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ASX Announcements: September 24, 2004

MAJOR METALLURGICAL TESTWORK PROGRAMME & INVESTIGATION OF GEOCOAT® BACTERIAL OXIDATION TECHNOLOGY

The Directors are pleased to announce that Republic Gold has commenced an extensive metallurgical testwork programme on its 75%-owned Northcote Project. The testwork, predominantly on core samples, will be aimed at both oxide and sulphide mineralisation and is expected to take approximately 3 months. The results of this testwork programme will be used in the Company’s Northcote Project feasibility studies, which will commence shortly.

The directors are also pleased to announce that the Company has begun an investigation into the suitability of the GEOCOAT® bacterial oxidation technology, which may offer reductions in capital and operating costs, for all of its Hodgkinson Basin projects, including the Northcote Project.

The oxide testwork will investigate the heap leaching characteristics of the mineralisation. Included in this testwork will be an examination of the impacts of stibnite (antimony sulphide) mineralisation and oxides of antimony within the oxide mineralisation.

The sulphide testwork will investigate the amenability of the mineralisation to bacterial oxidation. Testwork will be performed to give basic parameters for crushing, grinding and flotation. The sulphide testwork will also investigate the separation of the sulphide concentrate into a gold/pyrite/arsenopyrite concentrate and a stibnite concentrate.

Two methods of bacterial oxidation testwork will be performed; BIOX®, the bacterial oxidation technology owned by Goldfields Limited of South Africa, and GEOCOAT®, owned by GeoBiotics LLC of the USA. The last significant exploration programme at Northcote in sulphide mineralisation was carried out in the late-1980’s. At this time bacterial oxidation was just in the process of being commercialised and as such was not a technology that was available to be used on Northcote mineralisation. The Directors believe that the significant advances made over the subsequent 15 years with the proven BIOX® technology support the potential for a viable commercial sulphide operation at Northcote.


Recent developments with GEOCOAT® may offer additional benefits for Republic’s mineralisation type. GEOCOAT® is a relatively new technology from a commercial perspective, with the Agnes Mine in South Africa apparently successfully utilising the technology over the past 12 months for the first time. A director of the Company will visit the Agnes Mine shortly to assess the technology. On the evidence the Company has seen to date, GEOCOAT® appears to be a simple technology, combining bacterial oxidation with heap leaching. These are two treatment techniques that the technical Directors have extensive experience in. The GEOCOAT® process involves coating crushed and sized waste rock with a sulphide concentrate and bacteria and stacking the material on a heap leach pad for the duration of the oxidation phase. Once oxidation is completed to the required level, the material is removed from the pad, the oxidised concentrate is washed off, neutralised and the treated in a CIP/CIL plant. As the oxidation phase is carried out on a heap leach pad it is apparent that considerable capital and operating cost savings could be achieved with GEOCOAT®.

For more information, please contact: Greg Barns ([email protected]) on 0419 691 846 or John Kelly ([email protected]) on 0418 577579.

This news item can be viewed on the Web at http://www.republicgold.com.au/news/2004-09-24.php.