| ||Wed Dec 10, 2008|
Firestone Ventures Completes Additional Positive Metallurgical Testwork on the Torlon Hill Zinc Deposit
| ||December 10, 2008 - Firestone Ventures Inc. (FV:TSX-V; F5V:FSE) is pleased to announce positive results from a second round of metallurgical testing conducted on its road-accessible Torlon Hill zinc-lead deposit. The first round of testing was completed by SGS Lakefield and focused on mineralogical studies and "base-case" dense media separation and flotation work (see news release September 17, 2008). |
Firestone commissioned Electrometals Canada Inc. to conduct a low-cost preliminary test to assess the amenability of zinc at Torlon Hill to acid/alkaline leaching with the production of zinc metal through electrowinning. Electrometals Canada engaged Process Research Associates Ltd. (PRA) to carry out the testwork. Electrometals Canada Inc. is a subsidiary of Australia-based Electrometals Technologies. Electrometals Canada is engaged in the design, testing and manufacturing of EMEW electrowinning equipment. PRA is a Canadian company offering a full range of laboratory and pilot plant research.
"This was the second in a series of preliminary testwork programs designed to look for methods to optimize zinc recoveries. We are very pleased with this initial characterization test which shows that the zinc ore from Torlon Hill is readily soluble under both acidic and alkaline conditions. This shows us further work is warranted and that the potential exists to produce a concentrated zinc solution that may be suitable for direct electrowinning and production of zinc metal." says Lori Walton, President of Firestone Ventures. "The relatively simple mineralogy of the Torlon ore may be a factor in the positive results."
A composite metallurgical test sample from Torlon Hill ore returning an average grade of 12.9% zinc and 3.5% lead was used for the Electrometals/PRA metallurgical testwork. This test was done directly on ore material and not on a pre-concentrated product. Results from alkaline leach scoping tests using a caustic (NaOH) leach solution were encouraging. Key highlights from this work include:
• Overall leach recoveries approaching 80% for zinc and 60% for lead. Additional testwork was recommended to examine a two-stage leach with interstage grinding in order to potentially increase leach recoveries.
• The production of a high concentration solution that is suitable for direct electrowinning of zinc.
• Very little dissolution of aluminum, silica or any other deleterious sample components.
Solutions from the alkaline leach testwork were then processed via zinc cementation to remove metals such as lead, cadmium and copper and subjected to direct electrowinning. A final zinc metal cathode "sponge" product was produced which contained 99.5% zinc.
In addition to the alkaline leaching, the Torlon composite metallurgical sample was also subjected to acid leaching conditions. Following a dense media separation ("DMS") stage to eliminate +80% of the acid-consuming calcium phase in the mineral a baseline sulfuric acid leach was performed at a pH of 2. Promising results were achieved with 95% of the contained zinc being solubilized with very little extraction of iron or other gangue materials. Overall acid consumption was reasonable at approximately 100 kg/t in excess of what would theoretically be recovered during subsequent zinc electrowinning.
Torlon Hill Mineralogy and Geology
Smithsonite (ZnCO3) is the prevalent zinc mineral at Torlon Hill, occurring as a replacement to limestone, and resulting in high grade mineralization locally exceeding 40% zinc. Other non-sulphide zinc minerals are relatively rare, but minor amounts of a hydrous zinc-carbonate (hydrozincite) and hydrated zinc-silicate (hemimorphite) are seen locally in the weathering zone. The lead-carbonate mineral cerussite is important locally. There is no evidence of deleterious zinc-clay minerals. Traces of sphalerite have been found in a sulphide (mostly galena-pyrite) zone at the base of the deposit. Silver-rich galena veinlets cross-cut the pervasive zinc-replacement mineralization.
Torlon Hill is an intensely oxidized zinc-lead (plus silver) mineralized body hosted in Permian dolostone breccia and limestone. The carbonate unit has been tectonically thrust over a serpentinized basement sequence at the boundary between the North American Tectonic Plate and the Caribbean Plate. The "tectonic crush zone" is pervasively mineralized with thick zones returning in excess of 10% and locally up to 40% zinc. The area surrounding Torlon Hill has high potential for hosting additional structurally controlled non-sulphide zinc deposits in addition to conventional Mississippi Valley-Type mineralization.
This news release has been reviewed and approved by J. Cleary, CPG, Qualified Person, Al Workman, P.Geo., Vice President of Watts, Griffis and McOuat Limited and D. Koningen, P.Eng. The road-accessible Torlon Hill project is located 18 kilometres northwest of the city of Huehuetenango, which is situated on the Pan-American Highway in western Guatemala. Firestone owns a 100% interest in the Torlon Hill Project.
Firestone Ventures Inc. is a Canadian-based resource exploration and development company. The common shares of the Company are currently listed on the TSX Venture Exchange (symbol FV) and the Frankfurt Stock Exchange (symbol F5V). For further information please contact:
Lori Walton, P. Geol., President
Toll Free: 1-888-221-5588
Fax: (780) 428-3476
Trading Symbol: FV:TSX-V;F5V: FSE
For Investor Relations please call: Contact Financial Inc. at (604) 689-7422
This news release may contain forward looking statements, being statements which are not historical facts, including, without limitation, statements regarding potential mineralization, exploration results, resource or reserve estimates, anticipated production or results, sales, revenues, costs, "best-efforts" financings or discussions of future plans and objectives. There can be no assurance that such statements will prove accurate. Such statements are necessarily based upon a number of estimates and assumptions that are subject to numerous risks and uncertainties that could cause actual results and future events to differ materially from those anticipated or projected. Important factors that could cause actual results to differ materially from the Company's expectations are in Company documents filed from time to time with the TSX Venture Exchange and provincial securities regulators, most of which are available at www.sedar.com. The Company disclaims any intention or obligation to revise or update such statements. The TSX Venture Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release.
You can view the Next News Releases item: Tue Jan 13, 2009, Firestone Ventures Files NI 43-101 Technical Report on Torlon Hill Zinc-Lead Project
You can view the Previous News Releases item: Mon Dec 8, 2008, Firestone Ventures Update for 2008/2009 Field Season
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