Chesapeake receives positive metallurgical and processing results
Symbol: TSX V-CKG
------------------------------------------------------------------------- Mineral Eq. Eq. Resource Tonnes Gold Gold Silver Silver Gold Gold Zinc Zinc Class ---------------------------------------------------------------- Ktonnes g/ Oz. X g/ Oz. X g/ Oz. X % Lbs. X tonne 1,000 tonne 1,000 tonne 1,000 1,000 ------------------------------------------------------------------------- Measured 181,317 0.74 4,314 17.9 104,349 0.98 5,713 0.19 757,905 ------------------------------------------------------------------------- Indi- cated 521,939 0.62 10,404 17.4 291,989 0.86 14,432 0.16 1,837,225 ------------------------------------------------------------------------- Measured + Indi- cated 703,256 0.65 14,697 17.5 395,685 0.90 20,349 0.17 2,630,177 ------------------------------------------------------------------------- Inferred 74,000 0.80 1,903 16.0 38,067 1.02 2,427 0.13 211,640 ------------------------------------------------------------------------- Notes: Resource is tabulated at a 0.5 g/t Equivalent Gold cutoff grade, Equivalent Gold equals Gold+ Silver/72, Assumes 100% metal recovery
The gold-silver mineralization at Metates occurs in sulfide stockwork veinlets or disseminations in both intrusive and predominant sedimentary host rocks. Mineralogical and metallurgical testing at Resource Development Inc. ("RDI"), Hazen Research ("Hazen") and other facilities has demonstrated that the gold-silver mineralization is variably refractory and primarily associated with pyrite. Metallurgical tests have been performed on core samples weighing over 6.2 tonnes and from which 48 individual composite samples and two master composite samples have been generated. Metallurgical tests to date include over 166 leach tests, 75 flotation tests, 21 roasting tests and 15 pressure oxidation tests. Chesapeake has focused its metallurgical efforts on the evaluation of commercially proven process alternatives that have low technical risk and provide the best combination of metal recovery and operating economics. Highlights from the test work are:
- Gold and silver recoveries into a bulk rougher sulfide concentrate average greater than 90% can be achieved at a relatively coarse grind size - Gold and silver recoveries average greater than 97% and 85%, respectively, from the concentrates following pressure oxidation using relatively low temperature, pressure and residence time with no re-grinding of the concentrate - Overall gold recoveries in the range of 85% to 90% and silver recoveries in the range of 80% to 85% through both flotation and pressure oxidation are targeted
Testing at RDI and Hazen have demonstrated that the generation of a bulk rougher sulfide flotation concentrate followed by oxidation of the concentrate would achieve high recoveries of gold and silver during subsequent cyanidation. Several different oxidation methods were evaluated. Roasting and pressure oxidation are the most well known and employed at numerous precious metal mining operations throughout the world. Oxidation of the concentrate by either method also allows for the recovery of an economically viable zinc by-product at prevailing zinc prices.
The roasting oxidation method produces concentrated sulfuric acid of a quality that is widely used in copper oxide mines, the production of chemical fertilizers and other industrial applications. Chesapeake has conducted several acid market studies and engaged in preliminary discussions with fertilizer companies concerning the potential long term supply of acid from Metates. Alternatively, pressure oxidation produces a low grade sulfuric acid and Chesapeake is evaluating the potential of producing elemental sulfur as a saleable by-product from this method. Marketable elemental sulfur and/or sulfuric acid could generate long term revenue that will lower precious metal cash costs and reduce environmental risks associated with acid neutralization and residue management.
Chesapeake continues to advance Metates towards the completion of a NI 43-101 Preliminary Economic Assessment (scoping study) technical report ("PEA"). M3 Engineering of
In support of the work at M3, Independent Mining Consultants has prepared a preliminary mine schedule based on the NI 43-101 resource estimate at an ore mining rate of 60,000 tonnes per day from a pit measuring 2.5 kilometers long, 1.7 kilometers wide and 600 meters deep. At this mining rate and assumed overall gold and silver metal recoveries of 85%, Metates could produce in excess of 550,000 ounces of gold equivalent (gold and silver) annually over a 35 year mine life. Precious metal production is the highest and the stripping ratio is the lowest in the first eight years of production which will enhance capital recovery and payback. A PEA, however, has not yet been completed and accordingly, there can be no assurance that the results will be positive. Also, mineral resources that are not yet mineral reserves do not have demonstrated economic viability.
In the PEA, M3 will be providing the estimated capital and operating costs of a fully integrated mining operation. To date, Chesapeake's engineering team and consultants have completed the site design and plant processing layout options, the permanent transportation and pipeline corridors, power and water availability. Given the large resource base and metallurgical test results, M3 is evaluating production rates of 90,000 tonnes per day and higher. The PEA report is expected to be completed in early 2010.
CHESAPEAKE GOLD CORP "P. Randy Reifel" ----------------- P. Randy Reifel President The TSX Venture Exchange does not accept responsibility for the adequacy or accuracy of this news release.
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For further information: on Chesapeake and its Metates Project, please visit our website at www.chesapeakegold.com or contact investor relations at (604) 731-1094
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