CALGARY, July 11 /CNW/ - Alhambra Resources Ltd. (TSX-V: ALH) ("Alhambra" or the "Corporation") announces the results for preliminary independent metallurgical test work completed by SGS Lakefield Research Europe ("SGS") on two representative samples of sulphide (primary) gold mineralization from the East zone of the Uzboy gold deposit.
Gold recovery rates of 94% and 90% were realized from these tests. The preliminary metallurgical test work completed to date shows that the sulphide gold mineralization in both the West (see News Release dated June 14, 2007) and East zones of the Uzboy gold deposit exhibit similar leaching characteristics with respect to leach times and percentage gold recovery. Based on these similar leach characteristics, it appears that the gold mineralization from both zones could be treated in the same facility.
Alhambra plans to conduct additional testing on the sulphide gold mineralization on a larger combined representative sample of sulphide gold mineralization from both the West and East zones of the Uzboy gold deposit during the rest of 2007. The combined sample will be tested at a pilot plant scale. This will provide data which will be used to design a preliminary process flow sheet for use in a Pre-Feasibility Study. The data should provide expected gold recoveries for a potential continuous tank leach type operation.
The results of the preliminary metallurgical test work from the East zone have been forwarded to ACA Howe International Limited ("Howe") and will be included in the Preliminary Assessment of the gold resources contained in the sulphide portion of the Uzboy gold deposit.
Detailed Metallurgical Test Work
The test work was completed by SGS, a leader in providing mineral processing and analytical services to the mining industry, at their laboratories in Truro, Cornwall, England. Detailed results of the two tests are summarized below.
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Test East "W" Test East "E"
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Gold Gold
Product Amount Assay Extraction Amount Assay Extraction
(ml) (g/ml) (%) (ml) (g/ml) (%)
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8 hour solution 1,970 0.69 88.8 2,044 1.61 92.8
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24 hour solution 1,945 0.68 87.6 2,019 1.62 93.4
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48 hour solution 1,920 0.70 90.1 1,995 1.63 94.0
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The East zone of the Uzboy gold deposit is divided into two separate areas of gold mineralization. The northeast (Test East "E") and the southwest (Test East "W") areas of gold mineralization are separated by intrusive dikes.
After 48 hours of leaching, the gold recoveries were estimated to be 94.0% for Test East "E" and 90.1% for Test East "W". The calculated head grade for sample Test East "W" was 1.47 grams per tonne ("g/t") gold and for Test East "E" was 3.25 g/t gold.
Test East "W", considered to be representative of the sulphide gold mineralization in the southwest portion of the East zone, had a head assay of 1.49 g/t gold. Test East "E", considered to be representative of the sulphide gold mineralization in the northeast portion of the East zone, had a head assay of 3.77 g/t. The head assays are based on a fire assay of a representative sample from each of the samples tested. The calculated head grades are based on the sum of the gold recovered by leaching and amount of gold remaining in the sample after leaching. The correlation between the calculated head grade and the head assay for Test East "W" is excellent. Test East "E" shows a 13% variance between the calculated head grade and the assay head grade and is interpreted to be due to a "nugget" effect in the sample.
A nugget effect generally occurs in gold mineralization when some particles of gold are significantly larger than the majority of the gold particles. The addition or lack of one of these particles in the head assay sample can impact the gold content of the sample tested.
Uzboy West and East Zone Comparison
The results for the preliminary metallurgical test work completed on the West zone of the Uzboy gold deposit are set out in a News Release dated June 14, 2007. A brief comparison of the lithologies, alteration mode of gold occurrence and preliminary metallurgical information for the West and East zones of the Uzboy gold deposit is set out below.
The West zone is located approximately 300 metres ("m") west of the East zone of the Uzboy gold deposit. The gold mineralization in both zones is hosted in highly sheared and in some instances brecciated andesite and its tuff equivalent that exhibits strong carbonate alteration.
The gold mineralization in the West zone occurs within a zone of intense sericite-quartz-sulphide alteration that imparts a bleaching effect to the host rock and contains from 1% to 3% pyrite with minor (less than 1% combined) chalcopyrite, sphalerite, galena and arsenopyrite. The gold mineralization in the West zone occurs as discrete grains disseminated in the rock and in micro-fractures as discrete free grains. The gold grains range in size from 1 to 25 microns with the majority of the grains occurring in the less than 5 micron grain size range. Gold also occurs as discrete grains within pyrite and in solid solution with pyrite. A minor component of the gold occurs in silica.
Detailed petrographic and mineralogical studies of the gold mineralization from the East zone are in progress. The preliminary information collected to date indicates that the alteration surrounding the gold mineralization in the East zone appears to be of lower intensity than the alteration in the West zone. The alteration zone is characterized by 1% to 5% pyrite with approximately 1% combined concentrations of chalcopyrite, galena, sphalerite and arsenopyrite. No information is available regarding the grain size distribution and modes of occurrence for the gold mineralization.
Detailed Metallurgical Test Work Procedures
Sample Test East "W" weighed approximately 17 kilograms ("kg") and the sample of Test East "E" weighed approximately 20 kg. Approximately 1 kg from each sample was selected for preparation and testing. Sample Test East "W" was ground to 89.9% passing 45 micrometres (325 mesh) and sample Test East "E" was ground to 88.8% passing 45 micrometres (325 mesh). The ground material for each test was transferred to separate bottles and alkaline cyanide solution with lime was added to the ground material to create a slurry that consisted of 35% solids by weight. The cyanide concentration used in each test was 0.5 grams/litre at a pH level of between 10.5 and 11. The samples were continuously leached for 48 hours. Aliquots of solution were collected after 8, 24, and 48 hours and analyzed for gold concentration to determine percentage gold extraction at that time. After 48 hours of testing, the samples (final residue) were filtered, dried, weighed, and assayed to determine the gold content in the sample after leaching. Reagent consumption averaged 0.25 kg of cyanide per tonne and 0.49 kg of lime per tonne. SGS Lakefield Research Europe is registered under the International Standards Organization ("ISO") 9001-2000.
About Alhambra
Alhambra is a Canadian based gold exploration and production corporation engaged in the exploration of and production from its 100% owned Uzboy Project. Alhambra is currently in its sixth year of operations in the Republic of Kazakhstan.
Alhambra common shares trade on The TSX Venture Exchange under the symbol ALH and in Germany on the Frankfurt Open Market under the symbol A4Y. The Corporation's website can be accessed at www.alhambraresources.com.
Elmer B. Stewart, MSc. P. Geol., President of Alhambra, is the Corporation's nominated Qualified Person responsible for monitoring the supervision and quality control of the programs completed within the Uzboy Project. Mr. Stewart has reviewed and verified the technical information contained in this news release.
The TSX Venture Exchange Inc. has neither approved nor disapproved the
information contained herein.
This news release contains forward-looking information including but not limited to comments regarding the timing and content of upcoming work programs and potential mineral recovery processes. Forward-looking information includes disclosure regarding possible future events, conditions or results of operations that is based on assumptions and courses of action, and therefore, involves inherent risks and uncertainties. For any forward looking information given, management has assumed that the analytical results it has received are reliable and the metallurgical testing methodologies applied are consistent with industry standards. Although management has a reasonable basis for the conclusions drawn, actual results may differ materially from those currently anticipated in such statements. For such statements, we claim the safe harbor for future.
