FAVOURABLE METALLURGICAL RESULTS FROM AVINO';S OXIDE TAILINGS PROJECT
Avino Silver & Gold Mines Ltd. (TSX: ASM, NYSE American: ASM) announced promising metallurgical results from its Oxide Tailings project, which has a resource of 5.7 million tonnes with a silver equivalent grade of 95 g/t. The project aims to reprocess oxidized material previously underutilized due to limitations in conventional methods. Highlights include a 408% increase in measured and indicated resources since 2021 and significant recoveries of gold (up to 89.5%) and silver (up to 90.4%) using conventional techniques. The results pave the way for a Pre-Feasibility Study and align with Avino's growth strategy in Mexico.
- 408% increase in measured and indicated resources since 2021.
- Significant recoveries: Ancient Oxides gold recovery up to 89.5%, silver recovery up to 90.4%.
- Oxide Tailings project aligns with five-year growth plan to become an intermediate silver producer.
- Decline in inferred resources by 77% since 2021.
- Decrease in grades for both Ag and Au in inferred resources, indicating potential challenges in resource quality.
These results below will form the basis for the metallurgical analysis of a Pre-Feasibility Study ("PFS") on the Project.
In addition, a table can be viewed at the end of this release showing a comparison between the 2021 and 2023 mineral resource estimate on the Oxide Tailings as contained in the respective technical reports which can also be viewed on Avino's profile on SEDAR.
"We are very pleased with these metallurgical results, which demonstrate excellent metal recoveries that would be suitable for a precipitating into bullion," commented CEO
The project consists of three types of tailings that are categorized by grade as well as identified in three stratigraphic layers within the deposit based on the time period when they were processed. They are, Ancient Oxides, Recent Oxides and Sulphides, and each type was sampled and tested separately. The average grades are shown below.
Table 1: Average Grade of Each Tailings Type | |||
Sample | Description | Au g/t | Ag g/t |
Ancient Oxides | Original | 0.45 | 101.0 |
Recent Oxides | Original | 0.48 | 37.0 |
Sulphides | Original | 0.24 | 21.0 |
The project exhibits an excellent response using conventional metallurgical techniques.
Ancient Oxides
Gold Recovery up to
Recent Oxides
Gold Recovery up to
Sulphides
Gold Recovery up to
The conventional bottle roll test parameters for the three samples were achieved at a particle size of eighty percent passing 75 microns using 500 to 1000ppm sodium cyanide and a retention time of 60-72 hours. The metallurgical test program was completed by SGS de Mexico ("SGS"), a leading metallurgical testing and consulting firm based in
The testwork program included chemical analysis, size fraction analysis, agglomeration, bulk leaching extractable gold test, bottle roll test to simulate agitated leaching, column leaching tests to simulate heap leaching, flotation, and cyanide detoxification using sodium hypochlorite.
Flotation was investigated at a variety of grind sizes, reagent levels and operating conditions. A Bulk leach extractable gold test was performed to understand the leaching response of each respective size fraction on each sample. While each size fraction of each sample did show a variation in leaching performance it was determined that there were not significant portions of gold locked away rendering any sample unleachable. With that in mind, various leaching conditions and three particle sizes were investigated per sample. Each sample performed best with a 75um ("micron") grind size, furthermore it did not appear that the addition of lead nitrate or oxygen provided superior leach results. Finally, a column leach test was performed on each sample in order to replicate the performance of a potential heap leach. The flotation, agitated leach and column leach results are shown per sample are shown below.
Table 2: Summary of Recoveries for the Sulphides Sample | ||
Description | Au | Ag |
Flotation | 45.8 | 46.5 |
Table 3: Summary of Recoveries for the Ancient Oxide Sample | ||
Description | Au | Ag |
Flotation | 46.3 | 45.5 |
Table 4: Summary of Recoveries for the Recent Oxide Sample | ||
Description | Au | Ag |
Flotation | 47.6 | 45.5 |
In addition to these leaching and flotation results, ongoing testing consists of the thickening, filtering, communition optimization, cyanide detoxification, gravity testwork as well as specific gravity and bulk density testwork that will be fed into the PFS for appropriate flowsheet design, sizing and costing.
Oxide Tailings Mineral Resource Comparison Table | ||||
2023 Mineral Resource Estimate¹ | 2021 Mineral Resource Estimate² | Net Change | ||
Measured Resources | Mt | 3,809,000 | - | ∞% |
Grade | Ag g/t | 63 | - | ∞% |
Grade | Au g/t | 0.48 | - | ∞% |
Grade | AgEq g/t | 102 | - | ∞% |
Metal Contents | 7.7 | - | ∞% | |
Metal Contents | 59 | - | ∞% | |
Metal Contents | AgEq Moz | 12.5 | - | ∞% |
Indicated Resources | Mt | 1,877,000 | 1,120,000 | 68 % |
Grade | Ag g/t | 41 | 89 | -54 % |
Grade | Au g/t | 0.49 | 0.42 | 17 % |
Grade | AgEq g/t | 81 | 124 | -35 % |
Metal Contents | 2.5 | 3.2 | -22 % | |
Metal Contents | 30 | 15 | 100 % | |
Metal Contents | AgEq Moz | 4.9 | 4.5 | 9 % |
Measured and Indicated Resources | Mt | 5,686,000 | 1,120,000 | 408 % |
Grade | Ag g/t | 56 | 89 | -37 % |
Grade | Au g/t | 0.48 | 0.42 | 14 % |
Grade | AgEq g/t | 95 | 124 | -23 % |
Metal Contents | 10.2 | 3.2 | 219 % | |
Metal Contents | 88 | 15 | 487 % | |
Metal Contents | AgEq Moz | 17.4 | 4.5 | 287 % |
Inferred Resources | Mt | 278,000 | 1,230,000 | -77 % |
Grade | Ag g/t | 65 | 85 | -24 % |
Grade | Au g/t | 0.44 | 0.47 | -6 % |
Grade | AgEq g/t | 101 | 125 | -19 % |
Metal Contents | 0.6 | 3.4 | -82 % | |
Metal Contents | 4 | 19 | -79 % | |
Metal Contents | AgEq Moz | 0.9 | 5.0 | -82 % |
¹ Reference: Mineral Resource Estimate Update for the Avino Property, |
² Reference: Amended Resource Estimate Update For The Avino Property, |
To view these reports in their entirety, please refer to Avino's profile on SEDAR at www.sedar.com. |
About Avino
Avino is a silver producer from its wholly owned
ON BEHALF OF THE BOARD
"David Wolfin"
________________________________
President & CEO
This news release contains "forward-looking information" and "forward-looking statements" (together, the "forward looking statements") within the meaning of applicable securities laws and the United States Private Securities Litigation Reform Act of 1995, including the amended mineral resource estimate for the Company's Avino Property located near Durango in west-central Mexico (the "Avino Property") with an effective date of
References to Measured & Indicated Mineral Resources and Inferred Mineral Resources in this press release are terms that are defined under Canadian rules by National Instrument 43-101 ("NI 43-101"). On
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