Edjudina Gold Project
Edjudina Gold Project, Western Australia
GIB 100%
GIB’s Edjudina Gold Project is 145km north east of Kalgoorlie and is located in the heart of the Eastern Goldfields of WA. The project comprises multiple parallel lines of nearly continuous historic gold workings over a 13km strike in which high grade veins have been worked. A haul road owned and operated by Northern Star Resources Limited runs through the north of the project directly to the Carosue Dam milling complex 45 km to the south-west.
The Company acquired the Edjudina Project in July 20201 and quickly discovered the significant Neta Gold Prospect (discovery hole was 36m at 4.0 g/t Au from 4 metres), which has now been the subject of a significant amount of drilling and metallurgical work by GIB.
Figure: Location, Edjudina Gold Project
1.0 JORC Resource, Neta Prospect
On 14 November 2023 GIB reported the maiden JORC Inferred and Indicated Resource (Mineral Resource Estimate, or MRE)2 for the Neta Prospect at the Edjudina Gold Project:
Table: JORC Indicated & Inferred Gold Resource, Neta Prospect
- Cut-off 1g/t;
- Rounded to significant figures; can result in rounding errors
This MRE was compiled with reasonable prospect of eventual economic extraction factors being applied. Mineralisation starts from surface and a third of the resource, including all oxide ore, is in the Indicated category. The resource itself is attractive with mineralisation from surface and good grades, including high grade shoots.
The Company has done well to discover this Neta Prospect Resource. The Edjudina line of workings has been prospected and mined, on and off, since 1897 and this resource at the Neta Prospect had been missed until it was discovered and delineated by GIB geologists.
There are ten gold leach pads dating from the 1980s within GIB’s tenure. These will be attractive complement to the Neta gold resource.
2.0 Metallurgical Testwork
Initial metallurgical testing3 of Material from the Neta Gold Prospect, a part of the Edjudina Gold Project in WA, indicates:
- Gold extraction of up to 92.6% from the oxidised, medium grade material.
- Gold extraction of up to 94.5% from the fresh, high grade material.
- Gold extraction of up to 88.6% from the fresh, medium grade material
- One fresh sample of lower grade material with an elevated sulphide content, indicated a lower gold extraction of 76.7%. This lower recovery is likely due to the higher sulphide content in this sample which, by observation, is not representative of the Neta Prospect as a whole.
- There is considerable scope to optimise these results with further testing by changing variables including grind size, residence time, reagent concentrations, regrinds etc.
- None of the leach tests indicated extreme cyanide or lime consumption. This is a positive indicator at this stage. Further reagent optimisation can be completed in any future testwork programs.
Gold extraction from the three different phases of metallurgical testwork is:
Table: Neta Prospect Best Gold Recoveries Summary – Direct Cyanidation
| Testing | Extraction Au | Leach Time | Oxidation | Comment |
| Phase | % | Hours | State | |
| 1 | 92.6 | 48 | Oxide | Medium Grade (MG) |
| 2 | 76.7 | 24 | Fresh | Low Grade (LG) |
| 3 | 94.5 | 48 | Fresh | High Grade (HG) |
| 3 | 88.6 | 24 | Fresh | Medium Grade |
GIB is pleased with these first pass metallurgical results, especially for the medium grade oxide material (92.6%) and the high grade fresh material (94.5%), which are such important components of the Neta Gold Prospect in terms of gold endowment.
The results for the Phase 2 low grade and to a lesser extent the Phase 3 medium grade ore, suggest that arsenical minerals and/or reactive pyrite contribute significantly to the lower extraction achieved for these samples. Residue grade testing indicates these ores may contain a refractory component, as opposed to being refractory ores.
There is considerable scope to optimise these results with further testing by changing variables including grind size, residence time, reagent concentrations, regrinds etc. Future programs should also focus on improving the residue grade of the fresh samples, including possible concentration via flotation and concentrate treatment options. Arsenopyrite associated refractory gold component
References:
1GIB Acquires Option to Purchase the Historic and High Grade Edjudina Gold Project in the Eastern Goldfields of WA; GIB ASX Release dated 16 July 2020
2Edjudina Gold Project,Maiden JORC Resource – Neta Prospect; GIB ASX Release dated 14 November 2023
3Excellent Metallurgical Results from the Edjudina Gold Project; GIB ASX Release dated 15 December 2022
4Edjudina Gold Project, WA. Mining Licence Update; GIB ASX Release dated 24 April 2024
Competent Persons Statement
The information in this report that relates to previously reported exploration results and new exploration results is based on information compiled by Mr. Jim Richards who is a Member of The Australasian Institute of Mining and Metallurgy and a Member of the Australian Institute of Geoscientists. Mr. Richards is a Director of Gibb River Diamonds Limited. Mr. Richards has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as Competent Person as defined in the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. Mr. Richards consents to the inclusion in the report of the matters based on the information in the form and context in which it appears
Jim Richards is a director of Gibb River Diamonds Limited and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which they are undertaking to qualify as a competent Person as defined in the December 2004 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. Mr Richards consents to the inclusion in this report of the Information, in the form and context in which it appears.
