Corner Bay receives Alamo leach test results
Corner Bay Minerals Inc BAY
Shares issued 11,541,109 Jun 9 close $2.45
Mon 12 Jun 2000 News Release
Mr. Peter Mordaunt reports
Initial column leach tests on the company?s 100-per-cent-owned Alamo Dorado silver/gold deposit in Sonora, Mexico, have yielded positive results. The preliminary column leach results of the phase 1 pit and overall composite samples have confirmed the viability of heap-leaching ore at the project with average silver equivalent recoveries ranging from 63 per cent* to 68 per cent*. Gold and silver continue to leach from the samples, and it is expected that ultimate recoveries will increase from these levels. The test work is being carried out by Metcon Research Inc. of Tucson, Ariz. Samples for this program came from large diameter diamond drill core collected by the company in the fall of 1999. All drill cores were shipped to the Metcon research facility in Tucson where Metcon prepared the composite samples. These composites were then loaded into 1.5-metre-high and 15.24-centimetre-wide columns. Recoveries, particularly for silver, are sensitive to crush size. The preliminary results reported here are for material that was sized to 100 per cent passing 3/8 of an inch. Two composite samples created from the drill core and placed under leach are reported in the following table.
Column Leach
Results in Progress
Column Sample Leach Time Ag
(Days) Recovery
Phase I pit composite
(with low grade and
high grade) 116 67%
Overall composite
(with low grade and
high grade) 100 61%
Column Leach
Results in Progress
Column Sample Au Ag equivalent
Recovery Recovery*
Phase I pit composite
(with low grade and
high grade) 71% 68%
Overall composite
(with low grade and
high grade) 75% 63%
Indicated gold recoveries in this preliminary report are likely understated as the gold concentration levels presently being measured in the leach solutions are below detection limits. It is anticipated that these values will increase once a full metallurgical balance is performed on the columns after leaching has finished. Ultimate recoveries are expected to be in line with bottle roll tests that yielded 90 per cent gold recovery.
Interpretation of results
Phase 1 pit composite so far has yielded 71 per cent gold and 67 per cent silver recovery (68 per cent silver-equivalent*) over 116 days?gold and silver continue to leach. The phase 1 pit composite is representative of material expected to be mined during the initial years of production. The overall composite with low-grade and high-grade samples has yielded 75 per cent gold and 61 per cent silver (63 per cent silver-equivalent*) in 100 days. Separate column tests for high-grade and low-grade materials are being run to determine if recoveries could be increased by segregating high-grade material. Encouraging preliminary test results support this hypothesis.
Future work at Alamo Dorado
The results of this initial metallurgical test program indicate that heap leaching at Alamo Dorado is technically and economically feasible, and should result in recoveries of at least 63 per cent* on a silver-equivalent basis. Based on this, the company is now in a position to advance planning for possible development of an open-pit, heap-leach, silver/gold mine at the project.
A resource and reserve prefeasibility study on the Alamo Dorado project was completed last fall by Mintec. That study indicated a resource of 119,054,900 equivalent silver ounces and a minable, open-pit reserve containing 100,159,800 equivalent silver ounces. The company anticipates receiving a final metallurgical report by Metcon by October of this year. A revised resource and reserve report by Mintec, which will incorporate new drilling data (including the high-grade results previously reported in news release Nos. 2000-03 and 2000-04) is also expected to be complete later this year. Corner Bay?s management is extremely encouraged by these preliminary results. *Silver equivalents based on $5 (U.S.) per ounce Ag and $300 per ounce Au.
¸ Copyright 2000 Canjex Publishing Ltd. canada-stockwatch.com |
