METEORIC RESOURCES NL For personal use only
ASX ANNOUNCEMENT
9 FEBRUARY 2022
Additional Metallurgical Test-work Confirms Exceptional
Gold Recoveries at Butchers Creek
Key Highlights
- Continued test-work demonstrates straightforward non-refractory metallurgical ore characteristics, with a likely processing route incorporating a simple industry standard CIL cyanide leach plant
- Whole of ore leaching achieved a gold dissolution of 95-96% after only 24 hours leach time
- Physical characteristics indicate a soft to medium hardness which is readily amenable to conventional comminution (crushing) equipment
- Akin to Composite #1, the results from Composite #2 confirm a simplified flowsheet requiring either a potential low-cost treatment facility or ore which is also amenable to toll treatment
Meteoric Resources NL (ASX: MEI) ("Meteoric" or "the Company") is pleased to announce the final results for metallurgical test work completed on Composite #2 (Tranche 2) from the sulphide zones at the Butchers Creek Gold Deposit, located at the Company's wholly owned Palm Springs Project in Western Australia.
As with Tranche 1 (see ASX Announcement 13th December 2021), Tranche 2 was designed as a series of sighter tests to gauge the complexity required to recover gold using standard sulphide ore screening techniques.
Samples of half core from Butchers Creek holes BCRD484 (Composite #1) and BCRD486 (Composite #2) were sent to ALS laboratories in Perth where the two composites, one from each hole, were formulated.
Managing Director, Dr Andrew Tunks said "The metallurgical test results from Composite #2 again produced outstanding results that confirm a low cost, simple "whole of ore" flowsheet using Cyanide in leach (CIL) is suitable for Butchers Creek gold-rich ore. These results will be fed into the current scoping study which is due for release to the market in the current Quarter."
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Metallurgical Test Program
Each composite was formulated at ALS Laboratories in Perth from half HQ core sent from site, with all test work carried out under the supervision of Trinol Pty Ltd in Perth.
Prior to compositing, half-core samples were set aside to measure the physical characteristics - UCS, Crushing Index (CWi) and Ball Milling Index (BBMi).
Head samples were examined by XRD to gauge the extent of sulphide minerals present, then subjected to the following standard test regime:
- Grind Establishment.
- Gravity followed by direct cyanide leach.
- Gravity recovery followed by flotation, ultra fine grinding to 10 microns of the concentrate and leaching of the tailings.
- Whole of ore leaching
The full metallurgical testing flowsheet is included below in Appendix 1.
Composites
Composite #1 was made from Hole BCRD484 (Table 1).
Table 1. Composite # 1 details | ||||||||||||||||||
Sample ID | Sample | Composite ID | As Received | Composite | Assay | |||||||||||||
Description | Weight (kg) | Gold g/t | Sulphur % | |||||||||||||||
Palm Springs | ||||||||||||||||||
BCRD484 | Half Core | BCRD484 Fresh | 48.3 | 1.42 | 1.44 | |||||||||||||
Composite #1 | ||||||||||||||||||
Composite #2 was made from Hole BCRD 486 (Table 2).
Table 2. Composite # 2 details | ||||||||||||||||||
Sample ID | Sample | Composite ID | As Received | Composite | Assay | |||||||||||||
Description | Weight (kg) | Gold g/t | Sulphur % | |||||||||||||||
Half Core, | Palm Springs | |||||||||||||||||
BCRD486 | BCRD486 Fresh | 42.5 | 1.94 | 1.46 | ||||||||||||||
Surface Moisture | ||||||||||||||||||
Composite #2 | ||||||||||||||||||
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Mineralogy
The XRD analyses for Composite #1, shown below, confirmed moderately sulphidic ore containing just over 1% combined sulphides, but which also contained calcite and carbonate-rich minerals, ~4% by mass. Such carbonate-rich ores will assist with moderating any potential acid forming properties of the tailings and reduce lime consumption in the process (as reported ASX Announcement 13th December 2021).
Table 3. XRD Mineralogy
Ore Mineral Assembly | Composite #1 - Mass % |
Pyrrhotite | 1 |
Pyrite and/or hematite | < 1 |
Clay minerals | < 1 |
Chlorite | 16 |
Muscovite | 1 |
Plagioclase | 38 |
K-feldspar | 24 |
Quartz | 16 |
Calcite | 2 |
Siderite type carbonate | 2 |
Physical Properties
The measured physical properties indicate a weak to moderately hard ore which would not pose issues in terms of the design or selection of conventional crushing and grinding equipment.
Table 4. Physical Properties | |||||
Property | Unit | Value | Comment | ||
Comp. #1 | Comp. #2 | ||||
UCS | MPa | 14.9 ~ 30 | 12.2 ~56.7 | Weak to moderately hard | |
CWi | kWh/t | Ave. 6.0 | Ave. 6.2 | Low | |
BBMi | kWh/t | Ave.17.0 | Ave. 17.3 | Moderately hard |
Leaching Tests
Composite #1 (updated)
Recoveries including a gravity component have been revised in this announcement, as the laboratory found a technical issue with the analysis of gravity concentrates following the first series of tests (as reported ASX Announcement 13th December 2021). This has now been corrected and resulted in lower gravity recoveries (Table 5). The "whole of ore" result was not affected.
Table 5. Leach Test Data Composite #1 | ||||||||||||
Test Detail | Grind | Gold Assay | g/t | Au Extraction | ||||||||
Composite #1 | ||||||||||||
P80 um | Individual | Head | Gravity | 24 hr cyanide | 48 hr cyanide | |||||||
Gravity/Direct | 75 | 1.22/1.58/1.59/1.29 | 1.42 | 12.2% | 90.7% | 92.3% | ||||||
Cyanide leach | ||||||||||||
Gravity/Flotation/ | ||||||||||||
UFG Conc./Direct | 75 | 1.22/1.58/1.59/1.29 | 1.42 | 12.7% | 96.1% | 96.2% | ||||||
Cyanide leach | ||||||||||||
Whole of ore leach | 75 | 1.22/1.58/1.59/1.29 | 1.42 | 0 | 96.4% | 94.7% |
Composite #2:
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Table 6. Leach Test Data Composite #2 | |||||||||||||
Test Detail | Grind | Gold Assay | g/t | Au Extraction | |||||||||
Composite #2 | |||||||||||||
P80 µm | Individual | Head | Gravity | 24 hr cyanide | 48 hr cyanide | ||||||||
Gravity/Direct | 75 | 1.81/1.77/2.54/1.64 | 1.94 | 48.7% | 96.8% | 97.2% | |||||||
Cyanide leach | |||||||||||||
Gravity/Flotation/ | |||||||||||||
UFG Conc./Direct | 75 | 1.81/1.77/2.54/1.64 | 1.94 | 48.2% | 96.4% | 97.4% | |||||||
Cyanide leach | |||||||||||||
Whole of ore leach | 75 | 1.81/1.77/2.54/1.64 | 1.94 | 0 | 95.1% | 96.5% |
Note: All leach tests were done at a conventional grind size of p80 = 75 microns.
Gravity gold recovery was determined in a mini-Knelson Concentrator and the results of 48% gravity recoverable gold were obtained for Composite #2. However, the overall gold recoveries at 24 hours leach time, even in conjunction with flotation, were only marginally improved from 95% to 96%. As such, as detailed in results reported in December, the extra capital and operating cost of gravity and flotation may not be justifiable. This will be subject to further close examination as development of Palm Springs continues.
The "Whole of Ore" leach tests produced the highly encouraging recovery of 95-96% gold after a leach time of only 24 hours. Further test work will be undertaken to see if these recoveries can be improved with extra cyanide residence time as suggested by Composite #2 results.
The most important outcome from the all the test work is the high leach recovery of gold achieved on straight "Whole of Ore" leaching, which indicates the gold is well liberated and not locked up or influenced by the presence of moderate amounts of sulphides.
Further Work
The next phase of evaluation will be to use these results as a basis for a Scoping Study based on a fit for purpose CIL plant and associated mining and infrastructure at Butchers Creek.
This release has been authorised by the Board of Meteoric Resources NL.
For further information, please contact: | |
Dr Andrew Tunks | Victoria Humphries |
Managing Director | Investor and Media Relations |
Meteoric Resources | NWR Communications |
E: ajtunks@meteoric.com.au | E: victoria@nwrcommunications.com.au |
T: +61 400 205 555 | T: +61 431 151 676 |
Competent Person Statement
The information in this announcement that relates to exploration results is based on information reviewed, collated and fairly represented by Mr Peter Sheehan who is a Member of the Australasian Institute of Mining and Metallurgy and a consultant to Meteoric Resources NL. Mr Sheehan has sufficient experience relevant to the style of mineralisation and type of deposit under consideration, and to the activity which has been undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. Mr Sheehan consents to the inclusion in this report of the matters based on this information in the form and context in which it appears.
The information in this release that relates to metallurgy and metallurgical test work has been reviewed by Mr Noel O'Brien, FAusIMM, MBA, B. Met Eng. Mr O'Brien is not an employee of the Company but is employed as a contract consultant. Mr O'Brien is a Fellow of the Australasian Institute of Mining and Metallurgy, he has sufficient experience with the style of processing response and type of deposit under consideration, and to the activities undertaken, to qualify as a competent person as defined in the 2012 edition of the "Australian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves" (The JORC Code). Mr O'Brien consents to the inclusion in this report of the contained technical information in the form and context as it appears.
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APPENDIX 1.
Figure 1. Metallurgical Test Program Flowsheet - Butchers Creek Comminution Test Work
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Meteoric Resources NL published this content on 08 February 2022 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 08 February 2022 22:27:05 UTC.
