African Gold Group, Inc., is pleased to report on metallurgical test work recently completed by SGS Lakefield (SGS) on a composite of oxide mineralization from AGG’s Kobada, Mali gold project.
The primary objective of the test work was to investigate the amenability of the Kobada oxide ore sample to gold extraction using gravity separation as the sole means of gold recovery or extraction. The results of the test(s) are considered excellent and demonstrate the amenability of Kobada oxide ore to gravity concentration and extraction.
The as-received composite sample that was delivered to SGS weighed 287 kg. The sample was selected from 127 separate intervals that were derived from 8 different drill holes. The individual intervals, derived from the 8 distinct drill holes, were selected to reasonably represent or emulate the entire Kobada, Zone 1 deposit.
The 287 kg composite sample, as received by SGS, assayed 1.93 g/t Au. The first phase of the test process was to de-slime the sample by wet screening and cycloning to break down the clay aggregates and remove the fine fraction (de-sliming). The oversize fraction was then filtered, dried and riffled into test charges.
The fine (slimes) fraction made up 57% of the as received sample mass. This fine fraction was analyzed for gold content and assayed 0.13 g/t Au, representing just 4% of the gold.
The remaining 43% of the mass, the oversize material, contained 96% of the gold and assayed 4.28 g/t (as calculated from gravity test work).
The sample was also characterized through a gold deportment study and analytical analysis. The gold deportment study identified 26 gold grains in the sample submitted with over 97% found as liberated grains with an average size of 12μm. The largest gold grains observed were approximately 30μm. Native gold was the only gold mineral identified.
An Extended Gravity Recoverable Gold (EGRG) test on a 10-kg oversize or de-slimed sample provided a Gold Recovery Grade number of 92.3%. This is an exceptionally high result and indicates that approximately 90% of the gold in the sample could be recovered via gravity.
As can be seen in Table 1 below, most of the gold (82.6%) is recovered in Stage 1 after no grinding, while 89.7% is recovered in grinding the sample to a P80 of 249 µm. The overall gold deportment by size indicated that 73% of the gold was contained in the +150 µm fraction
Table 1: EGRG Test Result Summary
|Grind P80||Product||Mass||Grade||Au Recovery|
|476||Stage 1 Concentrate||0.75||469||82.6|
|249||Stage 2 Concentrate||0.68||45||7.1|
|56||Stage 3 Concentrate||0.63||18||2.6|
|Total Knelson Concentrate||2.06||191||92.3|
“The economic implications of being able to recover approximately 90% of the gold contained within the oxide profile at our Kobada, Mali project based solely on gravity recovery, cannot be overstated. It is well known, within the mining industry, that the cost (capex) of building a gravity plant will be significantly less than the cost of building a comparable cyanide agitation leach plant. In addition, operating costs, for gravity, will be significantly less, on a relative basis, when compared to the cost of operating an equivalent cyanide plant. Combine this with an oxidized profile that averages approximately 100 vertical meters from surface, at Kobada, Mali, plus the fact that our step-out holes are growing Zone 1 to the north and south, lends further credibility to our confidence in the economic viability of the development of our Kobada gold project,”
Pierre Lalande, P.Geo., Director designate.
African Gold Group, Inc., based in Toronto, Canada, is engaged in the identification, acquisition and exploration of prospective gold projects that are situated along significant gold trends within West Africa. To date, the Company controls a total of twelve gold concessions that are consolidated in five distinct standalone exploration projects, of which three projects are located in Ghana and the remaining two are located in Mali, West Africa.
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On Behalf of the Board:
Michael A. J. Nikiforuk,
African Gold Group, Inc.
Michael A. J. Nikiforuk
(416) 644-8892 ext 101
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