Copper Millberry refers to high-purity, unalloyed copper scrap consisting of clean, uncoated copper wire. It is the highest grade of copper scrap in the recycling industry, typically containing 99.90%–99.99% copper.
Its bright reddish appearance and exceptional purity make it ideal for producing electrical-grade copper for wires, conductors, tubes, and industrial castings.
Typical Chemical Composition
| Element | Typical % |
|---|---|
| Copper (Cu) | 99.9 – 99.99 |
| Oxygen | Trace |
| Iron | < 0.01 |
| Lead | < 0.005 |
| Zinc | < 0.005 |
| Other impurities | Minimal |
Purity Requirement:
Millberry must be free from insulation, coatings, oil, grease, solder, and oxidation
to qualify as premium grade.
Physical Properties
| Property | Typical Value |
|---|---|
| Density | 8.94 g/cm³ |
| Melting Point | 1083 °C |
| Electrical Conductivity | 97 – 101% IACS |
| Thermal Conductivity | 385 – 401 W/m·K |
| Color | Bright reddish copper |
| Magnetic | Non-magnetic |
| Crystal Structure | FCC |
Mechanical Properties (Annealed Copper)
| Property | Typical Value |
|---|---|
| Tensile Strength | ~200 MPa |
| Yield Strength | ~70 MPa |
| Elongation | 40 – 50% |
| Hardness | ~45 HB |
Mechanical strength is developed later during rolling, drawing, or alloying.
Strengthening & Metallurgical Behavior
Millberry copper has a face-centered cubic (FCC) lattice with minimal impurity scattering, ensuring excellent conductivity and ductility.
✔ No strengthening at scrap stage
✔ Strength introduced downstream by cold drawing, rolling, or alloying
✔ Low impurity content prevents hot shortness and hydrogen embrittlement
Key Characteristics
✔ Extremely high purity
✔ Bright, clean appearance
✔ Uncoated and unalloyed
✔ Excellent remelting behavior
✔ Minimal slag generation
✔ High global market demand
Refining & Processing
Millberry is directly charged into furnaces with minimal refining, resulting in very low oxidation losses and metal recovery above 99%.
Available Forms
Bare bright copper wire
Wire bundles or loose coils
Pressed or baled millberry
Typical wire diameter: ≥ 1 mm
Packaging: bales, coils, jumbo bags
Applications
Primary Uses
Wire rod production,
billet casting,
tube and sheet manufacturing
Alloy Production
Brass,
bronze,
copper-nickel alloys
Recycling & Trading
Smelters,
refineries,
commodity export
Advantages
✔ Highest-value copper scrap
✔ Near-virgin copper purity
✔ Lower refining energy consumption
✔ Cost-effective alternative to cathodes
✔ Sustainable and recyclable
Why Choose Copper Millberry?
Copper Millberry is chosen when manufacturers need high-purity copper feedstock with lower cost than cathodes, minimal refining losses, and reliable metallurgical performance.
Millberry vs Other Scrap Grades
| Grade | Purity | Value | Refining Effort |
|---|---|---|---|
| Millberry | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | Very Low |
| Berry / Candy | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | Low |
| Heavy Copper | ⭐⭐⭐ | ⭐⭐⭐ | Medium |
| Mixed Scrap | ⭐⭐ | ⭐⭐ | High |
Copper Millberry is the premium recycled copper feedstock, offering near-virgin purity, excellent remelting behavior, high recovery rates, and strong global demand.