Avino Silver and Gold Recovery: Flotation and Cyanidation Methods

Source: AVINO SILVER AND GOLD MINES LTD (2026)
Website: https://www.avino.com/

Critical Data

Overview

Avino Silver and Gold Mines Ltd. operates a comprehensive mineral processing facility at the Avino Property, located in Mexico. The existing mill employs a conventional flotation circuit with four separate circuits achieving a combined throughput of 2,500 tonnes per day (tpd), producing a copper concentrate enriched with silver and gold. Since restarting operations in Q3 2021, the mill has consistently processed ore from the Avino ET vein, with recent feed from La Preciosa underground development being co-processed starting in Q4 2025. The facility has demonstrated strong metallurgical performance: in Q1 2026, silver recovery averaged 81%, gold recovery 73%, and copper recovery 84% from feed grades of 56 g/t silver, 0.42 g/t gold, and 0.42% copper. In addition to the existing operation, Avino is advancing a proposed reprocessing plant for historic oxide tailings, designed to treat 2,250 tpd using tank cyanide leaching followed by the Merrill-Crowe process to produce silver-gold doré. Over a nine-year life-of-mine (LOM), average recoveries of 77.2% for silver and 74.9% for gold are projected from an average head grade of 54.5 g/t silver and 0.47 g/t gold. Tailings will be detoxified, filtered, and deposited in a lined dry stack facility, reflecting a commitment to environmental stewardship. This combination of proven flotation technology and innovative cyanidation recovery positions Avino as a significant silver and gold producer.

Key Process Stages

• Stage 1: Comminution – Run-of-mine (ROM) ore is crushed and ground in ball mills to achieve a particle size suitable for liberation. The target grind size is optimized to maximize exposure of silver, gold, and copper minerals to the subsequent flotation process, though specific P80 values are not publicly reported.
• Stage 2: Conventional Flotation – The ground slurry is fed into four separate flotation circuits (Circuit #1 at 250 tpd, Circuit #2 at 250 tpd, Circuit #3 at 1,000 tpd, and Circuit #4 at 1,000 tpd). Reagents are added to produce a bulk copper flotation concentrate that carries the silver and gold values. Circuit #1 has been modified to handle Avino ET ore and will produce a gold-silver concentrate when processing La Preciosa material.
• Stage 3: Concentrate Thickening and Dewatering – The flotation concentrate is thickened in a conventional thickener and then dewatered using a filter press to reduce moisture content. The final copper concentrate, containing silver and gold, is shipped to off-site smelters for metal recovery.
• Stage 4: Oxide Tailings Cyanide Leaching – For the proposed reprocessing facility, historic oxide tailings will be reclaimed using front-end loaders and trucks, then slurried and leached in agitated carbon-in-leach (CIL) tanks with sodium cyanide. The target residence time and cyanide concentration are designed to extract up to 77.2% silver and 74.9% gold over the LOM.
• Stage 5: Merrill-Crowe Process and Doré Production – The pregnant leach solution is clarified, de-aerated, and then passed through a Merrill-Crowe circuit where zinc dust is added to precipitate silver and gold. The resultant precipitate is smelted in a furnace to produce silver-gold doré bars. The barren solution is recycled, and the leach residue undergoes cyanide detoxification before being filtered and stacked in a dry tailings facility.

Additional Interesting Data and Summary

The Avino Property recovery methods encompass both established flotation operations and a future tailings reprocessing facility that together represent a comprehensive metals extraction strategy. In 2025, the existing mill processed 736,935 dry tonnes, producing 1,157,828 ounces of silver, 7,621 ounces of gold, and 5,667,996 pounds of copper at average recoveries of 84% for silver, 73% for gold, and 84% for copper. By Q1 2026, feed from La Preciosa underground development (14,098 tonnes) was successfully co-processed, demonstrating operational flexibility. The proposed oxide tailings reprocessing plant, designed for a 2,250 tpd nominal capacity over a nine-year life-of-mine, will process a total of 6,708.6 kilotonnes of historic tailings. The LOM average head grades are 54.5 g/t silver and 0.47 g/t gold, with projected recoveries of 77.2% for silver and 74.9% for gold, yielding approximately 9.07 million ounces of silver and 76,000 ounces of gold as doré. Annual production varies significantly: Year 1 is lower due to ramp-up, while Years 2 and 5 are peak years (e.g., Year 5: 1,573.4 koz silver, 9.7 koz gold). Environmental sustainability is a key design element—the tailings reprocessing includes cyanide detoxification and dry stack tailings disposal in a lined facility, minimizing water consumption and environmental liability. While specific energy and water consumption data are not provided in the source document, the use of a dry stack tailings facility indicates a lower water footprint compared to traditional slurry impoundments. The integration of the oxide tailings project extends the Avino Property’s production profile and converts a historic liability into a valuable resource. Looking forward, the successful processing of La Preciosa ore at the Avino mill suggests potential for expanded throughput if underground development progresses. The combination of proven flotation circuits and advanced cyanidation technology positions Avino to maintain robust silver and gold production while adopting best practices in tailings management.

Key Processes: Flotation, Cyanidation, Gravity Separation

Target Commodities: Gold, Silver, Copper