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Bismuth metal

Bismuth oxide

Properties

Chemical symbol: Bi
Name: Bismuth
CAS No.: 7440-69-9
Molar mass: 208.98 g/mol
Density: 9.78 g/cm³
Melting point: approx. 271.4 °C
Boiling point: approx. 1564 °C
Color: silvery with a slight reddish tint
Form: ingots, bars, granules, droplets or crystals
Special properties: strong diamagnetism and expansion on solidification

Bismuth (Bi) is a metallic element with a characteristic silvery appearance and a slight reddish tint. The material is brittle and has a comparatively low melting point of approximately 271.4 °C. Depending on the application, bismuth is supplied as ingots, bars, granules, droplets or melt-grown crystals.

Bismuth has several unusual physical properties. It exhibits pronounced diamagnetism and has very low thermal conductivity compared with many other metals. When solidifying from the melt, its volume increases by approximately 3.3%, which supports accurate mold filling and helps reduce shrinkage-related casting defects.

Compact bismuth is stable in dry air. When heated or exposed at the surface, a thin bismuth oxide layer, Bi₂O₃, can form. On melt-grown crystals, this oxide film can produce characteristic interference colors ranging from gold and green to blue and violet.

Compared with heavy metals such as lead and thallium, bismuth has substantially lower toxicity and is therefore used in various lead-free materials. This makes bismuth metal useful in specialty solders, low-melting alloys and other applications where reduced lead content is desirable.

Industrial bismuth production is mainly associated with the refining of copper, lead and tin ores, where the metal is often recovered as a by-product. Metallurgical separation and electrolytic refining processes are used to isolate and purify the material.

Bismuth metal is used in lead-free alloys, specialty solders, thermoelectric materials, pharmaceutical compounds, cosmetic pigments and metallurgy. Would you like to buy bismuth? Auremo can provide information about available product forms and delivery conditions. The bismuth price, bismuth metal price and bismuth price per kg depend on purity, product form, quantity and order specifications.

Advantages

• Relatively low toxicity compared with many heavy metals
• Suitable for lead-free alloys and solders
• Low melting point of approximately 271.4 °C
• Expansion on solidification of approximately 3.3%
• Accurate filling of complex casting molds
• Pronounced diamagnetic behavior
• Low thermal conductivity
• Decorative interference colors on oxidized crystal surfaces

Applications

• Lead-free soft solders
• Low-melting specialty alloys
• Brass and other technical alloys
• Thermal fuses and fusible safety elements
• Bismuth telluride Bi₂Te₃ for Peltier devices
• Bismuth selenide Bi₂Se₃ for thermoelectric materials
• Production of pharmaceutical bismuth compounds
• Bismuth oxychloride BiOCl pearlescent pigments
• Foundry technology
• Metallurgical additives
• Scientific applications involving diamagnetic properties

Auremo offers bismuth and other specialty metals for industrial, technical and research applications. If you have questions about purity, product form, available quantities or delivery conditions, please contact us directly.