African Gold Group Reports Continued Positive Metallurgy Recovery Results Demonstrating Sulphides are Treatable in CIL Oxide Plant
TORONTO, March 31, 2021 (GLOBE NEWSWIRE) -- African Gold Group, Inc. (TSX-V: AGG) (“AGG” or the “Company”) is pleased to announce updated test results from metallurgical testing on sulphide material from its flagship Kobada Project, in southern Mali. The results continue to advance the opportunity of increasing reserves without further drilling, by demonstrating sulphides can be processed through the oxide plant as designed in the feasibility study, thus generating a more robust mine plan with larger tonnage and increased gold output.
Highlights from the metallurgical testing include:
- Comminution tests indicate a Bond Work Index (BBWi) of 13,5 Kwh/t with medium hardness sulphide and abrasiveness (Ai) of 0.2487
- Cyanide consumption at 0.75 kg/t is a low-medium cyanide consumer and fits into current DFS plant design
- Lime requirement of 0.38 kg/t indicate a very low lime consumption, meaning that operating costs for treating sulphides are expected to be low
Danny Callow, CEO, African Gold Group states:
“The ongoing results from a comprehensive sulphide metallurgical testing campaign continue to give us great confidence in the amenability of the Kobada sulphides to be treated easily through our existing Gravity and CIL process with very good recoveries. In addition, there appears to be no requirements for any change to the gravity and CIL process circuit to accommodate the sulphides. Work is underway to optimise the grinding requirement of the sulphides versus oxides, and these results are due out soon. This is the best we could have hoped for in terms of optimising the sulphide testwork, and this means that the process plant design already completed to an advanced detailed engineering level can accommodate the sulphides.”
“We are confident that we have a substantial sulphide resource below the oxides, and the results of this testwork will enable us to quickly convert a portion of the existing measured and indicated sulphide resources into reserves. Apart from a huge oxide upside opportunity, the addition of sulphides treatable through our existing plant design adds more value to the size of the Kobada project.”
The comprehensive metallurgical testing program was conducted by Maelgwyn South Africa (MSA) on composite samples from all defined mineral zones (north, south, and central domains) of the main shear zone.
The ongoing sulphide ore testwork program involved the following:
- Optimised cyanidation testwork
- Additional comminution studies to determine optimal grind size and abrasiveness of the ore
Optimised cyanidation testwork
Cyanidation testwork indicates a low to medium cyanide consumption required for high gold dissolution rate. Other projects in the region typically consume between 0.85 – 1.38 kg/t, so this is considered a low cyanide consuming ore.
| Test No. | Cyanide Consumption kg/t | Lime Consumption (kg/t) | Gold Dissolution (%) | |
| 1 | 0.09 | 0.40 | 57.1% | |
| 2 | 0.27 | 0.40 | 59.1% | |
| 3 | 0.40 | 0.39 | 71.7% | |
| 4 | 0.55 | 0.39 | 76.1% | |
| 5 | 0.75 | 0.38 | 93.4% | |
| 6 | 1.44 | 0.36 | 93.9% | |
Results from comminution testing
- Bond Ball Work Index (“BBWi”) - 13.5 kWh/t
- Bond Abrasion Index (“Ai”) - 0.2847
| Property | Soft | Medium | Hard | Very Hard |
| BBWi | 7-9 | 9-14 | 14-20 | >20 |
| Ai | 0.05 | 0.30 | 0.80 |
Based on these results the sulphide ore at the Kobada Project is classified as medium hardness and medium-soft abrasiveness.
Effect of Grind
Gold dissolution tests were conducted on gravity middlings and tails by varying grinds 75 to 212 µm as shown in the table below. It can be noted that dissolution of gravity middlings and tails reduced with an increase in grind size - results are in line with expectations.
| Grind P80 (µm) | Feed Grade (g/t) | Gravity Tails Recovery (%) | Gravity Conc Dissolution (%) | Gravity Tails Dissolution (%) | Combined Dissolution (%) | Cyanide (kg/t) | Lime (kg/t) | ||||
| 212 | 0.54 | 41.46% | 96.37% | 50.65% | 70.37% | 1.20 | 0.22 | ||||
| 150 | 0.54 | 41.46% | 96.37% | 66.52% | 79.90% | 1.18 | 0.21 | ||||
| 106 | 0.54 | 41.46% | 96.37% | 89.14% | 93.48% | 1.44 | 0.2 | ||||
| 75 | 0.54 | 41.46% | 96.37% | 93.55% | 96.13% | 2.38 | 0.24 | ||||
Further optimisation work from OMC will determine any possible changes to mill design to support finer grinding, however the rest of the process plant design can accommodate the sulphides without any further design changes. In addition, additional variability testing will take place over the next few weeks.
Corporate Update
The company would like to announce some structural corporate changes to its senior management team and office services agreement.
The Company would like to welcome Paul Bozoki to the team as Chief Financial Officer. Mr. Bozoki is a seasoned dual Canadian and U.S. CPA with over 25 years of accounting, tax and corporate finance experience, mainly in the mining industry. Mr. Bozoki replaces Ryan Ptolemy, the former Chief Financial Officer of the Company.
Additionally, the Company would like to announce that it has agreed to part ways with Kenny Choi, the former Corporate Secretary of the Company and Dr. Andreas Rompel, the former Vice President Exploration. Mr. Ptolemy, Dr. Rompel and Mr. Choi will remain available to ensure a smooth transition. The Company’s Board of Directors and management would like to express their gratitude to Mr. Ptolemy, Dr. Rompel and Mr. Choi for their invaluable contributions since joining AGG in 2018 and wishes each of them all the best in their future endeavours.
The Company also announces that it has terminated its services agreement at 65 Queen Street West and relocated its registered head office to 100 King St W #1600, Toronto, ON M5X 1G5.
Option Grant
The Company has granted a total of 2,800,000 stock options to certain officers, directors and consultants of the Company pursuant to the Company’s stock option plan. The stock options vest immediately and may be exercised at a price of $0.115 per option for a period of five years from the date of grant. This grant of options is subject to the approval of the TSX Venture Exchange.
About African Gold Group
African Gold Group is a TSX Venture Exchange (TSX-V: AGG) listed exploration and development company with a focus on building Africa’s next mid-tier gold producer. The Company has a highly experienced board and management team with a proven track record in the African mining sector operating mines from development through to production. AGG’s principal asset is the Kobada Project in southern Mali, which is in an advanced stage of development having completed the 2020 definitive feasibility study and is targeting gold production of 100,000 oz per annum. As well as the initial Kobada Gold Project, other exploration locations have been identified on the Kobada, Farada and Kobada Est concessions, offering potential for an increase in resource. For more information regarding African Gold Group visit our website at www.africangoldgroup.com.
For more information:
Danny Callow
President and Chief Executive Officer
+(27) 76 411 3803
Danny.Callow@africangoldgroup.com
Scott Eldridge
Non-Executive Chairman of the Board
(604) 722-5381
Scott.Eldridge@africangoldgroup.com
Daniyal Baizak
VP Corporate Development
(647) 835-9617
Daniyal.Baizak@africangoldgroup.com
Camarco (Financial PR)
Gordon Poole
Nick Hennis
+44 (0) 20 3757 4997
AfricanGoldGroup@camarco.co.uk
Cautionary statements
This press release contains “forward-looking information” within the meaning of applicable Canadian securities legislation. Forward-looking information includes, but is not limited to, statements regarding, processing of sulphide materials, appointment of officers and the grant of incentive stock options. Generally, forward-looking information can be identified by the use of forward-looking terminology such as “plans”, “expects” or “does not expect”, “is expected”, “budget”, “scheduled”, “estimates”, “forecasts”, “intends”, “anticipates” or “does not anticipate”, or “believes”, or variations of such words and phrases or statements that certain actions, events or results “may”, “could”, “would”, “might” or “will be taken”, “occur” or “be achieved”. Forward-looking information is subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of AGG to be materially different from those expressed or implied by such forward-looking information, including but not limited to: receipt of necessary approvals; general business, economic, competitive, political and social uncertainties; future prices of mineral prices; accidents, labour disputes and shortages and other risks of the mining industry. Although AGG has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking information. AGG does not undertake to update any forward-looking information, except in accordance with applicable securities laws.
NEITHER 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.
