Lead-Acid Battery Fundamentals

Recycling Indicators

• Recovery rate refers to the volume of material recovered from a waste stream, and is often defined as the volume of material recovered from a waste stream divided by the amount of material in the generated waste.
• Recycling rate refers to the volume of material collected for recycling, generally including any material rejected during processing, divided by the volume (weight) of waste generated.
• Recycling efficiency is the total amount of material available for reuse affected by any material losses during the recycling process itself.

Magnetic Separations

• Magnetic separation is based on the difference in magnetic susceptibility.
• Diamagnetic materials have a small negative susceptibility and cannot be separated by magnetic separation.
• Paramagnetic materials have a small positive susceptibility and can be separated from diamagnetic matrix by high field intensity.

Electrostatic Separations

• Electrostatic separation uses electric conductivity for separation.
• Particles can be charged by high voltage corona charging or by letting them pass by charged plates (anode).
• Suitable for millimeter size and finer feeds, and is often arranged in cascades.

Lead-Acid Battery

• Invented in 1859 by Gaston Plante and is widely used as a stationary battery and the Starting-Lighting-Ignition (SLI)-type battery.
• Grid plates are produced from lead alloys to improve mechanical strength, creep resistance, castability, and minimizing the hydrogen evolution reaction.
• The reaction at the anode is Pb + HSO4- → PbSO4 + H+ + 2e-, and at the cathode is PbO2 + H+ + HSO4- + 2e- → PbSO4 + 2H2O.

Lead-Acid Battery Composition

• Lead (alloy) components (grid, poles, …): 25-30%
• Electrode paste (fine particles of PbO2 and PbSO4): 35-50%
• Sulfuric acid (10-20% H2SO4): 10-20%
• Polypropylene: 5-8%
• Other plastics (PVC, PE, etc.,): 4-7%
• Ebonite: 1-3%
• Other materials (glass, etc.,): <1%

Applications

• Electric/electronics: computer hard discs (Pt, Ru), iridium crucibles for high-purity single crystals.
• Printed wiring boards (PWBs) or PWB-containing fractions, processors, connectors, and small electronic devices like mobile phones.

Umicore’s PM-integrated Smelter-Refinery Facility

• Treats printed wiring boards (PWBs) or PWB-containing fractions, processors, connectors, and small electronic devices like mobile phones.
• Contains approximately up to 350 ppm Au, 1500 ppm Ag, and 200 ppm Pd, together with other metals like Cu, Pb, Ni, Fe, Al, Sn.

Indium

• Applications:
  • Flat-panel display devices: 74%
  • Architectural glass: 10%
  • Solders (temperature indicators in fire-control systems): 10%
  • Surface coating of optical lenses, bonding agents between nonmetallic materials and for dental: 3%
  • Other (semiconductor for laser diodes or indium in nuclear reactor control rods): 3%

Tellurium

• Applications:
  • Cadmium-tellurium-based solar cells: 40%
  • Thermo-electrics (semiconducting, bismuth telluride used in cooling devices): 30%