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11.4.3 Printed Circuit Boards
They are employed in computers as well as in electronic equipment for mechanical
support, i.e. to connect the electronic components electrically by means of conductive pathways. Printed circuit systems place an essential role in all electric and electronic equipment. By means of additive and subtractive methods, circuit patterns are
created. It works as a platform for mounting semiconductor chips and capacitors. The
printed circuit boards contribute 3% of Electronic-waste in the overall Electronicwastes generated. The materials such as aluminium, copper, iron and steel, lead, zinc,
paper, and plastics are normally found in printed circuit boards. Metal, ceramic, and
plastic compositions are found to be 40%, 30%, and 30%, respectively. Some concentrations of precious metals such as gold and palladium are found richer than their
natural ores. Recycling process such as mechanical, automated, and semiautomated
approaches is followed. The mechanical approach involves two steps; the first step
consists of the separation of different components and materials, and the second step
involves further separation and processing (Hall and Williams 2007, Guo et al. 2010a,
b). In automated approach the use of image processing identifies the reusable parts in
printed circuit boards by comparing the shape and labels in the database which are
gathered from the manufacturers and from the reuse market. The reusable products
and the hazardous components are separated in dismantling cell. The semiautomated
approach is found to be flexible. The electronic components are removed by a combination of heating above the solder melting point. Semiautomated dismantling cell
was connected for separating the reusable and hazardous component (Yi et al. 2007).
11.4.4 Cooling and Freezing Appliances
The release of chlorofluorocarbon is seen due to improper disposal of cooling and
freezing appliances. It is reported that more than three-fractional amount of ozonedepleting substance is released from refrigerants and foams in cooling and freezing
appliances. Scarp steel, compressors, cables, plastics, glass, and oil are the material
compositions of refrigerators. Ferrous and non-ferrous metals account for 50% and
8% and plastics account for 20–25%. Polystyrene has high value in the secondary
market and used as an insulating material in refrigerators and freezers. New cooling
and blowing agents with less impact on the surroundings have to be introduced to
the field of refrigerators and freezers.
11.4.5 Batteries
Batteries consist of one or more than one electrochemical cells, which are connected, in series as well as in parallel in order to produce electrical energy. The cell
consists of anode, cathode, and electrolyte. Batteries play a major role in electrical
K. Grace Pavithra et al.
11.4.3 Printed Circuit Boards
They are employed in computers as well as in electronic equipment for mechanical
support, i.e. to connect the electronic components electrically by means of conductive pathways. Printed circuit systems place an essential role in all electric and electronic equipment. By means of additive and subtractive methods, circuit patterns are
created. It works as a platform for mounting semiconductor chips and capacitors. The
printed circuit boards contribute 3% of Electronic-waste in the overall Electronicwastes generated. The materials such as aluminium, copper, iron and steel, lead, zinc,
paper, and plastics are normally found in printed circuit boards. Metal, ceramic, and
plastic compositions are found to be 40%, 30%, and 30%, respectively. Some concentrations of precious metals such as gold and palladium are found richer than their
natural ores. Recycling process such as mechanical, automated, and semiautomated
approaches is followed. The mechanical approach involves two steps; the first step
consists of the separation of different components and materials, and the second step
involves further separation and processing (Hall and Williams 2007, Guo et al. 2010a,
b). In automated approach the use of image processing identifies the reusable parts in
printed circuit boards by comparing the shape and labels in the database which are
gathered from the manufacturers and from the reuse market. The reusable products
and the hazardous components are separated in dismantling cell. The semiautomated
approach is found to be flexible. The electronic components are removed by a combination of heating above the solder melting point. Semiautomated dismantling cell
was connected for separating the reusable and hazardous component (Yi et al. 2007).
11.4.4 Cooling and Freezing Appliances
The release of chlorofluorocarbon is seen due to improper disposal of cooling and
freezing appliances. It is reported that more than three-fractional amount of ozonedepleting substance is released from refrigerants and foams in cooling and freezing
appliances. Scarp steel, compressors, cables, plastics, glass, and oil are the material
compositions of refrigerators. Ferrous and non-ferrous metals account for 50% and
8% and plastics account for 20–25%. Polystyrene has high value in the secondary
market and used as an insulating material in refrigerators and freezers. New cooling
and blowing agents with less impact on the surroundings have to be introduced to
the field of refrigerators and freezers.
11.4.5 Batteries
Batteries consist of one or more than one electrochemical cells, which are connected, in series as well as in parallel in order to produce electrical energy. The cell
consists of anode, cathode, and electrolyte. Batteries play a major role in electrical
K. Grace Pavithra et al.