How Antimony Trioxide is Produced
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Re-volatilizing crude antimony trioxide from oxidized stibnite (
Sb₂S₃) in furnaces at 500–1,000 °C:followed by purification via sublimation.2 Sb₂S₃ + 9 O₂ → 2 Sb₂O₃ + 6 SO₂ -
Direct oxidation of antimony metal (dominant in Europe):
The product forms via sublimation and is collected in filters.
4 Sb + 3 O₂ → 2 Sb₂O₃
Alternative methods include reacting antimony trichloride with water and alkaline hydrolysis of stibene. Commercial antimony trioxide typically achieves 99.2–99.5% purity with trace impurities.
Global production: China leads with ~80% of output. Major producers include Duter Co., Xingtai Deyi Chemical, US Antimony Corporation, and Nihon Seiko Co.
Common Uses of Antimony Trioxide
- Flame retardant synergist: Combined with halogenated materials for fire resistance in electronics, textiles, leather, and coatings.
- Catalyst in PET/polyester: Accelerates polymerization; used in PET water bottles.
- Ceramic opacifier: Provides whiteness and opacity.
- Glass fining agent: Removes bubbles, improves clarity.
- Product forms: Available in wetted grades (3–4% plasticizer), concentrates up to 90% active, and combined with fillers for flame-retardant properties.
Conclusion
Antimony trioxide plays a critical role across multiple industries despite health concerns. Its flame-retardant synergy, catalytic role in PET, and ceramic/glass uses highlight its versatility.
With China dominating production and global demand growing, its carcinogenic classification and 0.5 mg/m³ TLV demand strict safety measures.
Balancing industrial utility with health precautions will remain vital for manufacturers and regulators worldwide.