Trial Processing Accelerates at the Old Pirate Gold Project
Perth, Nov 11, 2013 AEST (ABN Newswire) - ABM Resources NL (
ASX:ABU) ("ABM" or "The Company") presents an update on the Trial Mining and Processing at the Old Pirate High-Grade Gold Project in the Northern Territory of Australia.
Trial Processing Update:
- Trial processing beyond halfway mark with >5,000 tonnes complete.
- Split shift processing 180 to 220t per day with completion anticipated early December.
- Plant feed (head grades) continue to exceed expectation.
- Tails grades continuing to indicate high rates of in-plant recovery (>90%) from gravity only processing.
Table 1. Summary of processing to date.
----------------------------------------------------------Tonnes Processed 5,067t Head Grade Average (1) 14.7g/t Tail Grade Average (2) 1.3g/tIn-plant Gravity Recovery (%) (3) 91.10%Gold Delivered to Perth Mint (4) 1,233 ounces/ 38.4kg*Gold In Circuit (5) 945 ounces / 29.4kg ----------------------------------------------------------Total Gold (Delivered or In Circuit) 2,178 ounces / 67.8kg----------------------------------------------------------
*Does not include approximately 4kg of gold (estimated) recovered on-site / pending transit.
Footnotes to Table 1:
1. Head grade average is based on sampling from feed conveyor and estimate from grade control data where feed conveyor samples are pending.
2. Tail grade average based on tails sample results received to date.
3. In-plant recovery is weighted to tonnes and actual daily feed vs tail assays.
4. Gold based on out-turn from Perth Mint + gold in concentrate delivered pending refining.
5. Gold in circuit estimated based on weighted averages from 1, 2, 3, 4.
Trial Mining Update:
- >7,000 tonnes of high-grade material mined on the basis of known mineralised zones.
- ~2,000 tonnes of additional material stockpiled where re-sampling indicated grades of 5 to 15g/t gold.
- Continued detailed mapping and sampling to understand the geometry and distribution of grade in the mineral system providing new extensional drill targets.
Darren Holden, Managing Director said, "We are very pleased with the recent accelerated progress on the Trial Processing with weekly gold deliveries to the Perth Mint generating positive cash-flow. The technical information we have received to date is very encouraging and we aim to have Stage One mining completed over the coming weeks. We will not have a complete reconciliation until the circuit and the ball mill are cleaned out at the end of the trial. However, all indications are that the grade of the 5,000t processed to date, including gold in circuit, exceeds the published resource estimation grade.
Insights gained through the opening up of the geology of this mineral system continue to provide extensions to known veins and additional targets on what is possibly one of the last high-grade open-pit mineable gold systems in Australia."
Trial Processing Update
To date a total of more than 5,000 tonnes of the Stage 1 Trial Processing has been completed and based on our current schedule, with anticipated throughput of 180 to 220 tonnes per day, the Trial Processing will be complete early to mid-December.
Recovered Gold, Head Grade versus Tail Grade and Gold-In-Circuit for In-Plant Recovery
The Company has been conducting weekly gold shipments since early October. To date approximately 1,200 ounces of gold valued at approximately $1.7M have been delivered to the Perth Mint Refinery. In addition a further 4 kilograms of high-grade gold concentrate has been produced from 400 tonnes processed since the last shipment and is not included in Table 1 or Chart 1 in link below.
The head grade and tail assaying lag production by approximately 2 weeks (due to laboratory sample turn-around times) but information received to date continues to show strong in-plant recoveries averaging 91%. (refer to Appendix 1 for further information). Gold to tails is principally from the finer fractions (including <53microns) and, following the completion and analysis of the Trial Processing, the Company will be considering strategies to increase fine gold gravity recovery. It is important to note that ABM is utilising a small and fully lined tailings storage facility, and is also developing strategies to recover the gold in this tails storage during Stage 2.
As noted in the previous release and confirmed by an independent metallurgist, the gold in circuit is building-up, principally in the ball mill. The build-up is currently estimated at 945 ounces. This is considered standard in the early stages of gold processing, especially for material with a high free / gravity gold content for similar reasons that makes the project amenable to gravity recovery as the principal processing method. Overall gold out-turns are increasing as gold in circuit builds up and approaches steady state. Following the completion of the Trial Processing, the ball mill will be stripped clean and final reconciliations will be possible. The gold in circuit estimation in Table 1 is based on a calculation involving head grade (from feed assays and grade control data), tails grade and gold produced and is to be considered as a guideline only pending gold recovery when cleaning the mill.
See Chart 1 in link below for details / progress to-date.
Trial Mining
The Company has, to date, mined more than 9,000 tonnes of gold-bearing material from the numerous trial pits including Golden Hind, Old Pirate South, East-Side veins, SE Veins, Old Pirate Central / Eastern Limb and the Western Limb. The 9,000 tonnes include approximately 7,000 tonnes of material extracted on the basis of known mineralisation, and a further 2,000 tonnes of material not previously thought to be mineralised, where re-sampling determined a gold content between 5 and 15g/t gold. Trial Mining of the 10,000 tonne parcel is expected to be completed shortly.
Trial Mining has revealed a number of new structures and has improved understanding of the detailed shape, orientation and thickness variation of the mineralised veins. The plunge of various high-grade zones is slightly shallower than previously thought, around 20 degree southerly plunge. These observations will improve targeting of near surface high-grade extensions to potentially increase openpit resource areas. Following the completion of Trial Mining ABM will update its existing models and open-pit optimisations to reflect the increased knowledge and will commence the review of near-deposit / near-surface extensional targets for drilling.
To view diagrams and charts, please visit:
http://media.abnnewswire.net/media/en/docs/ASX-ABU-657083.pdf
About ABM Resources NL
ABM Resources (ASX:ABU) is developing several gold discoveries in the Central Desert region of the Northern Territory of Australia. The Company has a multi-tiered approach to exploration and development with a combination of high-grade production scenarios such as the Old Pirate High-Grade Gold Project, large scale discoveries such as Buccaneer, and regional exploration discoveries such as the Hyperion Gold Project. In addition, ABM is committed to regional exploration programs throughout its extensive holdings including the alliance with Independence Group NL at the regional Lake Mackay Project.
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