African Gold Group, Inc., Bulk Metallurgical Testing of Composite RC Drill Intervals That Emulate Kobada Deposit Completed: Visible Gold Observed in 100% of Sample Concentrates
TORONTO, ONTARIO--(Marketwired - Dec 17, 2013) - African Gold Group Inc. ("AGG" or the "Company") (TSX VENTURE:AGG) is pleased to announce that a team of engineers, under the direction of Bumigeme Inc., has completed the metallurgical test work associated with processing a total of 128 composite reverse circulation ("RC") drill intervals that emulate the Kobada deposit from surface down through to fresh bedrock. All samples are compiled from Reverse Circulation ("RC") drill cuttings that represent between 30 meters and 50 meters of drill intercepts, derived from one or more holes, within a specific horizon or layer of mineralization, within the deposit. Each of the processed samples weighed between 0.8 to 1.5 metric tonnes. The longer the drill intercept(s) for a given sample the greater the weight of the respective sample.
A total of 500 samples had originally been identified by AGG's technical team for processing through a fully constructed and commissioned pilot plant. The plant, specifically designed for metallurgical research, has a capacity throughput of up to 2 tonnes per hour.
Metallurgical Engineers, onsite at Kobada, have reached a consensus that further testing of composite bulk samples of RC drill intercepts, beyond the 128 samples just completed, would be redundant. Essentially, the 128 processed samples represent testing the Kobada deposit over 800 meters of drilled strike length from surface through the oxidized profile measuring approximately 100 vertical meters in depth, into fresh bedrock.
Significantly, the average grade of the 128 sample population that has just been processed through the gravimetric pilot plant was approximately 0.4 g/t Au, based on Leachwell given grade. Furthermore, 75 of the 128 sample population, representing 59% of the total sample population, had a grade that was less than 0.3 g/t Au or below cutoff grade and therefore classified as waste material, based on sample support derived from RC drilling and lab results based on 2 kg Leachwell analysis.
The Company is pleased to report that visible gold ("VG") has been reported in 100% of the concentrates as well as 100% of the tails of the 128 bulk samples that have been processed through the gravimetric pilot plant. AGG's Senior Geologist, Pierre Lalande reports that approximately 50% of the 128 sample concentrates contain a range of five to six coarse gold grains that collectively comprise greater than 50% of the weight of visible gold contained within the respective concentrate. The balance of the gold contained within the respective concentrate from the above stated population consists of a range of 200 - 300 grains of fine gold. (http://media3.marketwire.com/docs/agg1217fig1.jpg)
The three primary objectives of the metallurgical test program are to validate the following:
- Demonstrate that analyzing the gold grade based on 0.8 to 1.5 metric tonne samples should result in a higher gold grade being reported as compared to analyzing the same drill interval based on 50 g FA and/or 2 kg Leachwell analysis. (It is important to increase both the "sample support" (volume of material) and "aliquot" (amount of material actually analyzed) to counteract the "nugget effect" at Kobada.)
- Generate further confirmation that a Bulk Mining model applies to Kobada and that all material contained within the mineralized structural corridor should be processed through the gravimetric gold recovery plant - including material that is defined as waste based on drill sample support and Leachwell analysis.
- Study and evaluate the gravimetric process for gold recovery for the Kobada project with a process that emulates commercial operation. It should be noted that gravimetric process modifications will ultimately be adopted to reduce gold content contained within tailings.
Each of the 128 samples that have been processed through the gravimetric pilot plant will be subjected to 1,000 g screen metallic fire assay of the head sample, as well as, the concentrate(s) and the tail(s). AGG anticipates all samples associated with this body of metallurgical test work will be shipped to the lab prior to year end. Test results will be reported upon receipt of results from the lab.
The results of this body of metallurgical test work represent an important phase of work that is essential to concluding AGG's Feasibility Study for a 1,500 tonne/day gravity (gold recovery) plant for Kobada.
Please activate the link below to view a gallery of images of AGG's Pilot Plant - onsite at Kobada, Mali.
http://www.africangoldgroup.ca/index.php?option=com_joomgallery&func=detail&id=74&Itemid=56#joomimg
It is important to note that 100% of the mineralized material from surface through to the lower saprolite horizon is completely oxidized. It is anticipated that the transition zone of the deposit will also be amenable to a gravity process of gold recovery as it is significantly oxidized. Of equal importance in anticipating a high gold recovery rate utilizing gravity processing at Kobada is the fact the oxide zone does not require grinding (only scrubbing). Furthermore, all previous metallurgical test work, including laboratory tests of bulk sample(s) and field testing of approximately 1,200 samples, with an average weight of 10 kg per sample, derived from RC drill cuttings from various layers of the deposit, have yielded high rates of gold recovery, utilizing gravity processing.
Metallurgical Work To Focus On Testing Bulk Samples From Lateritic Profile
AGG's technical team has shifted its focus to generating bulk samples that are derived from the lateritic profile of the deposit. The lateritic profile measures in a range of 1 meter, up to approximately 10 meters in total thickness and is situated immediately below the iron enriched surface of in situ material. As of this date, AGG has processed a total of four, one tonne samples, from the lateritic profile. The processing of all four samples yielded visible gold in both the concentrate(s) and the tails, of each respective sample. One of the four samples was generated from the Gossokorodji ("Gosso") region, situated 5 kilometers east of the Zone 1 main deposit. Multiple grains of coarse gold were observed and the total visible gold content was measured to weigh 1.51 g/t Au. (http://media3.marketwire.com/docs/agg1217fig2.jpg)
AGG notes the presence of an abundance of evidence, consisting of historical and current artisanal mining that would suggest a significant resource, contained within the first 10 meters of the Kobada concession, may have not been detected by analytical procedures to date, due to the nugget effect. Testing bulk samples from this region over several kilometers of strike length and laterally for kilometers across strike will be our immediate focus.
Updated Resource Estimate Highlights (June 18, 2013)
- 2,306,000 Oz Au Measured and Indicated resources (contained within 80.61 million tonnes at 0.87 g/t Au using a 0.3 g/t Au cutoff) derived from drilling on 25m x 25m centers over a total of 3,200 meters of strike length between sections 600S and 3,800S, representing an 88% increase in infill drilled strike length relative to the 1,700 meters of strike length reported in the 2011 Inferred resource estimate.
- 542,000 Oz Au Inferred Resource (contained within 17.88 million tonnes at 0.94 g/t Au, using a 0.3 g/t Au cutoff), predominantly contained from within the Sulphide portion of Zone 1. Included, 186,000 Inferred ounces reported for the Foroko North Deposit (5.16 million tonnes at 1.13 g/t Au at a 0.3 g/t Au cutoff). Foroko North is a satellite deposit situated on a separate and distinct structure from Zone 1. It represents one of seven airborne geophysical targets generated by the 2010 airborne survey.
- Average grade of 0.87 g/t Au reported in the updated resources estimate represents a 10% increase in grade as compared to the average grade of 0.79 g/t Au reported in the 2011 resource estimate that formed part of AGG's PEA.
- Further potential remains to significantly increase both the oxide and sulphide resources along strike and at depth for both Kobada, Zone 1 and Foroko North deposits and elsewhere on the 215 sq km concession where airborne geophysical and geochemical anomalies coincide with extensive areas of gold diggings.
Please click here to view the complete press release detailing AGG's updated resource estimate, published June 18, 2013.
African Gold Group Inc., based in Toronto, Canada, is fully focused and committed to putting its Kobada, Mali gold project into production.
Additional information is available on the Company's website at www.africangoldgroup.com and on www.sedar.com and through the Company's offices at Sun Life Financial Tower, Suite 2518, 150 King St. West, Toronto, Canada, M5H 1J9.
On Behalf of the Board:
Michael A. J. Nikiforuk, President, Director
Neither the 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.
Contact
African Gold Group Inc.
Michael A. J. Nikiforuk
(647) 288-0453
majn@africangoldgroup.com
www.africangoldgroup.com