Apr 04, 2008 14:28 ET
Metallurgical Tests Performed by Macusani Yellowcake Indicate High Uranium Recovery-96% Uranium Recovered in 5 Hours
TORONTO, ONTARIO--(Marketwire - April 4, 2008) - Macusani Yelowcake Inc. (the "Company") (TSX VENTURE:YEL) President and CEO, Peter Hooper, stated: "We are delighted with the latest bottle tests carried out at the SGS Laboratories in Lima. These very high recovery rates confirm our previous testing and indicate that our concept of a heap leach uranium mine is real."
ROLLED BOTTLE TESTS: URANIUM RECOVERIES
A composite sample collected from Platform 2 on Colibri II concessions has been analysed at SGS Laboratories in Lima and reported a head grade of 590 ppm Uranium (1.39 lb/ton U3O8). The 400 kg composite sample has been crushed and riffled at SGS Laboratories.
Bottle rolled tests using aliquots of 400g have been used for metallurgical recovery tests using diluted sulphuric acid as the leaching agent.
The conditions of the test are listed below:
Aliquots weight: 400 grams
L/S ratio: 10
Grain size: 80% passing 200 mesh
PH: 1.8
Time: 300 minutes
Initial H2SO4 amount: 4.82 cc
Initial H2SO4 concentration: 2.0967 g/l
Head grade: 590 ppm U
The table and graph below exhibit the behaviour of the Uranium-rich
material during the acid leaching test.
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Pregnant Solution
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Chemical
Consumption U
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Time H2SO4 H2SO4 gr/ used
(minutes) pH H+ (Kg/t) (cc) (Kg/ton) ppm ton % U CaCO3
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0 7.71 21.39 4.82 0.000 0.00 0.00 0.00 0.4
20 2.12 7.40 3.12 14.000 59.23 592.30 57.77 0.5
40 1.90 9.24 2.70 26.151 64.79 657.20 64.10 1.0
60 1.82 18.49 0.57 29.058 81.00 825.38 80.50 1.1
120 1.83 20.34 0.15 30.117 89.74 919.51 89.68 1.2
240 1.82 22.19 -0.28 29.327 93.87 967.85 94.40 1.2
300 1.82 22.19 -0.28 28.537 94.90 985.26 96.10
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11.350
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Residual (g/t): 40.00
Calculated Head (g/t): 1,025.26
Assayed Head (g/t): 590.00
U Solubility in Acid (%): 96.10
To view the graph associated with this release, please visit the following link: http://media3.marketwire.com/docs/yel0404.pdf
The Company believes that the conclusions emerging from this initial leaching test are very encouraging and demonstrates the good leaching parameters of the Uranium ore present on the Macusani plateau.
A recovery of 96.10% was reached after 300 minutes of agitation in the rolled bottle and with an acid consumption of 28.54 kg of H2SO4 per tonne of ore. The Company notes that a recovery of almost 90% was reached after only 2 hours of processing.
On the same sample (the balance to 400 kg of the head sample) leach column tests are being run at present on the same ore material. The material has been crushed to 95% passing 2 inches. Two types of column leached tests are run, one of Uranium ore pre-soaked in sulphuric acid and one of untreated Uranium ore.
The column leach tests commenced on April 1 and will last at least 45 days.
At present more representative samples of U-rich rhyolites are being collected at Macusani for bottle rolled tests in order to characterise mineralogically and metallurgically the width and length of the large occurrence of Uranium mineralisation on Colibri II-II anomaly.
The metallurgical sampling and tests will continue for the entire duration of 2008.
About Macusani Yellowcake Inc.
Macusani Yellowcake controls over 49,000 hectares of mineral properties (Macusani, Munani, Lagunillas and Rio Blanco) in Puno in southeastern Peru. A 20,000 m diamond drilling program is underway on the Macusani Plateau along a 4 km long radiometric anomaly. Macusani believes that the properties located on the Macusani plateau are underlain by uraniferous volcanic rocks similar to those currently being drilled on nearby properties.
There are 24,296,285 common shares of Macusani Yellowcake Inc. outstanding, 32,876,260 common shares, fully diluted.
Neither 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.
For more information, please contact
Macusani Yellowcake Inc.Peter Hooper
President
+1-416-360-3402
peter@macyel.com
