TORONTO, ONTARIO--(Marketwire - Sept. 6, 2012) -
Editors Note: There are three 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 on four leach solutions with tenors ranging from 7 to 531 ppm uranium. Two resin types exhibited high uranium removal characteristics in single stage tests. Resin type I achieved removal efficiencies of 76 to 96.5% while resin type II achieved removal efficiencies of 65 to 93.0%. In two stage tests, uranium removal efficiency reached was in excess of 99.6% for resin type I.
President and CEO, Dr. Laurence Stefan, stated: "The recent ion exchange tests have found a suitable ion exchange resin capable of achieving above 99% removal of uranium from pregnant leach solutions. The results demonstrate the excellent applicability of the ion exchange technology for the uranium recovery from Macusani leach solutions. The use of ion exchange instead of solvent extraction, for the first stage of uranium recovery from leach solution, on the Macusani plateau has the advantages of reduced organic solvent losses through evaporation and reduced solvent extraction waste stream production. These advantages are positive both financially and environmentally."
Four pregnant leach solution (PLS) samples were dispatched to South Africa for ion exchange testing that were run under the supervision of Ed Hardwick of Cwenga Technologies, Johannesburg. The four feed solutions were first assayed for elements: uranium, aluminium, iron and calcium (see Table 1). The results indicated that only uranium was of commercial interest.
Table 1: Pregnant Leach Solution Assay Results
|Contained Elements||Sample 1||Sample 2||Sample 3||Sample 4|
Each solution was then contacted with four ion exchange (IX) resins types to check for potential uranium selectivity. Feed solution was contacted with each resin for two hours, decanted and analysed for uranium.
Table 2 contains the before and after tenors for sixteen shaking tests. The uranium removal efficiencies for these single stage tests are shown in Figure 1.
Table 2: Ion Exchange Resin Shake Test Results
|Description||Sample 1||Sample 2||Sample 3||Sample 4|
|ppm U||ppm U||ppm U||ppm U|
|Feed solution tenor||537||71||18||6.0|
|Resin I - discharge tenor||80||2.5||1.6||1.4|
|Resin II - discharge tenor||186||5.0||2.5||1.7|
|Resin III - discharge tenor||331||15||9.4||4.4|
|Resin IV - discharge tenor||507||22||15||5.8|
To view Figure 1: Ion Exchange Uranium Removal Results, please visit the following link: http://media3.marketwire.com/docs/yel_sept6_figure01.pdf
Both of these ion exchange resins (resin types I and II) were subsequently used for ion exchange testing in standard glass columns, in a two stage arrangement shown in Figure 2. Non-adsorption of uranium (high uranium tenor at the second pass column outlet) was high for resin type II. Resin type I was therefore isolated as the best resin from the four pre-selected resins.
To view Figure 2: Ion Exchange Column Test Arrangement, please visit the following link: http://media3.marketwire.com/docs/yel_sept6_figure02.pdf
Solution sample quantities restricted the number of tests. There was sufficient volume to test Sample 1 (530 ppm U) and a blend of Samples 2 and 3 (56 ppm U). Figure 3 illustrates the two stage ion exchange column tests for Sample 1. The volume of solution processed is expressed in terms of Bed Volumes (BVs). The bed volume is the volume of the bed of ion exchange resin in each column, 50 milliliters in this case. The overall uranium removal efficiency throughout the two stage test was greater or equal to 99.6%. The blended sample test provided comparable results over the volume of solution processed for Sample 1.
In order to achieve and maintain these high uranium recoveries in a continuous process the resin should be removed from service, before it is completely loaded, and replaced by fresh resin. This extra process may have economic implications and environmental concerns. If the resin is changed-over (replaced) when the first stage removal has dropped to 96% and 4% of the uranium (21 ppm U for a feed tenor of 530 ppm U - Sample 1) is still left in solution can be recycled back to the leaching process, which eliminates these economic and environmental implications. Such a target change over point is also shown in Figure 3.
To view Figure 3: Ion Exchange Column Test Results, please visit the following link: http://media3.marketwire.com/docs/yel_sept6_figure03.pdf
In conclusion, the recent ion exchange tests have found a suitable ion exchange resin capable of achieving a minimum of over 96% removal of uranium from pregnant leach solutions in a single stage and over 99% for a two stage system. Any remaining uranium would be returned to the process, and no uranium would be released, increasing the final uranium removal from pregnant leach solution to above 99%.
The Company believes that these test results are very encouraging and informative for the further development of the project. These ion exchange tests have determined working parameters for subsequent tests. Numerous tests have since been conducted in Lima, Peru, achieving equally encouraging results, which will be the subject of a future press release. Further ion exchange tests are planned followed by the investigation of the subsequent resin stripping, solvent extraction and precipitation stages. Initial bench-scale tests are to be conducted and would then progress to pilot plant tests.
Dr. Thomas Apelt, PhD (Chemical Engineering), CP(Met) MAusIMM, CEng MIChemE, Senior Process Engineer with GBM Mining Engineering Consultants Limited, an independent consultant to the Company, is a Qualified Person as defined under National Instrument 43-101 and has reviewed and approved 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.