Roscan testing shows 97.6% recovery from Kandiole
2021-10-25 04:06 PT - News Release
Mr. Nana Sangmuah reports
ROSCAN GOLD ANNOUNCES POSITIVE METALLURGICAL TESTING RESULTS FROM THE KANDIOLE GOLD PROJECT ACHIEVED 97.6% RECOVERIES FOR OXIDE AND 92.9% FOR FRESH MINERALIZATION SAMPLES AT FLAGSHIP MANKOUKE SOUTH TARGET
Roscan Gold Corp. has provided results from the metallurgical test work program completed on samples from gold prospects at Mankouke South (MS1), Mankouke Center-Kandiole (KN1) and the Kabaya (KB1-KB2) within the company's land package called the Kandiole projects located in west Mali, Africa.
Highlights
- All of the samples representing the deposits (Mankouke South MS1 and Center, Kandiole KN1, and Kabaya KB1-KB2) tested in this program exhibit non-refractory metallurgical features, indicating that a simple, industry-standard cyanide leach process provides excellent gold and silver extraction.
- Total gold recoveries by gravity, plus 48 hours of CIL (carbon in leach) on all prospects, have averaged 97 per cent for oxide (saprolite) samples, 89 per cent for a transition sample and 90 per cent for fresh mineralization samples.
- Flagship Mankouke South achieved 97.6 per cent in the oxide and 92.9 per cent in fresh rock.
- Both oxide and fresh mineralization are amenable to gravity concentration to recover free gold within the milling circuit.
- The gravity recovery average from all samples and CIL tests is 23 per cent.
- The coarse ore leach tests in two Kabaya saprolite samples, to examine heap leach amenability, provided an average of 79-per-cent recovery of gold and 93 per cent silver after eight days.
- One sample reached 88.4-per-cent gold recovery after 72 hours.
Nana Sangmuah, president and chief executive officer, stated: "This is a major derisking milestone for the Kandiole project confirming simple processing flow sheet with oxide recoveries 97 per cent including average gravity recoveries of 23 per cent and up to 58 per cent in certain deposits. We are also encouraged by the potential for silver byproduct credits at our relatively lower-grade Kabaya deposit which should further bolster project economics."
Further information
- All results from the gravity plus carbon-in-leach tests were positive, indicating that:
- The program included testing of gravity separation, grindability and grind size variability, agitated leach kinetics, carbon in leach (CIL) and for two of the composites, heap leaching amenability determinations. Results from this metallurgical test work provide significant progress in the resources estimation process.
- A simple gold processing flowsheet for these deposits (Mankouke South MS1 and Center-Kandiole KN1-Kabaya KB1-KB2) is applicable and will be considered in the maiden mineral resource estimation.
- The CIL results for the oxide zone, which carries a large proportion of the mineralization (70 to 80 per cent) at Mankouke South MS1 and Center-Kandiole KN1-Kabaya KB1-KB2, are particularly favourable with 97-per-cent total gold recovery.
- From different metallurgical tests, in Mankouke South, the most important portion of the overall mineralization, the gravity recovery reached 27 per cent in saprolite and 25 per cent in transition-fresh rock.
- In Kandiole, the gravity extraction varies from 48 per cent to 58 per cent, and in Kabaya the average is 23.3 per cent.
- Silver content of the Kabaya samples reaches 8.6 grams per tonne with an average of 3.6 g/t and recovery in the gravity plus leach tests is above 95 per cent for the saprolite.
- After further analysis of more Kabaya samples, the assays could demonstrate that silver is a potential economic byproduct.
- Encouraging leach kinetics indicate excellent gold extraction within 24 hours and averages only 0.5 per cent below the extraction obtained in the maximum time of 48 hours.
- Bond ball mill grindability of 3.3 to 6.2 kilowatt-hours per tonne (saprolite) to 10.4 to 21.5 kilowatt-hours per tonne (transition-fresh rock) is comparable with other gold operations in the region.
- Over all, the cyanide and lime consumptions indicated in this preliminary testing seem typical for these types of deposits.
In total, 12 composite samples of 20 to 40 kilograms have been sent for the metallurgical test work: two saprolite (oxide), one transition and two fresh rock samples from Mankouke, onesaprolite (oxide) sample from Mankouke Centre, one saprolite (oxide) sample from Kandiole, and four saprolite (oxide) and one fresh rock sample from Kabaya. Each composite comprised one-third of low-grade (0.3 to one g/t), one-third of medium-grade (one to three g/t) and one-third high-grade (greater than three g/t) drill sample intervals (all g/t values stated are for gold only).
For Mankouke South, the fresh rock has been separated between sedimentary and felsic intrusive rocks. Most of the composite samples have been prepared from one-fourth of NQ diamond drill core, one composite was reverse circulation samples only and three have been prepared with a mix of core and RC samples. All individual samples which comprise the composites are well distributed spatially in the mineralization.
The test work was undertaken by Base Metallurgical Laboratories, Vancouver, Canada, 200, 970 McMaster Way, Kamloops, B.C., Canada, V2C 6K2. The samples have been selected by Pascal van Osta, Roscan's vice-president of exploration.
Qualified person (QP) and National Instrument 43-101 disclosure
Greg Isenor, PGeo, director for the company, is the designated qualified person for this news release within the meaning of National Instrument 43-101 and has reviewed and verified that the technical information contained herein is accurate and approves of the written disclosure of same.
About Roscan Gold Corp.
Roscan Gold is a Canadian gold exploration company focused on the exploration and acquisition of gold properties in West Africa. The company has assembled a significant land position of 100-per-cent-owned permits in an area of producing gold mines (including B2 Gold's Fekola mine, which lies in a contiguous property to the west of Kandiole), and major gold deposits, located both north and south of its Kandiole project in west Mali.
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