MetalsTech Limited: Excellent Gravity and Flotation Recoveries at Sturec Gold Mine
August 25, 2020
Highlights
- Excellent gold recovery on transitional (semi-oxidised) and sulphide (fresh) ore from the Andrej Adit within the Sturec Gold Mine using gravity separation and flotation
- Gravity gold recoveries range from 52% to 74% increasing to up to 88% after flotation and increasing to up to 98% if flotation tailings are also leached
- Strong gold recovery profile of sulphide ore supports potential for simple gravity separation and flotation processing strategy which would significantly reduce CAPEX and allow Sturec to produce a gold concentrate for export out of Slovakia where it could be processed further using conventional processing for sulphide concentrates or sold
Commenting on metwork, MetalsTech Chairman, Russell Moran stated:
“The sulphide ore at Sturec is the primary target ore type and it has demonstrated excellent gold recoveries from simple gravity separation and flotation. This opens up a wide range of simple and low CAPEX processing opportunities for Sturec, if this gold recovery profile continues. We look forward to complementing this bulk ore metallurgical test work with further testing and gold and silver assays from the current diamond core drilling program to follow.”
MetalsTech Limited (ASX: MTC) (the Company or MTC) is pleased to provide shareholders with an update on its metallurgical testing program at the Company’s 100%-owned Sturec Gold Mine (Sturec).
Company personnel in Slovakia, under the supervision of an independent geological consultant took face samples of transitional (semi-oxidised) and sulphide (fresh) ore from the Andrej Adit at Sturec in May 2020. These samples were collected and couriered securely, under strict quarantine protocols to Nagrom Laboratories in Perth for bulk ore gold and silver recovery tests as a precursor to testing core samples to be obtained from the current diamond core drilling program.
The objective of testing the sulphide ore was to confirm that potentially economic levels of gold and silver recovery could be obtained using conventional gravity and flotation processes from this style of mineralisation, to produce gold and silver concentrates suitable for either treatment in Slovakia using a non-cyanide processing technology (such as thiosulphate) or suitable for export to elsewhere in Europe (e.g. Poland) where the concentrates could be directly smelted or further processed using traditional cyanide leaching.
Metallurgical Sampling
Two 100kg bulk samples were mined from within the Sturec Mineral Resource where it can be accessed from the Andrej Adit at -435970mE; -1230067mN; 656m RL; Datum: S-JTSK/ Krovak.
Two samples were taken:
- P4 Transitional (semi-oxidised sample) was taken on the existing face of the mineralisation; and
- P4 Fresh (sulphide sample) was taken at the same location as P4 transitional but it was taken from at least 50cm into the existing face where the sample was geologically identified as fresh.
These samples were then transported securely, under strict quarantine protocols to Nagrom Laboratories in Perth for various metallurgical testwork programs.
Metallurgical Testwork Results
An approximately 20kg sub-sample of P4 Transitional and P4 Fresh were first subjected to a standard Gravity Recoverable Gold (GRG) test.
This test involved:
- Grinding to p90 = 850 microns and processing in a Knelson gravity concentrator.
- Grinding the first stage tailings to p50 = 75 microns and processing that in the Knelson.
- Grinding the second stage tailings to p90 = 75 microns and processing that in the Knelson.
The results of the GRG test were:
Sample
P4 Transitional
P4 Fresh
Au Head calc g/t
9.52
5.05
Ag Head Calc g/t
49
44
Grind p90 microns
850
850
Au recovery
33.05%
16.96%
Ag recovery
4.52%
2.84%
Grind p50 microns
75
75
Au recovery
37.48%
31.34%
Ag recovery
10.87%
11.27%
Grind p90 microns
75
75
Au recovery
3.53%
4.01%
Ag recovery
3.73%
2.33%
Total gravity Au Recovery
74.06%
52.31%
Total gravity Ag Recovery
19.12%
16.44%
Gravity Tailing g/t Au
2.50
2.44
Gravity Tailing g/t Ag
40
37
The tailings from the third stage gravity concentration were further processed by conventional sulphide flotation, which resulted in a further 12% and 30% gold recovery respectively.
Overall, the combined gravity and flotation recoveries were:
Sample
P4 Transitional
P4 Fresh
Gravity Au Recovery
74.06%
52.31%
Gravity Ag Recovery
19.12%
16.44%
Flotation Au Recovery
13.94%
29.69%
Flotation Ag Recovery
15.13%
32.26%
Overall Au Recovery
88.00%
82.00%
Overall Ag Recovery
34.25%
48.70%
Gravity separation and flotation does not incorporate the use of cyanide.
The flotation tailings were further leached in cyanide to determine if there was residual gold available for recovery.
Sample
P4 Transitional
P4 Fresh
Au Recovery to Concentrate
88.00%
82.00%
Ag Recovery to Concentrate
34.25%
48.70%
Au recovery in Tailings leach
9.90%
14.90%
Ag recovery in Tailings leach
10.76%
16.25%
Total Au Recovery
97.90%
96.90%
Total Ag Recovery
45.01%
64.95%
If tailings were to be further leached using cyanide (which is not permitted in Slovakia however is permitted in other close neighbouring European jurisdictions), total recoveries of up to 98% for gold and 65% for silver may be achieved. These results provide confidence that Sturec may lend itself to producing an attractive flotation concentrate, with a favorable processing profile.
The Company is also conducting additional recovery testwork using non-cyanide leaching agents (which may be permitted in Slovakia), with such testing also to occur on drill core from the current program.
The current drill program is progressing well and at a faster rate compared to the rate of drilling in the first hole of the program. A number of one off “teething” issues have been rectified. We look forward to updating shareholders on further drilling progress and first assays when they become available.
ENDS
For further information, contact:
Russell Moran
Chairman
M +61 415 493 993
Nathan Ryan
Investor Relations
M +61 420 582 887
nathan.ryan@nwrcommunications.com.au
Gino D’Anna
Director
M +61 400 408 878
Caution Regarding Forward-Looking Information
This document contains forward-looking statements concerning MetalsTech. Forward-looking statements are not statements of historical fact and actual events and results may differ materially from those described in the forward-looking statements as a result of a variety of risks, uncertainties and other factors. Forward-looking statements are inherently subject to business, economic, competitive, political and social uncertainties and contingencies. Many factors could cause the Company’s actual results to differ materially from those expressed or implied in any forward-looking information provided by the Company, or on behalf of, the Company. Such factors include, among other things, risks relating to additional funding requirements, metal prices, exploration, development and operating risks, competition, production risks, regulatory restrictions, including environmental regulation and liability and potential title disputes.
Forward looking statements in this document are based on the company’s beliefs, opinions and estimates of MetalsTech as of the dates the forward-looking statements are made, and no obligation is assumed to update forward looking statements if these beliefs, opinions and estimates should change or to reflect other future developments.
Competent Persons Statement
The information in this announcement that relates to Exploration Results is based on information compiled by Dr Quinton Hills Ph.D., M.Sc., B.Sc. Dr Hills is the technical advisor of MetalsTech Limited and is a member of the Australasian Institute of Mining and Metallurgy (No. 991225). Dr Hills has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Dr Hills consents to the inclusion in the report of the matters based on their information in the form and context in which it appears.
The information in the report to which this statement is attached that relates to Mineral Resources for the Sturec Gold Deposit is based on information compiled by Mr Chris Grove, who is a Member of The Australasian Institute of Mining and Metallurgy (No. 310106). Mr Grove is a full-time employee of Measured Group Pty Ltd and has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Mr Grove consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.
The information in the report to which this statement is attached that relates to Metallurgy and metal recoveries for the Sturec Gold Deposit is based on information compiled by Mr Noel O’Brien, who is a Fellow of The Australasian Institute of Mining and Metallurgy (No. 226758). Mr O’Brien is the Principal of Trinol Pty Ltd and has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. MrO’Brien consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.