Friday 2nd December 2022 Font size:

Keegan Resources Inc

Wednesday, July 25th, 2007

Keegan is pleased to announce positive results from a preliminary metallurgical testing program at its Esaase project. Results indicate that gold is easily recovered from reverse circulation chips with limited or no grinding, reasonable amounts of reagents, and normal leach times, suggesting that Keegan may be able to use either a low cost, low energy dump leach or carbon in leach (CIL) technique on the deposit. With crushing (300 microns) that is up to three times coarser than that found in many Ghanaian leach mines, gold recoveries are 91 % from oxide, 87% from the transition and 75% from the fresh portions of the deposit respectively. Recoveries are high even with no additional crushing (see table 1 for full results and www.keeganresources.com for the full text of the report). As the study found coarse gold in the fresh portion of the deposit, Keegan is planning additional studies to ascertain whether even higher recoveries can be achieved.
Table 1. Summary of leach studies on reverse circulation chips
Zone, Average Drill Depth(meters), Particle Size(micron), Recovery(%)
Oxide 28 300 90.5
Transition 103 300 86.8
Fresh 140 300 75.2
Oxide 28 478 (as is) 85.8
Transition 103 929 (as is) 65.3
Fresh 140 1000 (as is) 66.8
Dan McCoy, President and CEO of Keegan states: “These results indicate that the gold at Esaase has a good chance of being recovered using low cost mining and milling methods. We will be working steadily to add value to Esaase both through additional metallurgical and engineering scoping studies as well as through continued discovery with exploration drilling in the coming months.”
The design, sampling, and interpretation of the program were completed by RSG Global, a division of Coffey Mining Company, who contracted Independent Metallurgical Laboratories Pty. Ltd. to perform the metallurgical tests and petrographic examination of the samples. Three composite samples weighing 10 kg were created from 20 samples each, taken from each different portion of the deposit and identified by type based on logging of oxidation and weathering. The leach test work was carried out over 72 hours at 40%w/w solids using Perth tap water. The pH, dissolved oxygen level, free cyanide level and dissolved oxygen level, free cyanide level and dissolved gold were monitored at 2, 4, 8, 12, 24, 48, and 72 hour intervals. Tests were conducted on the “as received” RC chips and at 75, 150, 300, and 800 micron grinds. Induced Coupled Polarization (ICP) multi-element analyses of the samples do not indicate the presence of any deleterious elements in significant quantities likely to effect cyanidation. Keegan plans additional resource delineation, metallurgical, community development and engineering and scoping studies in the coming months. Richard Haslinger, P. Eng., is the Qualified Person with respect to NI 43-101 at Esaase and has reviewed this release.

< go back
thyssenkrupp
LIUGONG DRESSTA
DSI
WEIR MINERALS
TAKRAF
Terex
BEUMER