Pershimco Reports Average 92.8% Gold Recovery from Oxide Metallurgical Testing
ROUYN-NORANDA, QUEBEC -- (Marketwire) -- 03/20/13 -- Pershimco Resources Inc. (the "Company" or "Pershimco") (TSX VENTURE: PRO)(FRANKFURT: BIZ) is pleased to report metallurgical test results from its 100% owned Cerro Quema gold deposit in Panama. Bottle roll tests using composites from the surface oxide resources confirmed this material is highly leachable, providing further evidence supporting the positive economic potential of the gold oxide project.
Highlights
-- Average recovery from the first 14 bottle roll tests of oxide material
is 92.8%;
-- Recoveries varied from 86.1% to 97.2% after 48 hours, for nominal feed
size at 100% minus 0.25" and 0.5";
-- To date, the leach kinetics indicate the bulk of the recovery potential
is regularly reached within 18-24 hours; and
-- Recovery differential for composite PO-08 tested at both 0.25" and 0.5"
is very low: 87.5% vs. 87.1%.
This first batch of metallurgical tests indicating consumption for cyanide and lime, for the tested oxide composites, is at the low end of typical values in most cases, with PO-17 being an outlier (to be checked for sulphur content).
All of the bottle roll recoveries for the 13 oxide composites tested surpassed 85%, with results commonly above 90% (see Table 1). As expected, the 14th composite, PS-07, a sample taken from the lower sulphide zone, achieved a recovery of 50%. As with some of the other sulphide samples tested but awaiting solution assays, the resulting cyanide and lime consumption for treating these samples is an order of magnitude higher than what is required with the oxide samples.
The Company expects additional results shortly as well as conventional and pulsed column leach test results being prepared at McClelland Laboratories Inc., in Nevada.
While historical metallurgical results have also demonstrated good gold recoverability from the oxide material, Pershimco's technical team recognizes the need for additional metallurgical testing using more contemporary laboratories and incorporating greater control methodologies.
Table 1. Summary Metallurgical Results, Scoping Bottle Roll Tests, Cerro
Quema
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MLI NaCN Au
Test Feed Conc. Recovery,
# Composite Size g/L %
-----------------------------------------------------------
CY-31 PO-08 12.5mm 0.50 87.1
CY-33 PO-14 12.5mm 0.50 95.1
CY-37 PS-07 12.5mm 0.50 50.0
CY-22 PO-01 6.3mm 0.50 86.1
CY-1 PO-02 6.3mm 0.50 93.3
CY-2 PO-03 6.3mm 0.50 90.0
CY-3 PO-04 6.3mm 0.50 93.2
CY-4 PO-05 6.3mm 0.50 96.9
CY-6 PO-07 6.3mm 0.50 94.7
CY-7 PO-09 6.3mm 0.50 94.1
CY-8 PO-10 6.3mm 0.50 96.2
CY-15 PO-17 6.3mm 0.50 94.1
CY-16 PO-19 6.3mm 0.50 94.3
CY-5 PS-05 6.3mm 0.50 97.2
CY-24 PO-08 6.3mm 0.50 87.5
MLI gAu/mt ore Reagent Req.
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Test Calculated kg/mt ore
--------------------------------
# Extracted Tail Head NaCN Lime
----------------------------------------------------------------------
CY-31 0.74 0.11 0.85 0.07 0.9
CY-33 0.58 0.03 0.61 less than 0.07 1.6
CY-37 0.02 0.02 0.04 1.35 13.4
CY-22 0.68 0.11 0.79 less than 0.07 2.0
CY-1 0.28 0.02 0.30 0.22 3.4
CY-2 0.09 0.01 0.10 0.10 3.4
CY-3 2.07 0.15 2.22 less than 0.07 2.3
CY-4 0.95 0.03 0.98 less than 0.07 1.0
CY-6 1.08 0.06 1.14 less than 0.07 1.0
CY-7 1.76 0.11 1.87 less than 0.07 2.6
CY-8 1.00 0.04 1.04 less than 0.07 2.8
CY-15 0.16 0.01 0.17 0.90 7.7
CY-16 0.99 0.06 1.05 less than 0.07 1.2
CY-5 1.76 0.05 1.81 0.15 2.9
CY-24 0.70 0.10 0.80 less than 0.07 1.0
Note: Composite nomenclature indicates whether the composite represents material from La Pava (Px) or Quema-Quemita (Qx), with "x" identifying the composite as either made of oxides (x=O) or sulphides (x=S).
Quality Assurance / Quality Control ("QA/QC")
Sample selection was based upon the drill hole database assay results, enabling samples to be chosen from both shallow and deep mineralized intercepts from many different parts of both the La Pava and Quema-Quemita ("QQ") deposits. Samples were taken mostly from the oxide zones with a few from limited sulphide intercepts that provided sufficient sample weight.
A total of 30 composites were created by mixing material from groups of drill holes in particular areas, with each composite representing a specific area in the orebody and only including either oxide or sulphide mineralization. Of the 30 composites, 22 were extracted from holes in La Pava (7 from drill core samples), of which 17 were from the oxide zone and 5 from the sulphide zone. The other 8 composites were taken from QQ, all from oxides and all made up of reverse circulation ("RC") cuttings only. Thus far, the small amount of diamond drilling conducted at QQ, which included stopping any holes once they exited the oxide zone, has limited the amount of core available for testing.
McClelland Laboratories Inc. ("MLI") finalized the preparation of the composites, from the individual samples obtained (2.35 wet tonnes, in 134 drums), dried and crushed the samples to the desired size distribution for testing, and extracted a head sample for assaying. As of late February 2013, MLI had completed bottle roll testing, with assaying results pending, and has charged the first leach columns. The initial results from the bottle roll tests are described in this press release.
The information contained in this press release has been reviewed and approved by Mr. John Kapetas, B.Sc. Hons, MAusIMM, MAIG and Mr. Pierre Lacombe, Eng. both Qualified Persons under NI 43-101 rules and standards.
About Pershimco Resources Inc.
Pershimco Resources Inc. is a Canadian-based resources and exploration company listed on the TSX Venture Exchange and the Frankfurt Exchange. The Company holds several mining properties in Canada and South America, including the advanced and extraction permitted Cerro Quema Project in Panama and the Courville Gold Project, in the Val-d'Or Gold Mining Camp, being explored in partnership with Osisko Mining Corporation. The Company is managed by skilled and reputable individuals with extensive mining, exploration and development experience. The Pershimco Team and its investors are the key to its success.
The Company's documents are available on www.sedar.com.
Please visit the Company's website at www.pershimco.ca.
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 news release. Statements made in this news release that are not historical facts are "forward-looking statements" and readers are cautioned that any such statements are not guarantees of future performance, and that actual developments or results, may vary materially from those in these "forward-looking" statement.
Contacts:
Alain Bureau, P. Eng.
President and Chief Executive Officer
+1 (819) 797-2180
ressources@pershimco.ca
Richard Leroux
Investor Relations
+1 (514) 993-4510
info@pershimco.ca