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About Electronics Recycling
If treated properly, electronic waste is a valuable source for secondary raw materials. However, if not treated properly, it is a major source of toxins and carcinogens. Rapid technology change, low initial cost and even planned obsolescence have resulted in a fast growing problem around the globe. Electronic waste represents 2 percent of America's trash in landfills, but it equals 70 percent of overall toxic waste.
Electronic waste is of concern largely due to the toxicity and carcinogenicity of some of the substances if processed improperly. For example, a typical computer monitor may contain more than 6% lead by weight.
Substances and elements contained in electronic waste:
- Substances in bulk: PCBs, PVC, thermosetting plastics, epoxy resins, and fiber glass.
- Elements in bulk: Lead, tin, copper, silicon, carbon, iron and aluminium.
- Elements in small amounts: Cadmium, mercury, thallium.
Applications of these substances and elements:
- Almost all electronics contain lead and tin (as solder) and copper (as wire and PCB tracks), though the use of lead-free solder is now spreading rapidly.
- Lead: solder, CRT monitors (lead in glass), lead-acid batteries
- Tin: solder, coatings on component leads
- Copper: copper wire, printed circuit board tracks, component leads
- Cadmium: light-sensitive resistors, corrosion-resistant alloys for marine and aviation environments
- Aluminium: nearly all electronic goods using more than a few watts of power (heatsinks), electrolytic capacitors.
- Iron: steel chassis, cases and fixings
- Silicon: glass, transistors, ICs, printed circuit boards.
- Nickel and cadmium: nickel-cadmium batteries
- Lithium: lithium-ion battery
- Zinc: plating for steel parts
- Gold: connector plating, primarily in computer equipment
- Americium: smoke alarms (radioactive source)
- Germanium: 1950s–1960s transistorised electronics (bipolar junction transistors)
- Mercury: fluorescent tubes (numerous applications), tilt switches (pinball games, mechanical doorbells, thermostats)
- Sulphur: lead-acid batteries
- Carbon: steel, plastics, resistors. In almost all electronic equipment.
Source: http://www.wikipedia.org |
