Initial Metallurgical Testing Returns High Gravity Recoveries of Over 80% Gold
VANCOUVER, BRITISH COLUMBIA -- (Marketwired) -- 05/16/13 -- Golden Reign Resources Ltd. (TSX VENTURE: GRR) (the "Company" or "Golden Reign") is pleased to announce initial metallurgical test results for its high-grade, near-surface San Albino Gold Deposit located in Nueva Segovia, Nicaragua. Metallurgical test work was performed by Inspectorate Exploration & Mining Services Ltd. ("Inspectorate"), of Richmond, British Columbia.
Highlights
-- Extremely high gravity recoveries of 80.2 to 84.4% gold were achieved on
composite samples A through C at a grind target P80 of 100 microns,
indicating the presence of significant amounts of coarse gold amenable
to gravity concentration.
-- Strong gold recoveries from sulphide flotation on all composite samples
ranged between 76.6 to 85.5% at a grind target of P80 of 75 microns
after 8 minutes of flotation.
-- The combination of gravity and flotation recovery methods is expected to
produce high overall gold recoveries.
-- The next phase of metallurgical testing, currently underway, is
sequential (full stream) testing of composites to develop an optimum
flow sheet for the mineralization. A test has been designed to obtain
the best possible combined recovery rates, utilizing gravity and
flotation conditions to optimize recovery from both oxidized and non-
oxidized mineralization.
Metallurgical Test Results
Initial test work, comprising gravity concentration, sulphide flotation and cyanide leaching, was conducted on four composite samples to determine gold and silver recovery rates and the optimal recovery method.
Three composite samples, A through C, represent sulphide material from drill core. Samples A and B, represent composite samples of drill core from each of the Arras and San Albino quartz vein material, respectively. Sample C represents country rock (schists) from the hanging and footwall of both main mineralized quartz veins - Arras and San Albino. Composite Sample D represents Arras vein material collected from trenches. The head grades of each sample are as follows:
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Head Assay on Composite Sample
Summary of Results
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Element Unit Composite A Composite B Composite C Composite D
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Gold (metallic screen) g/t 30.51 15.64 6.09 5.11
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Gold (fire assay) g/t 29.86 13.66 6.25 3.91
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Silver g/t 30.50 29.80 6.70 15.20
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Specific gravity g/cm3 2.79 2.84 2.76 2.68
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The metallurgical work performed on the samples included:
Gravity concentration. A 2 kilogram sample of each composite sample was ground to 80% passing 200 microns and 80% passing 100 microns then fed through a laboratory Knelson concentrator in three stages to simulate a continuous concentrator for gold and silver recovery. Results for composite samples A to C were impressive, with 69.2 to 71.2% gold recovery after just a single pass at 100 microns and gold recovery ranging from 80.2 to 84.4% after three passes at 100 microns. Recovery of gold for composite sample D was lower, at just under 52%, possibly due to the gold being too fine to recovery via gravity methods.
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Gold Gravity Recovery (%), per gravity test product
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Composite number A B C D
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Grind size (um) 200 100 200 100 200 100 200 100
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Total concentrate 77.9 84.4 70.6 81.6 70.4 80.2 51.8 51.2
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Calculated head 30.19 28.43 15.04 15.93 6.17 5.62 5.31 5.20
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Measured head 29.86 29.86 13.66 13.66 6.25 6.25 3.91 3.91
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Gravity recoveries of silver ranged from 51.4 to 68.6%, at 100 microns and from 58.7 to 67.9% at 200 microns for composite samples A through C, and were found to be inconsistently sensitive with respect to grind size.
Sulphide flotation. Rougher floatation tests were conducted on each composite sample at three different grinds, targeting a P80 of 149, 106 and 75 microns, over a total of four 2-minute stages. All composite samples responded well to flotation. Gold recoveries ranged from 76.6 to 85.5% at a target grind of P80 75 microns. Silver recoveries were in the range of 60 - 69%. Results indicate that the combination of gravity and flotation recovery methods could produce high overall recoveries. Sequential (full stream) testing of composites is currently underway.
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Gold Recovery (%), per sulphide flotation (87 microns grind size)
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Composite number A B C D
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Element Gold Silver Gold Silver Gold Silver Gold Silver
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Flotation
Recovery 80.5 69.6 85.5 69.0 76.5 31.5 81.5 65.2
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Cyanide leaching. A standard diagnostic leach was conducted on all composite samples. Samples A, B and D contained cyanide-soluble gold in the range of 78.6 to 89.3%. Sample C results were 43.9%. Testing was done using 20 g/L activated carbon as a Carbon-in-leach (CIL) bottle roll leach. Direct cyanide leaching proved to be less effective. The best recoveries were from composite D, collected from trench samples, as all of the graphite and sulphide materials were leached and oxidized, rendering cyanide leaching more effective. All of the other samples had some graphite and sulphides which scavenged the cyanide solution and reduced recoveries. The graphite content in composite C, which is composed primarily of the country rock (graphitic schist), scavenged the cyanide and made the leach less effective. A procedure to remove the graphite prior to leaching, such as gravity concentration or flotation, will improve recoveries significantly.
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Gold Recovery (%), per Diagnostic Cyanide Leach (CIL)
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Composite number A B C D
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Element Gold Silver Gold Silver Gold Silver Gold Silver
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Cyanide Soluble
(%) 81.9 75.8 78.6 54.4 43.9 55.3 89.3 88.6
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Second Phase - Metallurgical Testing Currently Underway
The next phase of metallurgical testing, currently underway, is sequential (full stream) testing of composites to develop an optimum flow sheet for the mineralization. Inspectorate has designed a test to obtain the best possible combined recovery rates. It will use gravity and flotation conditions to optimize recovery from both oxidized and non-oxidized mineralization. Inspectorate states, "With the high recoveries seen in both gravity and flotation and looking at the tailings analysis, these two processes will complement each other very well and should produce some very high combined recoveries. We could upgrade the concentrates to a very high grade for direct smelting, or do intensive leaching (after regrinding) on the gravity and rougher concentrates. The data from the combined tests will demonstrate the highest metals recovery we can get out of the mineralization without using cyanide".
Qualified Person
John M. Kowalchuk, P.Geo, a geologist and Company qualified person (as defined under NI 43-101) has read and approved the technical information contained in this news release on behalf of the Company.
On behalf of the Board,
Kim Evans, CGA, President & CEO
About Golden Reign:
Golden Reign Resources Ltd. is a publicly listed (TSX VENTURE: GRR) mineral exploration company engaged in exploring the San Albino-Murra Property and the El Jicaro Property, both of which are located in Nueva Segovia, Nicaragua.
The Company's land package comprises 13,771 hectares (138 km2) of highly prospective ground. Hundreds of historical mines and workings exist within the Corona de Oro Gold Belt, which is approximately 3 kilometres wide by 20 kilometres long and spans the entirety of the Company's land package.
For additional information please visit our website at www.goldenreign.com and SEDAR www.sedar.com.
Forward-Looking Statements: Some of the statements contained herein may be forward-looking statements which involve known and unknown risks and uncertainties. Such forward-looking statements are subject to a variety of risks and uncertainties which could cause actual events or results to differ materially from those reflected in the forward-looking statements, including, without limitation, risks and uncertainties relating to political risks involving the Company's exploration and development of mineral properties interests, the inherent uncertainty of cost estimates and the potential for unexpected costs and expenses, commodity price fluctuations, the inability or failure to obtain adequate financing on a timely basis and other risks and uncertainties. Such information contained herein represents management's best judgment as of the date hereof, based on information currently available.
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.
Contacts:
Golden Reign Resources Ltd.
Kim Evans, CGA
President & CEO
(604) 685-4655 or Toll Free: 1-888-685-4655
(604) 685-4675 (FAX)
www.goldenreign.com