Global Gold Mining has reported recoveries of up to 91.4% from metallurgical tests at its Sturec gold deposit in Slovakia, providing a useful processing input for the project’s pre-feasibility study. The result is encouraging, but the weaker 79.5% recovery from transitional material and the laboratory-scale nature of the work remain important qualifications.
- Fresh composite recovery of 91.4% to flotation concentrate
- Channel composite recovery of 91.0%
- Transitional material returned 79.5% recovery
- Flowsheet testing supports rougher concentrate regrinding and two cleaner stages
- Further variability testing planned using current drilling core
Fresh and Channel Samples Deliver Strong Recoveries
The most useful number in Global Gold Mining’s (ASX:GGM) latest Sturec update is not a headline resource figure but a processing result: fresh material produced 91.4% gold recovery to flotation concentrate, while an underground channel composite returned 91.0%.
Those outcomes came from laboratory testwork at ALS Metallurgy in Perth, supervised by Mining One Consultants. The fresh composite carried a head grade of 0.97 grams per tonne gold and produced a concentrate grading 20.2 g/t. The higher-grade channel composite assayed 2.89 g/t and generated an 84.4 g/t concentrate.
Flowsheet Narrows Around Flotation
The programme worked through grind size, gravity recovery, concentrate regrinding and cleaner-stage options before settling on a relatively straightforward flotation route. The selected conditions used a rougher grind of P80 75 micrometres, regrinding of the rougher concentrate to P80 15 micrometres and two stages of cleaner flotation.
Gravity-recoverable gold averaged about 23% in separate tests, but gravity-plus-flotation and flotation-only tests delivered similar recoveries under the conditions examined. That meant subsequent work omitted gravity recovery. A third cleaner stage also offered limited additional upgrade, keeping the proposed flowsheet from becoming more elaborate than the testwork required.
Transitional Material Is the Main Qualification
The result was not uniform across the tested material. The transitional composite returned 79.5% recovery, the weakest of the three variability tests, and was described as partly oxidised. Its head grade was 1.29 g/t gold.
That difference matters because the company’s stated 91.2% average for the fresh and channel samples excludes the transitional result. It is an arithmetic average, not a deposit-wide or production-weighted recovery, and the company cautions that flotation recovery to concentrate is neither final downstream recovery nor payable metal recovery.
Testwork Feeds the Sturec Pre-feasibility Study
The samples covered 196 intervals from 53 drill holes and 12 underground channel samples in the Andrej Adit, with total recorded source material of about 303 kilograms. That provides a meaningful laboratory dataset for initial flowsheet selection, but the company says the results apply to the tested composites and conditions rather than establishing recovery across the whole deposit.
Further metallurgical work using core from the current drilling programme is planned to assess variability in the material proposed for processing. For the Sturec pre-feasibility study, the immediate value of the announcement is therefore reduced processing uncertainty, rather than a finished production assumption.
Bottom Line?
The 91% recoveries strengthen the processing case for Sturec, but the next test is whether additional drilling confirms those results across transitional and other proposed feed domains.
Questions in the middle?
- How much of the proposed processing feed will comprise transitional material with the lower 79.5% recovery?
- Will further drilling-based composites reproduce the fresh and channel recoveries across a broader section of the deposit?
- What recovery, concentrate treatment and payable-metal assumptions will ultimately be used in the pre-feasibility study?