concentration followed by gold flotation from the gravity
tailing and cyanide leaching of the flotation concentrate resulted
in gold recoveries ranging from 89 to 93 %;
-- Gold recovery was found to be fairly independent of grind size in the
nominal P80 range of 150um, 100um, 74um, and 53um.
"We are delighted to achieve over 90% gold recovery rates in the metallurgical testing program," stated Seafield's President and CEO, Cesar Lopez. "Additional studies are underway to advance the project to prefeasibility stage and we look forward to continue validating the viability of our Miraflores Deposit."
Sample Characterization:
Test work was performed on 77 samples selected from fifteen quarter-core drill holes from the Miraflores Deposit and 13 channel-samples from argillaceous vein structures taken from the existing underground workings. Due to the presence of significant quantities of coarse gold, the sample intervals were selected to approximate the average grade of each rock type (geological unit) in the deposit. Three representative rock type composites were prepared for testing: White breccia, Green breccia, and Basalt. An additional composite sample of argillaceous rock type was prepared to represent the central part of the high-grade veins.
The breccias and basalt samples were selected to represent the bulk of the mineralization with the high-grade intervals removed. In addition, three composite samples of white breccia, combined with varying amounts of the argillaceous ore composite, were prepared to represent areas within the breccia pipe containing argillaceous structures of varying widths.
Table 1. Characterization of Mineralized Composite Samples
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Weight Average Average
Sample (Kg) Au, g/t Ag, g/t
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Measured Calculated Measured
(1) (2) (1)
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White Breccia 139 0.68 1.48 2.2
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Green Breccia 59 0.54 0.98 3
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Basalt 51 0.63 0.57 2.2
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Argillaceous Structure 41 22.31 26.4 78.5
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Source: Inspectorate Report
(1) Average of triplicate splits and metallics assays
(2) Average of calculated heads from metallurgical tests
A sample from each of the four composites was examined by Process Mineralogical Consulting Ltd. to characterize the minerals present, along with estimated mineral abundance, grain size, association and liberation data. The non-opaque minerals contained in these composites included: quartz, chlorite, actinolite, feldspar, montmorillonite, calcite, almandine andpyroxene. The white breccia, green breccia and basalt composites contained only trace amounts of fine grained chalcopyrite, sphalerite and galena. The argillized composite contained chalcopyrite, sphalerite and galena occurring as ternary particles with each other, or with non-opaque minerals and pyrite. Visible gold was observed in the argillized composite.
Metallurgical Summary:
Initial metallurgical test work was conducted to evaluate the effect of grind size, ranging from P80 150 - 53 microns, on gravity separation, gold flotation and cyanide leaching of Miraflores ores. Once optimum process parameters were established for the different unit operations, the three flow sheet options were evaluated.
Gold recovery results for the different flow sheets studied are presented in Table 2. As indicated above, the Miraflores samples are highly amenable to all three process options evaluated: i) gravity plus cyanidation option, the average gold recovery is 88.2%; ii) gravity plus flotation option, the average recovery is 96.4%; and iii) gravity plus flotation and cyanidation of the flotation rougher concentrate option, the average gold recovery is 91.4%.
Bond grindability testwork demonstrated that the green and white breccias have a Bond Ball Mill Work Index of 19.5 kWh/mt.
Acid-Base Accounting (ABA) testing conducted on green and white breccia flotation tailings revealed a net neutralization potential of 50-71 kg CaCO3 equivalent per tonne of sample, indicating that these breccia materials will not be potential acid producers.
The information presented in this news release is a summary of the report titled, "Metallurgical Testing on Samples From Miraflores Deposit-Quinchia, Colombia", issued by Inspectorate on March 16, 2012.
Table 2. Summary of Results on Miraflores Test Composites
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Average
Item Au Recovery %
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Green Breccia
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Gravity + Cyanidation 85.9
Gravity + Flotation 95.6
Gravity + Flotation + Cyanidation (1) 90
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White Breccia
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Gravity + Cyanidation 89.2
Gravity + Flotation 96.4
Gravity + Flotation + Cyanidation (1) 92.8
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Basalt
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Gravity + Cyanidation 89.4
Gravity + Flotation 95
Gravity + Flotation + Cyanidation (1) 89.1
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95% White Breccia + 5% Argillic Blend
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Gravity + Flotation 96.7
Gravity + Flotation + Cyanidation (1) 91
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85% White Breccia + 15% Argillic Blend
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Gravity + Flotation 98.3
Gravity + Flotation + Cyanidation (1) 94.1
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Note:
(1) Overall gold recoveries for each sample type were estimated based on
assuming that the 88% gold cyanidation extraction, obtained for flotation
concentrates produced from green and white breccias, also applies to the
flotation concentrates produced from basalts and argilleous structures.
Corporate Update:
Seafield is also pleased to provide an update on its exploration programs for 2012 at its Quinchia Gold Project:
- Underground Drifting to Commence at the Miraflores Deposit:
The Company plans to extend the existing tunnel at its Miraflores Deposit
by 150 metres to facilitate eventual underground drilling targeted at the
high-grade structures in the breccia pipe. Underground drilling is
expected to commence in Q4 2012.
- Regional Exploration Program to Identify More Targets:
Strong geological evidence of a NNW mineralization trend identified in
the region supports the speculation that additional anomalies exist in
the Company's concession. To date, 80% of Seafield's 6,757-hectare
property remains unexplored. Seafield plans to initiate regional
exploration efforts north of the Miraflores and Dosquebradas Deposits
with an aim to find additional drilling targets (see Map 1).
- Baseline Environmental Studies:
In preparation for the development of the Miraflores Deposit, Seafield
has initiated baseline environmental studies designed to identify key
information pertaining to social demographics, archaeology, surface water
and weather conditions in the district. The studies are underway and are
expected to be completed by Q4 2012.
- Streamlining Exploration Efforts:
In 2012, 1,676 metres of diamond core drilling has been completed at
Dosquebradas. The Company plans to focus its ongoing efforts on advancing
the Miraflores Deposit and executing its regional exploration program. A
further drill program at Dosquebradas will be reassessed in the future.
To view Map 1. Seafield's Quinchia Property, please visit the following link: http://media3.marketwire.com/docs/777027_map.pdf
Review by Qualified Person, Quality Control and Reports
The results of the Company's metallurgical testing program presented in this news release have been reviewed, verified and compiled by Eric Olin, MSc, MBA, RM-SME, Principal Process Metallurgist of SRK in Denver, Colorado. Mr. Olin has over 30 years' experience in the minerals industry with extensive consulting, plant operations, process development, project management and research & development experience with base metals, precious metals, ferrous metals and industrial minerals.
About Seafield Resources Ltd.
Seafield Resources Ltd. is a mineral exploration company focused on fast-tracking its advanced-stage gold project towards production in Colombia. Seafield's 100%-owned 6,757-hectare Quinchia Gold Project is located in Department of Risaralda, Colombia. Seafield's Miraflores Deposit currently has a NI 43-101 compliant Measured and Indicated resource of 1,925,542 ounces gold at 0.8 g/t and an Inferred resource estimate of 103,043 ounces gold at 0.6 g/t. Additionally, the Company recently announced an NI 43-101 compliant resource estimate for its Dosquebradas Deposit, also part of the Quinchia Gold Project, with Inferred resource estimate totalling 920,772 ounces gold at 0.5 g/t. Seafield Resources Ltd. trades its shares on the Toronto Venture Exchange (TSX-V) under the symbol SFF and in the United States using CUSIP 81173R101. For more details on the Company, please visit www.sffresources.com.
Forward-Looking Statement
This news release includes certain "forward-looking statements" within the meaning of that phrase under Canadian securities laws. Without limitation, statements regarding potential mineralization and resources, exploration results, and future plans and objectives of the Company are forward looking statements that involve various degrees of risk. Forward-looking statements reflect management's current views with respect to possible future events and conditions and, by their nature, are based on management's beliefs and assumptions and subject to known and unknown risks and uncertainties, both general and specific to the Company. Although the Company believes the expectations expressed in such forward-looking statements are reasonable, such statements are not guarantees of future performance and actual results or developments may differ materially from those in our forward-looking statements. The following are important factors that could cause the Company's actual results to differ materially from those expressed or implied by such forward looking statements: changes in the world wide price of commodities, general market conditions, risks inherent in exploration, risks associated with development, construction and mining operations, the uncertainty of future profitability and the uncertainty of access to additional capital. Additional information regarding the material factors and assumptions that were applied in making these forward looking statements as well as the various risks and uncertainties we face are described in greater detail in the "Risk Factors" section of our annual and interim Management's Discussion and Analysis of our financial results and other continuous disclosure documents and financial statements we file with the Canadian securities regulatory authorities which are available at www.sedar.com. The Company undertakes no obligation to update this forward-looking information except as required by applicable law. The Company relies on litigation protection for forward-looking statements.
Neither 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.
Contacts:
Seafield Resources Ltd.
David MacMillan
Investor Relations
(416) 361-3434 ext. 202
dmacmillan@sffresources.com
www.sffresources.com
