Granulated Tin refers to high-purity metallic tin processed into small granules, pellets, or shots rather than bulk ingots. It is not a separate alloy or grade, but a physical form of refined tin optimized for controlled melting, alloying, and precise dosing.
Granulation improves melting efficiency, reduces oxidation losses, and enables accurate composition control in soldering, alloying, and metallurgical processes.
Basic Identification
| Property | Value |
|---|---|
| Base Metal | Tin (Sn) |
| Typical Purity | 99.85% – 99.99% |
| Physical Form | Granules / pellets / shots |
| Crystal Structure | β-Tin (metallic white tin) |
Chemical Composition
| Element | Content (%) |
|---|---|
| Tin (Sn) | ≥ 99.85 – 99.99 |
| Lead (Pb) | ≤ 0.05 |
| Antimony (Sb) | ≤ 0.01 |
| Copper (Cu) | ≤ 0.01 |
| Iron (Fe) | ≤ 0.01 |
| Bismuth (Bi) | ≤ 0.01 |
✔ Electronic and pharmaceutical grades exceed 99.99% Sn
✔ Purity selection depends on solder reliability and corrosion resistance
Mechanical Properties
Mechanical properties are intrinsic to pure tin and are not affected by the granulated form.
| Property | Value |
|---|---|
| Tensile Strength | ~15 – 30 MPa |
| Yield Strength | ~10 – 20 MPa |
| Elongation | ~40 – 60% |
| Hardness | ~5 – 10 HB |
| Elastic Modulus | ~50 GPa |
Very soft and ductile — not suitable for load-bearing applications.
Physical Properties
| Property | Value |
|---|---|
| Density | ~7.31 g/cm³ |
| Melting Point | 231.9 °C |
| Boiling Point | ~2602 °C |
| Electrical Conductivity | ~15% IACS |
| Thermal Conductivity | ~66 W/m·K |
| Magnetic Behavior | Diamagnetic |
| Color | Silvery-white |
Strengthening & Tin Pest Behavior
Granulated tin is not heat-treatable and cannot be strengthened except by alloying (Sn-Cu, Sn-Ag, Sn-Sb).
Below 13.2 °C, very pure tin may transform into gray tin (α-tin), a phenomenon known as tin pest.
Granulated form has higher surface area and may be more susceptible in extreme cold environments. This is prevented by controlled storage and minor alloying.
Refining & Granulation Processing
Tin ore (cassiterite – SnO₂) is smelted and refined to high purity before granulation.
Granulation methods include:
✔ Water granulation
✔ Drip granulation
✔ Shot-making towers
✔ Inert gas granulation (ultra-high purity)
Key benefits:
✔ Rapid melting
✔ Reduced oxidation losses
✔ Accurate alloy chemistry
✔ Improved energy efficiency
Available Forms
✔ Granules (1–10 mm)
✔ Pellets and shots
✔ Beads and custom-sized granules
✔ Vacuum-sealed electronic-grade material
Applications of Granulated Tin
🔌 Lead-free solder manufacturing
⚙️ Bronze, Babbitt, and pewter alloying
🧪 Tin salts and chemical compounds
📦 Tinplate and corrosion-resistant coatings
Advantages of Granulated Tin
✔ Faster melting and reduced energy use
✔ Precise alloy composition control
✔ Lower oxidation losses
✔ Easy automated handling and dosing
✔ Higher process efficiency
Granulated Tin vs Tin Ingots
| Feature | Granulated Tin | Tin Ingots |
|---|---|---|
| Melting Speed | Very fast | Slower |
| Alloy Accuracy | High | Moderate |
| Handling | Excellent | Manual |
| Oxidation Loss | Low | Higher |
| Cost | Slightly higher | Lower |
Why Choose Granulated Tin?
Choose Granulated Tin when:
✔ Precision alloying is critical
✔ Fast melting and energy efficiency matter
✔ Lead-free solder production is required
✔ Automated dosing systems are used
✔ High-purity tin applications are involved
Granulated Tin is the preferred form of tin for modern electronics, foundries, chemical processing, and high-precision metallurgical operations.