African Gold Group Reports Free Milling Sulphides, 96% Gold Recoveries Through Gravity + CIL Process From Initial Sulphide Metallurgical Test Programme
TORONTO, March 16, 2021 (GLOBE NEWSWIRE) -- African Gold Group, Inc. (TSX-V: AGG) (“AGG” or the “Company”) is pleased to announce positive test results from metallurgical testing on sulphide material from its flagship Kobada Gold Project in southern Mali.
Highlights from the metallurgical testing include:
- High average gold recoveries of 96.1%
- Sulphide ore is free milling (non refractory)
- Current processing plant design (gravity + CIL) is well sized to treat additional sulphide ore
Danny Callow, CEO, African Gold Group states:
“From our ongoing drilling programme results, we are confident that we have a sizeable sulphide resource sitting below the oxides at our Kobada Gold Project. Based upon the geological interpretation to date, this could be far larger than the current oxide resource. Whilst we believe we have significant upside in the oxides along strike, it made sense to test the ability to treat the sulphides, especially those that fall within the current open-pit shell and are classified as a resource.
We could not be happier with the initial results from the comprehensive testwork programme, which shows that not only is the gold free milling, but that it displays optimal recovery through the existing gravity + CIL circuit already designed for the Kobada Gold Project oxides.
We are confident that some of our existing 345,000oz of sulphides as per our latest resource statement will fall within our open-pittable reserves and therefore be added to the overall reserve number as we seek to update the technical report from our additional oxide drilling results and sulphide testwork.”
Comprehensive metallurgical testing programme 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 sulphide ore testwork programme involved the following:
- Head grade assays (Multi Au x 3; Sg; As, Hg, S-package; Full ICP scan)
- Diagnostic leach
- Comminution testwork - to be performed after a review of the gold recovery results.
- Gravity recovery followed by intensive cyanidation on the gravity concentrate.
- Cyanidation on the gravity middlings and tailings which involved leach rate tests to determine the effect of time on gold dissolution.
Intensive cyanidation on gravity concentrate
The ILR tests indicate that a gold dissolution of 96.37% over 6 hours is achieved and this is consistent with what was obtained for saprolite and laterite. The current gravity recovery equipment selection is adequately sized to recover gravity gold from the sulphides.
| Leach Time | NaCN | Recovery | pH | Sample | Leached | Dissolved Oxygen Measured |
| Au | Au | Au | DO | |||
| Ppm | % | mg | mg | mg/L | ||
| 0 hrs | 20,000 | 0 | 11.64 | 0 | 0 | 15.93 |
| 1 hrs | 20,000 | 79.61 | 11.31 | 0.656 | 0.656 | 30.18 |
| 2 hrs | 20,000 | 91.48 | 11.16 | 0.753 | 0.098 | 22.49 |
| 4 hrs | 20,000 | 95.95 | 10.74 | 0.79 | 0.037 | 26.15 |
| 6 hrs | 20,000 | 96.37 | 10.47 | 0.794 | 0.003 | 21.71 |
| 7 hrs | 20,000 | 96.37 | 10.66 | 0.794 | 0 | 26.69 |
| 24 hrs | 20,000 | 96.37 | 10.6 | 0.794 | 0 |
Figure 1: Intensive cyanidation results
Leach results on middlings and tailings
| Time | Reagent Addition | Head | Residue | Carbon | Reagent Consumption | Dissolution (Calc) | Account | |||
| NaCN | CaO | Assayed | Calc. | Au | Au | NaCN | Sol + Carbon | Solid | Au | |
| g/t | Kg/t | Au (g/t) | Au (g/t) | g/t | g/t | Kg/t | Au % | Au % | % | |
| 2 hrs | 5,000 | 0.24 | 0.30 | 0.31 | 0.25 | 2 | 0.94 | 20.48 | 20.48 | 104.80 |
| 4 hrs | 0.24 | 0.30 | 0.29 | 0.14 | 5 | 0.94 | 51.05 | 51.05 | 95.33 | |
| 6 hrs | 0.24 | 0.30 | 0.31 | 0.02 | 10 | 1.99 | 93.52 | 93.52 | 102.93 | |
| 8 hrs | 0.24 | 0.30 | 0.33 | 0.02 | 11 | 1.84 | 93.92 | 93.92 | 109.73 | |
| 12 hrs | 0.24 | 0.30 | 0.33 | 0.02 | 11 | 2.13 | 93.92 | 93.92 | 109.73 | |
| 16 hrs | 0.24 | 0.30 | 0.30 | 0.02 | 10 | 2.54 | 93.38 | 93.38 | 100.67 | |
| 18 hrs | 0.24 | 0.30 | 0.31 | 0.02 | 10 | 2.43 | 93.61 | 93.61 | 104.29 | |
| 24 hrs | 0.24 | 0.30 | 0.31 | 0.02 | 10 | 2.38 | 93.55 | 93.55 | 103.39 | |
| 36 hrs | 0.24 | 0.30 | 0.32 | 0.02 | 11 | 2.42 | 93.66 | 93.66 | 105.20 | |
| 48 hrs | 0.24 | 0.30 | 0.32 | 0.02 | 11 | 2.59 | 93.66 | 93.66 | 105.20 | |
Figure 2: Leach test rate
The following is noted regarding the results:
- Rate of gold dissolution is high and the rate curve “plateaued” after 8 hours. An optimum residence time of 24 hours can be selected. Current leach design residence time of 24 hours will be more than adequate when treating sulphides.
- Lime requirements are low at 0.24kg/t- this is line with expectations as sulphides generally contain carbonates which will result in low lime demand.
- Cyanide optimization tests will be conducted to determine cyanide consumptions for design and operating cost estimates.
Ongoing comprehensive testwork will include additional comminution testing to determine optimal grind size, leach optimisation and further variability testing.
TSXV Final Approval
The Company is also please to announced that it has receive final approval from the TSX Venture Exchange with respect to the closing of the $4.6 million private placement of units of the Company (the “Offering”) (see press release dated February 24, 2021). As a matter of clarification, all warrants comprising the units of the Company issued under the Offering expire on February 24, 2023. Additionally, in connection with the closing of the Offering, the Company has paid aggregate finder’s fees of $115,757.50 in cash and 776,832 finder’s warrants (“Finder’s Warrants”) to certain finders.
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.
Qualified Person
The scientific and technical information contained in this press release has been reviewed, prepared and approved by Dr. Andreas Rompel, PhD, Pr. Sci. Nat. (400274/04), FSAIMM, Vice President Exploration of AGG, who is a "Qualified Person" as defined by National Instrument 43-101 - Standards of Disclosure for Mineral Projects.
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
(416) 861-2267
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, gold recoveries from the Kobada Gold Project, inclusion of sulphides into reserves and resources of the Kobada Gold Project, grant of incentive stock options and the Offering. 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.
This news release does not constitute an offer to sell or a solicitation of an offer to buy any of the securities in the United States. The securities have not been and will not be registered under the United States Securities Act of 1933, as amended (the “U.S. Securities Act”) or any state securities laws and may not be offered or sold within the United States or to U.S. Persons unless registered under the U.S. Securities Act and applicable state securities laws or an exemption from such registration is available.
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.
