How to Separate Antimony Ore?

Les beneficiation of antimony ore presents unique challenges that vary significantly by ore type. As a mining professional with extensive experience in antimony processing, I’ve developed specialized methods to maximize recovery rates while optimizing operational efficiency across different antimony ore classifications.

The best way to separate antimony ore depends on its type. For oxide ores, gravity separation works well. Sulfide ores respond better to flotation. Mixed ores need combined methods. Always test your ore first to choose the right process.

 

Understanding Antimony Ore Classifications

1. Antimony Sulfide Ore (Stibnite, Sb₂S₃)

• Caractéristiques: Naturally hydrophobic, coarse to medium grain structure
• Common associations: Pyrite, arsenopyrite, galena
• Processing advantage: Excellent natural floatability

Antimony sulfide ore is easy to float and often uses preferential flotation.

2. Antimony Oxide Ore

• Primary minerals: Valentinite (Sb₂O₃), cervantite (Sb₂O₄), stibiconite (Sb₃O₆(OH))
• Processing challenges: Hydrophilic surface properties, frequent clay/quartz intergrowth
• Size considerations: Fine particle liberation difficulties

Due to their hydrophilic surfaces, tendency to form sludge, and similar electrical properties to gangue, antimony oxide ores are difficult to process by direct flotation and yield low recovery rates; therefore, the industrial sector generally employs gravity pre-concentration or a combined gravity-flotation process to improve economic performance.

3. Complex Polymetallic Ores

• Special considerations: Requires sequential recovery of associated metals (l'or, plomb, tungstène, etc)
• Economic factors: Value of byproducts affects process selection

 

 

Now let’s look at specific methods for different antimony ores. Each type needs special treatment for good results.

 

How to Separate Antimony Oxide Ore?

Antimony oxide ores (such as Antimony Hua Sb₂O₃, Antimony Fang Sb₂O₄, Antimony Huang Sb₃O₆(OH), etc.) are very common but difficult to beneficiate. Because the antimony oxide ore surface is hydrophilic, floatability is poor, and it often coexists with clay, quartz, and other vein minerals, its beneficiation is more complex than antimony sulfide ore (antimony pyroxene Sb₂S₃). Many miners suffer from low recovery rates of antimony oxide ore.

For antimony oxide ores, gravity separation is most effective. The process uses the mineral’s natural density differences. Machines à jigger et tables à secousses work well. This method is simple, cost-effective, and environmentally friendly compared to chemical processes.

 

Understanding Gravity Separation for Oxide Ores

Gravity separation works because antimony oxide is much heavier than gangue minerals. Here’s how it works in detail:

1. Broyage: First, crush the ore to a 2- 5 mm size
2. Dépistage: Separate particles by size
3. La pêche à la turlutte: Uses pulsating water to sort minerals by density
4. Tables à secousses: Final concentration step

 

Key factors affecting results:

Factor	Importance	Ideal Range
Taille de l'alimentation	Critical	2- 5 mm
Débit d'eau	Very Important	Réglable
Machine settings	Important	Varies by ore

 

For best results:

• Keep feed rate steady
• Check water quality
• Clean machines regularly

The method gives 60-75% recovery for good quality oxide ores. It’s cheaper than flotation but works only for coarse particles.

Antimoine Oxide Ore Case

Ore characteristics: The grade in Yunnan is 1.5 degrees, mainly containing oxidized antimony minerals such as antimony ore and stibnite, which are difficult to separate.

Process flow: The raw ore is crushed to less than 2mm by a sand blasting machine, and then put into a jig for preliminary separation to enrich heavy minerals; the jig concentrate is finely selected by a shaking table, and density stratification is used to improve the grade of antimony ore and achieve effective purification.

 

How to Separate Antimony Sulfide Ore?

Antimony sulfide ore (mainly pyrite Sb₂S₃) is the most important antimony ore resource, usually coexisting with pyrite, poisonous sand, galena, and so on. Many miners lose valuable material using the wrong methods. Sulfide antimony ores need different treatment. Flotation is the dominant process for its sorting, which requires comprehensive consideration of the nature of the ore, symbiotic relationships, and environmental requirements.

Froth flotation is best for antimony sulfide ores. It uses chemical agents to make antimony repel water. The process gives high-grade concentrates with 90%+ recovery. Proper reagent selection is crucial for good results. 

 

Flotation Process Details

Sulfide ores respond well to flotation because of their surface properties. Here’s the complete process:

1. Broyage: Mill ore to 0.074mm (200 mesh)
2. Conditioning: Mix with reagents for 5-10 minutes
3. Flottation: Separation in special tanks
4. Déshydratation: Remove water from the concentrate

Common reagents used:

Reagent Type	Objectif	Common Choices
Collectionneur	Makes antimony repel water	Xanthates
Frother	Creates stable bubbles	Huile de pin
Modifier	Controls pH	Chaux

Important parameters:

• pH level: Keep at 7-9
• Pulp density: 30-35% solids
• Air flow: Adjust as needed

 

The process can achieve:

• Concentrate grade: 50-60% Sb
• Recovery rate: 85-95%

 

Antimoine Sulfide Ore Case

Ore characteristics: The antimony grade is about 10%, the antimony minerals are coarsely embedded, mainly stibnite, and the natural floatability is good.

Process flow: The raw ore is crushed and ground to monomer dissociation (-0.074 mm accounts for 60%-80%), and the slurry is adjusted to alkaline to inhibit pyrite, and butyl xanthate is collected. After a coarse-fine-sweep flotation process, a high-grade antimony concentrate is produced.

 

 

How to Separate Mixed Antimony Ore?

Its beneficiation needs to be combined with the differences in physical and chemical properties between sulfide ores (such as antimony pyroxene Sb₂S₃) and oxidized ores (such as antimony Huahua Sb₂O₃, antimony yellow Sb₃O₆ (OH)), and design a step-by-step sorting or joint process.

For mixed antimony ores, use combined gravity-flotation methods. First remove sulfides by flotation, then recover oxides by gravity. This approach gives complete recovery of all antimony minerals in the ore.

 

Difficulties in Separating Mixed Antimony Ores

Mineral properties vary greatly:

• Sulfide ores (antimonite): Highly hydrophobic, easy to float (need Pb²⁺ activation).
• Oxide ores (antimony ore, etc.): Highly hydrophilic, need sulfide activation before flotation (Na₂S treatment).
• Complex symbiotic relationship: Oxide ores often encapsulate sulfide ores or closely coexist with clay, quartz, and hematite.
• Severe mudification: Fine-grained oxide ores are prone to mudification, which interferes with sorting.

 

Processing Mixed Antimony Ores

Mixed ores need careful treatment to recover both mineral types:

Step-by-Step Process

1. Grind ore to liberation size
2. First flotation for sulfide minerals
3. Regrind flotation tailings if needed
4. Gravity separation of oxide minerals

Key equipment needed

• Broyeur à billes for grinding
• Flotation cells
• Jig machines
• Tables à secousses

Typical results

Mineral Type	Recovery Method	Taux de récupération
Sulfides	Flottation	85-90%
Oxides	Gravité	60-70%

Process challenges

• Need precise control
• Higher equipment costs
• More complex operation

For the best economics

• Test ore composition first
• Optimize each step separately
• Consider the whole process costs

Mixed Antimony Ore Case

Ore characteristics: Contains coarse-grained antimony sulfide ore, antimony oxide ore, and fine-grained antimony oxide ore, with complex composition, and the separation needs to take into account different minerals.

Process flow: The coarse-grained part is concentrated by gravity separation with a jig; the fine-grained antimony oxide ore in the gravity separation tailings is first sulfided with sodium sulfide, and then floated with a xanthate collector. Through the gravity separation-flotation combined process, the antimony ore in the mixed ore is efficiently recovered.

 

Conclusion

Antimony ore separation needs the right method for each ore type. Use gravity for oxides, flotation for sulfides, and combined methods for mixed ores. Always conduct comprehensive ore characterization (MLA/QEMSCAN) before process design. Pilot testing remains the most reliable method for predicting plant performance. New sensor technologies are reducing test requirements by 40-60% while improving accuracy. Proper process selection gives the best recovery and profits. For specific ore testing protocols or detailed flowsheet development, consult with our mineral processing engineers to optimize your antimony recovery operations. Meanwhile, our équipement minier can help with all these methods.