Tinka Reports High Zinc Recoveries in Metallurgical Tests from Ayawilca
VANCOUVER, June 5, 2019 /PRNewswire/ - Tinka Resources Limited ("Tinka" or the "Company") (TSXV & BVL: TK) (OTCPK: TKRFF) is pleased to announce the results of metallurgical testwork on composite zinc sulfide samples from the Company's 100%-owned Ayawilca property in central Peru. The metallurgical test program was carried out by XPS Consulting and Testwork Services, Ontario, under the coordination of Adam Johnston of Transmin Metallurgical Consultants.
Key Highlights
- The objective of the testwork was to develop a flowsheet using standard flotation for the zinc mineralization at West and South Ayawilca, which was successfully achieved.
- Testwork results have demonstrated that recoveries of 92% zinc at a concentrate grade of 50% zinc can be consistently achieved using a standard flotation process. Two locked cycle tests were carried out on two different styles of mineralization and both tests produced similar zinc concentrates.
- Potentially deleterious elements in the zinc concentrates (including silica, manganese, cadmium, mercury, and arsenic) were well below standard smelter penalty levels. A small penalty is anticipated for iron content in the concentrate.
- Indium in the two locked cycle zinc concentrates (719 ppm and 400 ppm, respectively) is very high and potentially payable, subject to the smelter and commercial arrangements.
- Details of the processing flowsheet for zinc and lead concentrates will be incorporated into the upcoming Preliminary Economic Assessment ("PEA"). The Company expects to release the results of the PEA for the Ayawilca zinc project before the end of June 2019.
Dr. Graham Carman, Tinka's President and CEO, stated: "We are very pleased with the results of the metallurgical testwork, which has been completed to a high standard, as it predicts very high zinc recoveries from the mineralization at Ayawilca. We believe the Ayawilca zinc concentrate will be desirable for many smelters due to the low levels of silica, manganese and other deleterious elements, as well as for the high indium levels. We look forward to completing our PEA before the end of June 2019. As the project progresses, we will continue to seek improvements in the zinc and lead metallurgy with additional testwork."
Table 1 highlights final grades and recoveries of two locked cycle flotation tests (AEC-02 and AEC-03) and a batch test (AEC-05) on drill core composite samples from West and South Ayawilca.
Table 1 – Summary of Ayawilca Flotation Test Results
Composite
| Test Type | Assays (% Zn) | Recovery (% Zn) | |
Feed | Concentrate | |||
AEC-02 | Locked cycle | 10.8 | 50.9 | 92.5 |
AEC-03 | Locked cycle | 10.2 | 50.5 | 94.1 |
AEC-05 | Batch cleaner | 6.5 | 52.1 | 90.7 |
Methodology
A flotation development program was conducted to determine best conditions for high zinc recovery to a high quality zinc concentrate. The program focused on the South and West Ayawilca areas, which host approximately 50% of the resource and most of the higher grade zinc zones that would be mined in the early years. While the resulting composites were higher grade than the average diluted mining grades, it is believed that the samples were representative of the different mineral textures that will be encountered at Ayawilca, and were spatially representative of the South and West Ayawilca zinc zones, and therefore representative with respect to flotation performance. The results were used to develop the proposed flowsheet and reagent scheme that will be discussed in more detail in the upcoming PEA.
Detail of Sample Composites
- Composite AEC-02 was comprised of 11 quarter core samples from 11 drill holes at West and South Ayawilca (91.6 m sampled). Composite AEC-02 had relatively high Zn/S ratios (i.e., low pyrite content) and relatively coarse-grained sphalerite textures.
- Composite AEC-03 was comprised of 17 quarter core samples (all different to AEC-02) from 15 drill holes at West and South Ayawilca (129.7 m sampled). Composite AEC-03 had relatively low Zn/S ratios (i.e., high pyrite content) and finer grained sphalerite textures.
- Composite AEC-05 was comprised of 4 quarter core samples (all used in AEC-03) from 4 drill holes at West and South Ayawilca (39.5 m sampled). Composite AEC-05 had relatively low Zn/S ratios (i.e., high pyrite content) and relatively fine grained sphalerite textures.
- Two high pyrrhotite quarter core samples were not included in the tests. The pyrrhotite mineralization at Ayawilca is a minor and discrete geometallurgical domain that will be studied in future flotation development phases.
Detailed assays of the two locked cycle concentrates are presented in Table 2.
Table 2 – Detailed Analyses of Locked Cycle Concentrates AEC-02 and AEC-03 from Ayawilca
Analyte | Unit | Detection | AEC-02 | AEC-03 | Analyte | Unit | Detection | AEC-02 | AEC-03 |
Al | % | 0.01 | 0.03 | 0.03 | Sr | ppm | 3 | 16 | 21 |
As | ppm | 5 | 319 | 242 | Ta | ppm | 0.2 | < 0.2 | < 0.2 |
B | ppm | 10 | < 10 | < 10 | Tb | ppm | 0.1 | < 0.1 | < 0.1 |
Ba | ppm | 3 | 4 | 4 | Te | ppm | 6 | < 6 | < 6 |
Be | ppm | 3 | < 3 | < 3 | Th | ppm | 0.1 | 0.2 | 0.1 |
Bi | ppm | 2 | 26 | 22 | Ti | % | 0.01 | < 0.01 | < 0.01 |
Ca | % | 0.01 | 0.05 | 0.05 | Tl | ppm | 0.1 | 1.5 | 2.7 |
Cd | ppm | 2 | 1800 | 1650 | Tm | ppm | 0.1 | < 0.1 | < 0.1 |
Ce | ppm | 0.8 | 0.9 | < 0.8 | U | ppm | 0.1 | 1.1 | 1.2 |
Co | ppm | 0.2 | 8.5 | 11 | V | ppm | 5 | < 5 | < 5 |
Cr | ppm | 30 | 90 | 90 | W | ppm | 0.7 | 1.1 | 0.8 |
Cs | ppm | 0.1 | 1 | 0.9 | Y | ppm | 0.1 | 1 | 0.9 |
Cu | ppm | 2 | 2280 | 1880 | Yb | ppm | 0.1 | < 0.1 | < 0.1 |
Dy | ppm | 0.3 | < 0.3 | < 0.3 | Zn | % | 0.01 | 50.9 | 50.5 |
Er | ppm | 0.1 | < 0.1 | < 0.1 | Au | ppb | 2 | 60 | 21 |
Eu | ppm | 0.1 | 0.1 | < 0.1 | Pd | ppb | 5 | < 5 | < 5 |
Fe | % | 0.05 | 13.1 | 14 | Pt | ppb | 5 | < 5 | 11 |
Ga | ppm | 0.2 | 11.7 | 10.6 | Ag | ppm | 3 | 52 | 51 |
Gd | ppm | 0.1 | 0.1 | 0.1 | Hg | ppb | 5 | 4570 | 4510 |
Ge | ppm | 0.7 | 0.9 | 1.5 | C-Total | % | 0.01 | 0.15 | 0.21 |
Ho | ppm | 0.2 | < 0.2 | < 0.2 | S-Total | % | 0.01 | 33.9 | 34.1 |
Hf | ppm | 10 | < 10 | < 10 | Co3O4 | % | 0.005 | < 0.005 | < 0.005 |
In | ppm | 0.2 | 719 | 399 | CuO | % | 0.005 | 0.303 | 0.253 |
K | % | 0.1 | < 0.1 | < 0.1 | NiO | % | 0.003 | 0.008 | 0.006 |
La | ppm | 0.4 | 0.5 | < 0.4 | SiO2 | % | 0.01 | 0.74 | 0.46 |
Li | ppm | 3 | 24 | 24 | Al2O3 | % | 0.01 | 0.08 | 0.1 |
Mg | % | 0.01 | 0.16 | 0.1 | Fe2O3(T) | % | 0.01 | 16.94 | 18.32 |
Mn | ppm | 3 | 1190 | 1700 | MnO | % | 0.001 | 0.144 | 0.206 |
Mo | ppm | 1 | 5 | 5 | MgO | % | 0.01 | < 0.01 | < 0.01 |
Nb | ppm | 2.4 | < 2.4 | < 2.4 | CaO | % | 0.01 | < 0.01 | < 0.01 |
Nd | ppm | 0.4 | < 0.4 | 0.4 | Na2O | % | 0.01 | < 0.01 | < 0.01 |
Ni | ppm | 10 | 20 | 10 | K2O | % | 0.01 | 0.01 | 0.01 |
Pb | ppm | 0.8 | 821 | 4830 | TiO2 | % | 0.01 | 0.01 | 0.01 |
Pr | ppm | 0.1 | 0.1 | 0.1 | P2O5 | % | 0.01 | 0.01 | 0.01 |
Rb | ppm | 0.4 | 0.7 | 0.4 | Cr2O3 | % | 0.01 | 0.01 | 0.01 |
Sb | ppm | 2 | 25 | 34 | V2O5 | % | 0.003 | < 0.003 | < 0.003 |
Se | ppm | 0.8 | 2.6 | 2.4 | Cl | % | 0.01 | 0.03 | 0.02 |
Si | % | 0.01 | 0.39 | 0.26 | F | % | 0.01 | 0.02 | 0.01 |
Sm | ppm | 0.1 | 0.1 | 0.2 | CO3 (calc) | % | 0.01 | 0.25 | 0.59 |
Sn | ppm | 0.5 | 378 | 413 | LOI | % | 15.26 | 15.52 | |
Notes to Table 2. Assays were carried out by Activation Laboratories, Ancaster, Ontario
Elements (except precious metals, zinc) were analysed using peroxide fusion, ICP-OES and ICP-MS.
Zinc was analysed by peroxide fusion and ICP-OES.
Precious metals (Au, Pd, Pt, Ag) were analysed with fire assay and ICP-OES finish.
Hg was analysed by cold vapour FIMS.
C-Total and S-Total were analysed by infra-red techniques.
Oxides were analysed by whole rock analysis XRF.
Qualified Person
The results of the metallurgical tests have been reviewed and verified by Mr Adam Johnston, FAusIMM, CP (Metallurgy) of Transmin Metallurgical Consultants, Lima, a qualified person as defined by National Instrument 43-101. Mr Johnston has 25 years of mineral processing experience and is a Fellow of the Australasian Institute of Mining and Metallurgy.
Dr. Graham Carman, Tinka's President and CEO, reviewed, verified and compiled the technical contents of this release. Dr Carman is a Fellow of the Australasian Institute of Mining and Metallurgy, and is a qualified person as defined by National Instrument 43-101.
About Tinka Resources Limited
Tinka is an exploration and development company with its flagship property being the 100%-owned Ayawilca carbonate replacement deposit (CRD) in the zinc-lead-silver belt of central Peru, 200 kilometres northeast of Lima. The Ayawilca Zinc Zone contains 11.7 Mt of Indicated Resources grading 6.9% zinc, 0.2% lead, 15 g/t silver and 84 g/t indium and 45.0 Mt Inferred Resources grading 5.6% zinc, 0.2% lead, 17 g/t silver and 67 g/t indium. The Ayawilca Tin Zone contains an Inferred Mineral Resource of 14.5 Mt at 0.63% tin, 0.21% copper & 18 g/t silver (November 26, 2018 release). A PEA is underway with results anticipated by end of Q2 2019.
On behalf of the Board,
"Graham Carman"
Dr. Graham Carman, President & CEO
Forward Looking Statements: Certain information in this news release contains forward-looking statements and forward-looking information within the meaning of applicable securities laws (collectively "forward-looking statements"). All statements, other than statements of historical fact are forward-looking statements. Forward-looking statements are based on the beliefs and expectations of Tinka as well as assumptions made by and information currently available to Tinka's management. Such statements reflect the current risks, uncertainties and assumptions related to certain factors including, without limitations, drilling results, the Company's expectations regarding the Ayawilca Project PEA, capitaland other costs varying significantly from estimates, production rates varying from estimates, changes in world metal markets, changes in equity markets, uncertainties relating to the availability and costs of financing needed in the future, equipment failure, unexpected geological conditions, imprecision in resource estimates or metal recoveries, success of future development initiatives, competition, operating performance, environmental and safety risks, delays in obtaining or failure to obtain necessary permits and approvals from local authorities, community agreements and relations, and other development and operating risks. Should any one or more of these risks or uncertainties materialize, or should any underlying assumptions prove incorrect, actual results may vary materially from those described herein. Although Tinka believes that assumptions inherent in the forward-looking statements are reasonable, forward-looking statements are not guarantees of future performance and accordingly undue reliance should not be put on such statements due to the inherent uncertainty therein. Except as may be required by applicable securities laws, Tinka disclaims any intent or obligation to update any forward-looking statement.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release
SOURCE Tinka Resources Limited
Share this article