- 01Vinatas Tecomatlán: 78.6% Sb recovery; 58% Sb conc.
- 02Follow-up: 75.8% Sb; gravity 68.3% Sb conc.
- 03MoU: ~80 t/mo Vinatas; closer processing lowers transport.
EV Resources (ASX: EVR) has confirmed that testing of an additional regional third-party ore source through its Tecomatlán plant in Mexico has returned high antimony recoveries using conventional flotation and gravity processing.
The program evaluated a combination of bulk flotation, controlled grinding, gravity concentration, and centrifugal recovery techniques to establish a practical preliminary processing route for material from the independently owned Vinatas project, located 170 kilometres from the plant.
Initial bulk flotation testwork achieved 78.6% cumulative antimony recovery and produced a flotation concentrate grading of 58.82% antimony using a conventional potassium amyl xanthate (PAX) and lead nitrate reagent scheme.
Follow-up flotation testing achieved 75.8% antimony recovery under similar grinding and reagent conditions, providing EV with encouraging evidence of repeatable metallurgical performance.
Tailings Concentrate Recovery
Further upgrading of the Test 2 bulk flotation concentrate through gravity cleaning on a Wilfley shaking table produced a stibnite concentrate grading 68.3% antimony and 4.36% silicon dioxide.
Wilfley tailings graded 38% antimony, indicating the potential for recirculation or further treatment as part of an optimised integrated flowsheet.
Three sequential passes of flotation tailings through a Falcon centrifugal concentrator recovered additional stibnite into secondary gravity concentrates and reduced the final tailings antimony grade from 6.14% to 2.17%.
These results are thought to demonstrate the potential for a gravity recovery stage on flotation tailings to increase overall stibnite recovery while reducing metal losses to final tailings.
Third-Party Antimony Supply
Included in the memorandum of understanding signed in May for third-party antimony supply, Vinatas complements previously reported metallurgical results using ore from the Chintantla mine, owned by Lucero Grupo Minero de Puebla.
The operation has an established history of antimony production and sales, with previous sales of run-of-mine ore to a processing facility in San Luis Potosí, located approximately 500km from the mine site.
Tecomatlán represents a significantly closer potential processing destination, providing an opportunity for Vinatas’ owner to reduce transportation costs and improve overall logistics.
EV confirmed that Vinatas could supply approximately 80 tonnes per month of lower or higher-grade material to the plant, depending on market conditions and mining schedules, initially as-mined without the need for significant upfront processing infrastructure at the mine site.
It is seen as an initial starting point with the potential for expansion through additional mine development, underground preparation, and improved access to mineralised zones.
Preliminary Processing Route
EV interim chief executive officer Miguel Barahona said the Vinatas material was amenable to conventional mineral processing technologies, and could be a preliminary processing route to producing a high-grade stibnite concentrate.
“Vinatas is now the second regional third-party feed source to demonstrate strong metallurgical performance using conventional processing technologies compatible with Tecomatlán,” he said.
“The results are another important step in building our regional processing model and demonstrate why we have developed Tecomatlán with a flexible combination of flotation and gravity processing.”
“Different regional ore sources may require different combinations of these circuits, giving us the ability to adapt the processing route to the characteristics of each feed.”
“We are continuing to build regional feedstock around Tecomatlán while progressing the plant toward proof-of-concept operations and the production of a marketable antimony concentrate.”
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