TORONTO, ONTARIO--(Marketwire - Aug. 9, 2012) -
Editors Note: There are two photos associated with this press release.
Macusani Yellowcake Inc. (the "Company") (TSX VENTURE:YEL)(FRANKFURT:QG1) is pleased to announce preliminary results from tests conducted using four large leaching columns that have been installed at Isivilla on the Macusani plateau and loaded with uranium-mineralized material obtained from metallurgical core drilled on the Colibri 2 & 3 tenement. High levels of uranium extraction were achieved, 91 to 98 %, resulting in low residual uranium content. Very low sulfuric acid consumption was observed, 9.6 to 10.5 kg/t. The test results are summarized below in Table 1.
|Table 1 : Large Column Leach Test Results Summary
|Head grade, ppm U
|Feed 100 % passing size, in
|Sulfuric Acid consumption, kg/t
|Leach solution tenor, ppm U
|Residue grade, ppm U
President and CEO, Dr. Laurence Stefan, stated: "The recent column leaching tests have returned high recovery rates with very low acid consumption and continue to demonstrate the very favourable metallurgical characteristics of the Macusani uranium mineralization. The results also hint towards low production costs. The excellent uranium extraction results obtained during these tests, which were run under simulated "mine conditions" and combined with the extremely low acid consumption, further support a technical and economic case for a low grade uranium heap leach operation on the Macusani plateau."
The Company believes that these results are very encouraging and informative for the further development of the project. Further column leach tests are planned followed by the progression to full height large-scale column and pilot plant tests.
Although the recent tests have been run at high altitude, 4500masl using local water and at local Andean climatic conditions in Macusani, the final recoveries were consistently better than most of the previous column leaching tests run in Lima under laboratory conditions. The main reason for this positive correlation may be due to the optimized conditions under which the tests were conducted as a result of the processing experience gathered during the previous tests.
Figure 1 below illustrates the progressive transition from early stage metallurgical testing towards pilot scale operation and the rapid progress made to date by the Company in understanding the metallurgical process and modelling of a probable flow-sheet for a future mine and uranium plant suitable for the treatment of Macusani uranium mineralization.
To view Figure 1, please visit the following link: http://media3.marketwire.com/docs/YEL-Figure1.jpg.
Test Methodology and Conditions
Four column tests were completed successfully on site, using site water and at site conditions (altitude, temperature, humidity). Approximately 460 kg of crushed sample was loaded into 16.5 inch diameter columns to a height of approximately 3.0 m. Crushed sample sizes of 100 % passing 1 inch and 2 inches were utilized. The columns were drip irrigated at 8 (l/h)/m² achieving a percolation velocity of around 1 m/d. An acid concentration of 15 g/l was maintained and a pH < 2. The duration of each test ranged from 45 to 50 days.
Figure 2 below shows representative leach extraction kinetics and acid consumption curves. The results indicate that the extraction and acid consumption are relatively consistent across the range of grade and feed size tested in the large format column with 90 % of the uranium extracted after 30 days of irrigation.
To view Figure 2, please visit the following link: http://media3.marketwire.com/docs/YEL-Figure2.jpg.
The breakdown of the uranium-mineralized rhyolites can be summarized as follows:
||day 3: column breakthrough
||day 18: 80% recovery
||day 30: 90% recovery
||day 50: commencement of column wash.
The leaching tests and associated analyses have been run by TECMMINE EIRL, under the supervision of Jose Mallqui Romayna, a Peruvian metallurgical consulting firm contracted by Global Gold SAC, the subsidiary in Peru of Macusani Yellowcake Inc., for in-house uranium metallurgical and processing investigations.
Dr. Thomas Apelt, PhD (Chemical Engineering), CP(Met) MAusIMM, CEng MIChemE, Senior Process Engineer with GBM Mining Engineering Consultants Limited, an independent consultant, is the Qualified Person, as defined under National Instrument 43-101, and has reviewed the scientific and technical data contained in this release.
About Macusani Yellowcake
Macusani Yellowcake Inc. is a Canadian uranium exploration and development company focussed on the exploration of its properties on the Macusani Plateau in south-eastern Peru. The Company has concessions which cover over 90,000 hectares (900 km2) and are situated near significant infrastructure. Macusani Yellowcake is listed on the TSX Venture Exchange under the symbol 'YEL' and the Frankfurt Exchange under the symbol 'QG1'. The Company has 167,047,475 shares outstanding. For more information please visit www.macyel.com.
This news release includes certain forward-looking statements concerning the future performance of Macusani's business, operations and financial performance and condition, as well as management's objectives, strategies, beliefs and intentions. Forward-looking statements are frequently identified by such words as "may", "will", "plan", "expect", "anticipate", "estimate", "intend" and similar words referring to future events and results. Forward-looking statements are based on the current opinions and expectations of management. All forward-looking information is inherently uncertain and subject to a variety of assumptions, risks and uncertainties, including the speculative nature of mineral exploration and development, fluctuating commodity prices, competitive risks and the availability of financing, as described in more detail in the Company's recent securities filings available at www.sedar.com. Actual events or results may differ materially from those projected in the forward-looking statements and Macusani cautions against placing undue reliance thereon. Neither Macusani nor its management assume any obligation to revise or update these forward-looking statements.
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.