E-Waste Management-Recycling&Recovery

1. Recycling and Recovery
S.Gomathy
Assistant Professor(Senior Grade)
KEC

2. Introduction
• Recycling and recovery of e-waste is concerned with the separation
of individual materials (copper, steel, polystyrene, etc.) into grades
that are saleable on the open market or to other secondary processors
• Japan was one of the first countries to legislate for e-waste
recycling through the Home Appliances Recycling Law (HARL)
• Japan are between 64 and 84% depending on the category of waste
• The EU introduced the Waste Electrical and Electronic Equipment
(WEEE) Directive in 2002;
• Recycling rates in the EU vary from 25 to 40% for medium and
large appliances

3. The recycling and recovery process is broadly similar throughout
the world and generally includes the following steps:
• Separation and sorting (different types of equipment are
sorted)
• De-pollution (toxic or environmentally harmful substances are
removed)
• Size reduction (equipment is shredded to liberate the different
materials)
• Materials separation (e.g. ferrous metals removed by
magnets)

4. Separation and Sorting
• Refrigeration equipment containing ozonedepleting substances
(CFCs and HCFCs) are collected and stored separately
• Televisions and monitors containing cathode ray tubes (CRTs)
are also collected separately due to the different process
required
• There are two general approaches: manual disassembly or
automated ‘opening’ followed by manual picking of the
hazardous components.
• Training of operators is key to the effectiveness of de-pollution
and segregation

5. Treatment
Mixed WEEE
• based on mechanical separation;
• Size classification and dust removal -the separation process
with many facilities operating parallel processes on different
size fractions.
• Manual sorting - to remove large identifiable items such as
circuit boards, stainless steel and cables

10. Refrigeration Equipment

12. Cathode Ray Tubes
 Equipment containing CRTs is processed in dedicated facilities because of the
need to contain and remove the phosphor coating inside the tube and to deal with
other hazardous materials in the glass and electrodes.
 The majority of facilities separate the panel glass from the funnel glass then
manually remove the inside coating.
 A number of methods exist to separate the panel and funnel, e.g. using a hot wire
or diamond saw.
 Some facilities crush the whole CRT and wash the coating out before separating
the two types of glass in an automated system, e.g. by density.

13. Individual Processes
Crushing/Diminution
• One of the most common pieces of equipment used for initial crushing and
shredding is a hammer mill. Hammer mills accomplish size reduction by
impacting a slow moving target with a rapidly moving hammer
• The magnitude of the collisions is normally increased by increasing
hammer speed; this produces particles of smaller mean geometric size

14. • Material disintegration may also be effected by the use of
metal crushers which have low specific energy consumption
and offer high operational immunity to the presence of solid
pieces and may be also used as a pre-stage prior to shredding

15. Size Classification
• Screeners are sifting units that are rotated as powder
is fed into their interior.
• The finer particles fall through the sieve opening and
oversized particles are ejected off the end.
• Water classifiers, such as elutriators and classifying
hydrocyclones, use settling or flow in water or
another liquid to separate or classify powdered
materials on the basis of particle size or shape.

16. Magnetic Separation
• Magnetic separators such as low-intensity drum types are widely
used for the recovery of ferromagnetic materials from non-ferrous
metals and other nonmagnetic materials.
Density Separation
• Several different methods may be deployed to separate heavier
fractions from lighter ones, the basis being the difference in density
to enable such.
• Gravity concentration separates materials of different specific
gravity by their relative movement in response to the action of
gravity and one or more other forces, such as the resistance to
motion offered by water or air.
• The motion of a particle in a fluid is dependent not only upon the
particle’s density, but also on its size and shape; large particles are
affected more than smaller ones

18. Eddy Current Separation
• When particles of non-ferrous metals pass over a rotating magnet at
high speeds, eddy currents are created in the non-ferrous metal,
which generates a magnetic field around them.
• When the polarity of that magnetic field is the same as the rotating
magnet, the non-ferrous metal is repelled from the magnet and it is
this action that enables separation of such metals from feedstock
material.
Electrostatic Separation
• The rotor type electrostatic separator, using corona charging, may be
utilised to separate raw materials into conductive and non-
conductive fractions.
• Electrostatic separation has been mainly used for the recovery of
copper or aluminium from chopped electric wires and cables and,
more specifically, for the recovery of copper and precious metals
from printed circuit board scrap.