Antimony Resources Starts 200t Plant Test to Prove It Can Produce Antimony
Key Takeaways
- Antimony Resources has begun a 200-tonne campaign at Tecomatlán, its first plant-scale processing of third-party material, with dry and wet commissioning complete.
- Chinantla, 8km from the plant, is the only binding feed source under a five-year agreement, while Vinatas and Coyul rely on non-binding MOUs.
- The headline 68.3% Sb for Vinatas is the gravity-upgraded grade; straight flotation delivered 58.82% Sb, and all figures are bench-scale.
- Coyul's best test lifted total recovery to 73.3% with tailings down to 1.5% Sb, but arsenic at 1.11% in the bulk concentrate still needs rejecting.
- Independent assay results and offtake agreements are the next catalysts, and the company warns there's no certainty the concentrate will meet specification or be sold.
Tecomatlán commences first antimony concentrate campaign
Antimony Resources (ASX: ANT) has commenced a 200-tonne Proof-of-Concept campaign at its Tecomatlán Processing Plant in Mexico. It is the first plant-scale processing of third-party material at the plant, and it is designed to produce the first bulk antimony concentrate from Tecomatlán.
Dry and wet commissioning is complete. Approximately 200 tonnes of material from Chinantla, located approximately 8km from the plant, is now being processed.
The Company describes the campaign as the start of its transition from explorer to antimony concentrate producer. That is the Company’s framing of the direction of travel, not a completed outcome. For you as an investor, it means the story is shifting from laboratory results to what a working plant can actually deliver.
The campaign is designed to validate the operating sequence at plant scale, including:
- production of the first bulk antimony concentrate at Tecomatlán
- confirmation of concentrate grade, recovery and impurity levels through independent assays
- evaluation of plant operating parameters and processing performance
- validation of handling, sampling, weighing and logistics procedures ahead of any commercial shipment
Executive Chairman Shane Menere set out the Company’s view:
Shane Menere, Executive Chairman
“Tecomatlán is now processing material, and that is the point where Antimony Resources begins the move from explorer to producer…”
Shane Menere, Executive Chairman
“…At a time when Western buyers are actively seeking antimony from outside China, a North American plant producing concentrate is exactly where we want to be.”
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Three regional feedstock sources underpin the hub
Feedstock is the raw material a processing plant needs to run. A plant relying on one supplier is exposed if that supplier stops delivering, which is why the Company has lined up three regional sources.
Chinantla, Vinatas and Coyul compared
Chinantla is under a binding five-year supply agreement. Vinatas and Coyul are covered by non-binding Memoranda of Understanding (MOUs), and there is no certainty that binding supply agreements will be executed.
All figures below are preliminary laboratory bench-scale results, not plant-scale results.
| Source | Status | Best Sb recovery | Concentrate grade | Processing route |
|---|---|---|---|---|
| Chinantla | Binding mineral supply agreement; 200t campaign underway | **81.1%** (bulk flotation) | Up to **62.9%** Sb (upgraded) | Flotation + upgrading |
| Vinatas | MOU; ~80 tonnes per month indicated | **78.6%** (flotation) | **58.82%** Sb (flotation); **68.3%** Sb (gravity upgraded) | Flotation + gravity + Falcon |
| Coyul | MOU; metallurgical testing underway | **73.3%** (flotation + Falcon) | **45.1%** Sb (primary bulk concentrate) | Flotation + Falcon |
Note the Vinatas grade. The announcement’s highlights cite 68.3% Sb, but that is the gravity-upgraded figure, while the straight flotation concentrate graded 58.82% Sb. Chinantla’s grade is “up to” 62.9% Sb.
Vinatas and Coyul detail
Vinatas is approximately 170km (straight line) from Tecomatlán. It has previously sold run-of-mine material to a processing facility in San Luis Potosí, approximately 500km from the mine site.
Vinatas has advised it can supply approximately 80 tonnes per month. These volumes and grade ranges were provided by the operator and have not been verified by the Company. Gravity upgrading produced a stibnite concentrate grading 68.3% Sb with only 4.36% SiO₂.
Coyul is approximately 28km from Tecomatlán, and its results are reported for the first time in this announcement. Test 4 was the best of four flotation tests, with key results of:
- feed grade of 4.20% Sb
- primary bulk concentrate grading 45.1% Sb at a concentration ratio of 24.1
- 44.6% Sb recovery into that primary concentrate
- cumulative flotation recovery of 67.7%, plus a further 5.6% from the Falcon centrifugal concentrator, for total cumulative recovery of 73.3%
- final tailings reduced to 1.5% Sb
| Parameter | Test 1 | Test 2 | Test 3 | Test 4 |
|---|---|---|---|---|
| Primary Conc. Grade (% Sb) | **17.8%** | **36.8%** | **17.0%** | **45.1%** |
| Primary Flotation Recovery (% Sb) | **8.7%** | **12.4%** | **33.6%** | **44.6%** |
| Total Cumulative Recovery (% Sb) | **47.2%** | **47.0%** | **50.0%** | **73.3%** |
| Final Tailings Grade (% Sb) | **3.0%** | **1.7%** | **1.6%** | **1.5%** |
Arsenic tends to float with antimony, reporting 1.11% As in the bulk concentrate. Further optimisation work is planned to focus on arsenic rejection through more selective reagents, recovery of antimony remaining in final tailings, and confirmation of the reagent scheme prior to any scale-up.
The Company holds no ownership interest in Chinantla, Vinatas or Coyul.
Why a flexible processing hub matters
Antimony concentrate is a partly refined product, made by separating antimony minerals from waste rock so it can be sold onward. Two methods do the separating. Flotation uses reagents and bubbles to lift antimony minerals away from waste, while gravity separation uses density differences to do the same.
Grade (the percentage of antimony in the concentrate) and recovery (the share of antimony captured from the feed) are the numbers to watch. Higher grade and recovery generally make for a more saleable product, and impurities such as arsenic matter too.
Tecomatlán’s combined flotation and gravity circuits allow each feed to be treated according to its own mineralogy, which the Company calls the core attribute of its regional processing hub model. Three sources also give diversity of feed, reducing reliance on any single supplier and supporting the objective of maximising utilisation as the plant moves toward continuous processing.
The wider backdrop matters too. Antimony is designated a critical mineral by the United States, the European Union and Australia, and is used in defence applications, munitions, energy storage, flame retardants and advanced manufacturing. China’s 2024 export restrictions have heightened Western focus on alternative supply, and the Company says production of a marketable concentrate with a prospective US buyer would position it as an emerging North American supplier.
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Next steps and what investors should watch
The announcement lists the following next steps:
- Complete the 200-tonne campaign and submit representative concentrate samples for independent assay.
- Release concentrate grade, recovery and impurity results once received.
- Evaluate a larger and potentially continuous processing program using campaign data.
- Progress the Vinatas MOU toward a binding supply agreement.
- Complete Coyul optimisation test work, focusing on arsenic rejection and confirmation of the preferred flowsheet.
The highlights also point to finalising agreements with offtakers (parties who agree to buy the product).
There is a funding angle as well. The Company is evaluating marketing options, and revenue from concentrate sales would provide a potential source of internally generated cash flow, complement existing funding and reduce reliance on equity as it advances Los Lirios toward a maiden JORC Mineral Resource and prepares its Nevada projects for drilling.
All of this depends on results. The Company states there is no certainty the campaign will produce antimony concentrate meeting the required specifications, or that any such concentrate will be sold.
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