Microsoft Word - pjn7878.doc
ABN 79 106 879 690
22 October 2014
The Manager Companies
ASX Limited
20 Bridge Street
SYDNEY NSW 2000 (4 pages by email)
Dear Madam,
Excellent gravity gold recovery from Wonogiri
• 71% recovery by gravity of free gold from a low grade (0.55 g/t gold) sulphide
ore composite (<75 micron).
• 50% recovery by gravity of free gold from a high grade (1.26 g/t gold) sulphide
ore composite (<75 micron).
• Tests indicate gravity tails from both composites are non‐acid producing,
assisting in waste and tailings disposal processes.
• Leach tests of gravity tails resulted in average CIL recoverable gold of 83.2% for the low grade ore composite and 83.9% for the high grade composite. No refractory gold is indicated.
• Further testwork to be undertaken to determine the most efficient metallurgical
parameters for processing the Randu Kuning gold and copper mineralisation.
The Directors of Augur Resources Ltd ('Augur' or 'the Company') are pleased to report the results of further metallurgical testing of the sulphide mineralisation from the Randu Kuning deposit at the Wonogiri project in central Java.
The metallurgical testwork investigated gold only recovery process options including gravity separation and cyanide leaching along with other diagnostic leaches. For this test program, two sulphide ore composites were prepared. One was a 'low‐grade' composite containing 0.55 g/t gold, 1.1 g/t silver and 0.23% copper which is typical of
the disseminated and stockwork, vein hosted, porphyry‐type mineralisation.
Level 2, 66 Hunter Street Sydney NSW 2000
Phone: +61 2 9300 3310 Facsimile: +61 2 9221 6333 Web: www.augur.com.au
Wonogiri project location and major porphyry deposits on the Oligocene‐Miocene Arc.
The other was a 'high‐grade' composite containing 1.26 g/t gold, 1.4 g/t silver and 0.27% copper deemed representative of the higher grade, structurally controlled, breccia/fault hosted (feeder) zones.
Both composites were of a primary, sulphide ore type compiled from core drilled within the conceptual starter pit. Sulphide ore represents over 90% of the resource. The testwork was completed in Jakarta, Indonesia at PT Geoservices under the direction of Mr Peter Wallwin of PWA Limited, based in Malaysia.
The following results were obtained:
Gravity Recoverable Gold ('GRG')
Four size fractions were evaluated for gravity recoverable gold using a Falcon centrifugal concentrator.
• Low grade composite shows average gravity recovery of 51.0%. This includes
≤36% in coarse fractions (>75 micron) and very high recovery of 71% in the fine grained fraction (≤75micron).
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• High grade composite shows average gravity recovery of 34.8%. This includes poor recovery (≤11%) in the >150 micron fraction but significantly better recovery of ≤60% in the ≤75 micron fraction.
• grains of 'free' gold were seen in the ≤75 micron fractions of both composites.
Diagnostic Leach
Diagnostic leaching was performed on the gravity residue (tails) of both composites to determine the recovery by carbon in leach ('CIL') as well as the association of residual gold contained/retained in other mineral species such as carbonate, silicates, pyrite and arsenopyrite.
• CIL recoverable gold results were good for both composites. Recoveries averaged 83.2% in the low grade composite and 83.9% in the high grade composite.
• The high grade composite showed a range in CIL recoverable gold from 71.3% in the fine fraction (≤75 micron) to 93.2% for the coarse (>300 micron) size fraction.
• The low grade composite showed a range in CIL recoverable gold from 74.1% in the fine fraction (≤75 micron) to 89.8% for the coarse (>300 micron) size fraction.
• Only a very minor amount of gold is determined to be associated with pyrite or
arsenopyrite, with 0.6% in the low grade composite and 2.5% in the high grade composite. This is significant as the results indicate that the ore is not of a refractory nature.
Direct Cyanidation
Four size fractions were evaluated for gold recovery using direct cyanide leaching.
• Overall gold recovery was 62.5% for the low grade composite and 50.6% for the high grade composite.
• 72% to 82% of the gold in the low grade composite was recovered in the >75
micron fractions and only 48% of gold was recoverable in the fine (≤75 micron)
fraction.
• 75% of the gold in the high grade composite was recovered in the >300 micron size fraction and only 47% in the ≤75 micron fraction.
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The lower gold recoveries in the fine fractions (≤75 micron) of both composites is anomalous given that the opposite is true for the GRG. This relationship will be investigated in future testwork.
Future Testwork
Although the results reported here are preliminary they are sufficiently encouraging to warrant further detailed testing. Future testwork will investigate optimisation of these tests and also of previous metallurgical testwork which investigated recovery of both gold and copper via flotation processing to produce a copper‐gold concentrate.
The flotation results indicated 89.0% recovery of gold and 93.4% recovery of copper to produce a high quality marketable concentrate with grades of up to 21.2% copper and
90.6 g/t gold. The objective of future work is to determine what combination of metallurgical parameters would be most efficient for processing the Randu Kuning gold and copper mineralisation.
For further information, please contact Peter Nightingale on +61 2 9300 3310. Yours sincerely
Peter Nightingale
Director pjn7878
Previous Disclosure
Information regarding Mineral Resources was prepared and first disclosed under the 2004 Edition of the 'Australasian Code for Reporting of 'Exploration Results, Mineral Resources and Ore Reserves'. It has not been updated since to comply with the 2012 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves' on the basis that the Company is not aware of any new information or data that materially affects the information and, in the case of the resource estimate, all material assumptions and technical parameters underpinning the estimate continue to apply and have not materially changed.
The information in this report that relates to the Mineral Resources is based on information compiled by Augur staff and contractors and approved by Michael Corey PGeo., who is a Member of the Association of Professional Geoscientists of Ontario (APGO) in Canada. Michael Corey is a full‐time employee of Augur and 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 a Competent Person as defined in the 2004 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'. Michael Corey has consented to the inclusion in this report of the matters based on his information in the form and context in which they appear.
Information that relates to Exploration Results was previously reported to the ASX on 22 July 2014 and is available to view on the Company's website at http://www.augur.com.au/www.augur.com.au. The Company confirms that it is not aware of any new information or data that materially affects the information or supporting documentation included in the original market announcement. The Company confirms that the form and context in which the Competent Person's findings are presented have not been materially modified from the original market announcement.
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