Copper Anode, Copper Electrode, Cu Anode, Electrolytic Copper Anode, 7440-50-8

COPPER ANODE (Cu ANODE)

1. Chemical Identity and Material Classification

• Product Name: Copper Anode, Cu Anode (Copper Anode), Electrolytic Copper Anode

• Material Type: Pure Copper (Cu) or Copper Alloys

• CAS Number: 7440-50-8 (copper)

• UN Number: Not classified as hazardous in solid form

• EINECS Number: 231-159-6

• Chemical Symbol: Cu

2. Chemical Composition (Typical, wt%)

3. Physical Properties

4. Mechanical Properties

5. Electrochemical Properties (Critical for Electroplating)

6. Metallurgical and Microstructural Characteristics

• Crystal structure: Face-centered cubic (FCC)

• Lattice parameter: a = 0.3615 nm

• Atomic radius: 0.128 nm

• Role of oxygen (Cu-ETP): Present as Cu₂O at grain boundaries → contributes to anode sludge formation

• Oxygen-free copper (Cu-OF): More homogeneous microstructure, lower sludge formation

• Recrystallization behavior: Recrystallization temperature ~200–300°C (depending on cold work)

• Stacking fault energy: ~78 mJ/m² (high – promotes cross-slip)

7. Production Methods

7.1 Electrolytic Refining (Primary Production)

• Feedstock: Blister copper (~98–99% Cu)

• Electrolyte: CuSO₄/H₂SO₄ solution (40–50 g/L Cu²⁺, 150–200 g/L H₂SO₄)

• Current density: 200–300 A/m²

• Cell voltage: 0.2–0.4 V

• Cathode product: Electrolytic copper cathode (≥99.99% Cu)

• Temperature: 50–65°C

7.2 Casting and Thermomechanical Processing (Anode Shaping)

• Process: Electrolytic cathodes → melting (1150–1200°C) → continuous casting → hot rolling → cold drawing/rolling → cutting

• Protective atmosphere: Inert gas (Ar or N₂) for oxygen-free copper

• Shapes produced: Plate, rod, nugget, ring, custom geometries

• Surface finish: Machined or polished to 1.6–3.2 μm Ra

7.3 Powder Metallurgy (for Special Applications)

• Process: Copper powder → pressing → sintering (800–900°C, H₂ atmosphere)

• Application: Porous anodes, high surface area requirements

8. Copper Anode Dissolution Mechanism

• Primary anodic reaction: Cu → Cu²⁺ + 2e⁻

• Side reactions:

  • Cu₂O (oxide) + 2H⁺ → Cu²⁺ + Cu + H₂O (in acidic baths)

  • Insoluble Cu₂O particles → sludge formation

• Difference from phosphorized copper: No phosphorus in pure copper → no protective phosphide film → higher sludge formation

• Sludge composition: Cu₂O, Cu, trace metals (As, Sb, Bi, Se, Te)

• Sludge particle size: Typically 1–50 μm

9. Application Areas – Electroplating Industry

9.1 Acid Copper Plating (Watts-type Bath)

9.2 PCB (Printed Circuit Board) Manufacturing

• Application: Panel plating, pattern plating, through-hole plating

• Current density: 1–3 A/dm²

• Requirement: High purity (≥99.9%) and low oxygen content

• Why phosphorized copper is preferred: Lower sludge → cleaner bath → fewer defects

9.3 Cathodic Protection Systems (Ships and Pipelines)

• Application: Galvanic anode (less common; zinc or aluminum preferred)

• Electrolyte: Seawater or soil moisture

• Current output: ~25 A·h/kg (low for copper)

• Driving voltage (vs. steel): ~0.2 V

9.4 Electrolysis and Electrowinning

• Application: Copper electrowinning (lead or stainless steel anodes preferred)

• Copper anode use: Used as soluble anode in copper refining

9.5 Decorative and Industrial Plating

• Substrates: Steel, brass, zinc die-cast, aluminum

• Typical layer sequence: Copper → nickel → chromium

• Anode service life: 6–18 months (continuous operation, bath-dependent)

10. Comparison of Copper Anode Types

11. Product Forms and Dimensions (Typical)

12. Quality Control and Testing Methods

13. Operating Recommendations for Electroplating Baths

• Pre-cleaning: Alkaline degreaser (60–80°C) → rinse with deionized water

• Anode bags: Polypropylene (PP) or polyester (75–150 μm mesh) – prevents sludge accumulation on cathodes

• Anode spacing: 50–150 mm from cathode (for uniform current distribution)

• Bath agitation: Low-pressure air (CO₂-free) or mechanical stirrer – maintains Cu²⁺ homogeneity

• Bath filtration: Continuous filtration (5–10 μm filter paper or cartridge)

• Phosphorus addition: Not required for pure copper anodes

• Current efficiency correction: Use 95–99% in Faraday's law calculations

• Anode replacement frequency: When thickness is reduced by 30–40% (prevents excessive sludge and uneven dissolution)

• Bath maintenance: Regular analysis of Cu²⁺, H₂SO₄, Cl⁻, and organic additives

14. Safety and Handling

• Hazards: No acute toxicity in solid form; fine dust may cause mechanical irritation

• Fire risk: Non-flammable in bulk form; fine copper powder (≥40 μm) may be combustible/explosive

• Reactivity:

  • Strong acids (HNO₃) → violent reaction, NOₓ gas evolution

  • Incompatible with oxidizers (chromates, permanganates)

  • Ammonia → forms deep blue copper-ammonia complex [Cu(NH₃)₄]²⁺

  • Acetylene → forms explosive copper acetylide (Cu₂C₂) in presence of moisture

• Personal Protective Equipment (PPE):

  • Gloves (nitrile or neoprene, >0.1 mm thickness, EN 374)

  • Safety glasses with side shields (EN 166) or chemical goggles

  • Dust mask (FFP2 or N95) – during cutting/grinding

  • Steel-toed boots (EN 345) – for heavy handling

  • Heat-resistant gloves – during thermal processing

• First aid:

  • Inhalation: Remove to fresh air; seek medical attention if respiratory irritation occurs

  • Skin contact: Wash with soap and water; copper dust may cause mild abrasion

  • Eye contact: Rinse with water for 15 minutes; seek medical attention

  • Ingestion: Unlikely for solid form; copper salts are toxic (seek medical attention)

15. Environmental and Disposal Information

• Ecotoxicity: Copper is toxic to aquatic organisms at low concentrations (LC₅₀ 0.1–1 mg/L for algae, crustaceans, and fish)

• Persistence in soil: Medium–high; forms complexes with organic matter

• Bioaccumulation potential: Low (BCF <100 for most aquatic species)

• Recyclability: 100% recyclable; high scrap value

• Waste classification (EU): 12 01 09 (non-hazardous metal waste, if clean)

• Disposal method: Send to authorized metal recycling facility; do not landfill or incinerate without recovery

• Copper-containing wastewater treatment: Ion exchange or precipitation (pH 8–9) → sludge → recycle or disposal

• Air emissions control: Baghouse filters or wet scrubbers for grinding/cutting operations

16. Storage and Shelf Life

• Storage conditions:

  • Dry, well-ventilated area (relative humidity <60%)

  • Away from acids, alkalis, ammonia, and oxidizers

  • Protect from direct sunlight

  • Wooden pallets or plastic racks (avoid direct metal-to-metal contact – galvanic corrosion)

  • Store indoors or under cover (prevents excessive tarnishing)

• Shelf life: Unlimited (no chemical degradation)

• Surface tarnish (patina): Aesthetic only; does not affect electrochemical performance

• Tarnish prevention: Store in original packaging or apply thin corrosion-preventive oil film for long-term storage (>12 months)

17. Transport Information

18. Synonyms and Common Names

• Copper anode

• Cu anode (Copper anode)

• Electrolytic copper anode

• Copper electrode

• Copper plating anode

• Anode en cuivre (French)

• Kupferanode (German)

• Anodo di rame (Italian)

• Ánodo de cobre (Spanish)

• Медный анод (Russian)

• 銅陽極 (Japanese)

• 铜阳极 (Chinese)

19. Certifications and Standards Compliance

20. Why Choose Copper Anodes? (Technical Summary)

• High electrical conductivity (97–101% IACS): Maximizes energy efficiency in electroplating and electrolysis

• Excellent thermal conductivity (385–401 W/(m·K)): Cooling advantage in high-current applications

• High corrosion resistance: Long service life in atmospheric and many aqueous environments

• Excellent workability: Soft, easy to shape; custom geometries available

• Economical: Lower cost compared to phosphorized or oxygen-free copper

• 100% recyclable: High scrap value – sustainable and cost-effective over lifecycle

• Wide availability: Stocked in all industrial regions

• Compatibility with standard bath chemistries: Works in Watts-type, pyrophosphate, cyanide, and fluoroborate baths

• Limitation note: For high-quality plating requiring minimal sludge (PCB, semiconductor, automotive decorative), phosphorized copper anodes (Cu-P) are recommended – they offer lower sludge formation (≤1% vs. 5–10%) and more stable polarization behavior.

This TDS is prepared in compliance with ISO 11014-1 format and is intended for electroplating engineers, production managers, quality control laboratories, cathodic protection specialists, and procurement professionals. Certificates of Analysis (CoA), Safety Data Sheets (SDS), mechanical test reports, and sample validation reports are available upon request.