Recycling critical raw materials from waste electronic equipment

Recycling critical raw materials
from waste electronic equipment
Table 29: Composition of a InxGa1-xN semiconductor chip LED, types A and B (see text)
Element In Ga N
Molar mass (g/mol) 114.82 69.72 14.01
Coefficient
Percentage (rounded)
Weight per LED [mg]
0.4
1.0
45%
58%
0.029
0.170
0.6
1.0
41%
35%
0.0325
0.5300
Chips of design A contain significantly less indium and gallium due to their smaller height.
The data on the composition of LED chips and luminescent substances and on the absolute
quantities of critical metals are very limited, mainly due to their classification as a trade
secret. These data and all the projections and deductions arising from them must be taken
purely as a general indication. Using the quantities of gallium and indium from chips of type A
in the calculations should lead to rather conservative estimates of the demand for rare
metals.
A demand forecast for 2030 can be estimated based on the material composition of type A
which is summarized again in Table 30 and assuming future growth rates for the LED
producing industries (ISI 2009):
Table 30: Typical content of critical metals in a white LED (used for projection of future demand)
1.0
1.0
14%
7%
Element In Ga Ce Eu Gd Y
Weight per LED [�g] 29.0 32.5 2.0 0.6 15.0 32.0
Indications of the future demand for gallium from the manufacture of LEDs can be derived
from estimates of the growth of the LED market as a whole. This market, which covers both
white and colored LEDs, is assumed to have a growth of 37% from 2006-2011,
corresponding to an annual growth rate of 6.5% (ISI 2009 citing Steele 2007). It is assumed
that the proportion of white LEDs increases from around 48% in 2006 to 60% in 2011,
corresponding to approx. 4.6% p.a. Using these assumptions, 21 billion white LEDs are
manufactured in 2009 and 25 billion in 2011, giving an annual growth rate of around 11%
(see Table 31). Two scenarios with different dynamics are considered for the period after
2011 (ISI 2001). Scenario A has rather conservative dynamics, being based on growth of the
total market of a fixed 6.5% p.a. and a constant proportion of white LEDs of 60%. This results
in an annual growth of the market for white LEDs of 6%. The more dynamic scenario B
envisages a growth in the total market of 15% p.a. from 2011-2020, followed by only 10%
from 2020-2030 due to increasing market saturation. The proportion of white LEDs increases
from 60% to 70% between 2011-2030. This corresponds to market growth for white LEDs of
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