Mr. Ian Slater reports
RED EAGLE MINING ANNOUNCES POSITIVE PRELIMINARY METALLURGICAL RESULTS OF 93% GOLD RECOVERIES FOR SANTA ROSA
Red Eagle Mining Corp. has received positive results for its metallurgical testwork on material from the San Ramon gold system in the Santa Rosa gold project in Colombia. Results to date show gold recoveries of 73 per cent to 85 per cent for conventional heap leach of the oxide material and 93 per cent for carbon in leach (CIL) of the primary material.
Oxide samples with grades of 7.4 grams per tonne (g/t) gold (Au) (48 kilograms) and 2.4 g/t Au (120 kilograms) produced leach results over six days of between 65-per-cent and 86-per-cent gold recovery depending on the crush size from one inch to 0.25 inch. The optimum result is likely a 0.5-inch crush size (giving recoveries of between 73 per cent and 85 per cent) which is easily achievable as the material is friable. Reagent consumptions are within the bounds of conventional heap leach operations. The samples were taken from near-surface adits and trenches. The second larger sample was taken as the gold grade of the initial sample (news release dated June 19, 2012) was unexpectedly high.
SAN RAMON OXIDE LEACH RESULTS -- 7.4 G/T AU SAMPLE
Top size Au recovery Ca(OH)2 NaCN
(inch) 144 hours (%) addition (kg/t) consumption (kg/t)
1.00 73.2 10.6 0.5
0.50 85.3 11.7 0.6
0.25 86.3 11.5 0.6
SAN RAMON OXIDE LEACH RESULTS -- 2.4 G/T AU SAMPLE
Top size Au recovery Ca(OH)2 NaCN
(inch) 144 hours (%) addition (kg/t) consumption (kg/t)
1.00 65.8 9.5 0.4
0.50 72.8 10.3 0.4
0.25 77.7 11.3 0.4
The primary (non-oxidized) sample with a grade of 0.9 g/t (54 kilograms) showed that over 25 per cent of the gold could be recovered by gravity concentration. The flotation process was able to recover 95.6 per cent of the Au in 12.5 per cent of the mass. Cyanide leaching of the concentrate for 48 hours recovered 97.8 per cent of the Au from the concentrate product. The overall process shows that high-intensity cyanide leaching of the flotation concentrate is able to extract 93.5 per cent of the Au. The cyanide and lime consumptions in the concentrate were 4.36 kilograms per tonne (kg/t) and 4.92 kg/t, respectively. The sample was taken from a recently mined crosscut in fresh rock which exposed the shear.
SAN RAMON PRIMARY LEACH RESULTS
Product Au (g/t) Distribution (%)
Pregnant solution 2.48 93.5
Leach residue 0.12 2.1
Flotation concentrate 5.58 95.6
Flotation tailings 0.04 4.4
"Based on the positive metallurgical results to date Red Eagle has commenced a bulk sampling program for a PEA level gold recovery study," commented Ian Slater, chief executive officer. "These preliminary test results indicate that the processing routes will likely be heap leach for the oxidized material and flotation followed by gravity concentration and CIL for the primary material."
The San Ramon structure trends east-west, dips 60 degrees to 70 degrees to the north, extends over 1,800 metres, is up to 60 metres in width and is exposed at surface. Drilling intercepts to date average 2.1 g/t Au to a vertical depth of over 250 metres (open at depth). The mineralization extends to surface where oxide channel sampling has averaged approximately one g/t Au to a depth of 50 metres. The 2012 work program for San Ramon includes:
- Phase two core drill program (24 holes totalling 5,400 metres) -- complete;
- Phase three core drill program in the near-surface oxides on 50-metre
spacing (25 holes totalling 1,922 metres completed to date out of a 5,000-metre
program) -- commenced in June with all assays pending;
- Preliminary metallurgical testwork -- complete;
- PEA level metallurgical testwork;
- National Instrument 43-101-compliant measured and indicated resource.
Environmental baseline studies and a preliminary economic assessment (PEA) will commence during 2012 and be released during 2013.
The tests were conducted at the Acme Metallurgical Laboratory in Vancouver, Canada. The scientific and technical information contained in this news release has been reviewed and approved by Michael Johnson, PGeo, who is a qualified person as defined under National Instrument 43-101.
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